scholarly journals Effects of Cyanobacterial Toxins on the Human Gastrointestinal Tract and the Mucosal Innate Immune System

Author(s):  
Barbara Kubíčková ◽  
Pavel Babica ◽  
Klára Hilscherova ◽  
Lenka Šindlerová

Cyanobacterial blooms occur with increasing frequency in freshwater ecosystems, posing a hazard to human and environmental health. Exposure of human to cyanobacterial metabolites occurs mostly via accidental ingestion through contaminated drinking water or during recreational activities and, most frequently, results in gastrointestinal symptoms. Despite the clinical manifestation, cyanobacterial metabolites are rather investigated for their toxicity towards specific organs or tissues, especially hepato-, nephro- and neurotoxicity, then for effects on the gastrointestinal tract and the associated lymphoid tissue. The aim of this review was to systematically summarize available literature on the effects on the gastrointestinal tract and the mucosal innate immune system and compile the data from both, in vitro and in vivo studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies. studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies.

2001 ◽  
Vol 1 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. Tarczyńska ◽  
Z. Romanowska-Duda ◽  
T. Jurczak ◽  
M. Zalewski

Eutrophication of reservoirs used for drinking water supplies is a very common problem, particularly in lowland reservoirs. Long water retention time (60-120 days) favours cyanobacterial bloom occurrence in Sulejów Reservoir, Poland. The localisation of the water intake in a bay exposed to north-east winds favoured the Microcystis bloom accumulation, which formed a 0.5 m thick dense scum for the first time in September 1999. Cyanobacterial hepatotoxins can pose a potential health problem because the presence of about 0.8 μg/l microcystins was detected in drinking water during three series of analysis. An investigation of the efficiency of each stage of water treatment processes in the elimination of microcystins showed that pre-chlorination, coagulation, and rapid sand filtration were ineffective in removing microcystins from water. Significant elimination was observed after ozonation and chlorination. The concentration of microcystins in bloom material was between 12 to 860 μg/g dry weight of phytoplankton biomass. Management strategies for reservoirs should consider the important role of ecohydrological processes, which are often very easy to regulate, and which can be useful for bio-manipulation of the water ecosystem.


2017 ◽  
Vol 62 (2) ◽  
pp. 60-65
Author(s):  
T. E. Sizikova ◽  
V. N. Lebedev ◽  
V. B. Pantukhov ◽  
S. V. Borisevich

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a new virus (SFTS virus) reported to be endemic to central and northeastern parts of China. SFTS virus, which is classified into the genus Phlebovirus (the Bunyaviridae family), is suspected to be a tick-borne virus owing to evidence in two species of ticks: Haemaphysalis longicornis and Rhipicephalus microplus. SFTS virus is detected among many species of domestic animals in China. The clinical symptoms of SFTS include fever, thrombocytopenia, leucocytopenia, gastrointestinal symptoms, neural symptoms, bleeding tendency. The fatality rate of SFTS is 6-30%. Person-to-person transmission of SFTS virus is possible through blood contact. Clinical and epidemiological studies of SFTS, the cases of SFTS outside China, person-to-person transmission of SFTS virus, evolutionary and molecular analysis of the emergent SFTS virus, and risk assessment of human infection with a novel phlebovirus are considered in this review.


2021 ◽  
Vol 93 (8) ◽  
pp. 923-931
Author(s):  
Maria D. Ardatskaya ◽  
Ludmila I. Butorova ◽  
Marina A. Kalashnikova ◽  
Nelli R. Nugaeva ◽  
Yury V. Ovchinnikov ◽  
...  

