Presence of Ctenocephalides canis (Curtis) and Ctenocephalides felis (Bouché) infesting dogs in the city of Aguascalientes, México

Prevalence and seasonal distribution of Ctenocephalides canis (Curtis) and Ctenocephalides felis (Bouché) infestations in urban dogs of the city of Aguascalientes, Mexico, were studied. Between January and December 2007, 863 dogs in the Municipal Canine and Feline Control Center were examined. Overall prevalence of infestation was 12% (95% CI 10-14). Seasonal distribution revealed that prevalences in spring and summer were highest, while autumn and winter had lower prevalences. Two infestation peaks were observed, i.e., in April (17.7%) and July (18.9%). A positive correlation was detected between prevalence and temperature during the winter season (P < 0.05). Prevalence in relation to gender showed that males were more frequently infested, 14% (95% CI 11-17), than females, 9.4% (95% CI 7-13); hair length did not affect differences in prevalence. Six hundred twenty-nine fleas were examined; 62% were C. canis and 38% C. felis . Dogs infested with only C. canis were 48% (95% CI 38-58), while 18% were infested only with C. felis (95% CI 11-27); the remainder, 34% (95% CI 24-44), had mixed infestations.     

Leishmania infection in humans, dogs and sandflies in a visceral leishmaniasis endemic area in Maranhão, Brazil

Leishmania infection in humans, dogs and sandflies was examined in the endemic visceral leishmaniasis (VL) municipality of Raposa, state of Maranh?o, Brazil. In this study, we examined Leishmania chagasi infection in the blood serum of both humans and Canis familiaris and the natural Leishmania sp. infection rate in the sandfly vector, Lutzomyia longipalpis. Enzyme-linked immunosorbent assay, indirect immunofluorescence reaction and polymerase chain reaction were performed to detect Leishmania infections in humans, dogs and sandflies, respectively. Overall, 186 out of 986 studied human beings were infected with L. chagasi parasites, representing an infection prevalence of 18.9%. An even higher infection rate was detected in dogs, where 66 (47.8%) out of 138 were infected. Among all Lu. longipalpis captured (n = 1,881), only 26.7% were females. The Leishmania infection frequency for the vector Lu. longipalpis was 1.56%. Remarkably, all infected sandflies were found in the peridomiciliary area. Furthermore, a high incidence of asymptomatic forms of VL in the human and canine populations was observed. The results of this study suggest autochthonous transmission of L. chagasi in this endemic area for visceral leishmaniasis because infection by Leishmania sp. was identified in all important elements of the transmission chain.     

Müllerian inhibiting substance in sex-reversed dogs

In normal males, