A novel non-surgical method for mild peri-implantitis- a multicenter consecutive case series.

AIM: The aim of the present study was to evaluate the effect on peri-implant mucosal inflammation from the use of a novel instrument made of chitosan in the non-surgical treatment of mild peri-implantitis across several clinical centers. MATERIALS AND METHODS: In this 6-month multicenter prospective consecutive case series performed in six different periodontal specialist clinics, 63 implants in 63 patients were finally included. The subjects had mild peri-implantitis defined as radiographic bone loss of 1-2 mm, pocket probing depth (PPD) ≥4 mm and a positive bleeding on probing (mBoP) score. The patients were clinically examined at baseline and after 2, 4, 12 and 24 weeks, and radiographs were taken at baseline and at 3 and 6 months. Treatment of the implants with the chitosan brush seated in an oscillating dental drill piece was performed at baseline and at 3 months. Reductions in the clinical parameters (PPD and mBoP) were compared between baseline and the later examination time points. RESULTS: Significant reductions in both PPD and mBoP were observed at all time points compared with the baseline clinical measurements (p < 0.001). The mean PPD and mBoP at baseline were 5.15 mm (4.97; 5.32) and 1.86 (1.78; 1.93), respectively, whereas the mean PPD and mBoP at 6 months were 4.0 mm (3.91; 4.19) and 0.64 (0.54; 0.75), respectively. Stable reductions in PPD and mBoP were evident up to 6 months after the initial treatment and 3 months after the second treatment. All 63 implants were reported to have stable radiographic levels of osseous support. CONCLUSIONS: This case series demonstrated that an oscillating chitosan brush is safe to use and seems to have merits in the non-surgical treatment of dental implants with mild peri-implantitis. To measure the effectiveness of the method, a multicenter randomized clinical trial needs to be undertaken.

A Nordic survey of management practices and owners' attitudes towards keeping horses in groups.

Keeping horses in groups is widely recommended but limited information is available about how this is implemented in practice. The aim of this survey was to describe how horses are kept in the Nordic countries in relation to sex, age, breed, and equestrian discipline and to assess owners' attitudes toward keeping horses in groups. Horse owners in Denmark, Finland, Norway, and Sweden were approached using a web-based questionnaire, which was translated into 4 languages and distributed online via equestrian forums, organizations, and social media. The number of respondents was 3,229, taking care of 17,248 horses. Only 8% of horses were never kept in groups, 47% were permanently grouped for 24 h/d, and 45% were stabled singly but grouped during turnout. Yearlings were most often permanently kept in groups (75%), mares and geldings more commonly during parts of the day (50 and 51%, respectively), and stallions were often kept alone (38%). Icelandic horses were more likely to be permanently kept in groups (36%) than warmbloods (16%) and ponies (15%). Twice as many competition horses (51%) were never grouped compared with horses used for breeding (20%) or leisure purposes (15%). The majority of respondents (86%) strongly agreed that group housing benefits horse welfare and that it is important for horses to have the company of conspecifics (92%). Nevertheless, not all horses were kept in groups, showing that attitudes toward group housing may not necessarily reflect current management. The risk of injury was a concern of many respondents (45%), as was introducing unfamiliar horses into already established groups (40%) and challenges in relation to feeding in groups (44%). Safety of people (23%) and difficulties handling group-kept horses (19%) were regarded as less problematic. Results suggest that the majority of horses have the possibility to freely interact with other horses, either as fulltime members of a group during 24 h/d or during turnout. Future research should address the extent to which being a part-time member of a group affects horse welfare. For permanent group housing to become more widespread, such as it is the case for most farm animals, future research could focus on solving some of the reoccurring problems perceived with keeping horses in groups. The dissemination of evidence-based information on all aspects around keeping horses in groups can ultimately stimulate further positive changes in the management of group-kept horses.

Elevated levels of salivary lactoferrin, a marker for chronic periodontitis?

