Development of a Simple and Rapid Method Based on Polymerase Chain Reaction–Based Restriction Fragment Length Polymorphism Analysis to Differentiate Helicobacter, Campylobacter, and Arcobacter Species

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of amplified DNA fragment of the 16S and 23S rRNA genes was performed on 35 Helicobacter, 24 Campylobacter, and 15 Arcobacter strains. PCR amplification generated a 1004-bp fragment of 16S rDNA and a 2.6-Kbp fragment of 23S rDNA from each strain. The amplicons were digested with DdeI and HpaII, respectively. For both assays, distinctive profiles were obtained for each genus. 23S rDNA PCR-RFLP analysis with HpaII enzyme identified Campylobacter and Helicobacter strains at the species level. Analysis of 16S rRNA gene with DdeI enzyme was not useful for the specific identification of Campylobacter and Arcobacter, although it discriminated among Helicobacter species. The PCR-RFLP technique allowed for the discrimination among these three related genus with only one restriction enzyme; therefore it can be a simple, rapid, and useful method for routine identification.     

Lower Permian bivalves from central Patagonia, Argentina

The earliest Permian faunal successions of central Patagonia show compositional changes that probably reflected the environmental warming at the end of the Gondwana glaciations. Bivalves of Asselian to probably Early Tastubian age are described. A new genus,Sueroa, is proposed to reunite a previously known species and a new species,Sueroa andreisi n. sp. Another five new species:Parallelodon? quichaurensis n. sp.,Heteropecten cortignasi n. sp.,Etheripecten saraviae n. sp.,Streblopteria montgomeryi n. sp. andPraeundulomya moreli n. sp. are described. Two previously known species:Malimania patagoniensis (González) andEuchondria sabattiniae González are revised and new occurrences are reported. A further eleven species are described, but they are left in open nomenclature being because they are insufficiently known; these are:Phestia? n. sp.,Modiolus sp.,Palaeoneilo sp.,Stutchburia sp.,Schizodus sp.,Vacunella? sp.,Edmondia sp.,Myonia? n. sp.,Myonia? sp. andPachymyonia? n. sp.     

Trypanosoma cruzi strains isolated from human, vector, and animal reservoir in the same endemic region in Mexico and typed as T. cruzi I, discrete typing unit 1 exhibit considerable biological diversity

In this study, three strains of Trypanosoma cruzi were isolated at the same time and in the same endemic region in Mexico from a human patient with chronic chagasic cardiomyopathy (RyC-H); vector (Triatoma barberi) (RyC-V); and rodent reservoir (Peromyscus peromyscus) (RyC-R). The three strains were characterized by multilocus enzyme electrophoresis, random amplified polymorphic DNA, and by pathological profiles in experimental animals (biodemes). Based on the analysis of genetic markers the three parasite strains were typed as belonging to T. cruzi I major group, discrete typing unit 1. The pathological profile of RyC-H and RyC-V strains indicated medium virulence and low mortality and, accordingly, the strains should be considered as belonging to biodeme Type III. On the other hand, the parasites from RyC-R strain induced more severe inflammatory processes and high mortality (> 40%) and were considered as belonging to biodeme Type II. The relationship between genotypes and biological characteristics in T. cruzi strains is still debated and not clearly understood. An expert committee recommended in 1999 that Biodeme Type III would correspond to T. cruzi I group, whereas Biodeme Type II, to T. cruzi II group. Our findings suggest that, at least for Mexican isolates, this correlation does not stand and that biological characteristics such as pathogenicity and virulence could be determined by factors different from those identified in the genotypic characterization.     

Differential distribution of antibodies to different viruses in young animals in the free-ranging rhesus macaques of Cayo Santiago

BACKGROUND: The breeding colony of free-ranging rhesus macaques was established in 1938 in Cayo Santiago (CS) with animals collected in northern India. The seroprevalence to cercopithecine herpesvirus type 1 (B virus) and simian retroviruses has been studied previously. RESULTS: This is the first report on the seropositivity to different viruses using samples collected shortly after removing animals (n = 245) from CS. All samples were negative for measles, simian immunodeficiency virus and simian type D retroviruses. The overall prevalence of antibodies was around 50% for simian T-lymphotropic virus I (STLV-I). For B virus, the prevalence was 38%. CONCLUSIONS: Data obtained showed marked differences in the antibody distribution to B virus and STLV-I within the free-ranging colony of rhesus macaques. Implication of these data for the Specific Pathogen Free program at the Caribbean Primate Research Center are also discussed.     

