Attachment of endospores of Pasteuria penetrans to males and juveniles of Meloidogyne spp.

Nematology ◽  
1999 ◽  
Vol 1 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Regina M.D.G. Carneiro ◽  
Onivaldo Randig ◽  
Leandro G. Freitas ◽  
Don W. Dickson

Abstract The attachment of endospores to Meloidogyne spp. males and second stage juveniles (J2) was evaluated in two different in vitro assays of seven isolates of Pasteuria penetrans from Florida, USA. In the first assay, endospores of all seven isolates adhered to J2 but not males of M. arenaria race 1. In the second assay, two isolates differed in the specificity of spore attachment to J2 of six Meloidogyne spp. Isolate B4, from Pratylenchus scribneri, showed a similar degree of attachment to J2 of M. arenaria race 2, M. javanica (two populations) and to M. incognita race 3, but did not attach to males of seven species. Isolate P100, from Meloidogyne sp., had high rates of attachment to M. javanica from Rio Grande do Sul State and to M. paranaensis, but lower rates to M. arenaria and M. javanica from Parana State. These data indicate that attachment ability depends not only on the Meloidogyne species but also on the particular population of a species. The high rate of attachment to male but not J2 M. hapla indicates that endospore attachment may also depend upon nematode stage, species, race and population and on Pasteuria isolate. Germinated endospores attached to male M. hapla were examined by scanning electron microscopy but few had successfully penetrated the cuticle. Adhesion des endospores de Pasteuria penetrans aux males et juveniles de Meloidogyne spp. - L'adhesion des spores de Pasteuria penetrans aux males et juveniles de deuxieme stade (J2) de Meloidogyne spp. a ete evaluee lors de deux differents tests in vitro comprenant sept isolats de P. penetrans provenant de Floride, USA. Lors du premier test les endospores des sept isolats ont adhere aux J2 mais non aux males de M. arenaria race 1. Lors du second test deux isolats se sont distingues quant a la specificite de l'adhesion de leurs spores aux J2 de six des especes de Meloidogyne. L'isolat B4, provenant de Pratylenchus scribneri, montre un taux d'adhesion similaire vis-a-vis des J2 de M. arenaria race 2, M. javanica (deux populations) et M. incognita race 3, mais n'adhere aux males d'aucune des sept especes. L'isolat P 100, provenant de Meloidogyne sp., Montre un taux d'adhesion eleve vis-a-vis tant de M. javanica provenant de l'Etat de Rio Grande del Sul que de M. paranensis mais ce taux est faible vis-a-vis de M. arenaria et M. javanica originaires de l'Etat du Parana. Ces donnees indiquent que la faculte d'adhesion depend non seulement de l'espece de Meloidogyne en cause mais egalement de la population particuliere de cette espece. Le taux eleve d'adhesion vis-a-vis des males, mais non des J2, de M. hapla indique que cette adhesion peut dependre du stade de developpement du nematode, de son espece, race ou population ainsi que de l'isolat lui-meme de P. penetrans. Les endospores fixees aux males de M. hapla, et ayant germe, ont ete examinees en microscopie electronique a balayage: peu d'entre elles avaient reussi a traverser la cuticule.

1997 ◽  
Vol 87 (3) ◽  
pp. 273-283 ◽  
Author(s):  
Z. X. Chen ◽  
D. W. Dickson ◽  
L. G. Freitas ◽  
J. F. Preston

Pasteuria penetrans is a bacterial parasite of root-knot nematodes that shows great potential as a biocontrol agent. Scanning and transmission electron microscopy were used to study the ultrastructure, morphology, and sporogenesis of four isolates of P. penetrans. The effects of different Meloidogyne spp. and tobacco cultivars on sporangium size and morphology of endospores attached to the cuticle of second-stage juveniles (J2) of root-knot nematodes also were investigated. The P. penetrans isolates and their origins were P-20 from M. arenaria race 1 in Levy County, FL; P-100 from Meloidogyne sp. in Pasco County, FL; B-4 from Pratylenchus scribneri in Seminole County, FL; and P-120 from Meloidogyne spp. in Alachua County, FL. Sporangia of the four isolates were identical morphologically and similar in their dimensions, ranging from 2.39 to 3.42 μm in diameter and from 1.38 to 2.38 μm in height. Different Meloidogyne spp. and tobacco cultivars had no effect on sporangium size. Endospores attached to J2 were visualized in three forms: endospores retaining the sporangium wall, endospores covered with a thin exosporium, and endospores without covering. Sporogenesis of P. penetrans was similar to that of other gram-positive bacteria and generally matched the seven-stage scheme reported for Bacillus thuringiensis.


