Olga González-Moreno

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

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.

Further report on Cryptosporidium in Barcelona zoo mammals.

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.

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

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.

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

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.

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

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.

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

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.

Ultrastructural observations of the tegument of Postorchigenes gymnesicus (Digenea: Lecithodendriidae)

The tegument of Postorchigenes gymnesicus has been studied by scanning and transmission electron microscopy. The general body tegument is spinous and contains mitochondria, biconcave disc-shaped vesicles bounded by an unitary membrane and displaying a protein content, and scarce spherical bodies. The tegument covering specialized body regions is aspinous. Few vesicles were evident in the tegument covering the suckers and oesophagus, being more abundant in the metraterm and cirrus where the tegument is thicker. Laurers canal has a thick tegument with sparse vesicles, mostly arranged close to the apical membrane. A direct association was evident between the basal lamina underlying the spines and the muscular subtegumental fibres, suggesting a motile character for the spine.

Terrestrial edible land snails as vectors for geographic dissemination of Brachylaima species.

Abstract: Cornu aspersum (= syn. Helix aspersa) snails imported into NE Spain from Algeria and South Africa, and intended for human consumption via sale in public markets, were analyzed to assess their contribution to geographic dissemination of Brachylaima species. Prevalence and viability studies of metacercariae were performed on Algerian and South African Brachylaima adults. Morphometric studies were performed by measuring 16 variables in metacercariae and 18 variables in adults. Principal component analyses (PCA) were performed to assess the contribution of each variable in the separation of the different groups. A MANOVA test performed on morphometric data from Brachylaima llobregatensis and Brachylaima mascomai Algerian and South African adults, revealed a significant multivariate main effect (P < 0.001) and univariate effects in 13 variables (P ≤ 0.001). Pairwise comparisons revealed significant differences in 13 variables between B. mascomai and Algerian adults, as opposed to 3 variables (testis I width, testis II width, and egg width) when compared with B. llobregatensis. South African adults had significant differences in 5 variables (body length, oral sucker length, oral sucker width, egg length, and egg width) when compared with B. llobregatensis, as opposed to 1 variable (testis II width) when compared with B. mascomai. Results from PCA showed 2 different groups: B. llobregatensis/Algerian adults (overlapped) and B. mascomai/South African adults (overlapped). Imported edible C. aspersum specimens can contribute significantly to the geographic spread of Brachylaima species by harboring infective metacercariae which could easily infect animals, given their heteroxenous character. Brachylaima llobregatensis has previously been detected in NE Spain only, and now this species appears to be parasitizing C. aspersum in Algeria (North Africa). This geographic dispersion could be favored by commerce in terrestrial snails such as C. aspersum.