Faecal contamination in public pools in Barcelona province: Cryptosporidium spp. and bacterial indicators.

A study was conducted of the occurrence of Cryptosporidium in indoor heated public swimming pools and of three bacterial indicators (Escherichia coli, faecal enterococci and Clostridium perfringens) on pool surrounds. Although all examined pools adhered strictly to the Spanish regulations, the influence of several parameters related to water conditions, pool structure, users and location on the presence of protozoa and bacteria was analysed. Cryptosporidium was detected in 18.8% of pools in 60% of the five towns studied. The maximum concentration was 13 oocysts/L in one swimming pool and one Jacuzzi. The bacterial indicators' prevalence on pool surrounds was higher than 50%, being present in all of the towns. Plastic surfaces presented the lowest bacterial prevalence, whereas painted surfaces were 100% positive. No differences were observed for pool surrounds with autonomous or disabled users. Risk of cryptosporidiosis in pool vessels indicated that concentrations over 1 oocyst/10 L enhance the risk of infection, even in one exposure. Guidelines for managing faecal accidents and public information on the importance of good hygiene behaviours in and around swimming pools are recommended to limit oocysts' presence.

Greenhouse gas emissions from stabilization ponds in subtropical climate.

Waste stabilization ponds (WSPs) are a cost-efficient method to treat municipal and non-toxic industrial effluents. Numerous studies have shown that WSPs are a source of greenhouse gas (GHG). However, most reports concerned anaerobic ponds (AP) and few have addressed GHG emissions from facultative (FP) and aerobic/maturation ponds (MPs). In this paper, GHG emissions from three WSP in series are presented. These WSPs were designed as anaerobic, facultative and aerobic/maturation and were treating agricultural wastewater. CH4 fluxes from 0.6 +/- 0.4 g CH4 m(-2) d(-1) in the MP, to 7.0 +/- 1.0 g CH4 m(-2) d(-1) in the (AP), were measured. A linear correlation was found between the loading rates of the ponds and CH4 emissions. Relatively low CO2 fluxes (0.2 +/- 0.1 to 1.0 +/- 0.8 g CO2 m(-2) d(-1)) were found, which suggest that carbonate/bicarbonate formation is caused by alkaline pH. A mass balance performed showed that 30% of the total chemical oxygen demand removed was converted to CH4. It has been concluded that the WSP system studied emits at least three times more GHG than aerobic activated sludge systems and that the surface loading rate is the most important design parameter for CH4 emissions.

Positive co-occurrence of flea infestation at a low biological cost in two rodent hosts in the Canary archipelago.

Non-random assemblages have been described as a common pattern of flea co-occurrence across mainland host species. However, to date, patterns of flea co-occurrence on islands are unknown. The present work investigates, on one hand, whether the decrease in the number of species on islands affects the pattern of flea co-occurrence, and on the other hand, how the cost of higher flea burdens affects host body mass. The study was carried out in the Canary Islands (Spain) using null models to analyse flea co-occurrence on Rattus rattus and Mus musculus. Results supported aggregation of flea species in Mus but not in Rattus, probably due to the relationship between abundance and both prevalence and intensity of infection of the main flea species parasitizing Mus. In addition, heavy individuals of both rodent species showed the highest flea burdens as well as higher species richness, probably due to the continued accumulation of fleas throughout life and/or immunological resistance mechanisms. Whatever the mechanisms involved, it is clear that co-occurrence and high parasite intensities do not imply a detrimental biological cost for the rodents of the Canary Islands.

Xenopsylla spp. (Siphonaptera: Pulicidae) in murid rodents from the Canary Islands: an update.

The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.

