scholarly journals Sporulation Strategies and Potential Role of the Exosporium in Survival and Persistence of Clostridium botulinum

2022 ◽  
Vol 23 (2) ◽  
pp. 754
Author(s):  
Inês M. Portinha ◽  
François P. Douillard ◽  
Hannu Korkeala ◽  
Miia Lindström

Clostridium botulinum produces the botulinum neurotoxin that causes botulism, a rare but potentially lethal paralysis. Endospores play an important role in the survival, transmission, and pathogenesis of C. botulinum. C. botulinum strains are very diverse, both genetically and ecologically. Group I strains are terrestrial, mesophilic, and produce highly heat-resistant spores, while Group II strains can be terrestrial (type B) or aquatic (type E) and are generally psychrotrophic and produce spores of moderate heat resistance. Group III strains are either terrestrial or aquatic, mesophilic or slightly thermophilic, and the heat resistance properties of their spores are poorly characterized. Here, we analyzed the sporulation dynamics in population, spore morphology, and other spore properties of 10 C. botulinum strains belonging to Groups I–III. We propose two distinct sporulation strategies used by C. botulinum Groups I–III strains, report their spore properties, and suggest a putative role for the exosporium in conferring high heat resistance. Strains within each physiological group produced spores with similar characteristics, likely reflecting adaptation to respective environmental habitats. Our work provides new information on the spores and on the population and single-cell level strategies in the sporulation of C. botulinum.

2004 ◽  
Vol 23 (8) ◽  
pp. 413-419 ◽  
Author(s):  
Cetin Kaymak ◽  
Ela Kadioglu ◽  
Hulya Basar ◽  
Semra Sardas

In this study, genotoxic effects of repeated sevoflurane anaesthesia were investigated in rabbits with or without antioxidant supplementation. Twenty-one New Zealand male rabbits were included in the study and randomized into three groups as: placebo treated (Group I), vitamin E supplemented (Group II) and selenium supplemented (Group III). Vitamin E and selenium were given intraperitoneally for 15 days before anaesthesia treatment. Anaesthesia was administered using 3% sevoflurane in 4 L/min oxygen for a 3-hour period and continued for 3 days. Blood samples were collected before anaesthesia (Sample 1), after the first, second and third days of sevoflurane administration (Sample 2, Sample 3 and Sample 4 respectively) and the last samples were taken 5 days after the last sevoflurane administration (Sample 5). Genotoxic damage was examined using the comet assay. The degree of damage is assessed by grading the cells into three categories of no migration (NM), low migration (LM) and high migration (HM) depending on the fraction of DNA pulled out into the tail under the influence of the electric field. The number of comets in each sample was calculated (1 × number of comets in category NM + 2 × number of comets in category LM + 3 ×number of comets in category HM) and expressed as the total comet score (TCS), which summarizes the damage frequencies. In Group I, a significant increase in the mean TCSs was observed for Samples 3 and 4 as compared with Sample 1. However, there were no significant differences between Samples 1, 2 and 5. The mean TCS of Sample 4 was significantly higher than Sample 1, 2 and 3 in Group II. Group III demonstrated no significant mean TCSs for any experimental conditions. Statistical differences were also observed between the groups with significant P values. This experimental study points out the presence of DNA damage with repeated sevoflurane anaesthesia and the genoprotective role of antioxidant supplementation on DNA damage in mononuclear leukocytes of rabbits by highly sensitive comet assay.


1990 ◽  
Vol 258 (6) ◽  
pp. E907-E917 ◽  
Author(s):  
M. Frexes-Steed ◽  
M. L. Warner ◽  
N. Bulus ◽  
P. Flakoll ◽  
N. N. Abumrad

This study examines the independent effects of insulin and amino acids on protein metabolism after a 12-h and 4-day fast in healthy volunteers. Leucine (Leu) kinetics were examined during sequential insulin infusions of 0 (group I) or 0.0125 (groups II and III), 1.2, and 10 mU.kg-1.min-1. Plasma Leu was maintained at 12-h fasted levels in groups I and II and at 84-h fasted levels in group III. Four-day fast (vs. 1 day, P less than 0.01) was associated with a 79% drop in plasma insulin and elevations in plasma Leu (122%), Leu rates of appearance (Ra) (21%), and Leu oxidation (56%), and no change in nonoxidative rates of disappearance (Rd). Insulin resulted in a dose-dependent suppression of endogenous Leu Ra with group III = I greater than II. Leu oxidation rose 1.7-fold in group III at the highest insulin dose but remained stable in the two other groups. In conclusion, 4-day fasting is associated with enhanced proteolysis and Leu oxidation with no change in nonoxidative Rd (protein synthesis). Elevated branched-chain (and other) amino acids were required to restore tissue sensitivity and specificity to the effects of insulin on protein metabolism after 4 days of fasting.


