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1.
Castro-Hermida JA Almeida A González-Warleta M Correia da Costa JM Rumbo-Lorenzo C Mezo M 《Parasitology research》2007,101(5):1443-1448
To determine the prevalence and intensity of infection of Cryptosporidium spp. and Giardia duodenalis in healthy adult domestic ruminants, faecal samples were collected from 379 cattle of between 3 and 13 years old, 446 sheep
and 116 goats selected at random from 60 dairy farms and 38 and 20 herds, respectively, in Galicia (NW Spain). Cryptosporidium spp. oocysts were detected in 32 cows (8.4%), 24 sheep (5.3%) and in nine goats (7.7%) from, respectively, 48.3% of the farms
and 34.2 and 30.0% of the herds. The intensity of infection in cows ranged between 25 and 5,924 oocysts per gram of faeces
(OPG), whereas in sheep and goats, the number of oocysts shed ranged from 8–515 OPG and from 17–782 OPG, respectively. Parasitization
by Cryptosporidium spp. was significantly higher (P < 0.05) in cows than in sheep and goats. G. duodenalis cysts were identified in 101 cows (26.6%), 86 sheep (19.2%) and 23 goats (19.8%) from, respectively, 96.6% of the farms and
92.1 and 90% of the herds. The number of cysts shed by cows ranged between 15 and 3,042 cyst per gram of faeces (CPG), whereas
the intensity of infection in sheep and goats ranged from 16–3010 CPG and from 15–1845 CPG, respectively, and was significantly
lower (P < 0.05) than in cows and sheep. The number of Cryptosporidium spp. oocysts isolated from sheep and goats was insufficient for successful polymerase chain reaction analysis. Nevertheless,
gene sequence analysis of the hsp70 and 18SrRNA genes of Cryptosporidium revealed the presence of only C. parvum in faecal samples from cows. Genotyping studies of the β-giardin and glutamate dehydrogenase genes of G. duodenalis revealed mainly assemblage E of Giardia in cows, sheep and goat faecal samples. Assemblage B of G. duodenalis was also detected in one sheep sample. These animals should be considered as a possible source of cryptosporidiosis and giardiosis,
thereby maintaining the infections on farms and in herds. 相似文献
2.
The intestinal protozoan parasite Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia) is a widespread enteric pathogen in human and domestic animals. This organism is one of the most common parasites in domestic dogs in Brazil. In this study, we determined the occurrence and genetic characterization of G. duodenalis isolated from dogs from south-central São Paulo state, Brazil. A total of 300 fecal samples were collected. Fecal specimens were screened for the presence of G. duodenalis using microscopy (zinc sulfate solution flotation technique) and polymerase chain reaction (PCR) targeting the small subunit ribosomal (SSU-rDNA) and glutamate dehydrogenase (GDH) genes. Genetic characterization was performed using restriction fragment length polymorphisms (RFLP) and sequencing analysis of the GDH gene. In addition, selected samples were further characterized by RFLP and sequencing of the β-giardin gene. The overall occurrence of G. duodenalis was 17.3% (52/300). The occurrence was higher in stray dogs (28%) than in household dogs (6.25%). Of the 36 PCR-positive samples that were selected for genotyping, only dog-specific genotype C (20 isolates), D (11 isolates) and mixed C?+?D (five isolates) isolates were detected in the study. This study provides current information on the infection rates of G. duodenalis genotypes in canine populations and describes for the first time the presence of mixed infections within host-specific C and D genotypes in dogs in Brazil. These genotypes were widespread and commonly found in domestic dogs living in urban and suburban environments of the studied area and confirmed the endemic status of Giardia in this region. 相似文献
3.