Paralytic shellfish toxins in the chocolata clam, Megapitaria squalida (Bivalvia: Veneridae), in Bahia de La Paz, Gulf of California

Occurrence and toxic profiles of paralytic shellfish toxins (PST) in the chocolata clam Megapitaria squalida were investigated. From December 2001 to December 2002, 25 clams were obtained monthly from Bahía de La Paz, Gulf of California. Additionally, net (20 µm) and bottle phytoplankton samples were also collected to identify toxic species. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. Toxicity in the clam was low and varied from 0.14 to 5.46 µg/STXeq/100 g. Toxicity was detected in December, March, April, June, and August. Toxin profile was composed mainly by STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX and B1. Gymnodinium catenatum was the only PST-producing dinoflagellate identified in the phytoplankton samples throughout the study period. G. catenatum was observed mainly in net samples from December 2001 to December 2002; however, in bottle samples, G. catenatum was only observed in five months. Highest abundance (2 600 cells l-1 ) was observed in March and the lowest (160 cells l-1 ) in June. G. catenatum mainly formed two-cell chains and rarely four or eight. The presence of PST in net phytoplankton samples support the fact that G. catenatum is the main source of PST in the clams. This study represents the first report of PST toxins in the chocolata clam from Bahía de La Paz

Se investigó la ocurrencia así como los perfiles de toxinas paralíticas (PST) en la almeja chocolata Megapitaria squalida (Sowerby, 1835), de la cual se recolectaron mensualmente 25 ejemplares de diciembre del 2001 a diciembre del 2000 en La Bahía de La Paz, Golfo de California. Simultáneamente, se obtuvieron muestras de fitoplancton de botella y de red (20 µM) para identificar especies tóxicas, así como para detectar la presencia de toxinas paralíticas. Las toxinas se analizaron por HPLC con una oxidación post-columna y detección fluorescente. La toxicidad en las almejas fue baja y varió de 0.14 a 5.46 µg/STXeq/100 g y se detectó en diciembre, marzo, abril, junio y agosto. El perfil de toxinas estuvo compuesto principalmente por STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX y B1, siendo similar al perfil observado en las muestras de red. Gymnodinium catenatum fue la única especie productora de toxinas paralíticas identificada en las muestras de fitoplancton a través de todo el período del estudio. G. catenatum se observó principalmente en muestras de red correspondientes a diciembre 2001-diciembre 2002; sin embargo, en muestras de botella, G. Catenatum solo fue observado en cinco meses. La abundancia más alta (2 600 céls l-1 ) se encontró en marzo y la más baja (160 céls l-1 ) en junio. G. catenatum se presentó formando cadenas de dos células y raramente de cuatro u ocho. La presencia de toxinas en las muestras de red donde esta especie es frecuente, apoya la idea de que G. catenatum sea la fuente principal de PST en las almejas. Este estudio representa el primer reporte de toxinas paralíticas en la almeja chocolata de Bahía de La Paz

Paralytic shellfish toxins in the chocolata clam, Megapitaria squalida (Bivalvia: Veneridae), in Bahía de La Paz, Gulf of California.

Occurrence and toxic profiles of paralytic shellfish toxins (PST) in the chocolata clam Megapitaria squalida were investigated. From December 2001 to December 2002, 25 clams were obtained monthly from Bahia de La Paz, Gulf of California. Additionally, net (20 microm) and bottle phytoplankton samples were also collected to identify toxic species. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. Toxicity in the clam was low and varied from 0.14 to 5.46 microg/STXeq/100 g. Toxicity was detected in December, March, April, June, and August. Toxin profile was composed mainly by STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX and B1. Gymnodinium catenatum was the only PST-producing dinoflagellate identified in the phytoplankton samples throughout the study period. G. catenatum was observed mainly in net samples from December 2001 to December 2002; however, in bottle samples, G. catenatum was only observed in five months. Highest abundance (2600 cells l(-1)) was observed in March and the lowest (160 cells l(-1)) in June. G. catenatum mainly formed two-cell chains and rarely four or eight. The presence of PST in net phytoplankton samples support the fact that G. catenatum is the main source of PST in the clams. This study represents the first report of PST toxins in the chocolata clam from Bahia de La Paz.

