A case from India of neurocysticercosis responsive to albendazole treatment.
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Adult↗
Biomedical subjects
E Pozio
Publications and source records attributed to E Pozio.
Genetic polymorphism at the beta-tubulin locus among human and animal isolates of Cryptosporidium parvum.
Sequence analysis of a fragment of the beta-tubulin gene was performed on 13 isolates of the parasite Cryptosporidium parvum, eight from humans and five from animals. A total of 12 synonymous substitutions and a deletion of two bases within the intron sequence were found. This genetic variation defined two alleles at the beta-tubulin locus, which can be identified by a simple polymerase chain reaction-restriction fragment length polymorphism assay. A total of 20 isolates were also tested using four available molecular markers. These analyses showed congruently that the C. parvum isolates segregate into two groups, one found exclusively in humans and the other found in both humans and animals. Since no recombinant genotypes were observed, the results are consistent with the hypothesis of a substantially clonal reproduction in this parasite.
Animals↗
Specificity and sensitivity of random amplified polymorphic DNA analysis for the identification of single larvae of Trichinella after experimental infection of pigs.
Single muscle larvae (ML) of Trichinella belonging to 5 species and 2 genotypes collected from 126 experimentally infected pigs and preserved in 75% ethyl alcohol at room temperature were identified by random amplified polymorphic DNA (RAPD) analysis to evaluate the specificity and sensitivity of this assay. A double-blind protocol was used to ensure that the interpretation of electrophoretic patterns after RAPD amplification was not influenced by an expected result. RAPD analysis of one larva from each sample showed a sensitivity of 100% when only samples with undamaged DNA were considered, and the specificity resulted in an 88% match with the species or genotype that had been used to infect pigs, whereas the identification reached 100% specificity when an additional one to four ML were examined.
Animals↗
Resolution of microsporidial sinusitis and keratoconjunctivitis by itraconazole treatment.
PURPOSE: To report successful treatment of ocular infection caused by the microsporidium Encephalitozoon cuniculi in a person with acquired immunodeficiency syndrome (AIDS) and nasal and paranasal sinus infection. METHOD: Case report. RESULTS: Microsporidial infection in a person with AIDS and with chronic sinusitis and keratoconjunctivitis was diagnosed by Weber modified trichrome stain and transmission electron microscopy. Symptoms completely resolved with itraconazole treatment (200 mg/day for 8 weeks) after albendazole therapy (400 mg/day for 6 weeks) was unsuccessful. CONCLUSION: Itraconazole can be recommended in ocular, nasal, and paranasal sinus infection caused by E. cuniculi parasites when treatment with albendazole fails.
AIDS-Related Opportunistic Infections↗
Long-term survival of Cryptosporidium parvum oocysts in seawater and in experimentally infected mussels (Mytilus galloprovincialis).
Transmission of infectious oocysts of Cryptosporidium parvum via surface- and drinking-water supplies has been reported and many surface waters flow into the sea, potentially causing runoff of animal-infected faeces. Eating raw mussels is a common practice in many countries, increasing the public's risk of acquiring enteric pathogens. The aims of the present study were to estimate how long C. parvum oocysts remain infectious in artificial seawater, to determine if the oocysts are retained in mussel tissues (Mytilus galloprovincialis), and how long they maintain their infectivity. Oocysts were incubated in artificial seawater at 6-8 degrees C under moderate oxygenation and the infectivity of oocysts was tested five times, over a 12 month period after incubation in seawater, in BALB/c mice. Each pup was inoculated per os with 10(5) oocysts and killed 5 days p.i. Oocysts remained infectious for 1 year. Forty mussels held in an aquarium containing artificial seawater filtered out more than 4 x 10(8) oocysts in a 24 h period. Oocysts were detected in the gill washing up to 3 days p.i., in the haemolymph up to 7 days p.i., and in the intestinal tract up to 14 days p.i. Oocysts collected from the gut of mussels 7 and 14 days p.i. were observed to have infected mice. These results suggest that C. parvum oocysts can survive in seawater for at least 1 year and can be filtered out by benthic mussels, retaining their infectivity up to 14 days, so seawater and molluscs are a potential source of C. parvum infection for humans.
Animals↗
Identification of Trichinella isolates by polymerase chain reaction--restriction fragment length polymorphism of the mitochondrial cytochrome c-oxidase subunit I gene.