Potential pathogens carried by Spanish ibex (Capra pyrenaica hispanica) in southern Spain

The Spanish ibex (Capra pyrenaica hispanica) population of southern Spain was surveyed for potential pathogens associated with the conjunctiva, external ear canal, as well as reproductive and upper respiratory tracts. We sampled 321 ibex (131 adult males, 100 adult females, and 90 yearlings); these included 271 apparently healthy animals and 50 that were naturally infected with Sarcoptes scabiei. A total of 688 bacterial isolates were identified (377 gram-negatives, 225 gram-positives, and 86 Mycoplasma spp.); sex, age, location, infection with S. scabiei, and disposition of the animal (free-ranging versus captive) were evaluated as risk factors for infection. Infections with Mycoplasma agalactiae and Mycoplasma arginini were associated with age, having a higher frequency of isolation in young animals. With Escherichia coli, Mannheimia haemolytica, Pasteurella multocida biotype A, and Staphylococcus aureus, significantly higher isolation rates were associated with adults. The isolation frequency for E. coli was higher in females, whereas Moraxella bovis isolations were mostly associated with males. The presence of mange increased the risk of infection with both Streptococcus equi subsp. zooepidemicus and M. haemolytica. The geographic origin of sampled animals was related to the isolation of Branhamella ovis, M. agalactiae, and all Pasteurella sp. Isolations of M. haemolytica, P. multocida biotype A, E. coli, and B. ovis were more prevalent in samples from free-ranging rather than captive animals. Of the gram-positive bacteria, S. aureus represented the predominant species isolated from nasal, vaginal, and ocular samples. Mycoplasma agalactiae and M. arginini were the predominant Mycoplasma spp., and both were associated most often with the external ear canal. The most frequently isolated gram-negative bacteria included E. coli, M. haemolytica, P. multocida biotype A, and B. ovis. Isolation rates of gram-negative species varied by source. In nasal samples, M. haemolytica and P. multocida biotype A were isolated most frequently, whereas in ocular and vaginal samples, B. ovis and E. coli, respectively, were most frequently isolated.     

Toxicity and mode of action of Bacillus thuringiensis Cry proteins in the Mediterranean corn borer, Sesamia nonagrioides (Lefebvre)

Sesamia nonagrioides is one of the most damaging pests of corn in Spain and other Mediterranean countries. Bt corn expressing the Bacillus thuringiensis Cry1Ab toxin is being grown on about 58,000 ha in Spain. Here we studied the mode of action of this Cry protein on S. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other Cry proteins that were found to be active in this work (Cry1Ac, Cry1Ca, and Cry1Fa). Binding assays were performed with (125)I- or biotin-labeled toxins and larval brush border membrane vesicles (BBMV). Competition experiments indicated that these toxins bind specifically and that Cry1Aa, Cry1Ab, and Cry1Ac share a binding site. Cry1Ca and Cry1Fa bind to different sites. In addition, Cry1Fa binds to Cry1A's binding site with very low affinity and vice versa. Binding of Cry1Ab and Cry1Ac was found to be stable over time, which indicates that the observed binding is irreversible. The pore-forming activity of Cry proteins on BBMV was determined using the voltage-sensitive fluorescent dye DiSC(3)(5). Membrane permeability increased in the presence of the active toxins Cry1Ab and Cry1Fa but not in the presence of the nonactive toxin Cry1Da. In terms of resistance management, based on our results and the fact that Cry1Ca is not toxic to Ostrinia nubilalis, we recommend pyramiding of Cry1Ab with Cry1Fa in the same Bt corn plant for better long-term control of corn borers.