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E Pozio

Publications and source records attributed to E Pozio.

At least 145 records · Page 8Linked to original sources
PubMed1993

A method for collecting large quantities of Cryptosporidium parasites.

The intestinal mucoso may be regarded as a potential and abundant source of Cryptosporidium parvurn parasites from which all developmental stages might be collected. If intracellular stages could be recovered from the brush border, many of the limitations concerned with the use of oocysts and in vitro cultures may be overcome. Hans-Michael Muller, Lorella Ranucci, Edoordo Pozio and Andrea Crisonti discuss here how this can be done.

Journal Article↗
PubMed1993

Random amplified polymorphic DNA technique for the identification of Trichinella species.

The random amplified polymorphic DNA (RAPD) technique was successfully used to produce genetic fingerprints distinguishing between Trichinella spiralis and Trichinella britovi. The same patterns were obtained from purified and crude DNA preparations of pooled and single muscle larvae. RAPD fingerprinting was applied to muscle larvae preserved under different conditions and recovered from different hosts. Larvae recovered from fresh and frozen meat and stored at -20 degrees C for a long time or under 70% ethyl alcohol at room temperature for 30 d gave good and reproducible results. Single larvae recovered from a naturally infected wild boar and from a human biopsy gave fingerprints congruent to those obtained from T. britovi reference strains. The results prove that RAPD analysis is a quick method to distinguish between the autochthonous Trichinella species of Central-Southern Europe in less than 1 d after the detection of the infection. If necessary, the biological material can be frozen or stored under 70% ethyl alcohol at room temperature and sent to laboratories able to perform the RAPD analysis. The RAPD technique requires no prior knowledge of the molecular biology of the organism to be investigated and therefore appears to be a promising tool in parasitology for the identification of sibling species.

Animals↗
PubMed1993

Characterization and immunolocalization of a Cryptosporidium protein containing repeated amino acid motifs.

The oocyst wall is one of the components that permits cryptosporidia both to survive in the environment and to retain infectivity. With the aim of identifying Cryptosporidium proteins specifically expressed at the oocyst stage, we screened lambda gt11 genomic libraries of Cryptosporidium parvum with both an oocyst antiserum and a specific genetic probe. We isolated, from distinct libraries, two overlapping clones containing an open reading frame encoding a 1,252-amino-acid polypeptide. The analysis of the deduced amino acid sequence revealed unusually high contents of cysteine, proline, and histidine. The sequence was also characterized by two distinct amino acid motifs, each repeated several times. The DNA sequences coding for the amino acid repeats showed a high frequency of synonymous mutations, a result suggesting that the repeated motifs may be functionally and/or structurally important to the parasite. Antisera and monoclonal antibodies developed against a recombinant polypeptide encompassing the first 786 amino acids revealed that the corresponding protein in C. parvum had an apparent molecular weight of 190,000. Moreover, confocal microscopy analysis with immunofluorescence indicated that the protein was localized on the oocyst wall as a uniform stain and within the oocyst itself as bright granules in close association with the residual body.

Amino Acid Sequence↗
PubMed1993

Comparison of human trichinellosis caused by Trichinella spiralis and by Trichinella britovi.

The first documented report of an outbreak of human trichinellosis caused by Trichinella spiralis in Italy is described. Two family groups were involved. The source was wild boar meat products. The principal clinical features were fever (60%), myalgia (50%), and diarrhea (40%). The most useful laboratory indicators were eosinophilia (100%), elevated levels of creatine phosphokinase (CPK) (90%) and other muscle enzymes, parasite-specific IgG titers (100%), and anti-newborn larvae antibodies (30%). The levels of these responses correlated with the number of infective muscle larvae ingested, which was influenced by the length of time the ingested meat was cured. The clinical and biological features observed during human infection with T. spiralis appear to have been different from those reported during two outbreaks due to T. britovi, which occurred in southern Italy. The main distinctions between the two types of infections were a longer duration of parasite-specific IgG, increased CPK levels, and a more severe intestinal symptomatology in T. spiralis-infected patients than in those infected with T. britovi.

