Presence Of Protozoa Research Articles

Endoparasites of Red Deer (Cervus elaphus L.) and Roe Deer (Capreolus capreolus L.) in Serbian Hunting Grounds.

In this study, parasitological examinations were conducted from 2019 to 2023. Fecal samples were collected from 289 wild ruminants (158 red deer and 131 roe deer) from hunting grounds in Vojvodina, which belong to the public company Vojvodinašume. Using qualitative and quantitative coprological diagnostic methods, the presence of protozoa (coccidia and Buxtonella sulcata), nematodes (gastrointestinal strongyles, Trichuris spp., Capillaria spp., Dictyocaulus spp., and Muellerius spp.), cestodes (Moniezia spp.), and trematodes (Fasciola hepatica, Fascioloides magna, Paramphistomum spp., and Dicrocoelium dendriticum) in the form of single and mixed infections were confirmed. Coproculture was used to identify the infective larvae of gastrointestinal strongyles. The total prevalence of endoparasitic infections in hunting ground 1 was 89.77% in red deer and 92.85% in roe deer, while in hunting ground 2, it was 72.97% in red deer and 85.96% in roe deer. Knowledge of the prevalence and assessment of the intensity of parasitic infections in wild ruminants is necessary for designing health protection programs in hunting grounds and planning control strategies, which are significant for this branch of hunting and public health.

Understanding the Role of Free-Living Bacteria in the Gut of the Lower Termite Coptotermes gestroi Based on Metagenomic DNA Analysis.

Termites' digestive systems, particularly in lower termites with the presence of protozoa, are unique ecological niches that shelter a diverse microbiota with a variety of functions for the host and the environment. In 2012, the metagenomic DNA (5.4 Gb) of the prokaryotes that freely live in the gut of the lower termite Coptotermes gestroi were sequenced. A total of 125,431 genes were predicted and analyzed in order to mine lignocellulolytic genes. however, the overall picture of the structure, diversity, and function of the prokaryotic gut microbiota was not investigated. In the present study, these 125,431 genes were taxonomically classified by MEGAN and functionally annotated by the Kyoto Encyclopedia of Genes and Genomes (KEGG) and by the Carbohydrate-Active enZYmes (CAZy) and HMMER databases. As a result, 95,751 bacterial genes were classified into 35 phyla. The structure of the bacteria, typified by a high ratio of Firmicutes to Bacterioidetes, was distinct from the structure of the entirety of the bacteria in the lower or higher termites' guts. The archaea (533 genes) were distributed into 4 phyla, 10 classes, 15 orders, 21 families, 47 genera, and 61 species. Although freely living in the guts, the prokaryotic community was formed, developed, and adapted to exhibit unique interactions in order to perform mutual roles of benefit to their hosts. Methanobacteriales, accounting for 61% of the archaea symbionts, seem to play an important role in methanogenesis. Concomitantly, bacterial methanotrophs in the gut utilize methane and combine with other bacterial groups, including potential lignocellulolytic degraders, acetogens, sulfur bacteria, and nitrogen-recycling bacteria, to efficiently convert wood with little nitrogen into acetates via certain pathway modules specified by prokaryotes that freely live in the gut. This forms an important energy source for the termites. Furthermore, bacteria carry 2223 genes involved in the biosynthesis of 17 antibiotic groups. The gut bacteria also possess genes for the degradation of 18 toxic aromatic compounds, of which four are commercial pesticides against termites commonly used for the preservation of wooden constructions. Eight of the eighteen pathways were the first to be reported from the termite gut. Overall, this study sheds light on the roles of the freely living bacteria and archaea in the C. gestroi gut, providing evidence that the gut microbiome acts as the second host genome, contributing both nutrients and immunity to support the host's existence, growth, and development.

Ciliated Peritrichous Protozoa in a Tezontle-Packed Sequencing Batch Reactor as Potential Indicators of Water Quality.

