Use of Preservative Agents and Antibiotics for Increased Poliovirus Survival on Positively Charged Filters

Environmental surveillance of poliovirus (PV) and other non-enveloped viruses can help identify silent circulation and is necessary to certify eradication. The bag-mediated filtration system is an efficient method to filter large volumes of environmental waters at field sites for monitoring the presence of viruses. As filters may require long transit times to off-site laboratories for processing, viral inactivation or overgrowth of bacteria and fungi can interfere with virus detection and quantification (Miki and Jacquet in Aquatic Microb Ecol 51(2):195–208, 2008). To evaluate virus survival over time on ViroCap^? filters, the filters were seeded with PV type 1 (PV1) and/or MS2 and then dosed with preservatives or antibiotics prior to storage and elution. These filters were stored at various temperatures and time periods, and then eluted for PV1 and MS2 recovery quantification. Filters dosed with the preservative combination of 2% sodium benzoate and 0.2% calcium propionate had increased virus survival over time when stored at 25 °C, compared to samples stored at 25 °C with no preservatives. While elution within 24 h of filtration is recommended, if storage or shipping is required then this preservative mixture can help preserve sample integrity. Addition of an antibiotic cocktail containing cephapirin, gentamicin, and Proclin^? 300 increased recovery after storage at 4 and 25 °C, when compared to storage with no antibiotics. The antibiotic cocktail can aid sample preservation if access to appropriate antibiotics storage is available and sample cold chain is unreliable. This study demonstrated that the use of preservatives or antibiotics is a simple, cost-effective method to improve virus detection from ViroCap cartridge filters over time.     

DNA Heat Treatment for Improving qPCR Analysis of Human Adenovirus in Wastewater

PCR inhibitory substances in complex sample matrices can cause false negatives or under-estimation of target concentration. This study assessed DNA heat treatment for reducing inhibition during qPCR analysis of human adenovirus (HAdV) in wastewater samples. Inhibition was reduced by heat treating DNA, where mean HAdV concentration was increased by 0.71 log₁₀ GC/L (and up to 3.04 log₁₀ GC/L in one case), and replicate variability and false negatives were reduced. DNA heat treatment should be further investigated for improving reliability of HAdV concentration estimates in water, which can support more accurate assessment of health risks associated with viral pathogen exposure.     

Assessment and Evaluation of an Integrated Hybrid Anaerobic–Aerobic Sewage Treatment System for the Removal of Enteric Viruses

The capability of a cost-effective and a small size decentralized pilot wastewater treatment plant (WWTP) to remove enteric viruses such as rotavirus, norovirus genogroup I (GGI), norovirus genogroup II (GGII), Hepatitis E virus (HEV), and adenovirus was studied. This pilot plant is an integrated hybrid anaerobic/aerobic setup which consisted of anaerobic sludge blanket (UASB), biological aerated filter (BAF), and inclined plate settler (IPS). Both the UASB and BAF are packed with a non-woven polyester fabric (NWPF). Results indicated that the overall log₁₀ reductions of enteric viruses’ genome copies through the whole system were 3.1 ± 1, 3.3 ± 0.5, and 2.6 ± 0.9 log₁₀ for rotavirus, norovirus GGI, and adenovirus, respectively. Reduction efficiency for both norovirus GGII and HEV after the different treatment steps could not be calculated because there were no significant numbers of positive samples for both viruses. The overall reduction of rotavirus infectious units through the whole system was 2.2 ± 0.8 log₁₀ reduction which is very close to the overall log₁₀ reduction of adenovirus infectious units through the whole system which was 2.1 ± 0.8 log₁₀ reduction. There was no considerable difference in the removal efficiency for different rotavirus G and P types. Adenovirus 41 was the only type detected in the all positive samples. Although the pilot WWTP investigated is cost effective, has a small footprint, does not need a long distance network pipes, and easy to operate, its efficiency to remove enteric viruses is comparable with the conventional centralized WWTPs.     

Revisiting chronodisruption: when the physiological nexus between internal and external times splits in humans

In this Concepts & Synthesis paper, we expand the definition of chronodisruption in humans by proposing that it can be operationalized as the split nexus of internal and external times. With this premise, we suggest how chronotype may be used as a temporal marker (chronomarker) of exposure to chronodisruption in studies of cancer, and beyond, offer cancer risk predictions for observational research on the basis of a chronotype-related hypothesis and corollary, and point to first empirical data in humans. In an a priori way, we examine possible outcomes and perspectives for preventive measures following from our rationale and the suggested chronobiology-driven studies and close with overall advances of chronodisruption research.     

