Effects of solid manure particle fractionation on transport, retention, and release of Escherichia coli

Understanding the effect of manure particle fractionation on transport, retention, and release of bacteria plays a critical role in manure management and environmental policies that address soil and water bacterial pollution. Compared to soil particle size, there is less understanding of the importance of solid manure particle size and fractionation on bacterial fate and transport in soils. Four different cow manure particle sizes (0.25, 0.5, 1, and 2 mm) were used to investigate Escherichia coli fate in a saturated loamy sand soil. Leaching experiments were performed for up to 20 pore volumes. Preferential transport of chloride mitigated as manure particle size increased. The larger manure fractions (1 and 2 mm) showed greater heterogeneity in bacteria transport and release; smaller manure fractions (0.25 and 0.5 mm) had a greater bacteria retention with retarded release. Bacteria release was associated with transport and re-entrainment of manure particles through soil columns. The results highlighted the contribution of fine and transported particles as of primary importance for retention near the surface and transporting bacteria in soil. Similar retention shapes (i.e., exponential) for different fractions illustrated the similarity of manure source, where greater retention was observed at 0−3 cm depth for the smallest (0.25 mm) and largest (2 mm) manure fractions. The findings also highlighted the dependency of bacteria transport, retention, and release on manure physical fractionation, which should be considered in managing soil and manure practices in the field. © 2021 The Author

Particle fractionation controls Escherichia coli release from solid manure

Bacteria transport through soil is a complex process particularly when the cells are released from solid manures and co-transported with particles. This study focuses on understanding of the Escherichia coli release from different particle fractions (0.25-, 0.5-, 1-, and 2-mm) of solid manure and evaluating different influent boundary conditions during cell release from manure and when a solid manure is applied to the soil. The 0.25-mm and 2-mm particle sizes resulted a greater cell release compared to 0.5-mm and 1-mm fractions (p < 0.05). The shape and magnitude of the cell release curves (CRCs) from the original manure bulk were mainly influenced by the two 0.25-mm and 2-mm fractions, respectively. The arithmetic mean for normalizing the CRCs and the time variable- based normalized CRCs for the manure-treated soil were the robust variables in evaluation of the experimental data. However, a single maximum bacteria concentration could provide the realistic dataset for the modeling process. Evaluation of the root-mean-squared-error and Akaike criterion showed that the two- and three-parametric models are recommended for simulating the cell release from solid manure in comparison with one parametric models. This study also suggests considering separate microbial release evaluations, with regards to influent concentration, for manure and manure-treated soils to propose best management practices for controlling bacteria pollution. Further research will reveal the key roles of different woody components and soluble material ratios for the various solid manures in bacteria release

Particle fractionation controls Escherichia coli release from solid manure

Funding Information: This work was supported by Shahrekord University . Nasrollah Sepehrnia was supported by Alexander von Humboldt Foundation and Postdoctoral Fellowship at Leibniz University of Hannover, Germany. Publisher Copyright: © 2021 The Author(s)Peer reviewedPublisher PD

Molecular and cellular investigations on apoptosis-like cell death in human and animal Plasmodium parasites

Because of emerging resistances against the main antimalarial drugs there is an increasing need for new drugs with alternative targets. As a new target apoptosis can be considered as an appropriate option to attain this goal. There is little information available about programme cell death (PCD) in Plasmodium parasites, and the few we know comes from studies on PCD in P. falciparum and P. berghei. The general objective in this study was increasing the knowledge on P. vivax biology focusing on PCD apoptosis-like processes topic. The specific objectives were:\ud 1- Genetic characterization of two putative PCD genes: Plasmodium vivax apoptosis related protein (PvARP) and of P. vivax meta-caspase 1 (PvMC1). 2- Set-up of P. vivax short term in vitro cultures to study morphological features of PCD.\ud 3- Investigation at the ultra-structural level of morphological aspects of apoptosis-like phenomenon in Plasmodium by using P. falciparum and P. berghei as study model.\ud In this study, Plasmodium vivax apoptosis related protein (PvARP), P. vivax meta-caspase 1 (PvMCA1), P. falciparum meta-caspase 1 (PfMCA1) and P. vivax merozoite surface protein-1(PvMSP1) genes were characterized using PCR method among Plasmodium isolates collected from malaria patients with different origins of the world. PCR products of PvMCA1, PvARP and PfMCA1 genes were sequenced. Also Reverse Transcription-PCRs (RT-PCR) of PvMCA1, PvARP and PvMSP1 genes were performed among thirty frozen blood samples.\ud Analysis of the PvMCA1 gene clearly showed size polymorphism and among isolates analyzed, four different allele sizes were distinguished. Within 30 of the vivax isolates analyzed, four different allele sizes were detected for PvMSP1 gene. Characterization of PfMCA1 gene on thirty falciparum isolates did not show any variations on the basis of molecular length of amplicons. Characterization and sequencing of PvARP gene led to detection of the gene consisting 1975 nucleotides including 7 exons and 6 introns. PvARP amplicons among all analyzed isolates did not show any size variation. Specific RT-PCR products for PvARP and PvMSP1 genes were detected in ten of thirty samples, whereas PvMCA1 analysis amplified fragments only in two samples.\ud To carry out of Transmission Electron Microscopy (TEM) analyses, P. falciparum infected erythrocytes were obtained from continuous cultures. Also P. berghei infected erythrocytes were collected from untreated and treated infected BALB/c mice with Auranofin. Moreover a Short-term in vitro culture was set up for P. vivax and the parasites were treated with staurosporine and chloroquine. Incubation was stopped after 12 and 18-h stimulation. TEM sections were prepared from RBC pellets using specimen preparation process for TEM. Electron micrographs of different stages of P. falciparum and P. berghei were prepared and the different structures of the parasites were specified through comparison with the references. We couldn’t obtain TEM photos of P. vivax from the short term culture samples, due to the very low initial parasitemia and the disappearing of parasite in the treated samples.\ud In this study for the first time, size polymorphism in the P. vivax metacaspase 1 was identified. Recently, metacaspase proteins have identified in Plasmodium species and potentially involved in PCD of the malaria parasites. To know more about genetic diversity in vivax populations could provide useful information for the implementation of malaria control activities. We confirmed the presence of 7 exons and 6 introns in PvARP similar to PfARP gene. The absence of RT-PCR products of PvMCA1 in eight samples positively amplified for PvARP and PvMSP1 suggests the\ud hypothesis that probably these results could be associated with expression rate of PvMCA1.\ud In the TEM part of the study, the morphological changes of P. berghei exposed to the Auranofin were explored as a model in the frame of PCD study and structural alterations including vacuolization and parasite cell lysis with leakage of cytosol were observed. Although interesting results has been achieved in TEM samples from treated P. berghei, we have to consider these as preliminary results and more studies are recommended. To reproduce TEM protocol used with falciparum and berghei for P. vivax was hampered by a list of problems reported as follows:\ud 1) The inability to maintain P. vivax in continues cultures. 2) The difficult in recovering viable P. vivax parasites after the preservation in liquid nitrogen 3) The problems occurred during transport of fresh blood samples from endemic area to the equipped laboratory. 4) The problems to find other patients with higher level of parasitemia in an endemic area in Iran.\ud In this study, we succeeded in providing new information about the genetics of P. vivax and we believe that the TEM protocol we set up using P. falciparum and P. berghei could be a useful and crucial tool to study at the ultra-structural level the biology of this still neglected human parasite

The Prevalence of Intestinal Parasites and Associated risk Factors among Students of Jahrom University of Medical Sciences

Background: Parasitic infections, especially intestinal agents could affect social and personal hygiene and health; and to avoid the spread of pollution, monitoring the infectious sources is critical. Objective: The aim of this study is to estimate the prevalence of intestinal parasites and identify factors associated with intestinal parasitic infections among students of Jahrom University of Medical Sciences between 2013-1014. Materials and Methods: This study was carried out between September 2013and February 2014. A total number of 1293 stool samples were taken from 431 students and were examined by direct wet mounting and formalin-ether methods. A questionnaire for common risk factors was completed for each individual. Results: Overall, the prevalence of intestinal parasitic infections was estimated to be 125 (29%) that infected by pathogenic and non-pathogenic intestinal parasites. Various species of protozoan infections were detected: Entamoeba coli was the most common parasite (9.04%) followed by Blastocystis hominis (8.12%), and Giardia lamblia (4.64%). About 3.2% students were infected with multiple parasites. A significant association was observed between the prevalence of intestinal parasite infections with the type of accommodation (OR=1. 5; 95% CI: 1.1; 1.9), parents’ educational level (OR=1. 5; 95% CI: 1.1; 1.9) and gender (OR=1. 5; 95% CI: 1.1; 1.9). No age association was detected, and a slightly positive prevalence with increasing age was observed (p=0.66). Conclusions: These data showed intestinal parasites were slightly more prevalent than expected, that might be due to interior sources of infection in college, such as carrier students. Hence, performing periodic monitoring among students is a necessity to promote the hygiene of the students

Chapter Three - Heating up a cold case: Applications of analytical pyrolysis GC/MS to assess molecular biomarkers in peat

Intact peatlands serve as a globally important carbon sink. However, impacts from climate change, extraction, and drainage increase aerobic decomposition in these ecosystems—shifting their carbon flux from sink to source. A variety of projects are ongoing to restore peatlands to their natural or near-natural states; however, for carbon sequestration, net accumulation of peat relative to decomposition is of primary importance. Molecular analysis techniques provide information on peat growth and degradation trends dating from centuries to millennia. Pyrolysis coupled to gas chromatography mass spectrometry (Py-GC/MS) has been proposed for the rapid characterization of molecular biomarkers in organic matter. This paper reviews plant and microbial biomarkers analyzable via Py-GC/MS for peatland ecosystems, associated challenges, and future applications of the technique. It is noted that far fewer organism-specific biomarkers have been identified via Py-GC/MS for microbial communities in comparison to plant-based studies, and as a topic remains an area greatly needing additional research. In the future, through improved Py-GC/MS-derived fingerprinting of peatland molecular components, periods of degradation and growth could be more precisely distinguished and described, even in profiles where changes in contributing source material are not macroscopically visible