Francisco J. Márquez

Fischer–Tropsch synthesis of hydrocarbons over mesoporous Co/SBA-15 catalysts: the influence of metal loading, cobalt precursor, and promoters

The influence of cobalt loading (10–40 wt% Co), cobalt precursor, and promoters (Re, Mn) on the physico-chemical and catalytic properties of mesoporous Co/SBA-15 catalysts for the Fischer–Tropsch Synthesis (FTS) reaction (T=493 K, P=20 bar, H2/CO=2) has been investigated. Catalysts were characterized by N2 and Ar adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR). For Co/SBA-15 catalysts prepared from Co(II) nitrate the dispersion decreased and the extent of cobalt reduction increased with cobalt loading. A maximum CO conversion was found for the sample with ca. 30 wt% Co loading, though the intrinsic activity of Co remained constant in the range of Co loading studied. More methane and less C5+n-paraffins were produced over the less reducible 10 wt% Co loading sample. The addition of ca. 1 wt% Re enhanced the reducibility of cobalt oxides and increased the catalyst activity, though the intrinsic activity of cobalt sites was not altered. Rhenium also favored the formation of long-chain n-paraffins (C10+) while decreasing methane selectivity. Promotion of cobalt with ca. 2 wt% Mn significantly improved cobalt dispersion but decreased its reducibility, producing catalysts that were less active than the unpromoted one. At similar cobalt loading (ca. 20 wt%), a much better dispersion and a stronger cobalt–support interaction leading to the formation of low-reducible cobalt silicates was observed for oxidized samples prepared from acetate and acetylacetonate precursors as compared to that derived from cobalt(II) nitrate, as evidenced by TEM, XPS, and TPR. The former catalysts were characterized by a low FTS activity and a product distribution shifted toward the formation of lighter products. Finally, at comparable Co loading Co/SBA-15 catalysts (nitrate precursor) were about 1.5 times more active per weight of total Co than a Co/SiO2 sample, with only minor differences in product selectivity.

Presence of Rickettsia felis in the cat flea from southwestern Europe.

Rickettsia felis, formerly called ELB agent, was identified by using molecular biology techniques in the cat flea (Ctenocephalides felis felis) from southwestern Spain. For the first time this flea-transmitted rickettsia has been detected within its vector in Eurasia.

Seroepidemiological study of Rickettsia felis, Rickettsia typhi, and Rickettsia conorii infection among the population of southern Spain

Rickettsia typhi and Rickettsia conorii, the etiologic agents of, respectively, murine typhus and Mediterranean spotted fever, are recognized as frequent causes of fever of intermediate duration in southern Spain; in addition, in recent years Rickettsia felis has been detected in potential vectors in this area. Nevertheless, limited data exist regarding the actual prevalence of past infection due to these three pathogens. In the present study, the prevalence of past infection due to R. felis, R. typhi, and R. conorii was determined in a representative population of southern Spain during 2002. In addition, the possible risk factors associated with exposure to these pathogens were investigated. An epidemiological survey was completed by all subjects included in the study. Serum samples were tested by indirect immunofluorescence assay. The prevalence of past infection due to R. felis, R. typhi, and R. conorii among the 504 total subjects was 6.5, 3.8 and 8.7%, respectively. In multivariate analysis, infection due to R. felis was independently associated with a high-risk occupation (one that required working outdoors in nature, close contact with domestic animals, or potential contact with rodents) (OR=5.8; 95%CI 2.1–15.6), while infection due to R. typhi was associated with older age (factor of 1.04 [95%CI 1.008–1.068]) and frequent insect bites (OR=10.3; 95%CI 2.3–45.5). Two factors were associated with infection due to R. conorii: a high-risk occupation (OR=9.3; 95%CI 3.7–23.2), and participation in outdoor activities (OR=7.2; 95%CI 1.4–38.5). The results confirm the widespread prevalence of past infection due to R. felis, R. typhi, and R. conorii in the population of southern Spain.