First report of Siphonaptera infesting Microtus (Microtus) cabrerae (Rodentia-Muridae-Arvicolinae) in Cuenca, Spain and notes about the morphologic variability of Ctenophthalmus (Ctenophthalmus) apertus personatus (Insecta-Siphonaptera-Ctenophthalmidae).

The fleas infesting Microtus (Microtus) cabrerae from three different areas of Cuenca province (Spain) have been studied. It is the first time that on ectoparasitological study of this badly known rodent has been done. Four Siphonaptera species have been detected: Rhadinopsylla (Actenophthalmus) pentacantha, Peromyscopsylla spectabilis spectabilis, Nosopsyllus fasciatus and Ctenophthalmus (Ctenophthalmus) apertus personatus, which was the most abundant species (26 males and 31 females of a total of 28 males and 35 females). Considering the great morphologic variability within the male processus basimerus ventralis (p.b.v.) of segment IX of C. personatus subspecies, three morphotypes have been recognised. The male polymorphism detected, would be the result of both host confinement and genetic selection acting on the parasite. It should be pointed out that C. (C.) apertus personatus is not narrowly host-specific, therefore further studies are required to clarify this taxonomic situation.

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

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.

A method for reducing the pocket complications of the internal infusion pumps in pediatric patients: a case report.

Internal infusion pumps are increasingly used as a safe method to deliver drugs in adult patients. However, a formal contraindication of this mode of therapy is the presence of a imbalance between the pump volume and the size of the abdominal wall as occurs in pediatric populations. We describe a method of implantation of an intrathecal infusion pump for baclofen therapy in a 10-year-old patient with cerebral palsy. Before the pump implantation we inserted a subcutaneous expander with a reservoir that was filled with saline solution every week. After three sessions, a pocket similar in size to an internal infusion pump was obtained. The result was a pump pocket with soft shaping and no edges that would not generate pressure sores or tissue tension after the pump insertion. This method could extend the use of internal infusion pumps in pediatric populations.

[Stomach content of Spondylus leucacanthus (Bivalvia: Spondylidae) and its relationship with reproduction and phytoplankton in Isla Danzante, Gulf of California]. / Contenido estomacal de Spondylus leucacanthus (Bivalvia: Spondylidae) y su relación con la temporada de reproducción y la abundancia de fitoplancton en Isla Danzante, Golfo de California.

During 1994 we collected specimens of Spondylus leucacanthus near Isla Danzante, Gulf of California. We measured seawater temperature, and sampled stomach contents and phytoplankton. The reproductive season was assessed through the gonadic index. There is a cool season from December to May and a warm season from June to November. The stomach content was composed of detritus (60%), phytoplankton (30%), and unidentified materials (10%). The highest abundance of phytoplankton cells in the bottom water and the stomach content were in March, April, and May, during the seasonal change of temperature. The gonadic index showed a single peak, confirming that the population has an annual pattern of reproduction. The start of gametogenic phase and maturity in the population coincide with the abundance of phytoplankton.

Pagetoid dyskeratosis of the cervix: an incidental histologic finding in uterine prolapse.