Adolescent↗
PubMed1993

Biochemical, biological, and genetic characterization of a sylvatic isolate of Trichinella.

Biological, biochemical, and genetic relationships of Trichinella isolates were assessed and compared from 3 species of Illinois fur-bearing mammals. Tongue muscle collected from 1987 through 1989 from 323 raccoons (Procyon lotor), 9 red fox (Vulpes fulva), and 1 coyote (Canis latrans) were digested and Trichinella muscle larval prevalences and mean intensities (larvae/g) determined. The prevalence and mean intensity of tongue muscle-stage larvae were 2.8% and 44.4% and 326 and 2 larvae/g for raccoon and red fox, respectively. The single coyote examined for muscle larvae was negative. Seven of 13 Trichinella isolates (5 raccoon, 2 red fox) were maintained and amplified in mice. Comparative analyses of DNA from larvae of these isolates and from other Trichinella isolates were performed by dot-blot hybridization using specific repetitive DNA probes. DNA from the 7 Illinois sylvatic isolates reacted with the Trichinella T5 isolate DNA probe pUPB-3.7 and did not cross-react with the Trichinella spiralis probe pBP-2. The sylvatic isolates of Trichinella were also analyzed using 27 allozymes. Their allozymic patterns were similar to Trichinella reference strain T5 from Pennsylvania, except for mannose phosphate isomerase. These results suggest that the Illinois wildlife isolates belong to the Trichinella T5 genotype according to the classification system established by the International Trichinella Reference Centre and as defined here by positive hybridization to the pUPB-3.7 probe. Results from Southern blot analyses using rRNA as a probe and allozyme patterns revealed some heterogeneity among geographical isolates of the T5 genotype.

Abdominal Muscles↗
PubMed1993

Arbitrarily primed polymerase chain reaction of individual Trichinella specimens.

Recently, 5 sibling species and 3 other phenotypes were identified in the genus Trichinella. Single primers of arbitrary nucleotide sequence were used to produce random amplified polymorphic DNA starting from decreasing amounts of Trichinella spiralis and Trichinella britovi DNA. Reproducible amplification products from 30 pg of DNA were obtained using 1 of 6 examined primers. These fragments distinguish between 2 European Trichinella species, T. spiralis, showing a 1,350-bp band, and T. britovi, showing 400- and 1,100-bp bands. The developed procedure allows the characterization of crude DNA preparations of single muscle-stage larvae, avoiding time-consuming passages of parasites in laboratory animals.

Animals↗
PubMed1992

Report on an outbreak of trichinellosis in Central Italy.

At the end of 1988 an outbreak of trichinellosis involving 48 persons occurred in a small town in Central Italy, near the Appennine mountains. The epidemic was caused by the ingestion of sausages recently made with wild boar meat. The people affected were mostly relatives and friends of hunters. Trichinella larvae were found in boar meat sausages and in cats fed with raw leftovers and proved to be Trichinella sp. 3 at biochemical typing. This species of parasite is the most frequently isolated species of Trichinella in Italy and other Southern European countries. Clinically the epidemic has shown a typical, uncomplicated febrile course in most patients, but two patients showed signs of cardiac damage and one intense abdominal pain, suggesting an acute abdomen.

Adolescent↗
PubMed1992

Serodiagnosis of cryptosporidiosis in Italian HIV-positive patients by means of an oocyst soluble antigen in an ELISA.