Spotted fever group Rickettsia in ticks from southeastern Spain natural parks

During an 8-years study, we collected from vegetation or domestic and wild mammals 1246 ticks (624 males, 511 females and 111 nymphs) belonging to 13 species in Jaen province (Andalusia) and we analyzed these ticks by PCR and sequencing for the presence of rickettsiae. Specific rickettsiae DNA was detected in 243 (19.5%) of the ticks tested. Sequence analysis of amplicons of gltA, ompA and ompB genes revealed that Ixodes ricinus were infected with R. monacensis, including strain IRS3, and R. helvetica (prevalences of 27.0% and 2.7%, respectively), while in I. ventalloi we found only this last species (12.5%). Moreover, Dermacentor marginatus presents R. slovaca (24.7%) and R. raoultii (59.9%). In Rhipicephalus sanguineus group ticks (Rh. sanguineus, Rh. turanicus and Rh. pusillus) only R. massiliae (15.2%) was found. Haemaphysalis punctata and Ha. sulcata were infected with a Rickettsia sp. near R. hoogstraalii (prevalence of 3.1% and 16.1%, respectively). In addition, Ha. punctata appeared infected with R. monacensis—like Rickettsia (1.0%) and R. raoultii (9.3%). None of I. hexagonus, Hyalomma lusitanicum, Hyalomma sp., Ha. hispanica or Rh. bursa studied ticks contained rickettsiae.

Ectoparasites of the endangered Iberian lynx Lynx pardinus and sympatric wild and domestic carnivores in Spain

Abstract Ectoparasites can cause important skin disorders in animals and can also transmit pathogens. The Iberian lynx Lynx pardinus has been stated to be the most endangered felid in the world and such vector‐borne pathogens may threaten its survival. We surveyed 98 wild carnivores (26 Iberian lynxes, 34 red foxes Vulpes vulpes, 24 Egyptian mongooses Herpestes ichneumon, 11 common genets Genetta genetta, two Eurasian badgers Meles meles, one polecat Mustela putorius) and 75 domestic but free‐ranging carnivores (46 cats Felis catus, 29 dogs Canis familiaris) from June 2004 to June 2006 in the two areas where the last lynx metapopulations survive: Sierra Morena and Doñana (Andalusia, southern Spain). A total of 65% of lynxes were parasitized (50% by ticks, 19% by fleas, 4% by lice, 31% by hippoboscid flies), as were 75% of foxes (58%, 60%, 0%, 19%), 71% of mongooses (50%, 4%, 46%, 0%), 54% of genets (18%, 36%, 0%, 0%), 30% of cats (22%, 14%, 0%, 2%), and 7% of dogs (surveyed only for ticks). Both badgers presented ticks, fleas and lice. Five species of ixodid ticks (Rhipicephalus pusillus Gil Collado, Rhipicephalus turanicus Pomerantzev and Matikashvili, Ixodes ricinus (Linnaeus), Ixodes hexagonus Leach and Ixodes ventalloi Gil Collado; and Hyalomma sp.), four species of fleas (Ctenocephalides canis Curtis, Pulex irritans Linnaeus, Spilopsyllus cuniculi (Dale), Xenopsylla cunicularis Smit), three species of chewing lice (Felicola (Felicola) inequalis (Piaget), Trichodectes (Trichodectes) melis (Fabricius), and Felicola (Lorisicola) isidoroi Pérez and Palma), and one species of hippoboscid fly (Hippobosca longipennis (Fabricius)) were found. We did not detect any cases of mange. Hippobosca longipennis is a new record for Spanish wildlife, and all the flea species are new records for the Iberian lynx. Fleas were more frequent on lynxes and foxes in winter than in spring. Rhipicephalus spp. were more frequent on cats in spring than in any other season. These and other epidemiological findings are discussed with respect to the conservation of the Iberian lynx.

Determination of the nature and reactivity of copper sites in Cu–TiO2 catalysts

XPS, temperature programmed reduction (TPR) and FTIR spectroscopy of adsorbed CO and the hydrogenation of crotonaldehyde were used to study the nature of the surface species present for two Cu–TiO2 catalysts (2 and 5% Cu) subjected to reduction in hydrogen at 523, 623 and 723 K. Despite TPR and XPS evidence for complete reduction, IR studies gave clear evidence for the presence of surface Cu(II) ions and two distinct types of Cu(I) sites. The large absorption coefficient for CO on the latter meant that spectra were dominated by bands due to CO on Cu+ even though these ions made up less than an estimated 10% of the total exposed copper sites. Exposed Cu+ remained after re-oxidation treatment, at 623 K in oxygen but this treatment, when followed by 523 K reduction, did not recover Cu(0) sites lost by high temperature reduction, indicating that sintering rather than encapsulation by TiOx was responsible for loss of copper surface area.

