Analysis of BoLA class II microsatellites in cattle infested with Boophilus microplus ticks: class II is probably associated with susceptibility

The aim of this study was to determine the role of certain bovine lymphocyte antigens (BoLA) regions in the resistance or susceptibility to Boophilus microplus tick infestation in two different breeds of cattle. The breeds were maintained, one in natural conditions and the second one in an experimental setting at the research station in Martinez de la Torre, Veracruz, Mexico. The study took place from June to August 2001 (natural infestation) using 33 crossbreed steers (crossbreed is here defined as 3/4 European = 1/2 Simmenthal x 1/4 Holstein x 1/4 Zebu, a cross resulting from F1 x Simmenthal), ranging from 15 to 20 months old. Fifty-nine F1 cows (1/2 Holstein x 1/2 Zebu) were included in the experimental setting, infested and followed during 25 days in November 2001 and 2002. Experiment A included thirty-one 2-7-year-old F1 cows, and experiment B included twenty-eight 18-24-month-old F1 heifers. Both groups were analysed separately and were not comparable because of the different infestation methods and genetic background. All ticks > or =4mm long were counted on the total body of F1 animals and on one side of the 3/4 European steers. In this case, susceptible animals were defined when having ticks = X + 1S.D. (29 +/- 16). In the experimental setting susceptibility was defined when the number of ticks was over the 75 percentile (> or =79). DNA was extracted from peripheral blood samples of all animals. The BoLA DRB3, DRBP1, RM185 and BM1815 microsatellite loci were amplified using a PCR method. Genescan software was used for analysis in an ABI sequencer. The SPSS statistical program was used and the comparisons were assessed using the Fisher's exact test. In the naturally infested animals, DRB3-184 was found positively associated with tick infestation (P = 0.018; Pc = NS; OR = 5; EF = 28%). DRBP1-128 was also found to be increased (P = 0.03; Pc = NS; OR = 6; EF = 42%). In the experimentally infested animals, two more loci were found to be associated, BM1815-152 (P = 0.01; Pc = NS; OR = 15; EF = 74%) and DRBP1-130 (P = 0.05; Pc = NS; OR = 4; EF = 77%). None of them remained significant after correction, indicating that a larger sample size is needed to confirm the results. This is the first study showing MHC genes associated with tick infestation based on class II microsatellite polymorphisms. Further studies are needed to confirm the susceptibility traits and to determine haplotype segregation in families.     

Aerobic bacterial flora of the nasal cavity in Gulf of California sea lion (Zalophus californianus) pups

Nasal swab samples from clinically healthy California sea lions pups (Zalophus californianus) from six different reproductive rookeries in the Gulf of California were collected to determine the type and frequency of the representative aerobic bacterial microflora of their nasal mucosa. A total of 114 samples were examined and 100 bacterial isolates were identified and typified by microbiological and biochemical standard tests. Fifty four isolates corresponded to Gram positive bacteria (54%) and 46 isolates to Gram negative bacteria (46%). Fifteen bacterial genera were identified, including Micrococcus, Arcanobacterium, Corynebacterium, Moraxella, Neisseria, Escherichia, Kurthia, Acinetobacter, Staphylococcus, Brevibacillus, Bacillus, Klebsiella, Stenotrophomonas, Pseudomonas and Aeromonas. The most frequently isolated genera were Moraxella (24%), Micrococcus (18%), and Corynebacterium (15%). These results show the presence in the nasal cavity of sea lions of several microorganisms. Although considered part of the normal microflora, they may also be opportunistic pathogens for their hosts and may act as a potential natural sentinel of environmental changes.     

Molecular evidence of Babesia caballi (Nuttall and Strickland, 1910) parasite transmission from experimentally-infected SCID mice to the ixodid tick, Haemaphysalis longicornis (Neuman, 1901).

Molecular evidence that suggests the possible role of the ixodid tick, Haemaphysalis longicornis and its eggs in the transmission of equine Babesia caballi parasites is presented herein. Using polymerase chain reaction (PCR) to assay for DNA in parasites, presumably acquired by ticks that were allowed to feed on splenectomized-SCID mice, experimentally exposed to in vitro-cultivated B. caballi, we have obtained positive bands that corresponded to the expected B. caballi-specific 430bp gene fragment in 50% of female ticks used, and in 75 and 25% of eggs and larval progeny, respectively. Also, parasite DNA was detected in ticks, eggs and larvae as late as the 16th to the 20th day post-host infestation. Present findings support to the potential role of H. longicornis in the transmission of B. caballi parasites. Its capability, however, to successfully transmit the infection to horses under natural conditions in the field needs to be further ascertained. To our knowledge, this is the first documented study incriminating H. longicornis as a most and likely biological vector of equine babesias.     