A sensitive, specific, and reproducible ELISA which incorporated an oocyst soluble antigen was used in order to detect specific Cryptosporidium immunoglobulins G and M in Italian HIV-positive patients. The soluble antigen was prepared from purified oocysts collected from experimentally infected calves. The serum working dilution was established at 1 in 50. Of parasitologically positive and HIV-positive patients, 95% showed specific IgG or IgM or both in their serum. Of HIV-positive patients, some of whom had diarrhoea of uncertain aetiology, 15.8% were found to have specific IgG. Both specific IgG and IgM were detected in the serum of an HIV-positive patient 1 year before the shedding of oocysts in the faeces. Sixteen (5.3%) of 300 presumed healthy people, positive for specific IgG, were all IgM-negative. Any significant cross-reactions with other parasitic infections were not observed. With a serum dilution greater than 1 in 25, only a low degree of positivity was observed with samples highly IgG-positive for Toxoplasma species. The ELISA showed a higher than expected prevalence of Cryptosporidium infection in Italian HIV-positive patients.

AIDS-Related Opportunistic Infections↗
PubMed1992

Epidemiology of sylvatic trichinellosis in north-western Italy.

Muscle samples from 7,142 wild boars (Sus scrofa), 80 free-ranging hogs, 1,462 red foxes (Vulpes vulpes) 90 mustelids, 15 Alpine marmots (Marmota marmota), 873 rodents and 92 insectivores were examined for Trichinella Railliet, 1895. A wild boar, a badger (Meles meles) and 30 foxes (2.1%) were found to be infected. Eleven vulpine isolates and the wild boar isolate were identified as Trichinella britovi. These results show that the wild boar has little significance as a reservoir of T. britovi in the area under study. A vulpine isolate resulted in low infectivity in experimentally-infected swine. The prevalence of trichinellosis in the vulpine population is higher in the mountains than in lowland areas and indicates the key role played by this carnivore in the epidemiology of T. britovi. Preliminary results from four field trials seem to demonstrate that differences in attitudes towards cannibalism exist between mountain and lowland foxes.

Animals↗
PubMed1992

Allozymic and biological characters of Trichinella pseudospiralis isolates from free-ranging animals.

To evaluate biological and biochemical variability in nonencapsulated Trichinella isolates, biological and allozymic studies were conducted on isolates of Trichinella collected from a raptoral bird (Aquila rapax) and a fox (Vulpes corsac) in Kazakhstan and from a dasyurid marsupial (Dasyurus maculatus) on the island of Tasmania, Australia. Allozyme profiles of bird and marsupial isolates showed close similarity with the type isolate of Trichinella pseudospiralis. The avian and fox isolates successfully interbred with the type T. pseudospiralis isolate, but they failed to interbreed with 3 encapsulating species, Trichinella spiralis, Trichinella nativa, and Trichinella britovi. The reproductive index assessed in 4 inbred and 1 outbred strains of mice was lower for the avian isolate than for the marsupial and the type T. pseudospiralis isolates (P < 0.001).

Animals↗
PubMed1992

Allozyme analysis of Trichinella isolates from various host species and geographical regions.

Allozyme analysis was carried out on 152 Trichinella isolates from synanthropic and wild animals and from humans; the isolates were collected from 5 continents. The analysis, involving 27 enzymes, revealed the presence of 8 distinct gene pools, termed T1-T8. Four of the genetic groups represent the 4 previously proposed species: Trichinella spiralis sensu stricto (T1), Trichinella nativa (T2), Trichinella nelsoni (T7), and Trichinella pseudospiralis (T4). The other 4, T3, T5, T6, and T8 are distinct from previously described species. The absence of allozymic hybrid patterns among even sympatric groups indicates a lack of gene flow among the groups. Principal component analysis and the unweighted pair group method of analysis were used to assemble allozyme patterns of the 152 isolates into discrete groups and to show their relative relationships. Both analyses indicated the presence of 8 primary clusters that correlated with the gene pools revealed by direct allozyme profile analysis. The absence of evidence of gene flow among the gene pools and the high level of allozymic differentiation between the cluster groups support the concept that the genus Trichinella is composed of several sibling species.

Animals↗
PubMed1992

Biological characterization of Trichinella isolates from various host species and geographical regions.