Tolerating an infection: an indirect benefit of co-founding queen associations in the ant Lasius niger

Pathogens exert a strong selection pressure on organisms to evolve effective immune defences. In addition to individual immunity, social organisms can act cooperatively to produce collective defences. In many ant species, queens have the option to found a colony alone or in groups with other, often unrelated, conspecifics. These associations are transient, usually lasting only as long as each queen benefits from the presence of others. In fact, once the first workers emerge, queens fight to the death for dominance. One potential advantage of co-founding may be that queens benefit from collective disease defences, such as mutual grooming, that act against common soil pathogens. We test this hypothesis by exposing single and co-founding queens to a fungal parasite, in order to assess whether queens in co-founding associations have improved survival. Surprisingly, co-foundresses exposed to the entomopathogenic fungus Metarhizium did not engage in cooperative disease defences, and consequently, we find no direct benefit of multiple queens on survival. However, an indirect benefit was observed, with parasite-exposed queens producing more brood when they co-founded, than when they were alone. We suggest this is due to a trade-off between reproduction and immunity. Additionally, we report an extraordinary ability of the queens to tolerate an infection for long periods after parasite exposure. Our study suggests that there are no social immunity benefits for co-founding ant queens, but that in parasite-rich environments, the presence of additional queens may nevertheless improve the chances of colony founding success.     

Detection Method for Avian Influenza Viruses in Water

Recent events have shown that humans may become infected with some pathogenic avian influenza A viruses (AIV). Since soil and water, including lakes, rivers, and seashores, may be contaminated by AIV excreted by birds, effective methods are needed for monitoring water for emerging viruses. Combining water filtration with molecular methods such as PCR is a fast and effective way for detecting viruses. The objective of this study was to apply a convenient method for the detection of AIV in natural water samples. Distilled water and lake, river, and seawater were artificially contaminated with AIV (H5N3) and passed through a filter system. AIV was detected from filter membrane by real-time RT-PCR. The performance of Zetapor, SMWP, and Sartobind D5F membranes in recovering influenza viruses was first evaluated using contaminated distilled water. SWMP, which gave the highest virus recoveries, was then compared with a pre-filter combined GF/F filter membrane in a trial using natural water samples. In this study, the cellulose membrane SMWP was found to be practical for recovery of AIVs in water. Viral yields varied between 62.1 and 65.9% in distilled water and between 1 and 16.7% in natural water samples. The borosilicate glass membrane GF/F combined with pre-filter was also feasible in filtering natural water samples with viral yields from 1.98 to 7.33%. The methods described can be used for monitoring fresh and seawater samples for the presence of AIV and to determine the source of AIV transmission in an outbreak situation.     

Prevalence of Norovirus Infection in Children and Adults with Acute Gastroenteritis,Tehran, Iran, 2008–2009

Noroviruses are one of important agents that cause acute viral gastroenteritis worldwide. These viruses are belonging to Caliciviridae family and are genetically diverse. To date, there is no valuable data about prevalence of norovirus infection and the dominant genogroup/genotype among Iranian population. The objective of this study was to determine the frequency of norovirus infection in Iranian patients with gastroenteritis referred to three hospitals of Tehran and to specify the dominant genogroup/genotype of this virus among our study population. A total of 293 patients with acute gastroenteritis were included in the study. Detection of norovirus was performed using RT-PCR method and confirmed by direct sequencing with specific designed primers for capsid region of norovirus genome. Phylogenetic analysis was performed using the neighbor-joining method. Norovirus strains identified in our study were subsequently categorized according to previously defined genogroup/genotypes. Of these, norovirus GII was dominant genogroup. Sixty-five percent (17 of 26) of positive samples were determined as GII and 35% (9 of 26) were determined as GI, respectively, in 2008–2009. And among 8 sequenced strains of genogroup II the most frequent genotype was GII.3. The results of this study indicated that norovirus must be considered as one of the infectious causes of acute gastroenteritis among Iranian population. We also found that GII.3 is more prevalent in our study population. To the best of our knowledge there is limited data about the role of noroviruses in children and adults’ acute gastroenteritis among Iranian patients and this prevalence and genotyping report of norovirus infection could be remarkable for further studies.