2013 ◽  
Vol 79 (12) ◽  
pp. 3867-3869 ◽  
Author(s):  
Elias Dahlsten ◽  
David Kirk ◽  
Miia Lindström ◽  
Hannu Korkeala

ABSTRACTThe role of the alternative sigma factor SigK in cold and osmotic stress tolerance ofClostridium botulinumATCC 3502 was demonstrated by induction ofsigKafter temperature downshift and exposure to hyperosmotic conditions and by impaired growth of thesigKmutants under the respective conditions.


1991 ◽  
Vol 261 (2) ◽  
pp. H443-H450 ◽  
Author(s):  
H. Toga ◽  
J. Usha Raj ◽  
R. Hillyard ◽  
B. Ku ◽  
J. Anderson

We have determined the sites of action of endothelin-1 (ET) in the lamb pulmonary circulation. The influence of cyclooxygenase inhibition and baseline vasomotor tone on ET effects was also studied. Lungs of 14 lambs (6-9 wk of age, 12.1 +/- 0.6 kg body wt) were isolated and perfused with blood. Group I lungs (n = 5) were untreated, group II lungs (n = 5) were treated with indomethacin to inhibit cyclooxygenase, and group III lungs (n = 4) were treated with indomethacin and a thromboxane A2 analogue, U-46619, to elevate vasomotor tone. All lungs were perfused with constant flow in zone 3, with left atrial and airway pressures being 8 and 6 cmH2O, respectively. We measured pulmonary arterial pressure and, by the micropuncture servo-null method, pressures in 20- to 50-microns diameter subpleural venules, both before and after each dose of ET was infused (50, 100, 250, and 500 ng/kg). Group I lungs, with high baseline vasomotor tone, exhibited a biphasic response to ET; 50-100 ng/kg of ET dilated both arteries and veins, whereas 500 ng/kg of ET constricted both arteries and veins. In group II lungs with low vasomotor tone, all doses of ET caused constriction of arteries only. In group III lungs (indomethacin treated with elevated vasomotor tone), 50-100 ng/kg of ET caused dilation of arteries and veins, whereas 500 ng/kg of ET induced constriction, this time only in arteries. We conclude that ET has both dilator and constrictor effects in arteries and veins of isolated, perfused lamb lungs. ET-induced arterial and venous dilation is dependent on initial vasomotor tone but not on cyclooxygenase metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)


2021 ◽  
Author(s):  
Shivkumar Gopalakrishnan ◽  
sangeetha kandasamy ◽  
S.Malini ◽  
S.Peer Mohamed ◽  
k.velmurugan

Abstract Background. Approximately 5% of COVID-19 patients suffer near fatal disease. Clinical and radiologic features may predict severe disease albeit with limited specificity and radiation hazard. Laboratory biomarkers are eyed as simple, specific and point of care triage tools to optimize management decisions.This study aimed to study the role of inflammatory markers in prognosticating COVID-19 patients.Methodology. A hospital based retrospective study was conducted on COVID-19 adult inpatients classified into three groups as mild disease-recovered [Group I], severe disease-recovered [Group II] and dead [Group III]. Categorical outcomes were compared using Chi square test. Univariate binary logistic regression analysis was performed to test the association between the explanatory and outcome variables. Unadjusted OR along with 95% CI was calculated. The utility of lab parameters (Ferritin, LDH, D dimer, N/L ratio and PLT/L ratio) in predicting severity of COVID-19 was assessed by Receiver Operative Curve (ROC) analysis. P value < 0.05 was considered statistically significant.Results. The mean age was 49.32 +/- 17.1 years. Among study population, 378 were Group I, 66 Group II, and 56 Group III. Median levels of Ferritin among the 3 groups were 62ng/mL, 388.50 ng/mL and 1199.50 ng/mL. Median value of LDH were 95U/L, 720 and 982.50(p <0.001). D-dimer values of 3 groups were 23.20ng/mL, 104.30 ng/mL and 197.10 ng/mL (p <0.001). CRP done qualitatively was positive in 2 (0.53%), 30 (45.45%) and 53 (94.64%) of patients. The odds of patients suffering severe COVID-19 rose with rising values of ferritin, LDH and D-dimer [unadjusted OR 1.007, 1.004 &1.020]Conclusion. One time measurement of serum ferritin, LDH, D-dimer and CRP is promising to predict outcomes for COVID 19 inpatients. Single qualitative CRP was equally good but more cost effective than quantitative CRP. The most specific combination was NLR, Lymphocyte percentage and D-dimer levels done between 7th – 10th day of symptoms.