Background. The novel coronavirus infection COVID-19 can be manifested by damage to the organs of the gastrointestinal tract (GIT). Damage to the gastrointestinal tract by the SARS-CoV-2 virus leads to a violation of the microbial-tissue complex of the mucous membrane of the digestive tract. A common gastroenterological manifestation of COVID-19 is diarrhea. Aim. Study of the clinical features of gastroenterological disorders and the possibility of optimizing the treatment of diarrheal syndrome in patients with COVID-19 with a mild form of viral infection. Materials and methods. The observation group consisted of 230 patients with mild COVID-19: K-group (n=115) with respiratory symptoms, I group (n=115) with gastrointestinal manifestations in combination and without signs of respiratory damage. In order to compare the effectiveness of treatment of diarrheal syndrome, patients of group I are randomized into 2 subgroups: Ia (n=58) prebiotic treatment (Zacofalk) and Ib (n=57) enterosorbents. Results. The development of gastrointestinal symptoms with SARS-CoV-2 infection is significantly more often noted in comorbid patients (67%). Gastrointestinal symptoms were dominated by diarrhea (93.9%) and flatulence (76.5%), in 1/3 of patients they were the first manifestos of infection. It was established that in 98.4% of patients of group I (against 42.6% of the K-group) signs of infectious intoxication were detected. In patients with gastrointestinal lesions, an elongation of the febrile period by 91.5 days was noted, a later (6 days) verification of the viral etiology of the disease. It was found that in patients of group I, the regression of clinical symptoms, the duration of viral disease, the dynamics of antibody formation, the prognosis for the development of IBS-like disorders in the post-infectious period depended on the treatment. In patients taking (Zacofalk), these indicators were significantly better. Conclusion. In mild cases, to reduce the severity of viral intestinal damage, for effective relief of intestinal symptoms, to reduce the risk of IBS-like symptoms, it is advisable to prescribe (Zacofalk) in an initial dose of 3 tablets per day.


1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).


Author(s):  
Malireddy S Reddy

The worldwide popularity of Dr. M.S. Reddy’s Multiple Mixed Strain Probiotic Therapy to treat or prevent the hospital acquired infections (nosocomial infections) arose a great interest in the medical community around the world (Reddy and Reddy, 2016; 2017). The following questions were raised on this subject: Does Multiple Mixed Strain Probiotics directly inhibit the pathogenic bacteria (C. diff) in the gastrointestinal tract or indirectly through modulation of the host immune system or both? To be more specific, what is the exact and/or hypothetical mechanism at molecular level behind the breakthrough discovery of Dr. M.S. Reddy’s Multiple Mixed Strain Probiotic Therapy?  To answer these questions, the specific immunomodulation regulatory functions of the individual Probiotic strains (on host) have beenresearched, investigated andoutlined in this article.  A detailed explanation(s) and hypotheses have been proposed outlining the possible cumulativedirect bacteriological and indirect immunomodulatory effects (at the molecular level) of the Multiple Mixed Strain Probiotics used in Dr. M.S. Reddy’s Multiple Mixed Strain Probiotic Therapy to successfully treat C. diff infection.  A detailed scientific and research attempts were made to correlate the Probiotic induced immune activities in relation to the reduction of the symptoms associated with the hospital acquired Clostridium difficile infection during and after the Multiple Mixed Strain Probioitc Therapy.  Results of the clinical trials, microbiological tests on feces, and the clinical blood tests significantly revealed that the reasons for the success of Dr. Reddy’s Multiple Mixed Strain Probiotic Therapy are multifold. Presumably, it is predominantly due to the immunomodulatory effect they have exerted on the host immune system along with the direct inhibition of C. diff bacteria by multiple Probiotics, due to the production of bacteriocins, lactic acid and nutritional competency.In addition, the size of the individual cells of the Probiotic strains in the Multiple Mixed Strain Probiotics and their significant effect on immunomodulation has been thoroughly discussed. Results clearly proved that if Probiotics are absent in the GI tract during C. diff infection, the chances of patient survival is zero.  This is because of the excess immune stimulation and incurable damage to the epithelial cell barrier of the gastrointestinal tract caused by C. diff bacteria.  The results also revealed, without any doubt, as of to-datethe latest discovery of Dr. M.S. Reddy’s Multiple Mixed Strain Probiotic Therapy is the best way to cure the deadly hospital acquired infections affecting millions of people around the world, with high degree of mortality.  This has been attested by several practicng medical professionals and scientists around the world (Reddy and Reddy, 2017).