Pagetoid dyskeratosis, is considered a reactive process in which a small part of the normal population of keratinocytes is induced to proliferate. The lesion is characterized by pale cells resembling those of Paget's disease within the epidermis. These cells have been seen as an incidental finding in a variety of benign papules most commonly located in intertriginous areas. Among the inductors of the lesion, friction is suspected. To the best of our knowledge, these pale cells have not been reported in the cervix. We describe the location of the lesion in the ectocervix and the incidence of this lesion in a group of 100 unselected patients surgically treated for uterine prolapse. Another group of 100 unselected patients treated for uterine leiomyoma was used as a control. Pagetoid dyskeratosis was found in 37 cases (37%) of uterine prolapse and in five cases (5%) of uterine leiomyomas. The lesion is more common in uterine prolapse (p <0.001) and is not significantly associated with cornification of the epithelium (p = 0.72343). The cells of pagetoid dyskeratosis show an immunohistochemical profile different from the surrounding squamous cells characterized by premature keratinization. Pagetoid dyskeratosis cells have shown positivity for high molecular weight cytokeratin and negative reaction for low molecular weight cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and human papilloma virus. Pagetoid dyskeratosis cells must be distinguished from artefactual clear cells, glycogen-rich cells, koilocytes, extramammary Paget's disease cells, and pagetoid spread of carcinoma cells to the cervix. In cases in which pagetoid dyskeratosis shows a florid expression, there is a hazard of overdiagnosis. The pathologist should be aware of the histologic features of pagetoid dyskeratosis in the ectocervix to avoid misdiagnosis and unnecessary treatment. Routine histologic study is usually sufficient to identify the lesion.

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.

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.

Abrocomaphthirus chilensis (Gomez), new combination (Phthiraptera-Anoplura), an ectoparasite of the Chilean rodent Abrocoma bennetti (Abrocomidae).

The same species of sucking louse (Phthiraptera-Anoplura) from the Chilean abrocomid rodent Abrocoma bennetti Waterhouse, 1837 was recently described as Eulinognathus chilensis Gomez, 1998 and as Abrocomaphthirus hoplai Durden & Webb, 1999. We discuss the nomenclature of this louse and confirm that its correct name is now Abrocomaphthirus chilensis (Gomez, 1998). After comparing type specimens designated from each description, we also document some morphological variation within this species with respect to the paratergal plate on abdominal segment 3 in the female which usually has two relatively long apical setae, but occasionally has only one.

[Presence in the eastern part of the Spanish Pyrenees of Amphipsylla sibirica sepifera Jordan and Rothschild, 1920 (Siphonaptera: Ceratophyllidae: Amphipsyllinae)]. / Présence dans la partie orientale des pyrénées espagnoles d'Amphipsylla Sibirica Sepifera Jordan et Rothschild, 1920 (Siphonaptera: Ceratophyllidae: Amphipsyllinae).

The detection of two males and one female of Amphipsylla sibirica sepifera on three Clethrionomys glareolus is pointed out. The rodents were taken in Alt Aneu and Espot, two towns of Lerida (a Spanish Province). The finding of this flea species on Spanish Pyrenees increases to the west its geographical distribution and adds one new species to the Iberian flea fauna.

The Cryptosporidium "mouse" genotype is conserved across geographic areas.

A 298-bp region of the Cryptosporidium parvum 18S rRNA gene and a 390-bp region of the acetyl coenzyme A synthetase gene were sequenced for a range of Cryptosporidium isolates from wild house mice (Mus domesticus), a bat (Myotus adversus), and cattle from different geographical areas. Previous research has identified a distinct genotype, referred to as the "mouse"-derived Cryptosporidium genotype, common to isolates from Australian mice. Comparison of a wider range of Australian mouse isolates with United Kingdom and Spanish isolates from mice and cattle and also an Australian bat-derived Cryptosporidium isolate revealed that the "mouse" genotype is conserved across geographic areas. Mice are also susceptible to infection with the "cattle" Cryptosporidium genotype, which has important implications for their role as reservoirs of infection for humans and domestic animals.

Secnidazole vs. paromomycin: comparative antiprotozoan treatment in captive primates.

The antiprotozoan activity of secnidazole was studied in Cercocebus t. torquatus, Cercopithecus campbelli, Erythrocebus patas (Cercopithecidae), and Gorilla gorilla (Pongidae) compared with that of paromomycin in Cercocebus t. lunulatus (Cercopithecidae), E. patas, and G. gorilla (Pongidae) by coprological analysis. The antiprotozoan activity of both drugs depended on the parasite species and the host species. The drugs acted in a similar way on Entamoeba coli parasitising C. t. torquatus, and E. patas. This activity was different from that observed on I. buestchlii from the same host species. Nevertheless, E. coli parasitising cercopithecids and pongids responded to drugs differently.

