Frans Ollevier

• KU Leuven

To select and characterize potential probiotic bacteria from the gut microbiota of Siberian sturgeon (Acipenser baerii), 129 strains isolated from the hindgut were screened for antagonistic activity against five fish pathogens. Ten isolates showed antagonism towards three or more pathogens. Nine of these isolates were Gram‐positive, belonging to La...

The in vitro fermentation of two Non-Digestible Oligosaccharide (NDO) preparations, Arabinoxylan- Oligosaccharides (AXOS) and Oligofructose (OF), and their respective monomeric sugars, xylose and fructose, were investigated by hindgut microbiota of two major aquaculture fish species, Siberian sturgeon (Acipenser baerii) and African catfish (Clarias...

The potential of a novel class of prebiotics, arabinoxylan-oligosaccharides (AXOS), was investigated on growth performance and gut microbiota of juvenile Acipenser baerii. Two independent feeding trials of 10 or 12 weeks were performed with basal diets supplemented with 2% or 4% AXOS-32-0.30 (trial 1) and 2% AXOS-32-0.30 or AXOS-3-0.25 (trial 2), r...

In recent years, a rotational system consisting of two rice crops followed by a fish pen culture during the monsoon flood period was adopted in parts of the flood-prone region of the Mekong Delta. In this paper, we use the survey data from 51 fish pen farmers at Co Do and Vinh Thanh district, Can Tho City, to investigate the factors affecting fish...

A series of experiments was conducted in rice (Oryza sativa L.)-fish aquariums and concrete tanks at Can Tho University, Vietnam, to investigate the feeding behavior and ability to control brown planthopper (BPH) (Nilaparvata lugens (Stål)) by fish. In the aquarium studies, fish species introduced were: (1) no fish (control), (2) common carp (Cypri...

Between 1991 and 2008 a total of 71 fish species was recorded in the brackish and fresh water zone of the Schelde estuary (Zeeschelde). The results were obtained from fish surveys from the cooling water filter screens of the power plant at Doel (between 1991 and 2008) and fyke net surveys along the length of the estuary between 1995 and 2008. Speci...

Levels of Cd, Pb, Cu, and Zn were measured in fourth-instar Chironomus gr. thummi and in three sediment fractions of Belgian lowland rivers, extracted with 1 M NH4-acetate, 1 M HCl, and 70% HNO3 - 30% H2O2. The percentages of deformed larvae and the mean population severities (MPS) of deformity for the head structures were compared by means of Pear...

Between 1991 and 2008 a total of 71 fish species was recorded in the brackish and fresh water zone of the Schelde estuary (Zeeschelde). The results were obtained from fish surveys from the cooling water filter screens of the power plant at Doel (between 1991 and 2008) and fyke net surveys along the length of the estuary between 1995 and 2008. Speci...

Fish-based indices monitor changes in surface waters and are a valuable aid in communication by summarising complex information about the environment (Harrison and Whitfield, 2004). A zone-specific fish-based multimetric estuarine index of biotic integrity (Z-EBI) was developed based on a 13 year time series of fish surveys from the Zeeschelde estu...

The tolerance and prebiotic effect following oral intake by healthy human subjects of arabinoxylan-oligosaccharides (AXOS), produced by partial enzymic hydrolysis of the wheat fibre arabinoxlyan, were studied. A total of twenty healthy subjects participated in the present randomised, placebo-controlled cross-over study. They consumed 10 g AXOS or p...

In this study, several process parameters that may contribute to the efficiency of ultrasound disinfection are examined on a pilot scale water disinfection system that mimics realistic circumstances as encountered in an industrial environment. The main parameters of sonication are: (i) power; (ii) duration of treatment; (iii) volume of the treated...

The objectives of this study were to (1) examine the effect of power ultrasound on the viability of both Legionella pneumophila and Acanthamoeba castellanii trophozoites and cysts, (2) investigate if intracellular Legionella replication in trophozoites positively affects bacterial resistance to ultrasound and (3) study if Legionella renders viable...

This mini-review focuses on changes in ATP and creatine phosphate concentrations in fish sperm under storage conditions. The storage of catfish sperm at 4 degrees C leads to ATP depletion and decreased sperm motility. The rate of intracellular ATP depletion can be diminished through the addition of energetic substrates to the sperm storage medium,...

To search for nondigestible but fermentable (NDF) carbohydrates and prebiotics with a potency to promote the growth of selected bacteria in vitro. The growth of three reference bacteria strains Bacillus subtilis LMG 7135(T), Carnobacterium piscicola LMG 9839, Lactobacillus plantarum LMG 9211 and one candidate probiotic bacteria Lactobacillus delbru...

Feeding habits and trophic relationships among three mormyrid species (Petrocephalus bovei, Marcusenius ussheri and Marcusenius furcidens) were assessed in the man-made Lake Ayame in Ivory Coast. The index of preponderance combining the occurrence and weight percentages of the identified prey items showed that these three mormyrid species mainly fe...

Information on movement patterns of marine fishes between estuarine populations and stocks at sea is fundamental to understanding their population dynamics, life history tactics and behavior. Furthermore, understanding estuarine habitat use by marine fishes is crucial for their effective conservation and integrated estuarine management. Although la...

Two freshwater fish species, Clarias gariepinus and Oreochromis mossambicus, were collected from pans, dry-season pools, and tributaries of the Save and Runde rivers in the southeastern lowveld of Zimbabwe from December 2004 until June 2006. Helminth parasites infecting these fish were isolated from the gills, skin, muscles, body cavity, gall bladd...

Trichogaster pectoralis Regan is often cultured successfully in rice fields in South-east Asia. However, since the advent of high-yielding rice varieties and intensive rice cropping, several reports suggest poorer growth performance of the species. In this paper, we investigated the growth performance of T. pectoralis in rice–fish systems character...

Rates of predation by tadpoles of Bufo regularis on larvae of the African catfish Heterobranchus longifilis were determined under controlled laboratory conditions. Predation rates were high on early stage yolk-sac and first-feeding larvae, which have a poorly developed escape ability. A steady decline in predation rates was found with an increase i...

br/> The results of a socio-economical survey of farming systems practising rice culture with introduced fish, rice culture with indigenous fish and rice monoculture in the semi-deep waters of the Mekong Delta, Vietnam, are presented. Rice and fish yields, inputs, and cost-benefits were computed to evaluate the agricultural effects of rice with fis...

Rice production, ricefield environment and the feeding ecology offish were studied in an experiment conducted at a rice-fish station in the Mekong Delta, Vietnam. In total, six treatments (three replicates) were investigated: four different polyculture combinations of small sized silver barb, Puntius gonionotus (Bleeker), Nile tilapia, Oreochromis...

An investigation was conducted under laboratory conditions to analyse the mechanisms of prey capture by tadpoles, Bufo regularis Reuss, and to determine the minimum size at which the predation pressure by tadpoles on the larvae of African catfish, Heterobranchus longifilis Val., becomes insignificant. It was observed that the tadpoles fed on the la...

Fish husbandry and rice culture management factors influencing the yield of introduced fish in ricefields of the Vietnamese Mekong Delta were studied by multiple regression analysis. A significant (P < 0.001) regression model was computed in which feed input and duration of culture period positively and ricefield area, rice seeding rate and the yea...

Diseases are among the greatest threats affecting the sustainability of shrimp aquaculture. In Ecuador, diseases of cultured shrimp have been quickly transmitted from one region to another. Therefore, an early detection system of impending epidemics could serve as an important management tool for the aquaculture sector. We developed a system for th...

The feeding habits of Synodontis comoensis (Siluriformes, Mochokidae) have been studied for the first time. Specimens caught in the Comoé River (Comoé National Park, Côte d’Ivoire) had fed on different types of food including insects (Diptera, Ephemeroptera, Hymenoptera, and Isoptera), molluscs (gastropods and bivalves), oligochaetes, and macrophyt...

Summary 1. It is poorly understood which traits translate larval stressors into adult fitness in animals where larval and adult stages are separated by metamorphosis. Although fluctuating asymmetry (FA) is often assumed to do so, especially in insects the relationship between larval stress, adult FA and individual quality is often absent. One sugge...

1. Mass at emergence is a life-history trait strongly linked to adult fitness. Therefore, when faced with transient food shortage in the larval stage, mass-correcting mechanisms are common. 2. These correcting mechanisms may carry costs with them. On one hand, these costs may be overestimated because they can be confounded with the direct effects o...

In order to reduce the risks of Legionnaires' disease, caused by the bacterium Legionella pneumophila, disinfection of tap water systems contaminated with this bacterium is a necessity. This study investigates if electrochemical disinfection is able to eliminate such contamination. Hereto, water spiked with bacteria (10(4)CFU Escherichia coli or L....

