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1.
Giardia isolates from eight horses from New York State (NY), USA and two horses from Western Australia (WA) were genetically characterized at the SSU-rDNA and triose-phosphate isomerase (TPI) genes. Phylogenetic analysis of the TPI gene provided strong support for the placement of both isolates of Giardia from horses in WA and a single isolate from a horse in NY within the assemblage AI genotype of G. duodenalis. Another two isolates from horses in NY placed within the assemblage AII genotype of G. duodenalis. Phylogenetic analysis of the TPI gene also provided strong bootstrap support for the placement of four G. duodenalis isolates from horses in NY into a potentially host-specific sub-assemblage of assemblage BIV. The results of this study are consistent with previous studies showing that assemblages AI and AII of G. duodenalis provide the greatest potential zoonotic risk to humans. Horses may therefore constitute a potential source for human infection of Giardia either directly or via watersheds.  相似文献   

2.
Giardia duodenalis and Cryptosporidium spp. are intestinal protozoan parasites that infect a wide range of host species, including humans. Molecular characterization of these parasites has demonstrated that a number of genotypes and species are common to both humans and animals, and that zoonotic transmission may occur. Numerous studies have reported a high prevalence of G. duodenalis and Cryptosporidium spp. in cattle, particularly calves, and these animals are frequently associated with zoonotic transmission. In the present study, a total of 143 faecal samples from adults, heifers and calves were collected from two dairy cattle farms in eastern Ontario, Canada. The prevalence and molecular characteristics of G. duodenalis and Cryptosporidium spp. in these animals were determined in order to investigate the potential for transmission between cattle and humans in this region. Following DNA extractions from faecal samples, nested-PCR protocols were used to amplify fragments of the 16S rRNA gene and the heat-shock protein 70 (HSP-70) gene for determining the prevalence of G. duodenalis and Cryptosporidium spp. infections, respectively. Genotypes of G. duodenalis, and species of Cryptosporidium, were determined by means of DNA sequencing of amplicons, and subsequent sequence alignment. Cattle on both farms showed a high prevalence of G. duodenalis (42.0%) and Cryptosporidium spp. (27.3%). G. duodenalis infections were more prevalent in calves and heifers than in adults, and Cryptosporidium spp. infections were only observed in calves and heifers. The zoonotic genotype, G. duodenalis Assemblage B was isolated from 24.5% of the cattle tested, while G. duodenalis Assemblage E was found in 17.5% of the cattle tested. The overall prevalence of the zoonotic species Cryptosporidium parvum in the animals tested was found to be 21.7%, while only 1.4% were infected with C. bovis. These findings suggest that there is a potential risk of zoonotic and/or zooanthroponotic transmission of G. duodenalis and C. parvum infections between cattle and humans in eastern Ontario, likely by means of contaminated water or food, or through direct faecal-oral transmission in the case of farmers and veterinary staff.  相似文献   

3.
【目的】 了解广东省不同地区猪源十二指肠贾第虫(Giardia duodenalis,简称贾第虫)的流行现状和分子特征,并评估其人兽共患风险。【方法】 从广东省10个地区采集新鲜猪粪样品,采用显微镜镜检,并应用巢式PCR对贾第虫谷氨酸脱氢酶(glutamate dehydrogenase,gdh)基因进行扩增,根据扩增结果计算不同地区和生长阶段猪贾第虫的阳性率。对所有的PCR阳性产物进行测序,将获得的贾第虫gdh基因序列进行BLAST比对,确定贾第虫的基因型;运用Mega 7.0软件的最大似然法构建进化树。【结果】 贾第虫包囊呈椭圆形,囊壁较厚,大小为(10~14)μm ×(7~10)μm,具有明显纵向轴柱,细胞核分布于轴柱两侧。521份受检样品中共检测出94份PCR阳性样品,阳性率为18.04%(94/521),其中茂名和清远的阳性率较高,分别达40.00%(10/25)和35.06%(27/77);肇庆和韶关的阳性率较低,分别为3.90%(3/77)和8.57%(3/35);佛山、江门、阳江、河源、广州和惠州的阳性率分别为11.11%(2/18)、15.31%(15/98)、11.43%(4/35)、13.33%(4/30)、9.38%(3/32)和24.47%(23/94)。不同饲养阶段的猪群的阳性率调查发现,母猪的贾第虫阳性率(24.55%)显著高于断奶仔猪(13.30%)(P<0.05),与育肥猪的贾第虫阳性率(19.23%)差异不显著(P>0.05)。基于gdh基因序列的基因分型和系统进化分析共发现5种贾第虫亚集聚体,即集聚体AⅠ和集聚体E的4种不同亚型,包括集聚体E1、E2、E10和E13,其中61.70%(58/94)测序阳性样品属于集聚体AⅠ,38.30%(36/94)属于集聚体E的不同亚型。【结论】 广东猪源贾第虫的感染较普遍,不同地区和不同生长阶段的猪感染率存在一定差异。其中,人兽共患性集聚体AⅠ为优势亚集聚体,表明广东省猪源贾第虫存在人兽跨物种传播的风险,应重视该病可能引起的公共卫生问题。  相似文献   

4.
To determine the prevalence of Giardia genotypes in 12–24 month old dairy heifers, fecal specimens were collected from two farms each in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida. Specimens, cleaned of fecal debris and concentrated using CsCl density gradient centrifugation, were subjected to PCR and DNA sequence analysis. Prevalence of Giardia infection, ranged from 11% to 75% on 14 farms with an average prevalence of 36% (204 positive cattle out of 571 examined). DNA sequence analysis of the 16S rRNA gene revealed 91% of the 204 Giardia isolates were Assemblage E, and 9% were Assemblage A. The prevalence of these genotypes varied greatly from farm to farm, with four farms having exclusively Assemblage E Giardia. Overall, Assemblage E was present in 33% of all animals tested and Assemblage A was present in 3% of the animals. Thus, while many of the heifers were infected with a genotype that is not known to be infectious for humans, 1–2 year old heifers on 10 of 14 farms did harbor zoonotic Assemblage A Giardia. Therefore, heifers cannot be overlooked as a potential source of human infectious cysts in the environment, with some farms representing a much higher risk than others.  相似文献   

5.
Microscopy, PCR and a Giardia CELISA test were used to determine the prevalence of Giardia in 40 faecal samples obtained from domestic cats in the Perth metropolitan area. A prevalence of 5, 80 and 60% was found by the tests, respectively. The results show that more sensitive techniques such as PCR may be necessary, and may yield more reliable results, in the detection of low levels of Giardia in domestic cats.  相似文献   

6.
The prevalence of Cryptosporidium and Giardia was studied on 10 intensively reared sheep and goat farms in the province of East Flanders, Belgium. Random faecal samples were collected and examined using the Merifluor((R)) immunofluorescence assay. Cryptosporidium positive samples were withheld for molecular identification using primers targeting the 18S rDNA, 70 kDa heat shock protein and 60 kDa glycoprotein gene. For the molecular identification of Giardia the beta-giardin gene and a recently developed assemblage specific PCR based on the triose phosphate isomerase gene were used. The prevalence of Cryptosporidium in lambs was 13.1% (18/137), on 4 out of 10 farms. In goat kids the Cryptosporidium prevalence was 9.5% (14/148), on 6 out of 10 farms. The molecular characterisation of Cryptosporidium positive isolates indicated that in lambs (n=10) the cervine genotype was predominant, whereas in the goat kids (n=11) only C. parvum was identified, with subgenotypes IIaA15G2R1 and IIdA22G1. The Giardia prevalence was 25.5% (35/137) in lambs with all 10 farms being positive, and 35.8% (53/148) in goat kids with 8 out of the 10 farms being positive. Both in the goat kids and in the lambs the host specific assemblage E was most commonly identified. However, the zoonotic assemblage A was identified in 6 out of 28 goat kids and in 2 out of 8 lambs, based on the beta-giardin sequence alignment. Using the assemblage specific PCR, mixed assemblage A and E infections were additionally identified in 2 lambs and in 5 goat kids. The results of the present study indicate that both Cryptosporidium and Giardia are common parasites on intensively reared sheep and goat farms in the province of East Flanders, Belgium, and that they are a potential source for zoonotic infections.  相似文献   

7.
A study was undertaken to determine the prevalences of Cryptosporidium and Giardia in dairy calves less than 6 months of age in Norway. Faecal samples were collected from a total of 1386 calves, between 3 and 183 days of age, in 136 dairy farms from three different areas of Norway. Faecal samples were examined for Cryptosporidium oocysts and Giardia cysts after concentration and immunofluorescent staining.

