The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Gürbüz Daş - One of the best experts on this subject based on the ideXlab platform.
-
diurnal variation in egg excretion by Heterakis gallinarum
Parasitology, 2019Co-Authors: Gürbüz Daş, Pal O Westermark, Matthias GaulyAbstract:Periodicity in nematode egg excretion may be of evolutionary origin as it can favour dispersal of the eggs in the environment. We investigated whether egg excretion by Heterakis gallinarum shows a repeatable pattern of periodicity. The faecal egg concentration and total number of eggs excreted within 4-h intervals were significantly affected by the sampling time within 1 day, but remained unaffected by the sampling day or interaction effects. By contrast, the total number of eggs excreted within 24 h did not differ among the 4 days of the study, collectively indicating repeatable egg excretion patterns. Both host feces and parasite egg excretion increased from night to late afternoon, followed by a decrease in the evening, resulting in higher egg excretion during daytime than the dark period. Feces excretion and worm fecundity showed overlapping diurnal rhythms with similarly timed phases, suggesting the existence of synchronicity between the host feces and nematode egg excretion patterns. We conclude that egg excretion by H. gallinarum is synchronized with host feces excretion and is higher during the daytime than during the dark period. This overlaps with the maximum activity of the day-active host and allows a maximal dispersal of the eggs in the environment.
-
Co-expulsion of Ascaridia galli and Heterakis gallinarum by chickens.
International journal for parasitology, 2018Co-Authors: Manuel Stehr, Matthias Gauly, Q. Sciascia, Cornelia C. Metges, Gürbüz DaşAbstract:Abstract Worm expulsion is known to occur in mammalian hosts exposed to mono-species helminth infections, whilst this phenomenon is poorly described in avian hosts. Mono-species infections, however, are rather rare under natural circumstances. Therefore, we quantified the extent and duration of worm expulsion by chickens experimentally infected with both Ascaridia galli and Heterakis gallinarum, and investigated the accompanying humoral and cell-mediated host immune responses in association with population dynamics of the worms. Results demonstrated the strong co-expulsion of the two ascarid species in three phases. The expulsion patterns were characterized by non-linear alterations separated by species-specific time thresholds. Ascaridia galli burden decreased at a daily expulsion rate (e) of 4.3 worms up to a threshold of 30.5 days p.i., followed by a much lower second expulsion rate (e = 0.46), which resulted in almost, but not entirely, complete expulsion. Heterakis gallinarum was able to induce reinfection within the experimental period (9 weeks). First generation H. gallinarum worms were expelled at a daily rate of e = 0.8 worms until 36.4 days p.i., and thereafter almost no expulsion occurred. Data on both humoral and tissue-specific cellular immune responses collectively indicated that antibody production in chickens with multispecies ascarid infections is triggered by Th2 polarisation. Local Th2 immune responses and mucin-regulating genes are associated with the regulation of worm expulsion. In conclusion, the chicken host is able to eliminate the vast majority of both A. galli and H. gallinarum in three distinct phases. Worm expulsion was strongly associated with the developmental stages of the worms, where the elimination of juvenile stages was specifically targeted. A very small percentage of worms was nevertheless able to survive, reach maturity and induce reinfection if given sufficient time to complete their life cycle. Both humoral and local immune responses were associated with worm expulsion.
-
density related effects on lifetime fecundity of Heterakis gallinarum in chickens
Parasites & Vectors, 2014Co-Authors: Gürbüz Daş, Matthias GaulyAbstract:Background Density related effects, both inverse density- and density-dependent, contribute to regulating population dynamics of parasites. We investigated whether density related effects are directly controlling lifetime fecundity of Heterakis gallinarum.
Kensuke Taira - One of the best experts on this subject based on the ideXlab platform.
-
Molecular identification of Heterakis spumosa obtained from brown rats (Rattus norvegicus) in Japan and its infectivity in experimental mice
Parasitology Research, 2014Co-Authors: Viliam Šnábel, Daisuke Utsuki, Takehiro Kato, Fujiko Sunaga, Barbara Gambetta, Kensuke TairaAbstract:Heterakis spumosa is a nematode of invasive rodents, mainly affiliated with Rattus spp. of Asian origin. Despite the ecological importance and cosmopolitan distribution, little information is available on the genetic characteristics and infectivity to experimental animals of this roundworm. Heterakis isolates obtained from naturally infected brown rats caught in 2007 in the city of Sagamihara, east central Honshu, Japan, and maintained by laboratory passages were subjected to mitochondrial sequence analysis and experimental infection in mice. Sequencing of the cox1 gene revealed that nucleotides of H. spumosa and previously examined Heterakis isolonche isolates from gallinaceous birds in Japan differed by 11.2–12.2 % that conforms to the range expected for interspecific differences. The two H. spumosa isolates differed by a single 138T/C non-synonymous substitution in the 393-bp mt sequence. In a dendrogram, the H. spumosa samples formed a subcluster with members of the nematode superfamily Heterakoidea, H. isolonche and Ascaridia galli . In an experimental infection study, ICR, AKR, B10.BR and C57BL/6 mice strains were inoculated with 200 H. spumosa eggs/head and necropsied at 14 and 90 days post-inoculation (DPI) when the number of worms was recorded. Eggs were initially detected in faeces from 32–35 DPI in ICR, AKR and B10.BR mice and the highest mean number of eggs per gram of faeces (EPG) was 4,800 at 38 DPI, 2,200 at 58 DPI and 800 at 44 and 72 DPI in ICR, AKR and B10.BR mice, respectively. No eggs were observed in faeces of the C57BL/6 mouse strain during the experiment. A similar number of juvenile worms were isolated from all mouse strains at 14 DPI, whereas no adult worms were detected in C57BL/6 mice at 90 DPI.