Forty isolates of Trichinella collected from 5 continents were compared for 7 biological characters: newborn larvae produced per female worm cultured in vitro at the seventh, eighth, and ninth day postinfection, host muscle nurse cell development time, reproductive capacity index in rats and chickens, and resistance of muscle larvae to freezing. The isolates also were compared by analyses of an environmental character of the location from which they were isolated: the isotherms for January and July. By factorial analysis of correspondence of the biological and environmental data, the 40 isolates were grouped into 8 gene pools (T1-T8). The environmental temperature-related distribution was more evident for the sylvatic isolates (T2, T3, T5, T6, T7, T8), than for T1, which was isolated from domestic pigs, and for T4, a bird-adapted, nonencapsulating genetic type. The 8 biological groups correlated closely with the 8 gene pools previously identified on the basis of allozyme analysis. These results support the concept that the genus Trichinella is composed of at least 5 distinct gene pools or sibling species: Trichinella spiralis sensu stricto (T1), Trichinella nativa (T2), Trichinella sp. (T3), Trichinella pseudospiralis (T4), and Trichinella nelsoni (T7), and 3 other groups of uncertain taxonomic status (i.e., T5, T6, and T8).

Animals↗
PubMed1992

Taxonomic revision of the genus Trichinella.

The analysis of genetic, biochemical, and biological data on about 300 Trichinella isolates, reported in the literature, allows a taxonomic revision of this genus. We propose the recognition of 5 sibling species, Trichinella spiralis (Owen, 1835) sensu stricto; Trichinella nativa Britov and Boev, 1972; Trichinella pseudospiralis Garkavi, 1972; Trichinella nelsoni Britov and Boev, 1972 sensu stricto; and Trichinella britovi n. sp., on the basis of biochemical and biological characteristics. Trichinella britovi n. sp. is characterized by distribution in the Palaearctic Region; newborn larvae (NBL) production in vitro of 35-55 NBL/72 hr; nurse cell development time (NC d.t.) between 24 and 42 days postinfection (d.p.i.); low reproductive capacity index (RCI) in mice, rats, and pigs; low resistance to freezing; 1 unique marker allozyme; and moderate pathogenicity for humans. The new species is most similar to Trichinella nativa but differs from it in 4 allozymes, in having less resistance to freezing, in having a different pattern of major ribosomal DNA fragments after endonuclease digestion, and in distribution area. Trichinella nativa is characterized by a holarctic distribution; hosts that are sylvatic mammals; NBL production in vitro 28-54/72 hr; NC d.t. between 20 and 30 d.p.i.; low RCI in mice, rats, and pigs; high resistance to freezing; 2 unique marker allozymes; and moderate to severe pathogenicity for humans. Trichinella spiralis sensu stricto is characterized by a cosmopolitan distribution in domestic pigs, associated wildlife, and humans; high NBL production in vitro (greater than 90 NBL/72 hr); NC d.t. between 16 and 37 d.p.i.; high RCI in mice, rats, and pigs; no resistance to freezing; 6 unique marker allozymes; and high pathogenicity for humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Biochemical resolution of European and African isolates of Trichinella nelsoni Britov and Boev, 1972.

Isoenzyme analysis was used to characterize 47 isolates of Trichinella nelsoni from Europe (EUR) and two from Kenya and Tanzania (AFR). In all, 27 isoenzymes showed polymorphism within the species. The EUR parasites, isolated from domestic, synanthropic, sylvatic animals and man, showed isoenzymatic profiles different from those exhibited by AFR parasites isolated from sylvatic animals. The EUR parasites showed polymorphism due to three isoenzymes, i.e. ME, MPI and PGM. Euclidean distance and a dendrogram were used to evaluate the relationships among isolates. The Euclidean values showed that EUR and AFR genotypes are distant from each other and from the reference strains T. spiralis s.str. and T. pseudospiralis. The genetic data indicate the absence of gene flow between AFR and EUR isolates. The biochemical results suggest the presence of genetic heterogeneity in T. nelsoni and support the existence of a zoogeographical segregation of the two gene pools. The authors propose that as operational labels, code T3 be assigned to EUR isolates and code T7, to AFR isolates.