The presence of colonial and solitary ciliated peritrichous protozoa was determined in a Sequencing Batch Reactor system filled with tezontle, a volcanic rock, economic, and abundant material that can be found in some parts of the world, like Mexico. The presence of these protozoa was related to the removal efficiencies of organic matter. Also, two novel staining techniques are proposed for staining both colonial and solitary peritrichous protozoa. The results show that tezontle promotes the growth of solitary and colonial ciliated peritrichous protozoa, which, once identified, could be used as indicators of the efficiency of the wastewater treatment process. Additionally, the staining techniques established in the current study allowed the precise observation of protozoan nuclei. They can represent a useful complementary methodology for identifying protozoan species present in water treatment processes, along with the already existing identification techniques. The number and variety of protozoa found in the system may be considered potential bioindicators of water quality during biological treatments.

Microbiological and parasitological quality of fruit pulps and juices used for detoxifying purposes

ABSTRACT The juice consumption with detoxifying properties has increased in the last few years, but inadequately produced food may transport pathogens. This study aimed to investigate the occurrence of parasitological and microbiological contamination in fruit juices and fruit pulp used for detoxifying purposes. Twenty samples were analyzed, 10 of fruit pulp and 10 juices from July to August 2018. Thermotolerant coliform, mold, and yeast were counted. Parasitological analysis was performed by spontaneous sedimentation method and sedimentation by centrifugation techniques. Results showed that 20% and 60% of the fruit pulp and juice samples exhibited thermotolerant coliform counts above 1 log CFU/mL, respectively. The results showed that 60% of the pulp samples presented mold and yeast counts above 3 log CFU/mL. The protozoa found in the samples were Endolimax nana, Entamoeba coli, and E. histolytica/E. dispar cysts. The presence of thermotolerant coliforms in juices is an indicator of the presence of enteropathogens, mainly Escherichia coli. The high mold and yeast populations and the presence of protozoa in the fruit pulp and juices indicate hygienic and sanitary failures in the food processing. It may be concluded that there is a need for supervision and training in Good Manufacturing Practices by health agencies, aiming at the food safe production. KEY WORDS: Coliforms; parasites; food hygiene; food safety.

Pathogenic microorganism in water supply systems for consumption of human settlements, Ucayali 2019

The objective of this study was to identify the presence of pathogenic microorganisms in water supply systems for consumption in human settlements in the city of Pucallpa, Ucayali region. For data collection, the "Protocol of procedures for sampling, preservation, conservation, transport, storage and reception of water samples for human consumption" was used, within the framework of the Quality Management System -NTP ISO/ IEC 17025. Samples from 12 water supply systems were analyzed, with 3 replications per water system. As a result, fecal coliform bacteria were identified in 66% of the systems in ranges from 2 CFU/100 ml to 31 CFU/100 ml, Thermo-tolerant coliforms in 25% of the systems in ranges from 2 CFU/100 ml to 5 CFU. /100 ml, E.coli in 25% of the systems in ranges from 1 CFU/100 ml to 2 CFU/100 ml, Salmonella spp. in 8.3% of the systems in ranges of 1 CFU/100 ml. However, the presence of Legionella spp., Pseudomonas aureginosa and Vibrio Cholerae was not identified in the systems. In 100% of the systems, the presence of Protozoa and Helminths was not identified. It is concluded that 66.6% of the water supply systems evaluated, present pathogenic microorganisms in the water destined for the consumption and use of the population to serve human settlements, therefore, they do not comply with the Maximum Permissible Limits established in the DS.031-2010-DIGESA "Regulation of the quality of water for human consumption".

Identification and Semi-quantification of Protozoa from the Digestive System Microbiota of the Lobster Cockroach Nauphoeta cinerea Oliver, 1789 (Insecta:Blattaria).