Giardia was found in 93% (127 out of 136) of the farms and in 49% (679 out of 1386) of the calves. Cryptosporidium was found in 53% (72 out of 136) of the farms and in 12% (167 out of 1386) of the calves. The level of Giardia and/or Cryptosporidium was low in the majority of the infected calves.

Infection peaked in the age group 2–3 months for both Cryptosporidium and Giardia. The prevalences of both parasites were higher in samples taken during winter than in samples taken during summer, and statistically significant differences were found when prevalences in different age groups of calves were compared between the three areas. A significantly lower prevalence of Cryptosporidium was found in calves housed in shared pens that were thoroughly washed more than three times a year than in calves from pens washed less often. For Giardia there was a trend for decreasing intensity of infection with increasing age in the sampled calves. For Cryptosporidium there was a trend for increasing herd prevalence with increasing number of calves in the herd, but this trend was not statistically significant. Other parameters which were investigated such as housing, feeding or management routines were not associated with prevalence or intensity of infection with either parasite.  相似文献   


8.
Anti-Toxoplasma antibody titres in 185 sera from clinically normal goats from 14 farms were assayed by both the latex agglutination and the indirect fluorescent antibody tests. The animals were of various breeds including Angora, New Zealand feral, Angora×feral, Saanen and Toggenburg. A high level of agreement between the two tests was obtained with 83.8% of titres corresponding to within one dilution and 96.8% to within two dilutions. In both tests, titres of 1:64 and above were considered positive. A total of 298 goat sera from clinically normal kids (n = 88), yearlings (n = 65) and adults (n = 145) from 17 farms were examined by the latex agglutination test. The prevalence of positive sera was 7% in kids, 23% in yearlings and 37% in adults. There was a significantly higher prevalence of positive sera in dairy than in fibre breeds.  相似文献   

9.
The occurrence of a goat disease caused by Mycoplasma mycoides subsp. mycoides LC in Hungary is reported. The disease occurred in two goat herds in the spring of 1999. In one herd 25% of the 4-12 weeks old kids (10 animals) while in the other herd 33% of the 6-12 weeks old kids (20 animals) became affected. The goat kids developed polyarthritis. The most severe lesions developed in the carpal joints. All animals died after 3-8 days of disease. Four dead kids were necropsied. All of them had serofibrinous and purulent polyarthritis, and in two animals bronchopneumonia, fibrinous pleuritis and meningitis were also found. In the articular exudates the presence of mycoplasmas was detected by PCR using a general mycoplasma primer. Mycoplasmas were cultured from the joints of all animals, from the abdominal parenchymal organs of two kids and from the lungs of one animal. The cultured mycoplasmas grew in strikingly large colonies, proved to be glucose positive, arginine negative and phosphatase positive, and liquefied the coagulated serum. They survived incubation at 45 degrees C for more than 24 h. Based upon their biochemical properties, the results of the immunofluorescence (IF) and growth inhibition tests and the sequence analysis of the PCR product, the cultured strains were identified as M. mycoides subsp. mycoides LC. Animals purchased in the previous autumn had been introduced to both farms. The disease may have been introduced with asymptomatic carrier animals, as earlier no similar disease had been observed at either farm.  相似文献   

