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Dive into the research topics where Mercedes Gracenea is active.

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Featured researches published by Mercedes Gracenea.


Veterinary Parasitology | 2000

The occurrence of Cryptosporidium parvum and C. muris in wild rodents and insectivores in Spain.

Jordi Torres; Mercedes Gracenea; M.S. Gómez; A Arrizabalaga; Olga González-Moreno

Five rodent and two insectivore species were investigated for Cryptosporidium at seven sites in north-eastern Spain. Of the 442 animals studied, 82 Apodemus sylvaticus, 1 A. flavicollis, 5 Mus spretus, 1 Rattus rattus, 8 Clethrionomys glareolus and 13 Crocidura russula were infected with only C. parvum. Eleven A. sylvaticus and 2 C. glareolus were infected with only C. muris and 16 A. sylvaticus, 1 M. spretus and 2 C. glareolus showed mixed infections. Both cryptosporidial species were found in most study areas. No causal relationship was found between intrinsic host factors (age and sex) and the parasitic prevalence in the most captured host species (A. sylvaticus and C. russula). Extrinsic factors such as collection site of host, seasonality and covering vegetation exerted different influence on the prevalence of Cryptosporidium. Small mammals could become one of the most important sources of cryptosporidial oocysts in those areas where neither farm animals nor significant human activity are present. This is the first study to report the infection of M. spretus and C. russula by C. parvum and the first finding of C. muris in M. spretus.


Parasitology Research | 2000

Further report on Cryptosporidium in Barcelona zoo mammals.

M.S. Gómez; Jordi Torres; Mercedes Gracenea; J. Fernandez-Morán; Olga González-Moreno

Abstract The prevalence of fecal shedding of Cryptosporidium in 36 primates (21 species and subspecies) and 62 herbivores (36 species and subspecies) housed at the Barcelona zoo was studied. Cryptosporidial oocysts were found in stool samples of 14 Primate, 18 Artiodactyla, 2 Perissodactyla, and 1 Proboscidea species. None of them showed symptoms related to the parasite. Neither the sex nor the group condition (alone or in a group) of the animals studied appeared to be correlated with parasitic prevalence. The results extend the host species range of the protozoan to 18 new animals (6 Primate, 10 Artiodactyla, 1 Perissodactyla, and 1 Proboscidea species) and confirm the endemic status of Cryptosporidium at the Barcelona zoo. We conclude that maintenance of the parasitic endemic status is probably due to the presence of animal carriers as well as to the physical features of some facilities where oocysts could remain viable and infectious.


Journal of Morphology | 1997

ULTRASTRUCTURAL STUDY OF SPERMATOGENESIS AND THE SPERMATOZOON IN POSTORCHIGENES GYMNESICUS (TREMATODA, LECITHODENDRIIDAE)

Mercedes Gracenea; J.R. Ferrer; Olga González-Moreno; M. Trullols

An ultrastructural study of spermatogenesis, spermiogenesis, and spermatozoa in Postorchigenes gymnesicus is presented. Cytoplasmic projections originating in nurse cells surround the spermatogonia, which are located at the periphery of the testes. Primary spermatocytes attached to a cytophore show synaptonemal complexes and a pair of centrioles. Spermiogenesis begins with the appearance of a cytoskeletal structure formed by an intercentriolar body and two perpendicular centrioles. An axoneme and a striated rootlet emerge from each centriole. The progressive rotation and fusion of both flagella with the median process occurs simultaneously with the migration of nucleus to the distal tip of the forming spermatozoon. The mature spermatozoon consists of three regions: (1) the nuclear region, containing the nucleus, one mitochondrion, two 9+1 axonemes, and cortical microtubules; (2) the intermitochondrial region, containing two axonemes; and (3) the mitochondrial region with another mitochondrion, two axonemes, cortical microtubules, and external ornamentation symmetrically and asymmetrically arranged coincidental with the cortical microtubules. Glycogen particles, absent in testicular cells, are abundant in the spermatozoon. Ultrastructural features of the non‐nuclear region of the spermatozoon are specific for P. gymnesicus and are proposed to characterize the spermatozoon of digenean species. J. Morphol. 234:223–232, 1997.