In vitro susceptibility of field isolates of Francisella tularensis subsp. holarctica recovered in Spain to several antimicrobial agents

Forty-two recent (1997-1999) Spanish isolates of Francisella tularensis subsp.holarctica were tested in a broth microdilution method for their susceptibilities to 29 antimicrobial agents, including penicillins, cephalosporins, cephamicins, monobactams, penems, aminoglycosides, tetracyclines, macrolides, quinolones, chloramphenicol and fosfomycin. The isolates were resistant to beta-lactam antibiotics and susceptible to chloramphenicol, ciprofloxacin, levofloxacin and norfloxacin.     

Comparative haematology and blood chemistry of endangered lizards (Gallotia species) in the Canary Islands

Blood samples were taken from the ventral coccygeal vein of 15 El Hierro giant lizards (Gallotia simonyi) (seven females and eight males), six La Gomera giant lizards (Gallotia bravoana) (four males and two females) and four Tenerife giant lizards (Gallotia intermedia) (two males and two females), and 31 blood parameters were measured. Among the haematological parameters there were significant differences between the three species in heterophils, azurophils and lymphocytes, but no significant differences in red blood cell count, white blood cell count, haemoglobin, packed-cell volume, monocytes, eosinophils and basophils. In terms of blood chemistry there were significant differences between the three species in cholesterol, triglycerides, glucose, sodium, chloride, urea, uric acid, total proteins, prealbumin, albumin and gamma globulins, but no significant differences in calcium, potassium, aspartate aminotransferase, alanine aminotransferase, creatine kinase, bile acids, alpha-1 and alpha-2 globulins and beta globulins.     

Chemical characterization of lignin and lipid fractions in industrial hemp bast fibers used for manufacturing high-quality paper pulps

The chemical composition of lignin and lipids of bast fibers from industrial hemp (Cannabis sativa) used for high-quality paper pulp production was studied. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of fibers showed a lignin with a p-hydroxyphenyl:guaiacyl:syringyl unit (H:G:S) molar proportion of 13:53:34 (S/G ratio of 0.64). p-Hydroxycinnamic acids, namely, p-coumaric and ferulic acids, were found in only trace amounts. Among the lipids, the main compounds identified by GC/MS of the hemp fibers extracts were series of n-alkanes, free and esterified sterols and triterpenols, waxes, and long-chain n-fatty acids. Other compounds such as n-aldehydes, n-fatty alcohols, steroid hydrocarbons, and steroid and triterpenoid ketones as well as steryl glycosides were also found.     

Production and composition of cider spirits distilled in "alquitara"

The capacity of alquitara (a traditional distillation system) to produce cider brandies is evaluated. To do so, the chemical composition of 12 fractions obtained during the distillation process and the cider brandies obtained from five ciders were analyzed (alcohol strength, methanol, volatile substances, furfural, and metals), taking into account European and Spanish legislation. During the course of distillation, an important increase in methanol, furfural, 2-phenylethanol, and metals in the last fractions was observed, while fusel oils were more abundant in the first fractions collected. Only acetaldehyde behaved differently, showing a minimum concentration in the middle fractions that might be explained by its formation on the surface of alquitara. On the other hand, the final distillates obtained by means of this method complied with the considered regulations. Worth highlighting in this regard are the low levels of a potential toxin such as methanol, as well as the detection of a constant ratio for methanol, ethanol, and fusel oil for the pairs of cider/spirits analyzed, which could be interpreted as an indication of good uniformity in the distillation system and method, thus guaranteeing product quality.     

Anaplasma marginale: lack of cross-protection between strains that share MSP1a variable region and MSP4

In Mexico, there are no commercial alternatives for the immunoprophylaxis of bovine Anaplasmosis, a disease responsible for great economic losses. Blood derived Anaplasma marginale used for immunizing susceptible cattle has shown promising results for homologous protection and controversial results against unrelated strains. The present study examined, under controlled conditions, the cross-protective potential of an immunogen composed of blood derived A. marginale of three strains against challenge with strains not included in the immunogens. Groups 1 and 2 were immunized with blood derived Anaplasma from strains Mexico, Morelos and Yucatan, group 4 with strains Morelos, Veracruz and Yucatan, two more groups (2 and 5) of equal conditions were inoculated with an adjuvant alone. Groups 1, 4 and 5 were challenged with Mexico strain; groups 2 and 3 were challenge-inoculated with strain Veracruz; groups 3 and 5 with strains Veracruz and Mexico as controls. Only animals in group 1, immunized and challenged with strain Mexico showed adequate protection. Both groups challenged with strains not included in the immunogens developed poor protection, while all the controls had to be treated to prevent death.