10.
An experimental study was carried out in neonatal goat kids to examine the infectivity of Cryptosporidium oocysts, pattern of oocyst shedding and morphological changes in the intestine during the infection. Cryptosporidium oocysts isolated from adult asymptomatic goats, and identified as C. parvum by polymerase chain reaction (PCR) were used in this study. Of three 4-day-old goat kids, two were orally infected with C. parvum oocysts (10(5) oocysts in 10 ml PBS/kid). One goat kid given 10 ml PBS only by the oral route served as a control. Cryptosporidium oocysts were detected in the faeces of one infected kid on day 3 post-inoculation (pi) whereas in the other 6 days pi. The faecal oocyst counts gradually increased and the peak counts in the two kids were 2 x 10(6)g(-1) (on day 12 pi) and 3.2 x 10(6)g(-1) (on day 14 pi). The increase in faecal oocyst output coincided with diarrhoea in an infected kid from days 10-17 pi. Although the oocyst excretion declined gradually after the peak, both infected kids excreted oocysts until euthanized on days 20 and 22 pi. Light and scanning electron microscopic investigations of the ileum revealed the endogenous stages on the brush border of the enterocytes, infiltration of neutrophils and mononuclear cells into the lamina propria, atrophy, stunting and fusion of villi. For purposes of comparison, goat Cryptosporidium oocysts were inoculated orally (10(3) oocysts/mouse) to eight, 1-week-old mice. All experimental mice excreted oocysts from day 3 pi, and four infected mice continued to excrete oocysts up to day 42 pi. The experimental infection described in goat kids resembled the natural disease in terms of oocyst excretion, clinical signs and intestinal pathology. The ability of oocysts excreted by asymptomatic goats, to infect goat kids and mice is likely to have a major impact on the epidemiology of cryptosporidiosis in livestock and man.  相似文献   

11.
Susceptibility to IVM (IVM) of “strain A” Haemonchus contortus which had been exposed to IVM four times over a 2-year period was compared to IVM susceptibility of “strain C” H. contortus which had no prior field exposure to IVM, by in vivo and in vitro methods. In vivo, the percentage reduction in faecal egg counts (FEC) and the total worm counts (TWC) were compared between control animals (lambs and kids) and animals treated with low dose IVM (20 μg/kg). In vitro susceptibility to IVM was evaluated by larval migration inhibition (LMI) after the two strains of H. contortus were exposed to different concentrations of IVM. The dose response, measured as the proportion of larvae inhibited from migrating, was used to estimate LD50. Although differences in response to IVM in the in vivo determinations were not significant, “strain A” H. contortus had a significantly higher LD50 than “strain C” in the LMI assay. Coincident with the conduct of the in vivo experiment, it was observed that “strain A” H. contortus established and survived better than “strain C” in the control lambs.  相似文献   

12.
Faecal egg count reduction tests (FECRT) and larval cultures were used to assess the prevalence of anthelmintic resistance amongst sheep and goats on farms served by Kenya's five regional Veterinary Investigation Laboratories. Twenty-four out of 42 farms tested (57%) showed resistance to at least one anthelmintic group. Resistance to levamisole was found in nine out of 35 sheep farms tested (26%) and 12 out of 24 goat farms (50%). Resistance to benzimidazole drugs was found in 10 out of 28 sheep farms (36%) and six out of 20 goat farms (30%). Larval cultures of post-treatment faecal samples showed resistance to be predominantly due to Haemonchus contortus. Twelve farms were routinely using substandard products which appeared to have no anthelmintic activity.  相似文献   

13.
A field trial, conducted over two consecutive years, was aimed at assessing the efficacy of the administration of spores of the nematophagous fungus Duddingtonia flagrans to young goats for the control of nematode parasite infections on a French commercial dairy goat flock. For both years, the first-year grazing kids were divided into two similarly managed groups (fungus and control groups): in 2003 a daily dose rate of 5 × 105 spores/kg body weight was given to the fungus-group animals, while in 2004 a daily dose rate of 106 spores/kg body weight was used; the other half of the kids, acting as control, did not receive the spores. Parameters measured every 3 weeks included nematode egg excretion, larval development in faecal cultures and pasture larval counts. Additionally, at the beginning, the middle and the end of each grazing season, the goats were weighed and blood samples for pepsinogen determination were collected. In 2003, similar results were recorded for all the measured parameters in the control and fungus groups. In contrast, in 2004, the kids receiving the spores showed lower faecal egg counts and pepsinogen levels at the end of the season and higher growth rate compared to kids of the control group.  相似文献   