2021 ◽  
Vol 17 (4) ◽  
pp. 346-356
Author(s):  
I. S. Lipatov ◽  
Yu. V. Tezikov ◽  
A. R. Azamatov

Background: An in-depth study of dismetabolic mechanisms in the genesis of pre-eclampsia (PE) has been updated because pregnancy is considered as a natural model of metabolic syndrome (MS), as well as the metabolic disorders are important in development of essential hypertension.Aims: to reveal clinical and laboratory parallels in pregnancy complicated by PE without MS and pregnancy proceeding on the background of MS to assess the role of metabolic disturbances in the development of PE.Materials and methods: 82 women with MS were examined in the dynamics of pregnancy and were divided into 2 groups depending on the implementation of PE: group I consisted of 50 women with PE on the background of MS, group II 32 women with MS without PE. We formed group III consisting of 44 pregnant women with PE without accompanying diseases to assess the pathogenetic value of metabolic disorders in the development of PE. The IV (control) group consisted of 30 healthy women with physiological pregnancy. Metabolic, hematological parameters, hormones, markers of the proinflammatory state, endothelial hemostasiological dysfunction, decidualization and placental angiogenesis, accumulation dynamics and distribution loci of adipose tissue were determined in all pregnant women.Results: In the groups of pregnant women with PE, changes similar to MS were revealed: pronounced diabetic and atherogenic disorders with the development of pathological insulin resistance, hyperinsulinemia and leptinemia, endothelial-platelet link hyperactivation, thrombotic and inflammatory status, visceral type of fat deposition, hyperuricemia, hypersympathicotonia. It is proved that in the hierarchy of mechanisms of PE formation, placental dysfunction is a secondary alteration factor, which additionally potentiates the insulin resistance increase and the effects of structural and functional destabilization of the vascular endothelium.Conclusions: The direction of metabolic changes during pregnancy, the common development of PE and MS indicate the important role of dismetabolic mechanisms in the formation of PE.


2019 ◽  
Vol 3 (2) ◽  
pp. 23-34
Author(s):  
El-Zahraa M. Meghezel ◽  
Heba A. Ahmed ◽  
Ashraf A Askar ◽  
Emad Eldin Nabil ◽  
Ashraf Elyamany

Background Identifying biomarkers for early detection of hepatocellular carcinoma (HCC) remains quite challenging. In this study we aimed to estimate the number of TIE2-expressing monocytes (TEMs) cells, which display pro-tumoral activities and are defined as CD14+, TIE2+, and angiopoietin-2; and its potential use as a possible diagnostic marker in HCC patients complicating HCV induced cirrhosis. Methods Current study was conducted on 112 patients. They were divided into two groups: Group I (78 patients) with HCC complicating HCV induced cirrhosis; and group II chronic hepatitis C patients (34 patients). Both groups were compared to (age and sex-matched) healthy persons as group III (38 persons). Result The number of the circulating TEMs: CD14+ and TIE2+ monocytes were significantly higher in the peripheral blood of HCC patients than HCV LC patients and healthy controls, sensitivity and specificity for HCC diagnosis were respectively: CD14 (89.7%, 83.3%), TIE 2 (76.9%, 83.3%), and Ang-2 (76.9%, 66.7%). Moreover, analysis of the P-value and the odd’s ratio showed that CD14 has the highest predictive value for HCC. Conclusion Our results suggest that TEMs and Ang-2can be used as diagnostic markers for HCC, especially among the high-risk group of patients.


2011 ◽  
Vol 48 (No. 4) ◽  
pp. 175-180 ◽  
Author(s):  
H. Zukalová ◽  
J. Vašák