Acta Parasitologica | 2009

Prevalence of intestinal parasites in shelter dogs and cats in the metropolitan area of Barcelona [Spain]

Mercedes Gracenea; M.S. Gómez; Jordi Torres

Prevalence of intestinal parasites in dogs and cats in Barcelona and surrounding areas was studied by analyzing 505 faecal samples of dogs and 50 of cats using a formol-ether diphasic method for helminths, a modified acid-fast technique for Cryptosporidium and other coccidian oocysts, and the Heindenhein technique for Giardia and Entamoeba trophozoites and cysts. Parasites were found in 26.9% of dogs and 34.0% of cats. Giardia duodenalis, Cryptosporidium sp., coccidian oocysts and Entamoeba sp. were detected in both dogs and cats. Taenia sp., Dipylidium caninum, Ancylostoma caninum, Toxocara canis, Toxascaris leonina, Trichuris vulpis and Uncinaria sp. were also found in dogs but only Ancylostoma tubaeforme and Toxocara cati in cats. There was a significant relationship for G. duodenalis and Cryptosporidium sp. with seasonality and for G. duodenalis with geographical origin in dogs. Significant differences were also found for T. canis between stray and domestic dogs and for T. vulpis between males and females.


Veterinary Parasitology | 2002

Transmission dynamics of Cryptosporidium in primates and herbivores at the Barcelona zoo: a long-term study.

Mercedes Gracenea; M.S. Gómez; Jordi Torres; E Carné; J Fernández-Morán

Factors influencing the transmission of Cryptosporidium in primates and herbivores housed at the Barcelona zoo have been analyzed. The relationship between continuous and discontinuous oocyst shedding, both animal housing conditions and abiotic factors (seasonality, humidity, temperature) was examined to explain the epizootiology of the protozoan. Thirty six fecal samples from each of 11 primates (Pongidae, Cebidae, Cercopithecidae and Lemuridae) and 22 herbivores (Elephantidae, Camelidae, Cervidae, Giraffidae and Bovidae) were examined over the period of 1 year. The parasite transmission was based on the chronic infection status of some animals serving as a source of successive reinfection for other animals. The environmental temperature and humidity (seasonality), the physical features of the facilities, the vicinity of the animals and the physiological status induced by captivity contributed to transmission. The long-term character of this study was essential for obtaining these results and interpreting the complex relationships.


Parasitology Research | 2011

Prevalence and associated factors of intestinal parasitisation: a cross-sectional study among outpatients with gastrointestinal symptoms in Catalonia, Spain

Olga González-Moreno; Laia Domingo; Jaume Teixidor; Mercedes Gracenea

The aim of this study was to report the prevalence of intestinal parasites in stool specimens from outpatients in Catalonia (Spain), and to evaluate the association of age, seasonality, and gender on general parasitisation and by the most frequent detected species. A total of 13,913 samples from 8,313 patients (1–3 specimens per patient) reporting digestive disorders were examined between 1999 and 2005 as a part of medical examinations. Samples were fixed with MIF solution and microscopically examined as wet mounts. Permanent stain was obtained by the modified Ziehl–Neelsen technique for intestinal coccidia. Nineteen species of intestinal parasites were identified. Blastocystis hominis (585 patients) was the predominant species, followed by Giardia duodenalis (321), Dientamoeba fragilis (131), Entamoeba coli (60) and Cryptosporidium sp. (59). Prevalence of helminths was low, being Enterobius vermicularis as the most frequently reported helminth (49 patients). The overall parasitisation was 1,136/8,313 (13.7%); prevalence in adults was 19.8% with a maximum in spring (14.8%). In the adjusted models, age was the main factor associated with infection: adults, with B. hominis and Entamoeba coli (odds ratio (OR) = 6.0 and OR = 8.5, respectively) and children, with Cryptosporidium and Giardia (OR = 2.0 and OR = 3.3, respectively). However, seasonality cannot be considered related with infection. The total prevalence was low, taking into account that all the subjects examined presented gastrointestinal symptoms and that species traditionally considered as non-pathogenic were included in the study.


Journal of Parasitology | 2002

LIFE CYCLE OF BRACHYLAIMA MASCOMAI N. SP. (TREMATODA: BRACHYLAIMIDAE), A PARASITE OF RATS IN THE LLOBREGAT DELTA (SPAIN)

Mercedes Gracenea; Olga González-Moreno

The terrestrial triheteroxenous life cycle of Brachylaima mascomai n. sp. (Trematoda: Brachylaimidae) is elucidated. Operculated, assymetric, embryonated eggs (25.4 × 12.7μm) are passed with feces of the natural (Rattus norvegicus and R. rattus) and experimental (albino and wild mice, albino rats, Apodemus sylvaticus, Mus spretus [Muridae] and the golden gerbil) definitive hosts and ingested by the helicid gastropod Pseudotachea splendida, the only natural and experimental first intermediate host. Microcaudate cercariae harbored in branched sporocysts in the digestive gland emerge from this snail and contact P. splendida, Otala punctata, Theba pisana, and Helix (C.) aspersa snails developing into unencysted infective metacercariae in the kidney. Definitive hosts are infected by ingestion of infected snails; the adult parasites inhabit the small intestine. Chaetotaxic cercarial pattern specific at acetabular (SII 8–10 papillae) and cephalic (CIII 13–15 papillae, H 16 papillae) levels. Three types of cercarial papillae are observed by scanning electron microscopy (SEM) and their arrangement is correlated with chaetotaxy for the first time in trematodes: argentophilic papillae with fingerlike process (cephalic, body, and acetabular levels), argentophilic papillae with opening (2 papillae in the M body level), and nonargentophilic dome-shaped papillae (alternated with argentophilic SII papillae on the ventral sucker). SEM detected interlacing network of ridges covering the metacercarial body. Adults with multidigitate tegumentary spines were observed by SEM. Subequal suckers; the acetabulum located in the posterior part of anterior fifth of body. Vitellaria extend from between middle level and anterior margin of anterior testis to between middle level and posterior margin of acetabulum. Uterus almost reaches the intestinal bifurcation.