The lobster cockroach Nauphoeta cinerea (N. cinerea) is indicated as a promising non-mammalian model, because it presents behavioral and biochemical alterations also observed in conventional models. In this research, we identified and characterized the distribution of protozoa that inhabit the digestive system (DS) of N. cinerea cockroaches. The adult specimens of N. cinerea used in this study (n = 32) were obtained at the Federal University of Santa Maria, dissected and had their visceral contents observed in bright-field microscopy without staining and after application of lugol, Ziehl-Neelsen staining, EA36 trichrome and simulated dark-field microscopy with application of nankin ink. The presence of protozoa in different portions of the DS was semi-quantified by a system of crosses (+). The main taxa observed were: amoebas (Archaemebae:Entamoebida), gregarins (Apicomplexa:Eugregarinide), coccidia (Apicomplexa:Eucoccidiorida), kinetoplastids (Kinetoplastea:Kinetoplastida) and oxymonads (Preaxostyla:Oxymonadida). The highest prevalence of amoebas and gregarines was observed in the medial portion of the DS, while for the other groups, this was seen in the final portion, and in the case of coccidia, such prevalence was specially evidenced by the alcohol-acid coloration. In the present work, the great biological diversity that exists in the microbiota of the digestive system of Nauphoeta cinerea was demonstrated, being possible to find several pathogenic species for humans such as Entamoeba histolytica/dispar/moshkovskii, Cryptosporidium sp. and Cyclospora cayetanensis. There is still a lot to know about the interactions between endocommensal protozoa and their respective invertebrate hosts, so the best way to clarify such relationships is through molecular and genetic test.

Polyethylene, polystyrene and lignocellulose wastes as mealworm (Tenebrio molitor L.) diets and their impact on the breeding condition, biometric parameters, metabolism, and digestive microbiome

This study aimed to identify the extent to which a diet of oatmeal and polymers affects the development of mealworms, their microbiome, the biochemical activity of their digestive system, and their feed-metabolizing capacity. With a polystyrene diet, feed loss was most significant, as indicated by FTIR (Fourier-transform infrared spectroscopy) of frass, which showed that polystyrene was the only compound that was chemically modified. Compared to the control diet, mealworm larvae developed best on polyethylene regranulate (PE-reg), quickly transiting from one developmental stage to another with minor mass loss. A lignocellulose-based diet was the least beneficial for mealworm development. A polystyrene diet was most beneficial in terms of the protein content in larvae, but the contents and quality (usefulness as food) of fatty acids in the insects fed these wastes were significantly lower than in the control insects. For each diet, specific microbial cultures formed, and the presence of protozoa and various biochemical activities suggested different survival strategies and assimilation mechanisms facilitating survival. Despite profound changes in the microbiota and biochemistry of the digestive tract of mealworms fed waste-based diets, this study indicates their potential for utilizing PE-reg and polystyrene.

Infection by intestinal parasites in disabled patients and their guardians

Introduction: intestinal parasitic infections are common major problem closely related to poverty, inadequate sanitation, insufficient health care and overcrowding. They cause significant morbidity among institutionalized patients, however, there are few studies that analyze the frequency of intestinal parasites in disabled patients that are not institutionalized. Objective: the aim of the present study was to determine the prevalence of intestinal parasitic infection in disabled patients and their guardians. Methodology: a total of 336 fecal samples were collected from 53 disabled patients and history of diarrhea during the study period and 31 guardians, parents and professional staff of Institution. Parasite research was carried out using zinc sulphate centrifugal-flotation technique, Lutz/Hoffman Pons and Janer method, Rugai method and Gram-Chromotrope, Leishman, Kinyoun, Kato-Katz and Trichrome stains were used. Results: we found 15.5% of positive sample for enteroparasites in all analyzed individuals (13/84), with 11.3% (6/53) of prevalence in disabled patients and 22.5% (7/31) for guardians, with significant difference. There was no difference between gender,but there was a higher number of positives in patients between 6 and 11 years of age. Monoparasitism and the presence of protozoa, especially Blastocystis hominis, were the most prevalent conditions. Conclusions: despite the aforementioned intrinsic susceptibility of patients with special needs, the prevalence of intestinal parasites was low. In guardians, the prevalence was higher, suggesting extreme attention to the care process, which may have prevented the transmission to their disabled patients contact.