We developed a polymerase chain reaction based approach using restriction fragment length polymorphisms of the mitochondrial cytochrome c-oxidase subunit I to identify nine genotypes (Trichinella spiralis, Trichinella britovi-European strains, Trichinella britovi-Japanese strains, Trichinella nativa, Trichinella nelsoni, Trichinella T5, Trichinella T6, Trichinella T8 and Trichinella pseudospiralis) in the genus Trichinella. Partial mitochondrial cytochrome c-oxidase subunit I genes of nine genotypes were amplified by polymerase chain reaction, sequenced, and digested with three restriction endonucleases (Mse I, Alu I and Bsp1248 I). This polymerase chain reaction based restriction fragment length polymorphism method allowed the identification of Trichinella genotypes. Trichinella spiralis, Trichinella britovi-Japanese strains, Trichinella nelsoni, T5 and Trichinella pseudospiralis were distinguishable by digestion with Mse I. Trichinella britovi-European strains and Trichinella T8 were distinguishable by digestion using Alu I, and Trichinella nativa and Trichinella T6 were distinguishable by double-digestion with Mse I and Bsp1286 I. The results obtained with this polymerase chain reaction based restriction fragment length polymorphism assay confirmed those previously reported by others and support the separation of the Japanese isolates as a new genotype, namely Trichinella T9.
Animals↗
Trichinella papuae n.sp. (Nematoda), a new non-encapsulated species from domestic and sylvatic swine of Papua New Guinea.
Encapsulated and non-encapsulated species of the genus Trichinella are widespread in sylvatic animals in almost all zoogeographical regions. In sylvatic animals from Tasmania (Australian region), only the non-encapsulated species Trichinella pseudospiralis has been reported. Between 1988 and 1998, non-encapsulated larvae of Trichinella were detected in five domestic pigs and six wild boars from a remote area of Papua New Guinea. Morphological, biological, and molecular studies carried out on one strain isolated from a wild boar in 1997 suggest that these parasites belong to a new species, which has been named Trichinella papuae n.sp. This species can be identified by the morphology of muscle larvae, which lack a nurse cell in host muscles, and whose total length is one-third greater than that of the other non-encapsulated species, T. pseudospiralis. Adults of T. papuae do not cross with adults of the other species and genotypes. Muscle larvae of T. papuae are unable to infect birds, whereas those of T. pseudospiralis do. The expansion segment V of the large subunit of the ribosomal DNA differs from that of the other species and genotypes. All of these features allow for the easy identification of T. papuae, even in poorly equipped laboratories. The discovery and identification of a second non-encapsulated species in the Australian region strongly supports the existence of two evolutionary lines in the genus Trichinella, which differ in terms of the capacity of larvae to induce a modification of the muscle cell into a nurse cell.
Animals↗
Identification and characterisation of three antigenic proteins from Cryptosporidium parvum sporozoites using a DNA library expressing poly-histidine tagged peptides.
To identify antigenic peptides of the parasite Cryptosporidium parvum, an expression library that allows for the production of chimeric proteins fused with a 6-histidine tag was made. The library was screened with C. parvum sporozoite rabbit anti-serum, and three positive clones (sa20, sa35, and sa40) were identified. The corresponding recombinant proteins (SA20, SA35, and SA40) were expressed in Escherichia coli and purified by metal-affinity chromatography. The sequence of sa20 and sa35 clones did not show any homology with known genes or proteins, whereas the 5' end of the sa40 clone showed homology with two previously identified C. parvum sequences. Hybridisations to intact chromosomes fractionated by pulsed-field gel electrophoresis revealed that the sa35 and sa40 sequences are localised on chromosome VII, whereas the sa20 sequence is localised on chromosome VI. Reverse transcriptase-PCR experiments showed the presence of mRNAs for sa35 and sa40 in the oocyst, whereas the sa20 mRNA was undetectable in this stage. The serological response to the three proteins was assayed in C. parvum-immunised rabbits and in immunocompetent individuals with cryptosporidiosis. The Western blot results indicated that rabbits, challenged with a sporozoite crude antigen or with an oocyst crude antigen, were highly responsive to these three antigens. Human serum samples showed a response to the three proteins, although the response to SA20 appeared to be unrelated to a recent C. parvum infection. These results suggest that the SA35 and the SA40 proteins may be useful in detecting C. parvum infections.
Amino Acid Sequence↗
Predilection sites of Trichinella spiralis larvae in naturally infected horses.
A total of 120 muscle tissues from three horses naturally infected with Trichinella spiralis were examined. The head was the most infected site. In particular, the muscles harbouring the highest number of larvae were: musculus buccinator (12, 411 and 1183 larvae g-1), the tongue (11, 615 and 1749 larvae g-1), m. levator labii maxillaris (17,582 and 1676 larvae g-1), and the masseter (4.9, 289 and 821 larvae g-1). Compared with the diaphragm, the number of larvae per gram was from 3.5 to 6.8 times higher in the tongue, from 3.5 to 6.5 higher in m. levator labii maxillaris, and from 2.5 to 4.6 higher in m. buccinator. Of the examined muscles, the diaphragm had from the 6th to the 15th highest level of infection (3.1, 166 and 256 larvae g-1). Published data from experimentally infected horses confirm these results, suggesting that efforts to detect predilection sites should focus on the head muscles.