14.
Prevalences of Cryptosporidium spp. oocysts in cattle (n = 486) on five selected farms in Morogoro municipality and three species of herbivorous wildlife (n = 87) from Mikumi National Park, Morogoro, Tanzania, were determined using the modified Ziehl-Neelsen staining technique. Of 486 bovine faecal samples, 5.3% were positive for Cryptosporidium spp. The prevalence of Cryptosporidium was higher in calves less than 3 months of age compared to weaned calves and adults. Cryptosporidium spp. oocysts were detected in both diarrhoeic and non-diarrhoeic animals, but there was a significantly higher prevalence (P < 0.001) of oocyst shedding in diarrhoeic than in non-diarrhoeic animals. Of the 87 faecal specimens from the wildlife species, 36 were from the African buffaloes (Syncerus caffer), 25 from zebra (Equus zebra) and 26 from the wildebeest (Connochaetes gnou). Cryptosporidium spp. oocysts were detected in eight (22%) buffaloes, seven (28%) zebras and seven (27%) wildebeests. Confirmation of the diagnosis was performed using anti-Cryptosporidium monoclonal antibody specific for Cryptosporidium muris, Cryptosporidium parvum and Cryptosporidium baileyi (Pathasure Cryptosporidium test kit).  相似文献   

15.
In a recent study of intestinal parasites in dogs and cats in Australia, Giardia was found to be the most prevalent parasite in dogs. The aim of the current study through the use of molecular tools was to determine the zoonotic significance of the Giardia and Cryptosporidium isolates recovered from dogs and cats during the Australian study. Of the isolates successfully amplified all but one of the Giardia from dogs was either Assemblage C and/or D, with one Assemblage A. Of the cat samples amplified all but one were Assemblage F, with one Assemblage D. We hypothesize that the lack of zoonotic Giardia Assemblages recovered is a result of their being a low prevalence of Giardia in the human population. The Cryptosporidium recovered from dogs and cats was determined to be C. canis and C. felis, respectively, a finding which supports growing evidence that Cryptosporidiumin companion animals is of limited public health significance to healthy people.  相似文献   

16.
A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8 μg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256 μg/ml (62 strains) and 512 μg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.  相似文献   

17.
To determine whether kids born on open range (subjected to stress due to management practices) had lower IgG concentrations and a higher mortality risk than kids born in a pen, serum IgG concentrations in 63 one-day-old kids were determined. Median Serum IgG concentrations one day after birth tended to be lower (p=0.09) in surviving kids born in the open than that of surviving kids delivered in pen (115 vs. 1119 mg dl−1). However, survival risk (71 and 82% for kids born on the open range and pen, respectively; n=79) were not significantly affected by site of kidding. Median IgG concentration of surviving kids born on a pen was not significantly different (p=0.13) compared to non-surviving kids (1118 vs. 115 mg dl−1). No differences were detected in either median serum IgG levels or death rates between male and female kids. Kids with IgG concentrations <800 mg dl−1 showed lower survival risks than those with higher concentrations. We concluded that typical management practices of kids delivered on open range at a goat operation under extensive conditions in northern Mexico tended to reduced colostrally acquired serum immunoglobulin levels, but had no effect directly on mortality.  相似文献   