Abundance of anuran parasites and pesticide pollution from lowland and highland golf courses

Aim: This study aimed to determine the pesticide pollution and prevalence of protozoa in anurans from lowland and highland golf courses in Malaysia and to observe the relationship between environmental factors (water quality index and pollutants) and the presence of protozoa in anurans. Methodology: Water quality index and pesticide levels (metsulfuron methyl) were measured at three locations, i.e. Jeriau river, Fraser's hill golf course in Pahang, and UKM Danau golf club in Selangor. Microscopy techniques were used to identify and examine the prevalence of protozoa and haemoparasites in anuran organs (stomach, kidney, liver, intestine, rectum, and blood). Results: A total of 140 anurans were collected from the study areas. Jeriau river had the highest water quality compared to Fraser's hill golf course and UKM Danau golf club. Metsulfuron methyl concentrations at all three locations were under permissible level (0.001–0.01 mg l-1). Approximately, 30% of the anurans were infected with ≥ 1 protozoa, of which 22.14% were from phylum Opalinata and 10.71% were from phylum Ciliophora (Nyctotherus cordiformis). Approximately 44.44% of the anurans were infected with ≥ 1 groups of haemoparasites, which included Trypanosoma, Haemogregarina, Lankesterella, Aegyptianella and Microfilaria. Interpretation: No significant relationship was found between the environmental parameters and the abundance of protozoa and haemoparasites in anurans from three locations, indicating that the prevalence of protozoa and haemoparasites in anurans is not influenced by environmental factors.

Environmental Management of Legionella in Domestic Water Systems: Consolidated and Innovative Approaches for Disinfection Methods and Risk Assessment.

Legionella is able to remain in water as free-living planktonic bacteria or to grow within biofilms that adhere to the pipes. It is also able to enter amoebas or to switch into a viable but not culturable (VBNC) state, which contributes to its resistance to harsh conditions and hinders its detection in water. Factors regulating Legionella growth, such as environmental conditions, type and concentration of available organic and inorganic nutrients, presence of protozoa, spatial location of microorganisms, metal plumbing components, and associated corrosion products are important for Legionella survival and growth. Finally, water treatment and distribution conditions may affect each of these factors. A deeper comprehension of Legionella interactions in water distribution systems with the environmental conditions is needed for better control of the colonization. To this purpose, the implementation of water management plans is the main prevention measure against Legionella. A water management program requires coordination among building managers, health care providers, and Public Health professionals. The review reports a comprehensive view of the state of the art and the promising perspectives of both monitoring and disinfection methods against Legionella in water, focusing on the main current challenges concerning the Public Health sector.

Dogs from public city parks as a potential source of pollution of the environment and risk factor for human health

A study was undertaken to determine the prevalence of zoonotic parasites in faeces of dogs who were visiting the public parks and to evaluate the risk they represented for the people and children visiting the same places. Parasitological analysis was performed on 300 samples of faeces, collected from public parks of the city of Niš (Tvrd– dava Park, C´ air Park, Sveti Sava Park); from autumn 2018 and spring 2019. Using standard qualitative and quantitative methods of coprological diagnostics, the presence of protozoa (Cystoisospora spp.), nematodes (Toxocara canis, Toxascaris leonina, Ancylostoma caninum / Uncinaria stenocephala, Trichuris vulpis and Capillaria aerophila), cestodes (Dipyllidium caninum, Taenia spp.) and trematode Alaria alata was determined. The prevalence of endoparasitoses were 58–70%, and the most prevalent were those of medium intensity. Depending on the research period, the four most frequent endoparasites were T. canis (36.66–38%), ancylostomatidae (24.66–32%), T. vulpis (20–28%) and A. alata (28%).