BACKGROUND AND OBJECTIVE: Whole saliva is a complex mixture of fluids essential for the well-being of the oral hard and soft tissues. Saliva contains numerous antimicrobial proteins that help protect the oral ecosystem from infectious agents. Chronic periodontitis is an infectious chronic inflammatory condition that affects the tooth-supporting structures and leads to their destruction. The aim of the present study was to investigate differences in concentrations of salivary lactoferrin in subjects with and without periodontal disease and correlate these values with clinical variables associated with periodontal disease. MATERIAL AND METHODS: Stimulated whole saliva was collected from 17 subjects with chronic periodontitis and 17 periodontally healthy control subjects. Data relating to bleeding on probing, probing pocket depth and horizontal bone loss were registered. Concentrations of lactoferrin, lysozyme and IgA in stimulated whole saliva were quantified using ELISA. RESULTS: Subjects with chronic periodontits showed higher concentrations of lactoferrin in stimulated whole saliva compared with periodontally healthy control subjects (p < 0.05). Salivary concentrations of lactoferrin were positively correlated with bleeding on probing (p < 0.001) and the number of sites with probing pocket depth ≥ 6 mm (p < 0.001). CONCLUSION: Lactoferrin is raised in stimulated whole saliva in subjects with chronic periodontitis and is correlated with probing pocket depth ≥ 6 mm.

Membrane fluidity determines sensitivity of filamentous fungi to chitosan.

The antifungal mode of action of chitosan has been studied for the last 30 years, but is still little understood. We have found that the plasma membrane forms a barrier to chitosan in chitosan-resistant but not chitosan-sensitive fungi. The plasma membranes of chitosan-sensitive fungi were shown to have more polyunsaturated fatty acids than chitosan-resistant fungi, suggesting that their permeabilization by chitosan may be dependent on membrane fluidity. A fatty acid desaturase mutant of Neurospora crassa with reduced plasma membrane fluidity exhibited increased resistance to chitosan. Steady-state fluorescence anisotropy measurements on artificial membranes showed that chitosan binds to negatively charged phospholipids that alter plasma membrane fluidity and induces membrane permeabilization, which was greatest in membranes containing more polyunsaturated lipids. Phylogenetic analysis of fungi with known sensitivity to chitosan suggests that chitosan resistance may have evolved in nematophagous and entomopathogenic fungi, which naturally encounter chitosan during infection of arthropods and nematodes. Our findings provide a method to predict the sensitivity of a fungus to chitosan based on its plasma membrane composition, and suggests a new strategy for antifungal therapy, which involves treatments that increase plasma membrane fluidity to make fungi more sensitive to fungicides such as chitosan.

The protein glass transition as measured by dielectric spectroscopy and differential scanning calorimetry.

The glass transition and its related dynamics of myoglobin in water and in a water-glycerol mixture have been investigated by dielectric spectroscopy and differential scanning calorimetry (DSC). For all samples, the DSC measurements display a glass transition that extends over a large temperature range. Both the temperature of the transition and its broadness decrease rapidly with increasing amount of solvent in the system. The dielectric measurements show several dynamical processes, due to both protein and solvent relaxations, and in the case of pure water as solvent the main protein process (which most likely is due to conformational changes of the protein structure) exhibits a dynamic glass transition (i.e. reaches a relaxation time of 100 s) at about the same temperature as the calorimetric glass transition temperature T(g) is found. This glass transition is most likely caused by the dynamic crossover and the associated vanishing of the alpha-relaxation of the main water relaxation, although it does not contribute to the calorimetric T(g). This is in contrast to myoglobin in water-glycerol, where the main solvent relaxation makes the strongest contribution to the calorimetric glass transition. For all samples it is clear that several proteins processes are involved in the calorimetric glass transition and the broadness of the transition depends on how much these different relaxations are separated in time.

Dynamics of a protein and its surrounding environment: a quasielastic neutron scattering study of myoglobin in water and glycerol mixtures.

