Interactions between Free-Living Amoebae and Legionella in the Environment

1988 ◽  
Vol 20 (11-12) ◽  
pp. 235-239 ◽  
Author(s):  
C. Harf ◽  
H. Monteil
Keyword(s):  
Liquid Medium ◽  
Ultrasonic Treatment ◽  
Guinea Pigs ◽  
Ecological Model ◽  
Aquatic Habitats ◽  
Environmental Waters ◽  
Free Living ◽  
River Waters ◽  
Natural Hosts ◽  
Cellular Replication

While their presence is common in the environment, culture and isolation of Legionella from environmental waters are fastidious. Free-living amoebae have identical aquatic habitats and are probable natural hosts for Legionella. In the laboratory it was shown that amoebae can feed on Legionella on solid and in liquid medium; both survived after several subcultures of amoebae. Amoebae were isolated from river waters and sediments. Cysts or trophozoites were subcultured; the amoebae were washed and harvested, then lysed by thermal shock and ultrasonic treatment. The lysates were positive for Legionella by IFD with different pools of antisera (A, B and C from CDC, Atlanta). Intra-peritoneal injection of the lysates in guinea-pigs allowed the isolation of L.pneumophila 1 from blood and various organs. Amoebae are likely to be natural hosts for Legionella and are convenient as an ecological model in the laboratory. Intra-cellular replication and inclusion in resistant cysts of amoebae give them a possibility of survival in unfavourable conditions.

Survey of algae and other terrestrial biota at Edward VII Peninsula, Marie Byrd Land

1989 ◽  
Vol 1 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Paul A. Broady
Keyword(s):  
Testate Amoebae ◽  
Aquatic Habitats ◽  
Free Living ◽  
Algal Communities ◽  
Continental Antarctica ◽  
Prasiola Crispa ◽  
Bird Colonies ◽  
First Time ◽  
Ciliate Protozoa ◽  
Stichococcus Bacillaris

The survey concentrated on algal communities but also gathered information on mosses, lichens and microfauna. All 23 nunataks in the Rockefeller and Alexandra mountains (77°00′–78°30′S, 152°–154°W) were visited, including ones both with and without nutrient enrichment from bird colonies. Over 30 species of algae were recorded with Cyanobacteria and Chlorophyta dominant as in other regions of continental Antarctica. Diatoms were not found. The most frequent algae were Cyanothece aeruginosa, Gloeocapsa spp., Oscillatoriaceae, Nostoc sp., Pseudococcomyxa simplex, Stichococcus bacillaris, cf. Desmococcus vulgaris, Prasiola crispa and Prasiococcus calcarius. Although lichens were the most visually prominent vegetation, free-living algae occurred in the widespread ‘non-aquatic’ habitats as epilithic, chasmoendolithic and edaphic communities as well as being epiphytic on the sparse moss cushions. Aquatic habitats were few and there were only three small ponds on or adjacent to nunataks. On ablating ice, cryoconite ponds contained Homoeothrix cf. rivularis, recorded for the first time in Antarctica. Preliminary identifications show 23 species of lichens and six species of mosses. No mites and collembola were seen. Samples contained testate amoebae, ciliate protozoa, rotifers and tardigrades but no nematodes.

scholarly journals Microsporidian Infection in a Free-Living Marine Nematode

2012 ◽  
Vol 11 (12) ◽  
pp. 1544-1551 ◽  
Author(s):  
A. M. Ardila-Garcia ◽  
N. M. Fast
Keyword(s):  
Marine Nematode ◽  
Free Living ◽  
Content Type ◽  
Infection Pattern ◽  
Transmission Electron ◽  
Muscle Tissues ◽  
Natural Hosts ◽  
In The Wild ◽  
Microsporidian Infection

ABSTRACT Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the “nematode killer” ( Nematocida parisii ). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans . We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are “nematode killers”; instead, microsporidiosis can be more versatile and chronic in the wild.

scholarly journals Fluorescent Acid-Fast Microscopy for Measuring Phagocytosis of Mycobacterium avium,Mycobacterium intracellulare, and Mycobacterium scrofulaceum by Tetrahymena pyriformis and Their Intracellular Growth

2001 ◽  
Vol 67 (10) ◽  
pp. 4432-4439 ◽  
Author(s):  
Eileen D. Strahl ◽  
Glenda E. Gillaspy ◽  
Joseph O. Falkinham
Keyword(s):  
Linear Relationship ◽  
Mycobacterium Avium ◽  
Tetrahymena Pyriformis ◽  
Mycobacterial Infection ◽  
Fresh Medium ◽  
Intracellular Growth ◽  
Free Living ◽  
Mycobacterium Intracellulare ◽  
Natural Hosts

ABSTRACT Fluorescent acid-fast microscopy (FAM) was used to enumerate intracellular Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceumin the ciliated phagocytic protozoan Tetrahymena pyriformis. There was a linear relationship between FAM and colony counts of M. avium cells both from cultures and within protozoa. The Ziehl-Neelsen acid-fast stain could not be used to enumerate intracellular mycobacteria because uninfected protozoa contained acid-fast, bacterium-like particles. Starved, 7-day-old cultures of T. pyriformis transferred into fresh medium readily phagocytized M. avium, M. intracellulare, and M. scrofulaceum. Phagocytosis was rapid and reached a maximum in 30 min. M. avium, M. intracellulare, and M. scrofulaceum grew within T. pyriformis, increasing by factors of 4- to 40-fold after 5 days at 30°C. Intracellular M. avium numbers remained constant over a 25-day period of growth (by transfer) of T. pyriformis. Intracellular M. avium cells also survived protozoan encystment and germination. The growth and viability of T. pyriformis were not affected by mycobacterial infection. The results suggest that free-living phagocytic protozoa may be natural hosts and reservoirs for M. avium, M. intracellulare, and M. scrofulaceum.