18.
A Mycobacterium avium subspecies paratuberculosis (MAP) vaccine that reduced the incidence of clinical disease or reduced fecal shedding of MAP would aid control of Johne's disease (JD). The objective of the present study was to evaluate the efficacy of four MAP vaccine combinations, including cell-wall competent (CWC) alum adjuvant, CWC-QS21 adjuvant, cell-wall deficient (CWD) alum adjuvant and CWD-QS21 adjuvant vaccines. Eighty baby goats were vaccinated at 1 and 4 weeks of age with one of these vaccines or a sham control vaccine consisting of alum adjuvant. Kids were challenged orally with approximately 6.0 × 109 organisms in four divided doses of 1.5 × 109 organisms using a goat isolate of MAP. Vaccinated challenged and challenged control groups had 10 and 6 kids per group, respectively. Half of the kids within each group were necropsied at either 6 or 9 months post-challenge. Gross and microscopic lesions and relative number of acid-fast bacilli were evaluated and scored at necropsy. Results indicated all challenged kids had some lesions compatible with JD suggesting none of the vaccines prevented infection. Three vaccines (CWC-alum, CWC-QS21 and CWD-QS21) reduced lesion scores by 46–51% at 9 months. CWD-alum vaccine resulted in a more severe (+33.5%) lesion score than sham-vaccinated challenged control. Lesion scores were greater at 9 months than at 6 months post-challenge in the sham-vaccinated challenged group and CWD-alum vaccinated group, while lesion scores were generally stable with remaining vaccines. Mean fecal CFU/g were significantly different across time from challenge to 9-month necropsy (p = 0.043) and the CWC-QS21 vaccine group had a marked reduction in fecal CFU/g at all time points post-challenge. A reduction in MAP CFU/g was also detected in necropsy tissues from kids given the CWC-alum, CWC-QS21 and CWD-QS21 vaccines, and increased CFU/g were detected in tissues from kids given the CWD-alum vaccine. Immunological tests evaluated included, humoral response evaluation by AGID, ELISA and Western blot, and cell mediated response by comparative PPD skin testing (M. avium, Old Johnin, M. bovis and Lot 2 Johnin PPD's), and production of MAP induced γ-interferon. Vaccination also resulted in false-positive PPD skin test reactions for M. avium PPD, Old Johnin PPD and γ-interferon tests. When a 2-mm cutoff above normal skin thickness was used to define positive skin test reactions, false-positive reactions for M. bovis were detected in only 2 of 32 kids given a vaccine with QS21 adjuvant.  相似文献   

19.
The influence of feeding urea-molasses blocks (UMB) on growth and gastrointestinal (GI) nematode parasitism of weaner goats grazing the same pasture was investigated on a farm in Nyandarua District, Kenya. Thirty female Small East African goat kids at an average age of 5 months were initially treated with albendazole orally (5 mg kg(-1) body mass) and randomly assigned into one of two groups: group I were fed UMB prepared using a cold process and group II kids (controls) received no block supplementation (NBS). The UMB were given in the evening when the animals returned from grazing and were consumed during the night at a rate of 95.0 g head(-1) day(-1). Supplementation was undertaken for 3 consecutive months from July to September 2001 and January to March 2002. Body mass of the kids and faecal egg counts were measured monthly and larval cultures were performed on positive faecal samples of kids of each group. Five goats from each group were randomly selected for slaughter and total counts and identification of worms at the end of June 2002. Significant differences (P < 0.05) were found in cumulative mass gains of kids in group I from September compared with those in group II. On termination of the study kids in group I had gained an average of (+/- SD) 20.4 +/- 1.4 kg while those in group II had gained 11.8 +/- 1.1 kg. From January 2002, faecal egg counts of the kids in the UMB group differed significantly (P < 0.05) from those of the NBS group and at slaughter, the mean (+/- SD) worm counts for the UMB group was 482 +/- 299 while that of the NBS group was 1 302 +/- 410. In all the goats, Haemonchus contortus was the predominant nematode recovered. These results indicate that UMB had significant effects in the control of GI nematode parasitism and enhanced growth of the young goats.  相似文献   

20.
A longitudinal study was conducted on two dairy farms to investigate the pattern of shedding of verotoxin-producing Escherichia coli (VTEC) in goats. Faecal samples were taken from 20 goat kids once weekly during the first 4 weeks of life and then once every month for the next 5 months of life, and from 18 replacement animals and 15 adults once every month for 12 months. The proportion of samples containing VTEC was higher for replacement animals and adults (85.7% and 78.7%, respectively) than for goat kids (25.4%). About 90% of the VTEC colonies isolated from healthy goats belonged to five serogroups (O33, O76, O126, O146 and O166) but the most frequent serogroups of these isolates, except one, were different in the two herds studied. E. coli O157:H7 was found in three goat kids on only one occasion. None of the VTEC isolates, except the three E. coli O157:H7 isolates, was eae-positive. The patterns of shedding of VTEC in goat kids were variable, but, in contrast, most of the replacement animals and adults were persistent VTEC shedders. Our results show that isolates of VTEC O33, O76, O126, O146 and O166 are adapted for colonising the intestine of goats but that, in contrast, infection with VTEC O157:H7 in goats seems to be transient.  相似文献   

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