Protozoan Cysts in Faecal Pellets of German Cockroaches (Blattella germanica), with Particular Emphasis on Lophomonas blattarum

PurposeThe aim of this study was to investigate protozoan cysts and oocyts in the faecal pellets of the German cockroach (Blattella germanica), with emphasis on the prevalence of Lophomonas blattarum.MethodsThirty adult Blattella germanica (12 males; 18 females) were trapped near Madrid, Spain. Expelled faecal pellets were collected in the laboratory over 5 days in two plastic containers. Protozoan cysts from one container were weighted and those in the other used for morphologically identification.ResultsProtozoan cysts/oocysts per gram of faecal pellet were: Nyctotherus sp. (0.0019/g), Entamoeba (0.0007/g), Balantidium coli (0.0001/g), Lophomonas blattarum (0.00038/g). Observation of 189 protozoan cysts/oocysts indicated the following prevalence: Nyctotherus sp. 65 (34.4%); Gregarina spp. 34 (18%); Entamoeba sp. 24 (12.7%); Cryptosporidium sp. 17 (9%); Coccidia 16 (8.4%); Lophomonas blattarum 13 (6.8%); Balantidium coli 4 (2.1%); and unclassified 16 (8.4%).ConclusionLophomonas blattarum has previously been demonstrated in the gut of cockroaches, but this is the first assessment of the prevalence in Blattella germanica in faecal pellets. The presence of protozoa in faecal pellets provides some evidence for one step in a hypothesised route of respiratory infection whereby protozoa from household insects enter the respiratory tract.

Co-cultivation of microalgae in aquaculture water: Interactions, growth and nutrient removal efficiency at laboratory- and pilot-scale

Microalgae biotechnology is of increasing importance and a central application concerns the treatment of wastewater. Here, its implementation in a recirculating aquaculture system (RAS) to lower the discharge of wastewater is studied. To better cope with external variations in culture conditions, a co-cultivation of two species of microalgae, Chlorella vulgaris and Tetradesmus obliquus, was used to obtain a more reliable and robust culture and was compared to monocultures. This approach was tested using RAS water both under sterile and non-sterile conditions at laboratory scale and then compared to a co-culture at pilot-scale in an open thin-layer photobioreactor. Performance of cultures was tested in terms of microalgae growth and nutrient removal efficiency. Furthermore, to better understand the interaction between environmental variables and each microalgae species, their relative frequencies in co-cultures as well as the presence of protozoa and bacteria were monitored. All growth experiments were carried out successfully and, unlike in a previous study, no crashes were observed. However, shifts in species frequency in co-cultures indicated that the two species were differentially affected by cultivation conditions. Despite nutrient limitation, the pilot-scale cultivation had a high productivity (13.3 g m−2 d−1) and final dry weight (11.1 g l−1) after 29 days and demonstrated its suitability for RAS water treatment.

Occurrence of human adenoviruses in a beach area of Guarujá, São Paulo, Brazil.

Along the coastal zone of the State of São Paulo, Brazil, diffuse discharges that flow directly to tourist beaches are responsible for introducing various pathogens into recreational waters. The objective of this study was to analyze, for the first time, the presence of protozoa (Cryptosporidium ssp and Giardia ssp), as well as human mastadenoviruses (HAdV-species C and F) and other species of adenoviruses (AdV) in beach drainage channels of Enseada and Perequê, municipality of Guarujá, São Paulo, Brazil. Protozoa were not detected in any sample over the course of the 11-month study. In relation to HAdVs, 100% (n=22) of the water samples presented contamination by at least one type of virus (C, D, or F species), suggesting potential risks to the public health following recreational exposure of beach users to these waters. PRACTITIONER POINTS: First report on the presence of human adenoviruses in urban drainage channels in the coast of São Paulo State, Brazil. Urban surface water runoff is responsible for introducing human adenoviruses linked to disease outbreaks in areas of intense recreation. Cryptosporidium oocysts and Giardia cysts were below the limit of detection for all analyzed samples. However, all sites were positive for at least one of the viral species (HAdV-C, HAdV-D, or HAdV-F). Viral loads found in the water were similar to those commonly found in the wastewater.