Crustacea: Copepoda

2017 ◽  
Author(s):  
Marianne Wooton ◽  
Claudia Castellani
Keyword(s):  
Life Cycle ◽  
Deep Ocean ◽  
Tree Of Life ◽  
Ocean Floor ◽  
Freshwater Lakes ◽  
Aquatic Habitats ◽  
Free Living ◽  
General Morphology ◽  
Wide Range ◽  
Family Level

This chapter describes the taxonomy of copepods. Copepods are small aquatic crustaceans and are considered to be one of the most abundant and diverse multi-cellular organisms on earth. Populating a wide range of aquatic habitats, from the deep ocean floor to high Himalayan freshwater lakes, copepods have many free-living as well as highly modified parasitic forms. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.

EXPERIMENTAL STUDIES ON STRONGYLOIDES AGOUTII IN THE GUINEA PIG

1940 ◽  
Vol 18d (9) ◽  
pp. 307-324 ◽  
Author(s):  
Henry J. Griffiths
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Mixed Type ◽  
Experimental Studies ◽  
Prepatent Period ◽  
Acquired Immunity ◽  
Patent Period ◽  
Free Living ◽  
Mode Of Development ◽  
One Year

The suitability and tolerance of the guinea pig to infection with Strongyloides agoutii presented an opportunity for the study of the bionomics of this species in an experimental host.Serial transfer of this nematode through the guinea pig yielded a mixed type (free males and filariform larvae) of free-living development in faecal cultures which occasionally reverted to the indirect mode common to S. agoutii. A reversion to the indirect mode of development was produced when ova from faeces of guinea pigs infected with S. agoutii were cultured in sterile agouti faeces.The termination of the prepatent period of S. agoutii in the guinea pig was shown to range from 7 to 10 days, and 71% of 58 animals were positive by faecal test by the eighth day. The patent period ranged from three to eight weeks.The guinea pig was shown to develop an absolute acquired immunity to re-infection with S. agoutii. This resistance has been retained over a period of at least 6 to 13 months. An age resistance was not observed in animals one year old and over.

Intraspecific Morphological Variation in Free-Living Stages of Strongyloides Papillosus (Nematoda, Strongyloididae) Parasitizing Various Mammal Species

2019 ◽  
Vol 53 (4) ◽  
pp. 313-324
Author(s):  
O. O. Boyko ◽  
Y. A. Gugosyan ◽  
L. I. Shendryk ◽  
V. V. Brygadyrenko
Keyword(s):  
Guinea Pigs ◽  
Morphological Variability ◽  
Maximum Size ◽  
Domestic Animals ◽  
The Body ◽  
Mammal Species ◽  
Free Living ◽  
Larval Stages ◽  
Almost All ◽  
Intraspecific Morphological Variation

Abstract Strongyloides papillosus Wedl, 1856 is one of the most widespread nematodes parasitic in domestic animals. This species has been recorded on almost all continents of the planet. It parasitizes the small intestine of rabbits, sheep and cattle. At laboratory conditions, this species can also infect guinea pigs. Morphological variability of S. papillosus in relation to host species has not yet been studied. Our research showed that L1 and L2 of S. papillosus reached their maximum size in all parameters in guinea pigs: for L1 — length and width of the body, length of esophagus and intestine; for L2 — width of body and length of intestine. L3 of S. papillosus had statistically reliable differences in almost all parameters (except the length of intestine) when parasitizing goats and rabbits. For L3 the width of the body and the length of the tail end, we determined differences between S. papillosus infecting rabbits and guinea pigs, and also goats and guinea pigs. Male S. papillosus were observed to have statistically reliable differences in all morphological parameters for goats and rabbits, and also for rabbits and guinea pigs. Practically all measurements (except the length of the tail) were larger for S. papillosus in guinea pigs and goats than those in rabbits. Free-living females statistically differed by larger size in goats and rabbits. The smallest dimensions were determined for all free-living stages of S. papillosus in goats (except males). The largest size in most cases was determined for larval stages of S. papillosus in guinea pigs.

scholarly journals Detection ofVibrio choleraeO1 and O139 in environmental waters of rural Bangladesh: a flow-cytometry-based field trial

2014 ◽  
Vol 143 (11) ◽  
pp. 2330-2342 ◽  
Author(s):  
L. RIGHETTO ◽  
R. U. ZAMAN ◽  
Z. H. MAHMUD ◽  
E. BERTUZZO ◽  
L. MARI ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Flow Cytometer ◽  
Environmental Waters ◽  
Fast Determination ◽  
River Waters ◽  
Quantitative Measurements ◽  
Time Period ◽  
Measurement Protocol ◽  
Hydrological System