International Journal for Parasitology | 1996

A survey for Cryptosporidium spp. in mammals at the Barcelona zoo

M.S. Gómez; T. Vila; Carlos Feliu; Isabel Montoliu; Mercedes Gracenea; J. Fernandez

Mammals housed at the Barcelona Zoo belonging to the orders Carnivora, Artiodactyla, Perissodactyla and Proboscidea were examined for Cryptosporidium infections. A total of 183 fecal samples from 17 carnivores and 34 herbivores revealed patent infections in only 6 herbivore species (5 artiodactyls of the families Bovidae and Giraffidae and 1 perissodactyl of the family Rhinocerotidae); all carnivores were negative. Intensity of infection was found to be generally low. Connochaetes taurinus taurinus, Gazella dorcas neglecta, Kobus ellipsiprymmus and Giraffa camelopardalis constitute new host species for the parasite.


Journal of Medical Primatology | 1996

Intestinal parasitism—protozoa and helminths—in primates at the Barcelona Zoo

M. Soledad Gómez; Mercedes Gracenea; Isabel Montoliu; Carlos Feliu; Antonio Monleon; J.M. Fernández; Conrad Enseñat

Abstract: The faunistic results regarding intestinal parasitism by protozoa and helminths in 21 primate species (three Cebidae, thirteen Cercopithecidae, one Hylobatidae, one Lemuridae, three Pongidae) are reported. The primate species were housed in four separate galleries. Six faecal samples of each host species were subjected to coprological analysis. Fifteen parasite species were detected: 11 protozoa (Entamoeba coli, E. chattoni, E. hartmanni, Iodamoeba bütschlii, Endolimax nana, Giardia intestinalis, Chilomastix mesnilii, Enteromonas hominis, Trichomonas intestinalis, Balantidium coli, and Blastocystis hominis) and 4 helminths (Ancylostoma sp., Strongyloides fuelleborni, Strongyloides sp., and Trichuris trichiura). The results reveal certain parasitic similarities between host species housed in the same gallery; however, these primate species do not always carry identical parasite species.


Journal of Parasitology | 2006

Life cycle and description of a new species of brachylaimid (Trematoda : Digenea) in Spain

Olga González-Moreno; Mercedes Gracenea

The life cycle of Brachylaima llobregatensis n. sp. (Trematoda: Brachylaimidae) is elucidated. Embryonated, operculated, asymmetric eggs (30.9 × 18.2 μm) are eliminated with feces of natural hosts wood mouse Mus spretus; white-toothed shrew, Crocidura russula; and an experimental host, domestic mouse, Mus musculus var. domesticus. The eggs are ingested by the helicid gastropod Helix (Cornu) aspersa, the only natural and experimental first intermediate host. The miracidium hatches from the egg, infects the snails, and develops into a branched sporocyst in the digestive gland. Microcaudate cercariae emerge from this snail and develop into unencysted metacercariae in the kidney of second intermediate host snails H. (C.) aspersa and Otala punctata (natural hosts) and Theba pisana (experimental host). Ingestion of infected snails leads to the infection of definitive hosts, with the adults inhabiting the middle part of the small intestine. There is a chaetotaxic pattern specific on the acetabular (SII 5–6 papillae) and body (papillae absent on PII) levels. Three types of cercaria papillae were observed by scanning electron microscopy: argentophilic papillae with fingerlike processes (cephalic, body, and acetabular levels); argentophilic papillae with opening (2 papillae in the M body level); and nonargentophilic dome-shaped papillae (on the cephalic CII level, alternating with argentophilic SII papillae on the ventral sucker). Suckers are subequal, with the acetabulum located in the posterior part of the anterior third of body. Vitellaria extend from anterior margin of acetabulum to between middle level and anterior margin of anterior testis.

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M.S. Gómez

University of Barcelona

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Jordi Torres

University of Barcelona

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J.R. Ferrer

University of Barcelona

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C. Feliu

University of Barcelona

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Carlos Feliu

University of Barcelona

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