Seeking the reuse of effluents and sludge from conventional wastewater treatment plants: Analysis of the presence of intestinal protozoa and nematode eggs

Some of the microorganisms present in urban wastewater, which include intestinal protozoa and nematodes, can be pathogenic. Their (oo)cyst and egg transmissible stages are very resistant to environmental stresses and disinfectants and they are therefore difficult to remove. Thus, they can constitute a health risk if water or sludge obtained in the purification of wastewater is reused for agricultural purposes. In this context, the presence of intestinal protozoa and nematodes were studied in influents, effluents and sludge from five wastewater treatment plants (WWTPs) in the north of Spain by optical microscopy and PCR techniques. The removal efficiency of different wastewater treatments was also compared. The presence of protozoa has increased among the population discharging waste to WWTPs in recent years. Cryptosporidium spp., Giardia duodenalis, Entamoeba spp. and nematodes were detected in all of the WWTPs. Indeed, this is the first report of Entamoeba histolytica and Entamoeba moshkovskii in Spanish WWTPs. The water treatments studied showed different removal efficiencies for each species of intestinal protozoa, with the aerated lagoons providing the best results. (Oo)cysts were also detected in sludge even after aerobic digestion and dehydration. To avoid risks, (oo)cyst viability should be analysed whenever the sludge is to be used as a fertilizer. This study reinforces the necessity of establishing legal limits on the presence of protozoa in WWTP effluents and sludges, especially if reuse is planned. Further studies are necessary for a better understanding of the presence and behaviour of intestinal parasites.

Foodborne Bacterial, Viral, and Protozoan Pathogens in Field and Market Strawberries and Environment of Strawberry Farms.

Field-grown strawberries, the environment of strawberry farms and fresh strawberries from marketplaces were examined for bacterial, viral, and protozoan pathogens. The presence of bacteria was determined using culture and real-time PCR (qPCR), presence of protozoa and viruses using qPCR and reverse transcription qPCR, respectively. The highest proportion of positivity was observed for Escherichia coli both in field and purchased strawberries (up to 48.6%). Finding of Cronobacter ranged from 0.6% to 9% both for field and market strawberries. The prevalence of other pathogens (Listeriamonocytogenes, Giardia intestinalis, Cryptosporidium sp., and Norovirus) in strawberries was below 4.5%; HAV was not detected at all. Positivity of the environment was determined to be lower than 2.1% for all microorganisms, except for E. coli. The concentration of pathogens in most samples did not exceed 100CFU/g using culture and 1.8×102 GE/g of strawberries or swabbing area 6.1×102 GE/mL or swabbing area of environmental samples using qPCR. All studied farms applied preventive measures such as drip irrigation, avoidance of organic fertilizers, and use of mulch foils or gloves for workers to decrease contamination of strawberries. Despite this, certain pathogens were found in fresh strawberries. Even at low concentrations, these pathogens can be a source of infection for consumers. Thus, their presence in strawberries is of particular significance as these are mostly consumed fresh and without any thermal processing. PRACTICAL APPLICATION: Nonlegislatively monitored pathogens of bacterial, viral and parasitic origin were found in strawberries. Monitoring the presence of these pathogens in ready-to-eat food is therefore meaningful and important in terms of food safety, especially in relation to pathogens with low infectious dose (for example, viruses, parasites).

Faecal contamination in public pools in Barcelona province: Cryptosporidium spp. and bacterial indicators.

A study was conducted of the occurrence of Cryptosporidium in indoor heated public swimming pools and of three bacterial indicators (Escherichia coli, faecal enterococci and Clostridium perfringens) on pool surrounds. Although all examined pools adhered strictly to the Spanish regulations, the influence of several parameters related to water conditions, pool structure, users and location on the presence of protozoa and bacteria was analysed. Cryptosporidium was detected in 18.8% of pools in 60% of the five towns studied. The maximum concentration was 13 oocysts/L in one swimming pool and one Jacuzzi. The bacterial indicators' prevalence on pool surrounds was higher than 50%, being present in all of the towns. Plastic surfaces presented the lowest bacterial prevalence, whereas painted surfaces were 100% positive. No differences were observed for pool surrounds with autonomous or disabled users. Risk of cryptosporidiosis in pool vessels indicated that concentrations over 1 oocyst/10 L enhance the risk of infection, even in one exposure. Guidelines for managing faecal accidents and public information on the importance of good hygiene behaviours in and around swimming pools are recommended to limit oocysts' presence.