Spotted fever group Rickettsia in brown dog ticks Rhipicephalus sanguineus in southwestern Spain

A total of 2,229 adults ticks (1,428 males and 801 females) belonging to the brown dog tick, Rhipicephalus sanguineus Latreille, 1806, collected from dogs in Seville province (Andalusia), distributed in 500 lots ranging from one to eight specimens per lot, were examined for the presence of rickettsiae by molecular techniques. Specific rickettsiae DNA were detected in 90 lots (18%) of ticks tested. Sequence analysis of amplicons revealed that R. sanguineus ticks were infected exclusively with Rickettsia massiliae (including the strain Bar-29). The results of this study extend the knowledge of the geographic distribution and prevalence of these spotted fever group (SFG) rickettsiae and indicate that at least two of them, with yet uncertain pathogenicity to humans, are present in brown dog ticks in south western Spain. Although Mediterranean spotted fever (MSF) is an endemic disease in Andalusia, Rickettsia conorii was not found, whereas R. massiliae, recently described as a pathogenic species, was highly prevalent in this area. Our data suggest that in Andalusia a number of MSF or MSF-like cases attributed to R. conorii could have been actually caused by other SFG rickettsia present in R. sanguineus, particularly, R. massiliae.

Detection and identification of Bartonella sp. in fleas from carnivorous mammals in Andalusia, Spain.

A total of 559 fleas representing four species (Pulex irritans, Ctenocephalides felis, Ctenocephalides canis and Spilopsyllus cuniculi) collected on carnivores (five Iberian lynx Lynx pardinus, six European wildcat Felis silvestris, 10 common genet Genetta genetta, three Eurasian badger Meles meles, 22 red fox Vulpes vulpes, 87 dogs and 23 cats) in Andalusia, southern Spain, were distributed in 156 pools of monospecific flea from each carnivore, and tested for Bartonella infection in an assay based on polymerase chain reaction (PCR) amplification of the 16 S–23 S rRNA intergenic spacer region. Twenty‐one samples (13.5%) were positive and the sequence data showed the presence of four different Bartonella species. Bartonella henselae was detected in nine pools of Ctenocephalides felis from cats and dogs and in three pools of Ctenocephalides canis from cats; Bartonella clarridgeiae in Ctenocephalides felis from a cat, and Bartonella alsatica in Spilopsyllus cuniculi from a wildcat. DNA of Bartonella sp., closely related to Bartonella rochalimae, was found in seven pools of Pulex irritans from foxes. This is the first detection of B. alsatica and Bartonella sp. in the Iberian Peninsula. All of these Bartonella species have been implicated as agents of human diseases. The present survey confirms that carnivores are major reservoirs for Bartonella spp.

Incidence and Distribution Pattern of Rickettsia felis in Peridomestic Fleas from Andalusia, Southeast Spain

Abstract:  The presence of Rickettsia felis was investigated in three species of pulicid fleas (Ctenocephalides felis, Ctenocephalides canis and Pulex irritans) collected in 38 locales in Andalusia (Spain) over the period 1999–2004. Amplification of a fragment of OmpB gene was positive in 54.17 % of lots of Ct. felis. The identity of the PCR bands was confirmed as R. felis by sequence data obtained directly from the PCR amplicon. No rickettsia was found in Ct. canis nor P. irritans.

Prevalence data of Rickettsia slovaca and other SFG rickettsiae species in Dermacentor marginatus in the southeastern Iberian Peninsula

Abstract:  In southern Spain, Dermacentor marginatus ticks can be infected with several genospecies of spotted fever Group (SFG) Rickettsia. We developed a nested polymerase chain reaction assay by using a species‐specific probe targeting the ompA gene to detect and differentiate between the two groups of rickettsiae previously described in D. marginatus. SFG rickettsia has been detected in 85.15% of ticks studied (26.7% of positives have been to R. slovaca, the causative agent of TIBOLA‐DEBONEL, and 73.3% to SFG rickettsia closely related to strains RpA4–JL‐02‐DnS14–DnS28).