Inactivation of glutathione reductase by 4-hydroxynonenal and other endogenous aldehydes.

4-Hydroxynonenal, a product of oxidative degradation of unsaturated lipids, is an endogenous reactive alpha,beta-unsaturated aldehyde with numerous biological activities. 4-Hydroxynonenal rapidly inactivated glutathione reductase in an NADPH-dependent reaction. Inactivation appears to involve the initial formation of an enzyme-inactivator complex, K(D) = 0.5 microM, followed by the inactivation reaction, k = 1.3 x 10(-2) min(-1). alpha,beta-Unsaturated aldehydes such as acrolein, crotonaldehyde, and cinnamaldehyde also inactivated glutathione reductase, although rates varied widely. Inactivation of glutathione reductase by alpha,beta-unsaturated aldehydes was followed by slower NADPH-independent reactions that led to formation of nonfluorescent cross-linked products, accompanied by loss of lysine and histidine residues. Other reactive endogenous aldehydes such as methylglyoxal, 3-deoxyglucosone, and xylosone inactivated glutathione reductase by an NADPH-independent mechanism, with methylglyoxal being the most reactive. However, 2-oxoaldehydes were much less effective than 4-hydroxynonenal. Inactivation of glutathione reductase by these 2-oxoaldehydes was followed by slower reactions that led to the formation of fluorescent cross-linked products over a period of several weeks. These changes were accompanied by loss of arginine residues. Thus, the sequence of events is different for inactivation and modification of glutathione reductase by alpha,beta-unsaturated aldehydes compared with 2-oxoaldehydes with respect to kinetics, NADPH requirements, fluorescence changes, and loss of amino acid residues. The ability of 4-hydroxynonenal at low concentrations to inactivate glutathione reductase, a central antioxidant enzyme, suggests that oxidative degradation of unsaturated lipids may initiate a positive feedback loop that enhances the potential for oxidative damage.

Substrate and cofactor specificity and selective inhibition of lactate dehydrogenase from the malarial parasite P. falciparum.

Lactate dehydrogenase from the malarial parasite Plasmodium falciparum has many amino acid residues that are unique compared to any other known lactate dehydrogenase. This includes residues that define the substrate and cofactor binding sites. Nevertheless, parasite lactate dehydrogenase exhibits high specificity for pyruvic acid, even more restricted than the specificity of human lactate dehydrogenases M4 and H4. Parasite lactate dehydrogenase exhibits high catalytic efficiency in the reduction of pyruvate, kcat/Km = 9.0 x 10(8) min(-1) M(-1). Parasite lactate dehydrogenase also exhibits similar cofactor specificity to the human isoforms in the oxidation of L-lactate with NAD+ and with a series of NAD+ analogs, suggesting a similar cofactor binding environment in spite of the numerous amino acid differences. Parasite lactate dehydrogenase exhibits an enhanced kcat with the analog 3-acetylpyridine adenine dinucleotide (APAD+) whereas the human isoforms exhibit a lower kcat. This differential response to APAD+ provides the kinetic basis for the enzyme-based detection of malarial parasites. A series of inhibitors structurally related to the natural product gossypol were shown to be competitive inhibitors of the binding of NADH. Slight changes in structure produced marked changes in selectivity of inhibition of lactate dehydrogenase. 7-p-Trifluoromethylbenzyl-8-deoxyhemigossylic acid inhibited parasite lactate dehydrogenase, Ki = 0.2 microM, which was 65- and 400-fold tighter binding compared to the M4 and H4 isoforms of human lactate dehydrogenase. The results suggest that the cofactor site of parasite lactate dehydrogenase may be a potential target for structure-based drug design.

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

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.