In this quasielastic neutron scattering (QENS) study we have investigated the relation between protein and solvent dynamics. Myoglobin in different water:glycerol mixtures has been studied in the temperature range of 260-320 K. In order to distinguish between solvent and protein dynamics we have measured protonated as well as partly deuterated samples. As commonly observed for bulk as well as for confined water, the dynamics of the surrounding solvent is well described by a jump diffusion model. The intermediate scattering function I(Q,t) from the protein (partly deuterated samples) was analyzed by fitting a single Kohlrausch-Williams-Watts (KWW) stretched exponential function to the data. However, due to the limited experimental time window, two different curve fitting approaches were used. The first one was performed with the assumption that I(Q,t) decays to zero at long times, i.e., it was assumed that all protein relaxations that are observed on the experimental time scale, as well as would be observed on longer time scales, can be described by a single KWW function. In the second approach we instead assumed that both the protein relaxation time tau(p) and the stretching parameter beta(KWW) were Q-independent, i.e., we assumed that the protein dynamics is dominated by more local motions. Advantages and disadvantages of both approaches are discussed. The first approach appears to work best at higher Q-values, indicating a power law relation of the Q-dependent protein dynamics for all samples and temperatures, whereas the second approach seems to work at lower Q-values, where the expected confined diffusion of hydrogen atoms in the protein gives the assumed Q-independent relaxation time. Independent of the chosen approach we find a significant correlation between the average relaxation time of the protein and the diffusion constant (or in this case the related relaxation time) of the solvent. However, the correlation is not perfect since the average relaxation time of the protein is more strongly dependent on the total amount of solvent than the diffusion constant of the solvent itself. Thus, the average relaxation time of the protein decreases not only with increasing solvent mobility, but also with increasing solvent content.

Chitosan permeabilizes the plasma membrane and kills cells of Neurospora crassa in an energy dependent manner.

Chitosan has been reported to inhibit spore germination and mycelial growth in plant pathogens, but its mode of antifungal action is poorly understood. Following chitosan treatment, we characterized plasma membrane permeabilization, and cell death and lysis in the experimental model, Neurospora crassa. Rhodamine-labeled chitosan was used to show that chitosan is internalized by fungal cells. Cell viability stains and the calcium reporter, aequorin, were used to monitor plasma membrane permeabilization and cell death. Chitosan permeabilization of the fungal plasma membrane and its uptake into fungal cells was found to be energy dependent but not to involve endocytosis. Different cell types (conidia, germ tubes and vegetative hyphae) exhibited differential sensitivity to chitosan with ungerminated conidia being the most sensitive.

Dynamical changes of hemoglobin and its surrounding water during thermal denaturation as studied by quasielastic neutron scattering and temperature modulated differential scanning calorimetry.

We have investigated the dynamical behavior of both the protein hemoglobin and its surrounding water during the denaturation process using modulated temperature differential scanning calorimetry, quasielastic neutron scattering, and frequency dependent conductivity measurements. To distinguish between the scattering from the protein and its surrounding water, neutron scattering measurements were performed on both a fully hydrogenated sample as well as a sample where the water and the exchangeable hydrogen atoms on the protein surface were deuterated. The experimental data show that the unfolding and aggregation processes are substantially overlapping in temperature. The unfolding process occurs in the approximate temperature range of 315-345 K, whereas the aggregation process starts around 330-335 K and is completed at 360 K. Furthermore, the results suggest that the secondary structure of the protein unfolds at about 325 K, and that this leads to an increased number of water molecule hydrogen bonded to the protein. Thus, the unfolding of the secondary structure reduces the number of mobile (on the experimental time scale of about 50-100 ps) water molecules. In contrast, the aggregation of protein molecules seems to have a minor effect on the dynamics of its surrounding water. In the case of the protein dynamics there are competing effects from unfolding and aggregation. The unfolding process increases the flexibility of the protein, whereas the initial aggregation reduces its dynamics. The conductivity seems to be negatively affected by both reduced water mobility and an aggregation of protein molecules.

Effect of chitosan on hyphal growth and spore germination of plant pathogenic and biocontrol fungi.

AIMS: To investigate the toxic effect of chitosan on important root pathogenic and biocontrol fungi (nematophagous, entomopathogenic and mycoparasitic). METHODS AND RESULTS: We have used standard bioassays to investigate the effect of chitosan on colony growth and developed bioassays to test spore germination. The results showed that the root pathogenic and mycoparasitic fungi tested were more sensitive to chitosan than nematophagous and entomopathogenic fungi. Chitosanases (and perhaps related enzymes) are involved in the resistance to chitosan. Two fungi, one sensitive to chitosan, Fusarium oxysporum f. sp. radicis-lycopersici, and one less sensitive, Pochonia chlamydosporia, were selected for ultrastructural investigations. Transmission electron microscopy revealed differences in the ultrastructural alterations caused by chitosan in the spores of the plant pathogenic fungus and in those of the nematophagous fungus. Confocal laser microscopy showed that Rhodamine-labelled chitosan enters rapidly into conidia of both fungi, in an energy-dependent process. CONCLUSIONS: Nematophagous and entomopathogenic fungi are rather resistant to the toxic effect of chitosan. Resistance of nematophagous and entomopathogenic fungi to chitosan could be associated with their high extracellular chitosanolytic activity. Furthermore, ultrastructural damage is much more severe in the chitosan sensitive fungus. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this paper suggest that biocontrol fungi tested could be combined with chitosan for biological control of plant pathogens and pests.