Hui-Wen A. Cheng Frances E. Lucy Thaddeus K. Graczyk Michael. A. Broaders Leena Tamang Michelle Connolly 《Parasitology research》2009,105(3):689-696
This study investigates the fate of Cryptosporidium parvum and C. hominis oocysts and Giardia duodenalis cysts at four Irish municipal wastewater treatment plants (i.e., Plant A, B, C, and D) that utilize sludge activation or
biofilm-coated percolating filter systems for secondary wastewater treatment. The fate of these pathogens through the sewage
treatment processes was determined based on their viable transmissive stages, i.e., oocysts for Cryptosporidium and cysts for Giardia. Analysis of final effluent indicated that over 97% of viable oocysts and cysts were eliminated, except at Plant C, which
achieved only 64% of oocyst removal. A significant correlation between the removal of oocysts and cysts was found at Plants A, B, and D (R = 0.98, P < 0.05). All sewage sludge samples were positive for C. parvum and C. hominis, and G. duodenalis, with maximum concentrations of 20 oocysts and eight cysts per gram in primary sludge indicating the need for further sludge
sanitization treatments. This study provides evidence that C. parvum and C. hominis oocysts and G. duodenalis cysts are present throughout the wastewater processes and in end-products, and can enter the aquatic environment with consequent
negative implications for public health. 相似文献
4.
V. V. Nefedova E. I. Korenberg N. B. Gorelova 《Molecular Genetics, Microbiology and Virology》2010,25(1):25-30
The four Borrelia burgdorferi sensu lato isolates obtained from I. ricinus ticks collected from the natural loci in Russia and Ukraine that had an unusual RFLP MseI pattern were studied using the sequencing of the rrfA-rrlB spacer and the rrs gene. Isolate Ir-5215 from a tick collected in southern Ukraine represented the recently described genospecies B. spielmanii, which is pathogenic for humans. The three atypical isolates Ir-3519, Ir-4721, and Ir-4812 had 100% identity with the sequence
of atypical European B. burgdorferi sensu stricto strains; they constituted a subgroup of B. burgdorferi sensu stricto based on multilocus sequence analysis (MLSA). These data are indicative of the genetic heterogeneity of the current group
B. burgdorferi sensu stricto. 相似文献
5.
There are evidences that Giardia trophozoites contain and/or release proteolytic enzymes that may be implicated in pathogenesis of giardiasis. This report
describes a preliminary characterization of the proteolytic activity in excretory/secretory (E/S) products of Giardia duodenalis trophozoites of an axenic Brazilian strain (BTU-11) and the reference strain Portland 1 (P1). The protease activity of E/S
products in conditioned medium by trophozoites of each strain was analyzed using substrate (gelatin and collagen) impregnated
SDS-PAGE and hemoglobin assay. The protease characterization was based on inhibition assays including synthetic inhibitors.
Proteolytic products were detected in the conditioned medium by trophozoites of both assayed strains. In the gels containing
copolymerized gelatin and collagen, E/S products promoted degradation of the substrates and the most evident proteolysis zones
were distributed in the migration regions of 77 to 18 kDa and 145 to 18 kDa, respectively, in the patterns of gelatinolytic
and collagenolytic activities. Degradation of hemoglobin was also observed, and the pattern of hydrolysis was similar in both
E/S products assayed. Inhibition assays showed that the main proteolytic activity in both E/S products is due to cysteine
proteases although the presence of serine proteases was also indicated, mainly in the hydrolysis of hemoglobin. 相似文献
6.
A.?Koskela ?.?Nilsdotter-Augustinsson L.?Persson B.?S?derquist 《European journal of clinical microbiology & infectious diseases》2009,28(6):655-660
Joint replacement surgery has improved the quality of life for hundreds of thousands of patients. However, the infection of
a joint implant is an important and serious complication, though the prevalence is low. Staphylococcus epidermidis is the most important pathogen involved in foreign-body infections. S. epidermidis is also a commensal that comprises a substantial part of the normal skin flora of humans. The possibility to demonstrate
potential specific virulence markers may facilitate the interpretation of the bacteriological findings, as well as the clinical
decision. The prevalence of the ica locus and insertion sequence IS256 by using polymerase chain reaction (PCR) among 32 clinical S. epidermidis isolates from prosthetic joint infections (PJIs) and 24 commensal isolates from nares and skin was investigated. Sixteen
(50%) of the 32 PJI isolates harbored the ica operon compared with one-third of the commensal isolates obtained from the samples of the skin and nares of healthy individuals.