Nematology ◽  
2004 ◽  
Vol 6 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Regina Carneiro ◽  
Myrian Tigano ◽  
Camila Lopes Jorge ◽  
Ana Cristina Oliveira Teixeira ◽  
Maria Célia Cordeiro

Abstract Pasteuria penetrans isolates from different geographical areas were tested for the ability of endospores to attach to secondstage juveniles and to colonise females of different populations of Meloidogyne spp. from coffee and other crops. Our results confirm that the spore attachment test cannot be used as the only criterion for screening for the efficiency of the bacterial isolate against nematodes. The percentage of females infected with the bacteria and the endospore concentration in 100 macerated females were the best approaches for screening the highly pathogenic isolates. Using these parameters, it was possible to select some isolates for M. javanica and M. arenaria race 2; one isolate, P12, for the three populations of M. paranaensis, and isolate P10 for the four races of M. incognita from coffee. The isolates exhibited poor pathogenicity on M. hapla, M. exigua, M. graminicola and M. mayaguensis. There was clear evidence that the greatest parasitism occurred when the isolates of P.penetrans were exposed to species of Meloidogyne that were genetically close to that from which the bacteria populations had been originally isolated. The dendrogram obtained from attachment of 18 P. penetrans isolates on 13 Meloidogyne spp. populations clearly defined subgroups of the bacteria related to their geographical origin. RAPD analyses were used for fingerprinting the genomes of P.penetrans isolates. Twenty 10-mer oligonucleotide primers of arbitrary sequence revealed 145 scorable binary characters. Cluster analysis showed a low (61%) to high (80%) level of genetic similarity among the isolates and that phenetic groups were sometimes related to pathogenicity.


Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 206-206 ◽  
Author(s):  
M. Karajeh ◽  
W. Abu-Gharbieh ◽  
S. Masoud

Meloidogyne arenaria (Neal) Chitwood (race 2) is reported for the first time in Jordan. The nematode populations were recovered from several vegetable crops, including tomato (Lycopersicon esulentum Mill), squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and bean (Phaseolus vulgaris L.), at Dier Alla in the northern area of the Jordan Valley. Symptoms included root galling, leaf chlorosis, and stunting. Galled plant root samples were collected during a survey conducted from May 2002 to August 2003 covering most of the irrigated agricultural areas of Jordan. Eighty-three Meloidogyne spp. populations were collected from various vegetable crops and fruit trees. Identification to species and race levels of the nematode populations was based on combination of currently available methods including nematode morphology, host preference based on the North Carolina (NC) differential host test (1), and cytogenetics and DNA-fingerprinting. Seventy of the eighty-three collected populations were identified as M. javanica, five as M. incognita (race 1), three as M. incognita (race 2), and five as M. arenaria (race 2). The perineal patterns of M. arenaria were characterized by a low, round to indented dorsal arch near the lateral field with irregular forks in the lateral field, fine smooth striae, and a distinct whorl. Race 2 was identified with the NC differential host test. Cytogenetic studies indicated that M. arenaria populations were triploid with an average of 52.2 chromosomes, while the populations of M. incognita (race 1), M. incognita (race 2), and M. javanica were hypotriploid with an average of 45.2, 46.1, and 46.7 chromosomes, respectively. Two polymerase chain reaction (PCR)-based assays were used to confirm species identification and to study genetic variability of the Meloidogyne spp. populations including sequence characterized amplified regions (SCAR) and random amplified polymorphic DNA (RAPD). In the SCAR-PCR-based assay (2), typical DNA products of 420, 670, or 1,200 bp in size were amplified by using extracted DNA of M. arenaria (race 2), M. javanica, or M. incognita (race 1 or 2), respectively, as template DNA. The RAPD-PCR primer, OPA-01, produced DNA patterns with bands that clearly distinguished M. arenaria from the other two Meloidogyne spp. To our knowledge, this is the first report of the root-knot nematode, M. arenaria race 2, in Jordan. References: (1) A. Taylor and J. Sasser, North Carolina State University Graphics, Raleigh, NC, 1978. (2) C. Zijlstra et al. Nematology 2:847, 2000.


