Isolation Of Protozoa Research Articles

Comparison of methods for isolation of protozoa from ruminal fluid

Isolation of protozoa from ruminal fluid taken from the same cow on five different days was carried out by three methods based on sedimentaton or on filtration using 10-μm mesh (PMB-10) or 20-μm mesh (PMB-20) polyester monofilament bags. Differences among means for percentage recoveries of protozoal numbers for the three isolation methods were statistically significant (P = 0.007), but those for dry matter and diaminopimelic acid (DAPA) recoveries were not (P > 0.1). The sedimentation method produced the lowest recovery of protozoa as well as the highest recovery of DAPA, which indicated the highest bacterial contamination. Among the filtration-based methods PMB-10 produced higher recoveries of protozoal numbers and dry matter than PMB-20, but with somewhat larger bacterial contamination. Among the three methods compared, filtration with PMB-10 was considered as the most suitable. Key words: Ruminal fluid, protozoal isolation, sedimentation, filtration

Isolation of protozoa from water associated with a legionellosis outbreak and demonstration of intracellular multiplication of Legionella pneumophila.

At the site of a legionellosis outbreak, amoebae and two ciliates, Tetrahymena sp. and Cyclidium sp., were isolated from cooling-tower water containing Legionella pneumophila. The Tetrahymena sp. and the amoebae repeatedly showed the ability to support intracellular multiplication of L. pneumophila. Both were isolated from cooling towers specifically implicated as the source for the spread of legionellosis. These protozoa may be reservoirs supporting the survival and multiplication of virulent legionellae in cooling-tower water.

The Cultivation of the Parasitic Protozoa Without Bacteria

SummaryA review of the literature shows that isolation of protozoa from bacteria does not present any formidable difficulties. Such isolation has been accomplished by methods based on principles involving positive or negative geotropism of protozoa, migration of protozoa away from bacteria through semi-solid media, mechanical separation of protozoa and bacteria by micro-isolation, or the differential action of poisons on cysts of protozoa and certain non-spore-forming bacteria.In cultivating isolated protozoa, provision must be made for a gradual adaptation to new conditions.Physical and chemical considerations which must be taken into account to provide a favorable medium include isotonicity of the fluid part of the medium with those of the tracts parasitized by the protozoa, a balanced food supply and a balanced interaction of various respiratory factors, vitamins and catalysts.The L.E.S. medium, providing both solid and liquid food, is probably the best for general use that has thus far been devised. Eutrichomastix colubrorum, Trichomonas foetus and T. Columbae, which may be considered as representative flagellate parasites of the digestive, urogenital and respiratory tracts, respectively, all find adequate nourishment in this medium in the absence of bacteria. However, for the growth of Endamoeba histolytica without bacteria the medium lacks certain essential factors, the discovery of which awaits future investigations.

Studies on the Morphology and Behaviour of Buxtonella sulcata from Cattle and of Balantidium coli from the Pig

1. A ciliate occurring in the caecum of about 25 per cent, of the cattle that were examined at Jeanerette, Louisiana, is herein classified as Buxtonella sulcata Jameson (1926) and it is proposed that it be removed from the Class Aspirigera, Family Isotrichidae, and included in the Class Spirigera, Order Heterotrichida.2. The ciliate is characterised by the position of the cytostome near the permanently open cytopyge and within the peristome which continues from the cytostome around the oral end of the body to the extreme aboral end which during locomotion is anterior.3. The infections were detected in slaughtered animals by examining faecal material in Syracuse watch glasses under the binocular microscope, this method of faecal diagnosis having advantages over the smear method.4. By the administration of Epsom salts the ciliates may be obtained from living cattle.5. A pipette is described and figured for the isolation of Protozoa.6. Death of Buxtonella sulcata in an unfavourable environment occurred by disruption of the endoplasm through the cytostome.7. Buxtonella sulcata disappeared from faecal material at room temperature more quickly than balantidia from the pig, but withstood manipulation under the microscope better than the balantidia.8. The passage of an individual between two obstructions suggested a means of intercellular tissue penetration by ciliates.9. The oral plug and the centralised neuromotor system described and figured by McDonald in Balantidium coli could not be differentiated by the writer, but McDonald's other morphological observations on the above ciliates were confirmed.