The IS256 was demonstrated in 26 (81%) out of 32 PJI isolates. By contrast, IS256 was found in one of 24 commensal isolates. In conclusion, IS256 may be superior to the ica operon as a marker of the invasive capacity of S. epidermidis, since it was found in most of the PJI isolates, but rarely among commensals. 相似文献
7.
Weida?Pan Yeqi?Fu Auwalu?Yusuf?Abdullahi Mingwei?Wang Xianli?Shi Fang?Yang Xingang?Yu Xinxin?Yan Pan?Zhang Jianxiong?Hang Guoqing?Li
To develop T m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5′-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10?5 and 4.88 × 10?5 ng/μL samples of assemblage A and F standard plasmids. The T m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia. 相似文献
8.
Trichomonas vaginalis is a human urogenital pathogen that causes trichomoniasis, the most common nonviral parasitic sexually transmitted infection
in the world. Presently, there are no reports on comparative sequence analysis as well as on the identification of phylogenetic
positions of T. vaginalis isolates from the Philippines relative to known trichomonads. In this study, 5.8S rDNA and the flanking internal transcribed
spacer (ITS) regions of 57 T. vaginalis isolates were sequenced. The phylogenetic positions of the isolates relative to known trichomonads were determined using
the model-based (GTR+Γ+I) neighbor-joining, maximum likelihood, and Bayesian-inference analyses and the nonmodel-based maximum
parsimony analysis. Construction of a phylogenetic tree showed the clustering of all the sequences in one branch together
with other T. vaginalis strains obtained through basic local alignment search tool search. Sequencing of the 5.8S rDNA gene and the flanking ITS1and
ITS2 regions of T. vaginalis isolates from the Philippines demonstrated low genetic polymorphism. However, comparison of the ribosomal DNA sequences may
have implications on some phenotypic characteristics of T. vaginalis. 相似文献
9.
Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails. 相似文献
10.
Karina?M.?Rebello Luzia?M.?C.?C?rtes Bernardo?A.?S.?Pereira Bernardo?M.?O.?Pascarelli Suzana?C?rte-Real Léa?C.?Finkelstein Rosa?T.?Pinho Claudia?M.?d’Avila-Levy Carlos?R.?Alves 《Parasitology research》2009,106(1):95-104
Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and
is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we
obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of
63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the
peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data
together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation
of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant
and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that
some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues
in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection. 相似文献
11.
12.
KR Tysnes A Jørgensen T Poppe PJ Midtlyng LJ Robertson 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2012,57(1):1-6
Although Giardia duodenalis is considered a parasite of mammals, different genotypes have been identified as infecting several species of freshwater
and marine fish in Australia. Establishment of G. duodenalis infection in common laboratory zebrafish (Danio rerio), could provide an excellent tool for a range of studies on Giardia. We conducted preliminary experiments to investigate this possibility. Zebrafish were inoculated with viable G. duodenalis cysts from two different Assemblages (A and D) using a modified oro-gastric tube. Direct microscopy and immunofluorescent
antibody test were used to check for Giardia cysts/trophozoites in the intestine, and histology was performed on intestinal mucosa to evaluate possible pathological changes.
Giardia cysts were successfully deposited in the zebrafish alimentary tract using a modified oro-gastric tube, and were maintained
in the fish gut for at least 8 days. Although a single trophozoite was observed in one fish three days post-exposure, we were
unable to demonstrate established, propagative infection under the conditions tested. 相似文献
13.