Animals↗
Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the identification of Trichinella isolates.
In the present study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was developed to identify 5 species (Trichinella spiralis, Trichinella britovi, Trichinella nativa, Trichinella nelsoni and Trichinella pseudospiralis) and 3 phenotypes of uncertain taxonomic status (Trichinella T5, T6, and T8). Eleven restriction endonucleases were used to restrict 3 DNA fragments (1) a 2800 bp fragment of the 43 kDa excretory-secretory (E-S) protein gene, (2) a 1250 bp fragment amplified with the primer pair SB147A and (3) a 372 bp fragment amplified with the primer pair SB372A. This RFLP method allows the identification of the 8 Trichinella phenotypes as follows: T. spiralis by the HinfI or DdeI endonuclease restriction of the 2800 bp fragment; T. nativa by the RsaI restriction of the 2800 bp fragment, or by the AluI restriction of the 1250 bp fragment; T. britovi and Trichinella T8 by the AluI restriction of the 1250 bp fragments, and can be discriminated between them by the SspI restriction of the 2800 bp fragment; T. pseudospiralis by the MspI restriction of the 372 bp fragment; T. nelsoni by the HhaI or AluI restriction of the 2800 bp fragment; Trichinella T5 by the HhaI restriction of the 2800 bp fragment; Trichinella T6 by the AluI restriction of the 1250 bp fragment; and Trichinella T8 by the SspI or RsaI restriction of the 2800 bp fragment. This study reveals also an intraspecifies polymorphism in the 2800 bp and 1250 bp fragments for T. britovi, Trichinella T5 and T6.
Animals↗
Gastric cryptosporidiosis: correlation between intensity of infection and histological alterations.
AIMS: A retrospective study was carried out to determine the histopathological alterations of the gastric mucosa associated with the presence of Cryptosporidium parasites in the stomach. METHODS AND RESULTS: Gastric biopsies from eight patients with AIDS and cryptosporidiosis were reviewed. Most individuals were males (7/8, mean age 34.7 years) intravenous drug users (6/8), with very low peripheral blood CD4 lymphocyte counts (< 150/mm3; mean 56/mm3). Endoscopic examination showed no significant mucosal abnormalities in half of the individuals; inflammation was observed in the other four individuals and was associated with erosions in two cases. The lesions observed (reactive changes, oedema, erosions, etc.) are not pathognomonic, since they are seen in most common acute and chronic gastrititis of various aetiologies (toxic, infectious, mechanical). The histological examination showed Cryptosporidium parasites in the antrum-pylorus of all examined persons, whereas only two of them had parasites in the corpus. Modifications of histological features consisted mostly of hyperplastic reactive changes of the gland epithelial and inflammation in the connective tissue of the lamina propria. No clear correlation was found between endoscopy and histological findings, whereas a close correlation between intensity of the infection and degree of histological alterations was observed. CONCLUSION: These findings suggest that, in individuals with AIDS, cryptosporidiosis and severe immunodepression, upper endoscopy with random gastric biopsies should be performed, even in the absence of endoscopically appreciable lesions. The diagnosis of gastric cryptosporidiosis has to rely on histological findings, and pathologists must be aware of the fact that Cryptosporidium parasites are mainly found in areas showing reactive hyperplasia.
AIDS-Related Opportunistic Infections↗
Cytokine profile induced by Cryptosporidium antigen in peripheral blood mononuclear cells from immunocompetent and immunosuppressed persons with cryptosporidiosis.
The proliferative response of peripheral blood mononuclear cells (PBMC) to a crude extract from Cryptosporidium parvum (CCE) was studied in persons who acquired cryptosporidiosis in the same outbreak (15 immunocompetent subjects with prior cryptosporidiosis and 22 human immunodeficiency virus [HIV]-positive persons with various levels of immunosuppression and active cryptosporidiosis) and in individual patients (8 HIV-positive patients with active cryptosporidiosis and 15 HIV-positive persons without history of cryptosporidiosis). PBMC from HIV-positive persons showed less proliferation to CCE and mitogens than did PBMC from immunocompetent subjects with prior cryptosporidiosis, independent of CD4 cell count. In immunocompetent subjects, cytokine gene expression was consistent with cytokine production, whereas in HIV-positive subjects it was not. The production of interferon-gamma in CCE-stimulated PBMC from both immunocompetent and HIV-positive subjects with cryptosporidiosis and the lack of interferon-gamma in CCE-stimulated PBMC from HIV-positive subjects without cryptosporidiosis indicate that C. parvum mainly induces a Th1 response.
Animals↗
Anaphylactic response to parasite antigens: IgE and IgG1 independently induce death in Trichinella-infected mice.
