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.

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.

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.

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.

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.

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.

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.

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.

Influence of antisera, purification procedures, and tracers on validity of a testosterone radioimmunoassay.

The levels of testosterone in pooled plasma from men and from women were measured by radioimmunoassay. Testosterone was isolated from plasma either by ether extraction (direct procedure) or by chromatography of the ether extract (chromatographic procedure). Three different antisera (all raised against testosterone-3-oxime albumin) were employed. An additional variable was the use of two tracers, [3H] testosterone and [125I] histamine testosterone. The latter tracer was employed in both a freshly prepared form and two months after labelling. The old tracer was used both in a nonpurified and repurified form. The results were compared with those given by one of the antisera using the assay with chromatography. The validity of this assay was verified earlier using a test of radiochemical purity. In the statistical evaluation of the data, it was found that the assays of both plasma pools gave the same results as the validated assay, even with two other antisera, but only when the chromatographic purification was used. The direct assays gave significantly increased values for testosterone in the male plasma pool with one antiserum, and in the female plasma pool with all three antisera. It is concluded that those assays maybe considered valid which give results statistically indistinguishable from those obtained by the valid assay. These were all chromatographic assays and, in the man, also two direct assays. The comparison of [3H] testosterone and [125I] histamine testosterone as tracers did not indicate any major differences in the validity of the assays. When the 125I-tracer was employed, a moderate (1.5-2 fold) increase of sensitivity was seen with all three antisera, and the antisera could be used in a 10-40 times higher dilution. Furthermore, it was possible to use [125I] histamine testosterone and obtain practically the same results after two months, whether repurified or not.

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.

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.

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.

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.

[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.

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.

[Presence in Barcelona of Holopleura pacifica (Anoplura, Hoplopleuridae) a parasite of Rattus norvegicus]. / Présence à Barcelone de Hoplopleura pacifica (Anoplura, Hoplopleuridae) parasite de Rattus norvegicus.

The occurrence of the louse Hoplopleura pacifica on Rattus norvegicus from Barcelona is reported. The rats infested were caught in two different biotopes: the sewer system and the port.

[Cheilo-maxillo-palatine clefts and associated malformations]. / Fisuras queilo-maxilo-palatinas y malformaciones asociadas.

Based on the experience in this service during the preceding 6 years, authors have carried out an statistical study of cleft lip palates, and at the same time, given the high frequency that these are seen to be associated with congenital malformation, classify them within a syndromic group or family.

[Factors influencing the house dust mite population IV. Altitude]. / Factores que influyen en la composición de la fauna de ácaros del polvo doméstico. IV. Altitud.

A study has been carried out on house-dust mites present in the buildings of 3 towns in Catalunya (Spain), with different altitudes: Reus (altitude, 76 m); L'Ametlla (altitude, 321 m); and Puigcerdá (altitude, 1.202 m). The period studied was between october, 1975 and september 1976. From this study, a negative correlation has been observed between the number of mites in house dust and the altitude of the town. This supports the results obtained by other authors. The decrease in the number of mites with increases in altitude is due to a decrease in the number of mites belonging to the Pyroglyphidae family. This family was present in all samples of house-dust studied, and generally in a greater number than other groups of mites. Of the three species of Pyroglyphidae more frequently present in house dust (Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei), D. pternyssinus was the most abundant as well as the most affected variations of R.H and temperature resulting from the variations of the altitude. D. farinae and E. maynei were found in low levels suggesting inadequate conditions of temperature and R.H. in the houses studied. Even if E. maynei was the most abundant species in Puigcerdá, this is due more to the decreased incidence of D. pteronyssinus than to an increase in the number of E. maynei.