Frequency and immunological consequences of Helicobacter pylori and intestinal parasite co-infections: a brief review

Helicobacter pylori is a Gram-negative, spiral bacterium capable of colonizing the gastric mucosa. Infections caused by this microorganism often lead to the development of various gastrointestinal complaints. Simultaneous human colonization by H. pylori and intestinal parasites is a common phenomenon. Moreover, the two groups of pathogens share the similar predisposing factors. The presence of parasites together with H. pylori can significantly influence the modulation of the host immune response. During H. pylori infection, strong polarization of Th1 cells is observed. The presence of protozoa, also contributing to the recruitment of Th1 cells, may well aggravate this response and exacerbate gastric mucosal damage. In contrast, intestinal helminth infection is associated with the polarization of lymphocytes towards Th2; their presence enhances the regenerative processes within the digestive tract and lowers the host overresponse. A literature review suggests that co-infection with intestinal helminths may serve as a buffering mechanism against the effects of H. pylori and/or protozoan infection, alleviating the Th1-dependent response and protecting against inflammations within the gastrointestinal tract.

Protozoa stimulate the plant beneficial activity of rhizospheric pseudomonads

AimsThe functioning of plant-associated bacteria is strongly influenced by their interaction with other organisms. For instance, bacteria upregulate the production of secondary metabolites in presence of protozoa and we hypothesised that this interaction may contribute to plant health.MethodsHere, we tested if the effect of beneficial pseudomonads on wheat growth and health is modified by co-inoculation with the bacterivorous amoeba Acanthamoeba castellanii. We assessed effects of this co-inoculation in absence and presence of the root pathogen Pythium ultimum.ResultsIn absence of amoebae, bacterial isolates had few beneficial effects and some isolates exacerbated growth inhibition by the pathogen (despite their reported beneficial effects in vitro). Effects on plant growth in absence and presence of the pathogen were negatively correlated. Co-inoculation with amoebae suppressed this relationship, leading to plant growth promotion in absence and reduction of deleterious effects in presence of the pathogen. The positive effect of amoebae in absence of the pathogen could be related to bacterial siderophore production in vitro.ConclusionsOur results illustrate the discrepancy between in vitro and in vivo effects of plant beneficial bacteria. Incorporation of other rhizospheric trophic components such as protists may be a key factor to influence the plant-beneficial potential of bacteria in vivo.

The occurrence of Entamoeba gingivalis among patients with periodontal disease

Abstract According to some studies, the Entamoeba gingivalis colonizing the gingival tissue is an important agent in bringing about periodontitis. Other studies, however, deem it an opportunist that is able to survive in the medium induced by periodontal disease. The aim of this study was to investigate the prevalence of Entamoeba gingivalis infection in patients from the Department of Periodontology, and compare this population with that of healthy people, so as to analyze the relationships between infection and patient sex and age. The result of this work is that in both groups, a correlation (p = 0,19) has been noted between the occurrence of amoebae and other diseases in the oral cavity. Indeed, 81,4% of all patients with some periodontal disease showed the presence of amoeba. Among those who are not afflicted with oral diseases, the presence of amoeba was indicated in 62,5% of the total. In addition, a correlation between the person's age and the presence of protozoa (p = 0,15) was strongly marked among women (p = 0,19). In the three age groups of women in this study (40-49, 60-69, and above 80 years), we observed a 100% presence of protozoa. Our study leads us to the conclusion that infections with Entamoeba gingivalis should be regarded as an factor that is associated with the pathological changes occurring in patients with periodontal diseases.