Dynamics of fresh and freeze-dried strawberry and red onion by quasielastic neutron scattering.

The microscopic behavior of fresh and freeze-dried strawberry and red onion at different water contents (45 and 20 wt % water) has been investigated by quasielastic neutron scattering (QENS). To distinguish between the dynamics of the water and the biological material isotopic (H/D) substitution was used. The results show that all samples exhibit an onset of anharmonic motions on the experimental time scale (3-100 ps) at about 230-240 K. Above 250 K the dynamics is mainly of translational character and strongly dependent on the hydration level. The diffusion constant increases rapidly with increasing water content and at 280 K it is approximately 20% higher for the hydration water in freeze-dried strawberry than in freeze-dried red onion and around 2 orders of magnitude faster for the hydration water than for the biological material. Moreover, the diffusion constant of the biological part is about 50% faster in freeze-dried strawberry than in freeze-dried red onion. It was also found that the average relaxation time is slightly faster in fresh strawberry than in freeze-dried strawberry. From the results we can conclude that the water dynamics is not only promoting motions in the biological material, it is also affected by the structure (and possibly also the dynamics) of the biological material. Thus, the microscopic properties of the biological materials are interrelated with the properties of their hydration water.

Type 2 diabetes and risk for periodontal disease: a role for dental health awareness.

BACKGROUND: Several studies have found correlations between diabetes and an increased prevalence of periodontitis. OBJECTIVE: To analyse, in a group of subjects with type 2 diabetes (T2D), (i) the association between medical characteristics and severe periodontal disease and (ii) dental care habits and knowledge of oral health. METHODS: One hundred and ninety-one subjects with T2D were examined. Based on assessment of marginal bone height in panoramic radiographs, two periodontal subgroups were identified: one periodontally diseased (PD+) and one periodontally healthy (PD-) group. All subjects completed a questionnaire about their medical and oral health. RESULTS: Twenty per cent of the subjects were classified as PD+. This was verified by clinical parameters. PD+ individuals had higher haemoglobin A1c (HbA1c) levels (p=0.033) and higher prevalences of cardiovascular complications (p=0.012). They were also less likely to be of Scandinavian origin (p=0.028) and more likely to smoke (p<0.001) than the PD- group. The PD+ group rated their oral health as poor (p<0.0001) and believed that T2D had an influence on their oral status (p<0.0001). CONCLUSION: The best predictor for severe periodontal disease in subjects with T2D is smoking followed by HbA1c levels. T2D subjects should be informed about the increased risk for periodontal disease when suffering from T2D.

Endophytic colonization of date palm (Phoenix dactylifera L.) leaves by entomopathogenic fungi.

Light and scanning electron microscopy together with fungal isolation techniques were used to detect entomopathogenic fungi within young and adult date palm (Phoenix dactylifera) petioles and to assess fungal survival in leaf tissues. The entomopathogenic fungi Beauveria bassiana, Lecanicillium dimorphum and Lecanicillium c.f. psalliotae survived inside leaf tissues at least 30 days after inoculation. Entomopathogenic fungi colonized inoculated petioles endophytically and were recovered up to 3cm from the inoculation site. Fungi were detected inside the parenchyma and sparsely within vascular tissue using microscopy techniques. Our results show that the entomopathogenic fungi used in this study survived and colonized date palm tissues in bioassays both under laboratory and field experimental conditions with no evidence of significant damage.

Dynamics of water in a molecular sieve by quasielastic neutron scattering.