&nbsp; Glucosinolates are the substituted esters of thio amino acids and their synthesis is based on the corresponding amino acids. Methionine and cysteine are the natural donors in the case of the Brassica plants and L-tryptophane in the indole glucosinolates, respectively. In Brassica genus, alkenyl glucosinolates are mostly present and their content and composition differ as far as the development stage and the part of the plant are concerned. The indole glucosinolates are present in a&nbsp;minority level. Their role of sulphur supply is questioned by their very low content between 2% in the beginning of vegetation and 0.1% in its end. Glucosinolates are discussed mostly from the aspect of their anti-nutrition, anti-microbial, anti-fungicidal, and anti-bacterial effects and as being natural bio-fumigants. Their decomposition products have the mentioned properties. The products originate by prepared passive protection by the two-component system. From the aspect of these properties, it is useful to divide them into the following three groups according to the characters of their decomposition products. The first group (I.), whose hydrolysis in the neutral and alkaline environment creates iso-thio-cyanates. These bioactive compounds form the natural protection of the plant with bio-fumigatory effects particularly. Their anti-nutritive effects can be compensated by iodine, contrary to the second group (II.). This group is created by hydroxy-glucosinolates, whose decomposition products &ndash; iso-thio-cyanates &ndash; are not stable and they cycle while producing substituted 2-oxazolidinethione (goitrine &ndash; VTO). These glucosinolates represent a&nbsp;serious problem in feed industry since the VTO has a&nbsp;strong goitrogenic property. The third group (III.) &ndash; glucosinolates containing the indole group or the benzene ring (Sinalbin), create thio-cyanates during their hydrolysis. The role of indole glucosinolates has not been completely clarified so far. Their anti-carcinogenic effects are studied and they fulfil the role of an active protection.


Biology ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 239
Author(s):  
Fatma M. Ghoneim ◽  
Hani Alrefai ◽  
Ayman Z. Elsamanoudy ◽  
Salwa M. Abo El-khair ◽  
Hanaa A. Khalaf

Background: Sodium valproate (VPA) is an antiepileptic drug (AED) licensed for epilepsy and used during pregnancy in various indications. Alpha-lipoic acid (ALA) is a natural compound inducing endogenous antioxidant production. Our study aimed to investigate the effect of prenatal administration of VPA on the pancreas of rat offspring and assess the potential protective role of ALA co-administration during pregnancy. Methods: Twenty-eight pregnant female albino rats were divided into four groups: group I (negative control), group II (positive control, ALA treated), group III (VPA-treated), and group IV (VPA-ALA-treated). The pancreases of the rat offspring were removed at the fourth week postpartum and prepared for histological, immune-histochemical, morphometric, molecular, and oxidative stress marker studies. Results: In group III, there were pyknotic nuclei, vacuolated cytoplasm with ballooning of acinar, α, and β cells of the pancreas. Ultrastructural degeneration of cytoplasmic organelles was detected. Additionally, there was a significant increase in oxidative stress, a decrease in insulin-positive cell percentage, and an increase in glucagon positive cells in comparison to control groups. Moreover, VPA increased the gene expression of an apoptotic marker, caspase-3, with a decrease in anti-apoptotic Bcl2 and nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional factor. Conversely, ALA improved oxidative stress and apoptosis in group VI, and a consequent improvement of the histological and ultrastructure picture was detected. Conclusion: ALA co-administration with VPA significantly improved the oxidative stress condition, histological and morphometric picture of the pancreas, and restored normal expression of related genes, including Nrf2, caspase-3, and Bcl-2. Administration of α-lipoic acid has a protective effect against VPA-induced pancreatic oxidative damage via its cytoprotective antioxidant effect.


2020 ◽  
pp. 112067212094433 ◽  
Author(s):  
Momen Mahmoud Hamdi ◽  
Islam Mahmoud Hamdi

Purpose: To compare between mitomycin C alone, porcine extracellular matrix alone, and combined low dose mitomycin C with porcine extracellular matrix in term of efficacy and safety in phaco-trabeculectomy surgery. Study design: Prospective comparative. Methods: Sixty eyes of 60 patients complaining of primary open angle glaucoma and cataract, undergoing phaco-trabeculectomy, were distributed into three groups: group I: surgery was augmented with mitomycin C, group II with porcine extracellular matrix, and group III with porcine extracellular matrix combined with low dose mitomycin C. Intraocular pressure was evaluated, postoperatively, at day 1, week 1, and 1, 3, 6, 9, and 12 months. Bleb vascularity, pre- and post-operative intraocular pressure lowering medications, success of IOP control and complications were also evaluated. Results: After 12 months, the mean preoperative intraocular pressure (mm Hg) improved from 30.85 ± 4.7, 33.8 ± 4.2, and 31.05 ± 5.4 mm Hg, in groups I, II, and III respectively, to 13.8 ± 4.7 (55.2%), 15.2 ± 4.8 (55%), and 13 ± 4.9 (58.1%) ( p > 0.05). Success of IOP control, postoperative IOP lowering medications and complications were comparable ( p > 0.05). Bleb vascularity was significantly different ( p < 0.05). Conclusion: Mitomycin C, porcine extracellular matrix and their combination are equally effective in phacotrabeculectomy.


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