Gut contents of sand goby Pomatoschistus minutus showed higher C and N isotope values than the food before consumption. This enrichment was more pronounced in the hindgut than in the foregut, probably because of preferential assimilation of 12C and 14N along the gastro-intestinal tract. The results indicated that the shift towards higher values in...

Environnemental Control of Shrimps Communities Structure along a Small West African Basin- Boubo River- Ivory Coast. The relationship between shrimps species and environmental variables were studied in Boubo River, a costal river in Ivory Coast. The river is submitted to the impact of human activities (dam construction and oils factory). This surve...

Investigation of the attachment and uptake of Legionella pneumophila by Acanthamoeba castellanii and Naegleria lovaniensis, as these are two critical steps in the subsequent bacterial survival in both amoeba hosts. Initially, the mode of Legionella uptake was examined using inhibitors of microfilament-dependent and receptor-mediated uptake phagocyt...

Biomarkers are widely used to assess pesticide stress, but their ecological relevance and exposure time dependent sensitivity is still heavily debated. We studied both aspects in larvae of the damselfly Coenagrion puella, comparing the impact of low doses of atrazine, carbaryl, and endosulfan on two key biomarkers (acetylcholinesterase [AChE] activ...

Biofilms are a major source of human pathogenic Legionella pneumophila in aquatic systems. In this study, we investigated the capacity of L. pneumophila to colonize floating biofilms and the impact of Acanthamoeba castellanii on the replication of biofilm-associated Legionella. Biofilms were grown in Petri dishes and consisted of Aeromonas hydrophi...

Despite their relevance for risk assessment, the interactive effects of pesticide and predation cues are poorly understood because the underlying behavioral and physiological mechanisms are largely unknown. To explore these mechanisms, we reared larvae of the damselfly Coenagrion puella at three different predation risk levels and a range of enviro...

ABSTRACT: Studies on diet or migration of organisms based on stable isotopes require precise estimates of how quickly stable isotope ratios change in the investigated tissues. Isotopic turnover rates in fish, however, are poorly understood. Prior to field applications of the stable isotope technique for investigating sand goby Pomatoschistus minutu...

Biofilms similar to those present in water distribution pipes of anthropogenic aquatic systems were simulated in a rotating annular reactor using a non-Legionella community consisting of Aeromonas hydrophila, Escherichia coli, Flavobacterium breve and Pseudomonas aeruginosa. The impact of this community and Acanthamoeba castellanii on the replicati...

Floating biofilms develop at the water-air interface and harbor numerous microorganisms, some of which are human pathogens like Legionella pneumophila. The presence of Legionella spp. and especially L. pneumophila in such biofilms was investigated. In parallel, the occurrence of Naegleria spp., Acanthamoeba spp., Willaertia spp., Vahlkampfia spp. a...

SummaryA gonadoliberin analogue (GnRHa) whose biological role is the stimulation of gonadotropin (GTH II) secretion, has been encapsulated together with intestinal absorption enhancers and proteolytic enzyme inhibitors. The capsules have been coated to prevent their solubilization at acid pH in the stomach. After oral delivery of the capsules by fo...

Data on the distribution in 1986 of the parasitic nematode in the swimbladder of the European eel (Anguilla anguilla L.) in Flanders (Belgium) are reported. In stations where imported eels have been used for restocking, samplings generally show high infection rates thus enhancing the spread of Anguillicola crassus in Flanders.

The viability of Anguillicola crassus larvae was studied under various environmental conditions. High températures and nigh salt concentrations considerably shorten the lifetime of the larvae. This is possibly one of the reasons why infection does not occur as massively in marine biotopes as it usually does in fresh water.

Free-living amoebae (FLA) are distributed ubiquitously in aquatic environments with increasing importance in hygienic, medical and ecological relationships to man. In this study, water samples from Belgian industrial cooling circuits were quantitatively surveyed for the presence of FLA. Isolated, thermotolerant amoebae were identified morphological...

We studied diel vertical migration (DVM) of a variety of zooplanktonic taxa. Our results fit the predictions of the predator avoidance hypothesis, with larger taxa performing normal migrations to avoid fish predation and smaller taxa performing reversed migrations, probably to avoid predation by Chaoborus. Cladocerans and adults of copepods display...