Matthias Gauly - One of the best experts on this subject based on the ideXlab platform.
-
diurnal variation in egg excretion by Heterakis gallinarum
Parasitology, 2019Co-Authors: Gürbüz Daş, Pal O Westermark, Matthias GaulyAbstract:Periodicity in nematode egg excretion may be of evolutionary origin as it can favour dispersal of the eggs in the environment. We investigated whether egg excretion by Heterakis gallinarum shows a repeatable pattern of periodicity. The faecal egg concentration and total number of eggs excreted within 4-h intervals were significantly affected by the sampling time within 1 day, but remained unaffected by the sampling day or interaction effects. By contrast, the total number of eggs excreted within 24 h did not differ among the 4 days of the study, collectively indicating repeatable egg excretion patterns. Both host feces and parasite egg excretion increased from night to late afternoon, followed by a decrease in the evening, resulting in higher egg excretion during daytime than the dark period. Feces excretion and worm fecundity showed overlapping diurnal rhythms with similarly timed phases, suggesting the existence of synchronicity between the host feces and nematode egg excretion patterns. We conclude that egg excretion by H. gallinarum is synchronized with host feces excretion and is higher during the daytime than during the dark period. This overlaps with the maximum activity of the day-active host and allows a maximal dispersal of the eggs in the environment.
-
Co-expulsion of Ascaridia galli and Heterakis gallinarum by chickens.
International journal for parasitology, 2018Co-Authors: Manuel Stehr, Matthias Gauly, Q. Sciascia, Cornelia C. Metges, Gürbüz DaşAbstract:Abstract Worm expulsion is known to occur in mammalian hosts exposed to mono-species helminth infections, whilst this phenomenon is poorly described in avian hosts. Mono-species infections, however, are rather rare under natural circumstances. Therefore, we quantified the extent and duration of worm expulsion by chickens experimentally infected with both Ascaridia galli and Heterakis gallinarum, and investigated the accompanying humoral and cell-mediated host immune responses in association with population dynamics of the worms. Results demonstrated the strong co-expulsion of the two ascarid species in three phases. The expulsion patterns were characterized by non-linear alterations separated by species-specific time thresholds. Ascaridia galli burden decreased at a daily expulsion rate (e) of 4.3 worms up to a threshold of 30.5 days p.i., followed by a much lower second expulsion rate (e = 0.46), which resulted in almost, but not entirely, complete expulsion. Heterakis gallinarum was able to induce reinfection within the experimental period (9 weeks). First generation H. gallinarum worms were expelled at a daily rate of e = 0.8 worms until 36.4 days p.i., and thereafter almost no expulsion occurred. Data on both humoral and tissue-specific cellular immune responses collectively indicated that antibody production in chickens with multispecies ascarid infections is triggered by Th2 polarisation. Local Th2 immune responses and mucin-regulating genes are associated with the regulation of worm expulsion. In conclusion, the chicken host is able to eliminate the vast majority of both A. galli and H. gallinarum in three distinct phases. Worm expulsion was strongly associated with the developmental stages of the worms, where the elimination of juvenile stages was specifically targeted. A very small percentage of worms was nevertheless able to survive, reach maturity and induce reinfection if given sufficient time to complete their life cycle. Both humoral and local immune responses were associated with worm expulsion.
-
density related effects on lifetime fecundity of Heterakis gallinarum in chickens
Parasites & Vectors, 2014Co-Authors: Gürbüz Daş, Matthias GaulyAbstract:Background Density related effects, both inverse density- and density-dependent, contribute to regulating population dynamics of parasites. We investigated whether density related effects are directly controlling lifetime fecundity of Heterakis gallinarum.
U Leonardo Mendoza - One of the best experts on this subject based on the ideXlab platform.
-
Heterakis spumosa SCHNEIDER, 1866 (NEMATODA: HETERAKIDAE) EN Rattus norvegicus (RODENTIA: MURIDAE) EN ICA, PERÚ Heterakis spumosa SCHNEIDER, 1866 (NEMATODA: HETERAKIDAE) IN Rattus norvegicus (RODENTIA: MURIDAE) IN ICA, PERU
2001Co-Authors: Rufino Cabrera, U Leonardo MendozaAbstract:In this paper Heterakis spumosa Schneider, 1866 is redescribed. It is a parasitic heterakid nematoda living in the caecum of murid rodent, Rattus norvegicus "gray rat" from district of Parcona, province of lea, Peru.
Leonardo U Mendoza - One of the best experts on this subject based on the ideXlab platform.
-
Heterakis spumosa schneider 1866 nematoda heterakidae en rattus norvegicus rodentia muridae en ica peru
Revista Peruana de Biología, 2014Co-Authors: Leonardo U MendozaAbstract:In this paper Heterakis spumosa Schneider, 1866 is redescribed. It is a parasitic heterakid nematoda living in the caecum of murid rodent, Rattus norvegicus "gray rat" from district of Parcona, province of Ica, Peru.