SUMMARYPresence ofVibrio choleraeserogroups O1 and O139 in the waters of the rural area of Matlab, Bangladesh, was investigated with quantitative measurements performed with a portable flow cytometer. The relevance of this work relates to the testing of a field-adapted measurement protocol that might prove useful for cholera epidemic surveillance and for validation of mathematical models. Water samples were collected from different water bodies that constitute the hydrological system of the region, a well-known endemic area for cholera. Water was retrieved from ponds, river waters, and irrigation canals during an inter-epidemic time period. Each sample was filtered and analysed with a flow cytometer for a fast determination ofV. choleraecells contained in those environments. More specifically, samples were treated with O1- and O139-specific antibodies, which allowed precise flow-cytometry-based concentration measurements. Both serogroups were present in the environmental waters with a consistent dominance ofV. choleraeO1. These results extend earlier studies whereV. choleraeO1 and O139 were mostly detected during times of cholera epidemics using standard culturing techniques. Furthermore, our results confirm that an important fraction of the ponds’ host populations ofV. choleraeare able to self-sustain even when cholera cases are scarce. Those contaminated ponds may constitute a natural reservoir for cholera endemicity in the Matlab region. Correlations ofV. choleraeconcentrations with environmental factors and the spatial distribution ofV. choleraepopulations are also discussed.

scholarly journals Genomes of Planktonic Acidimicrobiales: Widening Horizons for Marine Actinobacteria by Metagenomics

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Carolina Megumi Mizuno ◽  
Francisco Rodriguez-Valera ◽  
Rohit Ghai
Keyword(s):  
Metagenomic Data ◽  
Data Sets ◽  
Deep Chlorophyll Maximum ◽  
Photic Zone ◽  
Aquatic Habitats ◽  
Marine Habitat ◽  
Free Living ◽  
Marine Actinobacteria ◽  
Chlorophyll Maximum ◽  
Metabolic Versatility

ABSTRACTThe genomes of four novel marineActinobacteriahave been assembled from large metagenomic data sets derived from the Mediterranean deep chlorophyll maximum (DCM). These are the first marine representatives belonging to the orderAcidimicrobialesand only the second group of planktonic marineActinobacteriato be described. Their streamlined genomes and photoheterotrophic lifestyle suggest that they are planktonic, free-living microbes. A novel rhodopsin clade, acidirhodopsins, related to freshwater actinorhodopsins, was found in these organisms. Their genomes suggest a capacity to assimilate C2 compounds, some using the glyoxylate bypass and others with the ethylmalonyl-coenzyme A (CoA) pathway. They are also able to derive energy from dimethylsulfopropionate (DMSP), sulfonate, and carbon monoxide oxidation, all commonly available in the marine habitat. These organisms appear to be prevalent in the deep photic zone at or around the DCM. The presence of sister clades to the marineAcidimicrobialesin freshwater aquatic habitats provides a new example of marine-freshwater transitions with potential evolutionary insights.IMPORTANCEDespite several studies showing the importance and abundance of planktonicActinobacteriain the marine habitat, a representative genome was only recently described. In order to expand the genomic repertoire of marineActinobacteria, we describe here the firstAcidimicrobidaegenomes of marine origin and provide insights about their ecology. They display metabolic versatility in the acquisition of carbon and appear capable of utilizing diverse sources of energy. One of the genomes harbors a new kind of rhodopsin related to the actinorhodopsin clade of freshwater origin that is widespread in the oceans. Our data also support their preference to inhabit the deep chlorophyll maximum and the deep photic zone. This work contributes to the perception of marine actinobacterial groups as important players in the marine environment with distinct and important contributions to nutrient cycling in the oceans.

scholarly journals VARIABILITY OF BCG STRAINS (BACILLUS CALMETTE-GUÉRIN)

1951 ◽  
Vol 93 (6) ◽  
pp. 559-572 ◽  
Author(s):  
W. Emanuel Suter ◽  
René J. Dubos
Keyword(s):  
Liquid Medium ◽  
Guinea Pigs ◽  
Parent Strain ◽  
Tween 80 ◽  
Intrinsic Properties ◽  
Liquid Media ◽  
Limited Disease ◽  
Heterogeneous Populations ◽  
Percentage Distribution ◽  
Different Cultures

Three different cultures of BCG propagated for over 2 years in a liquid medium containing Tween 80 and albumin were found to differ in several of their intrinsic properties. Cultures of the three strains were found to consist of morphologically heterogeneous populations—each culture being made up of three main colonial types—spreading, intermediate, and non-spreading. The percentage distribution of colonial types was characteristic for each culture and remained constant during cultivation in liquid media. Injection of the various cultures into mice and guinea pigs resulted in a self-limited disease. The distribution, extent, and duration of the lesions were also characteristic for each culture. Both the spreading and non-spreading substrains derived from the various cultures exhibited the degree of attenuation of virulence characteristic of the parent strain.

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