A fast and accurate duplex real-time PCR (qPCR) was developed to detect and quantify the human pathogenic amoeba Naegleria fowleri in water samples. In this study, primers and probe based on the Mp2Cl5 gene were designed to amplify and quantify N. fowleri DNA in a single duplex reaction. The qPCR detection limit (DL) corresponds to the minimum DNA...

This study describes the development and evaluation of a specific Legionella pneumophila Taqman duplex real-time PCR (qPCR) for fast and reliable quantification of this human pathogen in suspected man-made water systems. The qPCR assay was 100% specific for all L. pneumophila serogroups 1-15 with a sensitivity of 60 genome units/l and an amplificat...

Real-time polymerase chain reaction melting curve analysis (MCA) allows differentiation of several free-living amoebae species. Distinctive characteristics were found for Naegleria fowleri, N. lovaniensis, N. australiensis, N. gruberi, Hartmanella vermiformis, and Willaertia magna. Species specificity of the amplicons was confirmed using agarose ge...

Tropical high Andes lakes are aquatic ecosystems with peculiar limnological characteristics that are related to their geographical location and high altitude, yet they remained understudied. We present the results of a standardized survey of morphometric, physico-chemical and biotic variables in 32 high altitude lakes of the Cordillera del Tunari (...

Feeding habits and trophic relationships among three mormyrid species (Petrocephalus bovei, Marcusenius ussheri and Marcusenius furcidens) were assessed in the man-made Lake Ayame in Ivory Coast. The index of preponderance combining the occurrence and weight percentages of the identified prey items showed that these three mormyrid species mainly fe...

Methyl-tert-butyl ether (MTBE), an anthropogenic chemical used as a gasoline additive, is being detected at an increasing frequency in the environment. The acute lethal concentration that kills 50% of the fish test population and the chronic effects of exposure to MTBE were investigated in the zebrafish (Danio rerio). Chronic exposure over three we...

The presence of high levels of Legionella pneumophila in man-made aquatic systems correlates with the incidence of nosocomial Legionnaires' disease. This requires a rapid, reliable, and sensitive quantification of L. pneumophila concentrations in suspected water systems. In this research, a homologous competitor was developed and evaluated in a L....

The effect of feeding and starvation on growth, gross body composition and fatty acid composition of body muscle and liver were investigated in juvenile African catfish (Clarias gariepinus). The relative composition of fatty acids was influenced by starvation. In both liver and muscle there were marked relative decreases of 14: 0, 16: 1n9 and 18: 1...

Preliminary experiments were undertaken to investigate the effect of dietary inulin (Raftiline ST), oligofructose (Raftilose P95) and lactosucrose on the growth and intestinal bacteria of the marine carnivorous turbot, Psetta maxima. Turbot larvae were weaned on compound diets containing 2% Rafiline ST, 2% Raftilose P95 or 2% lactosucrose; 2% cellu...

The culture of aquatic organisms is still hampered by the occurrence of unpredictable diseases in their early life stages, which are responsible for massive mortalities and considerable economic losses. A better understanding of the host-microbe interactions is certainly essential to develop effective solutions of disease control for the aquacultur...

Fish community structure in relation with environmental variables was studied in the Mé River (Ivory Coast, West Africa). Fifty-four freshwater fish species belonging to 35 genera and 20 families were listed. Eight of these species were reported for the first time in this river, whereas fifteen species reported earlier were not found in the pres...

Methyl tert-butyl ether (MTBE), a synthetic chemical used as a fuel additive, has been detected more frequently in the environment than previously. In this study, we examine the effects of MTBE (up to 100 mg/L) and its primary metabolite tertbutyl alcohol (TBA) (up to 1,400 mg/L) on the hatch rate and larval development of the African catfish Clari...

Despite the numerous physiological studies on flatfish and their economic and ecologic importance, only a few attempts have been made to construct a bioenergetics model for these species. Here we present the first bioenergetics model for European flounder (Platichthys flesus), using experimentally derived parameter values. We tested model performan...

The human pathogenic Legionella bacteria are found ubiquitously in natural and human-made aquatic environments as residents in biofilms, where close interactions with other microorganisms like protozoa are possible. Nosocomial legionellosis already has been linked frequently to Legionella-contaminated artificial water supplies. For this reason, a r...

Large numbers of young of the year herring (Clupea harengus L.) and sprat (Sprattus sprattus (L.)) typically enter and remain within North Sea estuaries during the winter months. The main purpose of this study was to examine their migration dynamics between the North Sea and the Schelde estuary using C and N stable isotopes. Prior to this, stomach...