We have investigated the dynamics of water confined in a molecular sieve, with a cylindrical pore diameter of 10 A, by means of quasielastic neutron scattering (QENS). Both the incoherent and coherent intermediate scattering functions I(Q,t) were determined by time-of-flight QENS and the neutron spin-echo technique, respectively. The results show that I(Q,t) is considerably more stretched in time with a slightly larger average relaxation time in the case of coherent scattering. From the Q dependence of I(Q,t) it is clear that the observed dynamics is almost of an ordinary translational nature. A comparison with previous dielectric measurements suggests a possible merging of the alpha and beta relaxations of the confined water at T=185 K, although the alpha relaxation cannot be directly observed at lower temperatures due to the severe confinement. The present results are discussed in relation to previous results for water confined in a Na-vermiculite clay, where the average relaxation time from spin-echo measurements was found to be slower than in the present system (particularly at low temperatures).

Dynamics of water in strawberry and red onion as studied by dielectric spectroscopy.

We have investigated the microscopic dynamics of strawberry and red onion by means of broadband dielectric spectroscopy. In contrast to most of the previous experiments on carbohydrate-rich biological materials, which have mainly considered the more global dynamics of the "biological matrix," we are here focusing on the microscopic dynamics of mainly the associated water. The results for both strawberry and red onion show that the imaginary part of the permittivity contains one conductivity term and a clear dielectric loss peak, which was found to be similar to the strongest relaxation process of water in carbohydrate solutions. The temperature dependence of the relaxation process was analyzed for different water content. The relaxation process slows down, and its temperature dependence becomes more non-Arrhenius, with decreasing water content. The reason for this is most likely that, on average, the water molecules interact more strongly with carbohydrates and other biological materials at low water content, and the dynamical properties of this biological matrix changes substantially with increasing temperature (from an almost rigid matrix where the water is basically unable to perform long-range diffusion due to confinement effects, to a dynamic matrix with no static confinement effects), which also changes (i.e., reduces) the activation energy of the relaxation process with increasing temperature (i.e., causes a non-Arrhenius temperature dependence). This further changes the conductivity from mainly polarization effects at low temperatures, due to hindered ionic motions, to long-range diffusivity at T>250 K . Thus, around this temperature ions in the carbohydrate solution no longer get stuck in confined cavities, since the motion of the biological matrix "opens up" the cavities and the ions are then able to perform long-range migration.

Clinical outcome observed in subjects with recurrent periodontal disease following local treatment with 25% metronidazole gel.

BACKGROUND: The aim of this study was to evaluate the clinical outcome in patients with recurrent periodontal disease following treatment with 25% metronidazole gel. METHODS: Twenty subjects in a maintenance care program but with recurrent periodontal disease participated. Three months after scaling and root planing, a total of 40 sites, 2 in each patient, with probing depth > or = 5 mm were selected. One site randomly selected was treated with metronidazole gel (test) and the other site with a placebo gel (control). Baseline and follow-up measurements included plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL). RESULTS: There were no statistically significant differences in PI, GI, BOP, PD, or CAL between test and control sites. CONCLUSION: This study showed that local treatment with 25% metronidazole gel did not seem to influence the clinical healing in this group of subjects with recurrent periodontal disease.

Dynamics of water in molecular sieves by dielectric spectroscopy.

We present recent dielectric data on the dynamics of water confined in molecular sieves with pore sizes 5 and 10 A. The dielectric measurements in the frequency and temperature ranges 10(-2)-10(6) Hz and 120-300 K show three relaxation processes for both samples. In the case of the 10 A pore the slowest process shows an Arrhenius temperature dependence at low temperatures (<220 K), while at high temperatures the relaxation appears to follow a more Vogel-Fulcher-Tammann (VFT) like behaviour. The relaxation time for this process is 100 s at about 170 K. The second slowest process is at low temperatures very similar to the main process of (bulk-like) water in a fully hydrated clay, but also this process seems to exhibit some kind of dynamical transition, in this case at T approximately 185 K. All the three processes in the 5 A pore exhibit Arrhenius temperature dependence, and two of them are considerably slower than the main relaxation in the hydrated clay. Thus, dynamics of bulk-like water is only observed in the 10 A molecular sieves, and most of the water molecules in both 5 and 10 A pores have considerably slower dielectric relaxation than has been observed for water confined in clay, most likely due to strong interactions with the considerably more hydrophilic inner surfaces of molecular sieves.

Colonization of plant roots by egg-parasitic and nematode-trapping fungi.