2003 ◽  
Vol 28 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Adriana K. Rodrigues ◽  
Leandro G. Freitas ◽  
Aristéa A. Azevedo ◽  
Silamar Ferraz

A bactéria Pasteuria penetrans é um parasita obrigatório do nematóide das galhas (Meloidogyne spp.) e produz esporos que persistem por anos no solo. A sua produção por cultivo in vitro ainda é inviável e a produção de inoculo requer o seu cultivo in vivo em nematóides parasitando plantas em vasos. Neste trabalho, buscou-se, por meio do estudo histológico de raízes, averiguar diferenças no desenvolvimento de P. penetrans em Meloidogyne spp. parasitando raízes de tomateiro (Lycopersicon esculentum), maxixe (Cucumis anguria) e camapu (Physalis angulata), e possíveis razões para estas diferenças, como forma e tamanho de células gigantes e das fêmeas do nematóide. O maxixe foi o pior dentre os hospedeiros em teste para a produção de inóculo e apresentou células gigantes anormais. A estrutura das células gigantes assim como o desenvolvimento da bactéria foram semelhantes no camapu e no tomateiro, entretanto o ciclo de vida de P. penetrans foi ligeiramente mais curto no tomateiro.


Nematology ◽  
2004 ◽  
Vol 6 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Gracia Liébanas ◽  
Pablo Castillo

Abstract Six crucifer species as potential cover crops, Ethiopian mustard (Brassica carinata line C-101), turnip (Brassica rapa cv. Norfolk), radish (Raphanus sativus), wild rocket (Eruca vesicaria), wild cabbage (Moricandia moricandioides) and white mustard (Sinapis alba), were tested for susceptibility to Meloidogyne arenaria race 2, M. incognita race 1 and M. javanica. Experiments were conducted under glasshouse conditions at 22-28°C for 2 months after inoculation of plants with eggs and second-stage juveniles. All crucifers were infected by Meloidogyne spp. The nematode and crucifer species significantly influenced the severity of root galling and nematode reproduction. Among the plants tested, turnip was the most suitable host for all three Meloidogyne spp. as indicated by severity of root galling and nematode reproduction. The least suitable hosts were wild rocket for M. arenaria, radish for M. incognita and white mustard for M. javanica. The reproduction fitness of M. javanica was greater than that of M. arenaria race 2 and M. incognita race 1 on all plants.


1979 ◽  
Vol 41 (03) ◽  
pp. 576-582
Author(s):  
A R Pomeroy

SummaryThe limitations of currently used in vitro assays of heparin have demonstrated the need for an in vivo method suitable for routine use.The in vivo method which is described in this paper uses, for each heparin preparation, four groups of five mice which are injected intravenously with heparin according to a “2 and 2 dose assay” procedure. The method is relatively rapid, requiring 3 to 4 hours to test five heparin preparations against a standard preparation of heparin. Levels of accuracy and precision acceptable for the requirements of the British Pharmacopoeia are obtained by combining the results of 3 to 4 assays of a heparin preparation.The similarity of results obtained the in vivo method and the in vitro method of the British Pharmacopoeia for heparin preparations of lung and mucosal origin validates this in vivo method and, conversely, demonstrates that the in vitro method of the British Pharmacopoeia gives a reliable estimation of the in vivo activity of heparin.


1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.


2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.


Author(s):  
Nidhi Sharma ◽  
Arti Singh ◽  
Ruchika Sharma ◽  
Anoop Kumar

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.


2019 ◽  
Vol 16 (2) ◽  
pp. 116-127 ◽  
Author(s):  
Ashwani Kumar ◽  
Vineet Mehta ◽  
Utkarsh Raj ◽  
Pritish Kumar Varadwaj ◽  
Malairaman Udayabanu ◽  
...  

Background: Cholinesterase inhibitors are the first line of therapy for the management of Alzheimer’s disease (AD), however, it is now established that they provide only temporary and symptomatic relief, besides, having several inherited side-effects. Therefore, an alternative drug discovery method is used to identify new and safer ‘disease-modifying drugs’. Methods: Herein, we screened 646 small molecules of natural origin having reported pharmacological and functional values through in-silico docking studies to predict safer neuromodulatory molecules with potential to modulate acetylcholine metabolism. Further, the potential of the predicted molecules to inhibit acetylcholinesterase (AChE) activity and their ability to protect neurons from degeneration was determined through in-vitro assays. Results: Based on in-silico AChE interaction studies, we predicted quercetin, caffeine, ascorbic acid and gallic acid to be potential AChE inhibitors. We confirmed the AChE inhibitory potential of these molecules through in-vitro AChE inhibition assay and compared results with donepezil and begacestat. Herbal molecules significantly inhibited enzyme activity and inhibition for quercetin and caffeine did not show any significant difference from donepezil. Further, the tested molecules did not show any neurotoxicity against primary (E18) hippocampal neurons. We observed that quercetin and caffeine significantly improved neuronal survival and efficiently protected hippocampal neurons from HgCl2 induced neurodegeneration, which other molecules, including donepezil and begacestat, failed to do. Conclusion: Quercetin and caffeine have the potential as “disease-modifying drugs” and may find application in the management of neurological disorders such as AD.


Sign in / Sign up

Export Citation Format

Share Document