In aquatic environments, Legionella pneumophila survives, in association with other bacteria, within biofilms by multiplying in free-living amoebae. The precise mechanisms underlying several aspects of the uptake and intracellular replication of L. pneumophila in amoebae, especially in the presence of other bacteria, remain unknown. In the present...

Eighty-four sites in the Comoé basin (Côte d'Ivoire, West Africa) were sampled to identify fish assemblages and their relationships with some environmental variables. Seventy-six freshwater fish species were collected from 22 families and 44 genera: 11 marine and/or brackish water species, one introduced species, and one hybrid form. Nine species w...

The optimal ratio of spermatozoa : egg (15 000 : 1) for artificial insemination of African catfish Clarias gariepinus gave fertilization and hatching rates of 80 and 67%, respectively. Below a sperm : ova of 3000 : 1 fertilization success decreased significantly. Excessive sperm (>15 000 : 1) partly inhibited fertilization success. Sperm motility w...

Fish collections on the cooling water filter screens of the Doel power plant were used to analyse temporal trends in estuarine fish populations of the upper Scheldt estuary, Belgium. Between 1991 and 2001, 62 species shared the estuary, with 15 species present at any one time. Identified were 23 marine stragglers, 16 freshwater species and four dia...

The aim of this study was to investigate the possibility of mucosal vaccination in African catfish (Clarias gariepinus) with Vibrio anguillarum O2 bacterins. The antigen was administered via different routes: anal intubation, oral administration, intraperitoneal injection and immersion. To monitor the antigen uptake, a competitive ELISA was used. T...

Shrimp farming is gradually changing the coastal landscape of many Asian countries. This paper examined the impacts of shrimp farming on the environment (mangrove forest, surface water, and soil) and socio-economic characteristics (loans, education and health) of a coastal district, Cai Nuoc, in the Mekong delta, Vietnam. Aerial photographs (1968 &...

Several descriptive and experimental studies were carried out in Laguna Bufeos during the last decade. This document aims at summarizing this information and generating an energy flux model for várzea lakes in the upper Amazon. The evidence shows that the lower trophic levels (algae and bacteria) are strongly bottom-up controlled, whereas intermedi...

Herring (Clupea harengus) enter and remain within North Sea estuaries during well-defined periods of their early life history. The costs and benefits of the migrations between offshore spawning grounds and upper, low-salinity zones of estuarine nurseries are identified using a dynamic state-variable model, in which the fitness of an individual is m...

This study is the first to characterize the limnological features of high-altitude peatland pools in the Andes cordillera (>4000 m). Data were collected at two different spatial scales: the scale of individual patches of peatland (bofedales; areas ranging between 0.01 and 10 ha) and the scale of 'localities' (areas of approximately 7 km2). Patterns...

A comparison was made between the oocyte diameter, pseudo-absolute fecundity (PAF) and egg quality of two strains of the catfish, Heterobranchus longifilis, maintained in outdoor ponds under a tropical highland climate in Cameroon. The results indicated that circannual endogenous rhythms for ovarian recrudescence and regression are absent in H. lon...

Two experiments, dealing with short-term storage of ova and thermal conditions to optimize gamete and eggs management in hatcheries of the African catfish, Heterobranchus longifilis, were carried out. In the first experiment, ova collected by stripping from two strains of H. longifilis were stored for intervals up to 8 h at two temperature regimes:...

A statistical modeling study was performed on the population fluctuations of the 15 commonest fish species frequenting the tidal Scheldt estuary in Belgium. These included marine juvenile and seasonal visitors, estuarine residents and diadromous fish species that were recorded on the filter screens of a power plant cooling-water intake between Sept...

It has been shown recently that African catfish (Clarias gariepinus) spermatozoa possess relatively low ATP content and low adenylate energy charge (AEC). One of the possible explanations for this phenomenon is that the spermatozoa actively catabolize adenine nucleotides. A relatively high rate of such catabolism could then contribute to the low AT...

Eleven soil samples (contaminated and non-contaminated top soils and aquifers) from seven different locations in Belgium were examined in lab-scale batch microcosms simulating in situ conditions for their indigenous capacity to biodegrade methyl tert-butyl ether (MTBE). The effect of implementing nutrients or additional oxygen and of the presence o...