María del Rosario Robles James E. Loudon John M. Kinsella Mandala Hunter-Ishikawa David S. Miller Michelle L. Sauther Frank P. Cuozzo 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2010,55(3):270-275
Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and
the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini
hosts will only be proven when additional records fill in the gaps in their distribution. 相似文献
14.
We investigated a DNA fragment and its flanking region deleted in the spontaneous Pi-a virulent mutant of Magnaporthe grisea Ina168. A new transposon-like sequence was identified from a region adjacent to the deleted fragment and was named Occan. Occan contained a 2,259-bp ORF interrupted by one 63-bp intron and had both a TA dinucleotide and 77 bp of perfect inverted repeats at both termini, without direct repeats. These features indicated that Occan is a member of the Fot1 family. RT-PCR analysis confirmed the expression of the putative transposase and the presence of an intron. Southern analysis of pulse-field gel electrophoresis-separated chromosomes indicated that Occan was dispersed in all chromosomes of the rice pathogen, Ina168. Copy numbers of Occan were also preserved in a host-specific manner amongst M. grisea isolates. In particular, rice pathogens contained a large number of the element inserted into their genome. Phylogenetic analysis with other known members of the Fot1 family revealed that Occan was dissimilar to any other known elements and it is thus proposed that Occan be separated to a new subfamily. 相似文献
15.
Foronda P Bargues MD Abreu-Acosta N Periago MV Valero MA Valladares B Mas-Coma S 《Parasitology research》2008,103(5):1177-1181
In Egypt, the genotyping study of Giardia intestinalis in human is limited. To determine the prevalence of G. intestinalis, faecal samples were collected from Egypt. Samples were concentrated using density gradient centrifugation. The samples were subjected to PCR and DNA sequence analysis for TPI gene. Prevalence of Giardia infection was 34.6% of 52 examined. DNA sequence showed that the Assemblage B was the most prevalent (80%) genotype, the 15% of the positive samples belonged to Assemblage E, and the 5% of them belonged to Assemblage A. Certainly, both genotypes A and B are highly common in human worldwide. However, up to now, Assemblage E had not been known to be infectious for humans. Therefore, this is the first time that Assemblage E is reported in human. However, further analyses of a second locus are required to confirm this result. The extent to which Giardia-infected cattle in Egypt might pose a risk of human infection is unknown. 相似文献
16.
17.
Repeat induced point mutation (RIP) is a gene silencing mechanism present in fungal genomes. During RIP, duplicated sequences
are efficiently and irreversibly mutated by transitions from C:G to T:A. For the first time, we have identified traces of
RIP in transposable elements of Aspergillus niger and Penicillium chrysogenum, two biotechnologically relevant fungi. We found that RIP in P. chrysogenum has affected a large set of sequences, which also contain other mutations. On the other hand, RIP in A. niger is limited to only few sequences, but literally all mutations are RIP-like. Surprisingly, RIP occurred only in transposon
sequences that have disrupted open reading frames in A. niger, a phenomenon not yet reported for other fungi. In both fungal species, we identified two sequences with strong sequence
similarity to Neurospora crassa RID. RID is a putative DNA methyltransferase and the only known enzyme involved in the RIP process. Our findings suggest
that both A. niger and P. chrysogenum either had a sexual past or have a sexual potential. These findings have important implications for future strain development
of these fungi. 相似文献
18.
Bardia A Tiwari SK Gunisetty S Anjum F Nallari P Habeeb MA Khan AA 《Inflammation research》2012,61(4):359-365
Objective
The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC). 相似文献19.
Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include
high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In
P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis.
Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed. 相似文献
20.
Emily Staples Beatriz Morillo-Gutierrez Jessica Davies Daniel Petersheim Michel Massaad Mary Slatter Dimitra Dimou Rainer Doffinger Scott Hackett Dinkantha Kumararatne James Hadfield Matthew D. Eldridge Raif S. Geha Mario Abinun James E. D. Thaventhiran 《Journal of clinical immunology》2017,37(5):415-418