2020 ◽  
Vol 10 (01) ◽  
pp. e137-e140
Author(s):  
Mosaad Abdel-Aziz ◽  
Nada M. Abdel-Aziz ◽  
Dina M. Abdel-Aziz ◽  
Noha Azab

AbstractThe clinical manifestations of novel coronavirus disease 2019 (COVID-19) vary from mild flu-like symptoms to severe fatal pneumonia. However, children with COVID-19 may be asymptomatic or may have mild clinical symptoms. The aim of this study was to investigate clinical features of pediatric COVID-19 and to search for the factors that may mitigate the disease course. We reviewed the literature to realize the clinical features, laboratory, and radiographic data that may be diagnostic for COVID-19 among children. Also, we studied the factors that may affect the clinical course of the disease. Fever, dry cough, and fatigue are the main symptoms of pediatric COVID-19, sometimes flu-like symptoms and/or gastrointestinal symptoms may be present. Although some infected children may be asymptomatic, a recent unusual hyperinflammatory reaction with overlapping features of Kawasaki's disease and toxic shock syndrome in pediatric COVID-19 has been occasionally reported. Severe acute respiratory syndrome-coronvirus-2 (SARS-CoV-2) nucleic acid testing is the corner-stone method for the diagnosis of COVID-19. Lymphocyte count and other inflammatory markers are not essentially diagnostic; however, chest computed tomography is highly specific. Factors that may mitigate the severity of pediatric COVID-19 are home confinement with limited children activity, trained immunity caused by compulsory vaccination, the response of the angiotensin-converting enzyme 2 receptors in children is not the same as in adults, and that children are less likely to have comorbidities. As infected children may be asymptomatic or may have only mild respiratory and/or gastrointestinal symptoms that might be missed, all children for families who have a member diagnosed with COVID-19 should be investigated.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Antonio Pizuorno ◽  
Nora A. Fierro ◽  
Edgar D. Copado-Villagrana ◽  
María E. Herrera-Solís ◽  
Gholamreza Oskrochi ◽  
...  

Abstract Background Covid-19 in Mexico is on the rise in different parts of the country. We aimed to study the symptoms and comorbidities that associate with this pandemic in 3 different regions of Mexico. Methods We analyzed data from SARS-CoV-2 positive patients evaluated at healthcare centers and hospitals of Mexico (n = 1607) including Northwest Mexico (Sinaloa state), Southeast Mexico (Veracruz state) and West Mexico (Jalisco state) between March 1 and July 30, 2020. Mexico consists of a total population that exceeds 128 million. Demographics, comorbidities and clinical symptoms were collected. Statistical descriptive analysis and correlation analyses of symptoms, comorbidities and mortality were performed. Results A total of 1607 hospitalized patients positive for COVID-19 across all 3 regions of Mexico were included. The average age was 54.6 years and 60.4% were male. A mortality rate of 33.1% was observed. The most common comorbidities were hypertension (43.2%), obesity (30.3%) and diabetes (31.4%). Hypertension was more frequent in West (45%), followed by Northwest (37%) and Southeast Mexico (29%). Obesity was around 30% in Northwest and West whereas an 18% was reported in Southeast. Diabetes was most common in West (34%) followed by Northwest (22%) and Southeast (13%). This might be related to the highest mortality rate in Northwest (31%) and West (37%) when compared to Southeast. Most common symptoms in our overall cohort were fever (80.8%), cough (79.8%), headache (66%), dyspnea (71.1%), myalgia (53.8%), joints pain (50.8%) and odynophagia (34.8%). Diarrhea was the main gastrointestinal (GI) symptom (21.3%), followed by abdominal pain (18%), and nausea/ vomiting (4.5%). Diarrhea and abdominal pain were more common in West (23.1 and 21%), followed by Southeast (17.8, and 9.8%) and Northwest (11.4 and 3.1%). Conclusion Our study showed a high mortality rate likely related to high frequencies of comorbidities (hypertension, obesity and diabetes). Mortality was different across regions. These discrepancies might be related to the differences in the frequencies of comorbidities, and partially attributed to differences in socio-economic conditions and quality of care. Thus, our findings stress the need for improved strategies to get better outcomes in our population.