The fish farming industry has been more focused on the quality of eggs or larvae rather than that of sperm, even though the quality of both gametes may affect fertilisation success and larval survival. In some species, poor sperm quality can be a limiting factor in their culture, however, even when fertilisation success is high, differences in sper...

The impact on antigen uptake and antibody response by the addition of absorption enhancers to Vibrio anguillarum O2 antigen was studied in oral vaccination trials of African catfish (Clarias gariepinus). Oral vaccination was achieved by feeding lag time coated pellets. The lag time coat prevents premature release of the encapsulated vaccine in the...

Two living specimens of the Atlantic croaker Micropogonias undulatus have been caught during recent years in Belgian waters (Southern Bight of the North Sea): one in August 1998 as a by-catch of the commercial shrimp fishery in coastal waters, another in October 2001 on a tidal flat in the brackish part of the Scheldt Estuary. These represent the f...

The aim of this study was to investigate the success of oral vaccination application in African catfish using Vibrio anguillarum O2 bacterins. The antigen uptake was followed by competitive enzyme-linked immunosorbent assay (ELISA). Serum antibody response was measured using an indirect ELISA. Several in vivo administration methods were investigate...

The aim of this study was to investigate African catfish (Clarias gariepinus) vaccination with Vibrio anguillarum O2 bacterins. To monitor the antigen uptake, a competitive enzyme-linked immunosorbent assay (ELISA) was developed. Serum antibody response was measured using an indirect ELISA. Sodium dodecylsulfate-polyacrylamide gel electrophoresis a...

In the freshwater area of Vietnam's Mekong Delta, Barbodes gonionotus (Bleeker), Cyprinus carpio L. and Oreochromis niloticus (L.) are often reared together in rice fields. The survival rate and specific growth rate (SGR) of C. carpio showed a large variance. To understand the underlying reasons for this variation, we used multiple regressions for...

Influence of various energetic substrates on ATP content and adenine nucleotide catabolism in African catfish, Clarias gariepinus spermatozoa was investigated. Present data indicate that sperm storage at 4C in the presence of different energetic substrates leads to time dependent ATP depletion. Among the substrates studied (i.e. glycine, glucose, o...

We assessed the impact of water hyacinth on the water quality of Lake Chivero, a highly eutrophic man-made reservoir near Harare (Zimbabwe). We compared water quality among limnetic (always without macrophytes) and littoral zones with and without hyacinths in randomly selected sites and along a transect from inflow to outflow of the lake. In additi...

We compared abundance and diversity of phytoplankton, zooplankton, and fishes among limnetic (P: always without macrophytes) and littoral habitats with (L +) and without (L- ) hyacinths in Lake Chivero, a man-made hypertrophic reservoir near Harare (Zimbabwe). In addition, the littoral macrophyte community, and macro-inver- tebrates associated with...

Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the ¢sh assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of ¢sh were taken in the cooling water of a power plant. Juveniles of eight species dominated the ¢sh assemblage: two goby species, herring, sprat,...

It is often claimed that fish stocked in rice fields have a significant impact on the rice pest population. However, there is little experimental evidence for this. We used the data of six experiments to find out whether a polyculture of silver barb Barbodes gonionotus (Bleeker), common carp Cyprinus carpio (L.) and Nile tilapia Oreochromis nilotic...

Legionella pneumophila, a Gram-negative bacterium, is the causative agent of legionellosis. Traditionally, culture methods are normally used to detect Legionella species in different types of water (e.g. surface or tap water, circulating systems, air conditioners and their cooling devices). In this study the PCR conditions to detect Legionella were...

To detect Naegleria spp, in particular Naegleria fowleri, the causative agent of human primary amoebic meningoencephalitis, a flagellation test (FT) is routinely used followed by a specific ELISA. A positive FT indicates the presence of Naegleria spp although some false negatives are likely to occur since parameters for enflagellation vary greatly....

Although traditional culture methods are appropriate for detection of Legionella species, such culture takes several days. Rapid detection (< 24 h) of individual Legionella is possible using fluorescent in situ hybridisation (FISH) on whole bacteria. Water samples were filtered and the concentrated bacteria were immediately detected (without cultur...

Biocidal activities of monochloramine and peracetic acid were studied on cysts of Naegleria lovaniensis. Until recently the most commonly used biocide to disinfect cooling water systems was hypochlorite. Owing to its negative impact on the aquatic environment, ecologically less harmful alternatives have been sought. As the biocidal activity of mono...