• The ability of the nematode-trapping fungus Arthrobotrys oligospora and the nematode egg parasite Verticillium chlamydosporium to colonize barley (Hordeum vulgare) and tomato (Lycopersicum esculentum) roots was examined, together with capability of the fungi to induce cell wall modifications in root cells. • Chemotropism was studied using an agar plate technique. Root colonization was investigated with light microscopy and scanning electron microscopy, while compounds involved in fungus-plant interactions were studied histochemically. • Only A. oligospora responded chemotropically to roots. Colonization of barley and tomato by both fungi involved appressoria to facilitate epidermis penetration. V. chlamydosporium colonized tomato root epidermis and produced chlamydospores. Papillae, appositions and lignitubers ensheathing hyphae on tomato were also found. Phenolics (including lignin), protein deposits and callose were present in papillae in both hosts. Both fungi were still present in epidermal cells 3 months after inoculation. • Nematophagous fungi colonized endophytically monocotyledon and dicotyledon plant roots. Arthrobotrys oligospora seemed to be more aggressive than V. chlamydosporium on barley roots. Both fungi induced cell wall modifications, but these did not prevent growth. The response of root cells to colonization by nematophagous fungi may have profound implications in the performance of these organisms as biocontrol agents of plant parasitic nematodes.

Matrilinear phylogeography of Atlantic salmon (Salmo salar L.) in Europe and postglacial colonization of the Baltic Sea area.

Sixty-four samples from 46 salmon populations totalling 2369 specimens were used for polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial ND1 region. The final analyses included 3095 specimens from 60 populations in Northern Europe. A subsample was analysed by RFLP of ND3/4/5/6. Representative RFLP haplotypes from different parts of the distribution area were sequenced and the phylogeny of European haplotypes and their relations to the North American lineage was described. The four common European haplotypes derive from the ancestral ND1-BBBA (rooting the European clade to the North American) by one-step substitutions: AAAA < AABA < BBBA > BBBB. The Swedish west-coast populations differ from the geographically close southern Baltic, indicating absence of inward and limited outward gene flow through the Danish straits during the last 8000 years. Within the Baltic Sea, only three ND1 haplotypes were detected and there was no variation for ND3/4/5/6. In the whole southern Baltic and in lakes Vänern, Ladoga and Onega the haplotype AABA dominated. Proposed postglacial colonization routes to the Baltic Sea are discussed in relation to the haplotype distribution pattern.

Growth of Arthrobotrys superba from a birch wood resource base into soil determined by radioactive tracing.

The ability of a nematode-trapping fungus to establish in field soil is an important characteristic when considering its use as a biological control agent. The outgrowth of the nematode-trapping fungus Arthrobotrys superba from wood was recorded by labelling the fungus with [(14)C]3-O-methylglucose and [(32)P]orthophosphoric acid and by using the soil sprinkling method. The fungus reached a distance of 7-8 cm during 25 days in heat-treated (60 degrees C) soil, detected by either radioactive tracing or the soil sprinkling technique. The two labelled compounds were co-distributed at all sampling times (r(2)=0.946) which indicates that the glucose pool (as methylglucose) and phosphorus content were correlated throughout the mycelium. In natural, non-heat-treated soil the fungus reached a distance of 1.5 cm from one disc of birch wood after 30 days, while it reached 3.2 cm during the same period when the food base was a pile of five inoculated discs. The experiments showed, for the first time, that a nematophagous fungus, A. superba, can grow out into soil from a piece of wood and supported by nutrients translocated from the resource base to the edge of the mycelium.

Rhizosphere Colonization and Control of Meloidogyne spp. by Nematode-trapping Fungi.

The ability of nematode-trapping fungi to colonize the rhizosphere of crop plants has been suggested to be an important factor in biological control of root-infecting nematodes. In this study, rhizosphere colonization was evaluated for 38 isolates of nematode-trapping fungi representing 11 species. In an initial screen, Arthrobotrys dactyloides, A. superba, and Monacrosporium ellipsosporum were most frequently detected in the tomato rhizosphere. In subsequent pot experiments these fungi and the non-root colonizing M. geophyropagum were introduced to soil in a sodium alginate matrix, and further tested both for establishment in the tomato rhizosphere and suppression of root-knot nematodes. The knob-forming M. ellipsosporum showed a high capacity to colonize the rhizosphere both in the initial screen and the pot experiments, with more than twice as many fungal propagules in the rhizosphere as in the root-free soil. However, neither this fungus nor the other nematode-trapping fungi tested reduced nematode damage to tomato plants.