Animals↗
PubMed1991

Identification of sylvatic Trichinella (T3) in foxes from France.

Thirty-three foxes (Vulpes vulpes) from a sample of 1912 collected in France were found to be infected with Trichinella spp. Four isolates were obtained for genetic identification. Isoenzymatic and biological analysis of these isolates revealed the presence of two distinct genetic types of Trichinella, Trichinella spiralis s.str. (T1) and Trichinella sp. (T3) (Trichinella nelsoni according to Soviet authors) in the fox population. The reproductive capacity index of these isolates in Wistar rats was high for T. spiralis and low for T3. This is the first report of T3 type from wild animals in France. The epidemiological implications are discussed.

Animals↗
PubMed1991

General introduction and epidemiology of trichinellosis.

All studies on trichinellosis have been based on the assumption that there is only one cosmopolitan agent of human and animal trichinellosis; Trichinella spiralis (Owen, 1835). In the past, swine and only a few synanthropic animals were considered reservoirs, and the presence of the parasite in sylvatic animals was considered rare. Breeding experiments before, and then biochemical approaches (isoenzymes and DNA analysis), showed the presence of a high genetic variability inside this genus, suggesting it be considered as polyspecific. At present, eight gene pools, named from T1 to T8, have been identified in the genus Trichinella. T1 (T. spiralis s str) is the etiological agent for the domestic cycle, with a cosmopolitan distribution related to swine breeding and human habits. However, in some areas this parasite passes from domestic to sylvatic animals and vice versa. Six gene pools are the agents for the sylvatic cycle at different latitudes, mainly in carnivores. T2 (T. nativa) is present in terrestrial mammals and seldom in sea mammals of arctic and subarctic regions. T3, T5, and T8 are present mainly in Canidae (T3), Ursidae (T5), Hyaenidae and Felidae (T8) of temperate-subtropical areas of Palearctic, Nearctic and South African regions, respectively. T6 is present in carnivores in the subarctic-temperate area of the Nearctic region; and T7 (T. nelsoni) in Hyaenidae and Felidae of Equatorial Africa. Only T4 (T. pseudospiralis) can infect both mammals and birds, and it shows a cosmopolitan distribution. Probably trichinellosis is present world-wide, but unknown in those areas where it has not been sought.

Animals↗
PubMed1991

Current status of food-borne parasitic zoonoses in Mediterranean and African regions.

Epidemiological data on food-borne parasitic zoonoses of Mediterranean and African regions are fragmentary. Several studies indicate that toxoplasmosis frequently occurs in Africa, but the epidemiological patterns in these countries are far from being complete. Serological investigations have been carried out with different methods and the results are not always comparable. Food habits, presence or absence of domestic and/or synanthropic felines, and environmental characteristics (damp or dry areas) seem to influence the prevalence of infection in man from 15 to over 60%. There are few reports on Sarcocystis infection in man, while its presence in domestic and sylvatic animals is well evidenced. Cysticercosis infection in cattle is widespread in Africa with a prevalence ranging from 2 to 50% in relation to breeding and human habits. In European countries of the Mediterranean area the prevalence of infection is below 2%. Cysticercosis infection in swine has almost disappeared in the Mediterranean area, while it is still present in some African countries. Human paragonimiasis is present in Western Africa with a prevalence ranging from 2 to 31%. Heterophyasis in man is present in Egypt, Tunisia, and Middle East. Sylvatic trichinellosis is widespread in Mediterranean (Trichinella sp.3) and African (T. nelsoni, Trichinella T8) regions. Domestic trichinellosis (T. spiralis spiralis) is present in Spain, France, Yugoslavia, Egypt, Gambia, and Nigeria in domestic and/or sylvatic animals. In Africa human trichinellosis is rare, mostly from religious and food habits. Till now very few control projects against food-borne parasitic zoonoses have been developed in Africa.

Africa↗