2021 ◽  
Vol 9 ◽  
pp. 205031212198963
Author(s):  
Artit Sangkakam ◽  
Pasin Hemachudha ◽  
Abhinbhen W Saraya ◽  
Benjamard Thaweethee-Sukjai ◽  
Thaniwan Cheun-Arom ◽  
...  

Introduction: Influenza virus favours the respiratory tract as its primary site of host entry and replication, and it is transmitted mainly via respiratory secretions. Nasopharyngeal swab is the gold standard specimen type for influenza detection, but several studies have also suggested that the virus replicates in the human gastrointestinal tract. Methods: A retrospective study was conducted on all patients positive for influenza virus and initially recruited as part of the PREDICT project from 2017 to 2018. The objectives of the study were to investigate whether rectal swab could aid in improving influenza detection, and if there was any correlation between gastrointestinal disturbances and severity of infection, using length of hospital stay as an indicator of severity. Results: Of the 51 influenza-positive patients, 12 had detectable influenza virus in their rectal swab. Among these 12 rectal swab positive patients, influenza virus was not detected in the nasopharyngeal swab of three of them. Gastrointestinal symptoms were observed for 28.2% patients with a negative rectal swab negative and 25.0% patients with a positive rectal swab. Average length of hospital stay was 4.2 days for rectal swab positive group and 3.7 days for rectal swab negative group. This difference was not statistically significant (p = 0.288). Conclusions: There is no correlation between influenza virus detection in rectal swab and gastrointestinal disturbances or disease severity, and there is currently insufficient evidence to support replicative ability in the gastrointestinal tract.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Eleni Keliri ◽  
Christia Paraskeva ◽  
Angelos Sofokleous ◽  
Assaf Sukenik ◽  
Dariusz Dziga ◽  
...  

AbstractBackgroundExcess loads of nutrients finding their way into waterbodies can cause rapid and excessive growth of phytoplankton species and lead to the formation of cyanobacterial harmful algal blooms (cyano-HABs). Toxic cyanobacteria produce a broad range of bioactive metabolites, some of which are known as cyanotoxins. These metabolites can negatively impact the ecosystem, and human and animal health, thus their presence needs to be closely monitored and mitigated. This study aimed to monitor St. George Lake (Athalassa National Forest Park, Cyprus) for its water quality characteristics, and initiate a new methodology to control the bloom that occurred in the lake during summer 2019, by comparing hydrogen peroxide treatment with novel metallic peroxide granules as source of hydrogen peroxide.ResultsLake monitoring showed that pH, salinity, total dissolved solids and conductivity varied throughout the year, and nutrients concentration was high, indicating a eutrophic lake. The cyanobacteriumMerismopediasp. bloomed in the lake between June and September 2019, comprising up to 99% of the phytoplankton biovolume. The presence of microcystin synthase encoding gene (mcyB, mcyE) was documented, however microcystins were not detected by tandem mass spectroscopy. Treatment with liquid hydrogen peroxide in concentrations 1 to 5 mg L−1had no effect on the phycocyanin fluorescence (Ft) and quantum yield of PSII (Fv/Fm) indicating an ineffective treatment for the denseMerismopediabloom (1 million cells mL−1 ± 20%). Metallic peroxide granules tested for their H2O2releasing capacity in St. George Lake water, showing that CaO2released higher H2O2concentration and therefore have better mitigation efficiency than MgO2granules.ConclusionThe present study highlights the importance of monitoring several water parameters to conclude on the different actions to be taken to limit eutrophication in the catchment area. The findings demonstrated that testing for the presence of genes involved in cyanotoxin production may not be sufficient to follow cyanotoxins in the water, therefore it should be accompanied with analytical confirmation. Treatment experiments indicated that slow release of H2O2from peroxide granules may be an alternative to liquid hydrogen peroxide when applied in appropriate doses, but further investigation is needed before it is applied at the field.Graphic Abstract


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