The response of animals infected with different Trichinella species (T. spiralis, T. britovi, T. pseudospiralis) to antigens of different Trichinella species was evaluated in outbred mice (CD1) and inbred mice (BALB/c, C3H, SJL, C57BL/6). In mice deficient for IgE or IgG1, T. spiralis only was used. In homologous conditions (i. e., same Trichinella species for antigens and infectious agent) mortality was very high (up to 100% in SJL and C57BL/6). The anaphylactic response in heterologous conditions was much lower and death was observed only in C57BL/6 and SJL mice. Experiments with deficient mice have shown that both specific IgE and IgG1 independently induce a fatal anaphylactic response.
Anaphylaxis↗
Freeze tolerance, morphology, and RAPD-PCR identification of Trichinella nativa in naturally infected arctic foxes.
Arctic foxes (Alopex lagopus) were collected from Greenland and Svalbard (N = 319). Twenty-four were infected with Trichinella (7.5%). Molecular analysis (random-amplified polymorphic DNA polymerase chain reaction) confirmed that all animals were infected with Trichinella nativa. Motile larvae were found in muscle tissue from all foxes after carcasses had been frozen for 1 yr at -18 C. Infective larvae were found in 2 foxes after a total of 4 yr storage at -18 C, which is longer than any previous observations. Morphological examination of the cysts showed large nurse cells and significant deposition of collagen and connective tissue. It is suggested that, within the geographical distribution of T. nativa, the more freeze-resistant isolates are found at higher latitudes.
Animals↗
Differentiation of Trichinella genotypes by polymerase chain reaction using sequence-specific primers.
A method was developed to identify species and genotypes within the genus Trichinella using polymerase chain reaction (PCR) and specific primers. Enzymatic amplification of 2 partially conserved and repetitive genomic DNA sequences that have been shown to be variable in length within the different Trichinella genotypes form the basis of this test. Within these regions of the genome, 4 sets of primers were evaluated from which 2 were chosen for their ability to differentiate among the genotypes under stringent primer annealing conditions while maintaining high yields of amplification product. Differences in the size of PCR products from multiple isolates of each genotype indicate sufficient variation to identify 7 of the 8 parasite groups within this genus. One primer set can differentiate among some genotypes working from a single larva. Identification of Trichinella genotypes will assist in distinguishing between sylvatic and synanthropic life cycles. Such information will be critical in tracing sources of trichinellosis by easily and unambiguously identifying likely host reservoirs and will provide valuable information for instituting methods of control.
Animals↗
Trichinella nativa in sylvatic wild boars.
Of 17 Trichinella isolates from domestic pigs and wild boars (Sus scrofa) in regions where Trichinella nativa is widespread among sylvatic animals, two wild boars from Estonia were found to be naturally infected with this Trichinella species. The other 15 animals were infected with Trichinella spiralis. Trichinella nativa is tolerant to freezing when in the muscles of carnivores. The biological characteristics and temperature tolerance of this species in swine need to be further investigated if pork is certified for consumption following freezing.
Animals↗
Trichinella pseudospiralis in sedentary night-birds of prey from Central Italy.
Trichinella pseudospiralis has been isolated from carnivorous and carrion-feeding mammals and birds in Eastern Europe, Asia, Australia, and North America, suggesting its cosmopolitan distribution. We conducted a survey to detect this parasite in raptorial and carrion-feeding birds in Italy, examining muscles from 205 animals by artificial digestion. We isolated from the breast muscle 1 larva from a tawny owl (Strix aluco) and 2 larvae from a little owl (Athene noctua). These larvae were identified as T. pseudospiralis by the polymerase chain reaction with a specific primer set. This is the first documented report of T. pseudospiralis in animals in Western Europe.
Animals↗
Establishing the Cryptosporidium parvum karyotype by NotI and SfiI restriction analysis and Southern hybridization.
The molecular karyotype of the coccidian parasite Cryptosporidium parvum has proven difficult to study because chromosomes of similar sizes migrate together when submitted to pulsed-field gel electrophoresis (PFGE). In the present work, the karyotype was studied by restriction of chromosome-sized DNA with the rare-cutting enzymes NotI and SfiI, followed by PFGE separation of the restriction fragments and Southern hybridization. These experiments showed that the C. parvum karyotype is formed by eight chromosomes, ranging in size from approximately 0.95 to 1.45 million base pairs (Mbp), accounting for a genome size of 9.6Mbp. As a first step towards the construction of a physical map of the C. parvum genome, a total of 20 probes, including 16 genes and the ribosomal DNA (rDNA) sequence, was mapped to intact chromosomes and to their restriction fragments. In this way, all chromosomes, but one, were identified by specific markers. A comparison of mapping data of homologous genes from different species belonging to the phylum Apicomplexa showed differences in the distribution of rDNA sequences and in the chromosomal localization of alpha- and beta-tubulin genes. The variation in genome size among these parasites is also discussed.
Animals↗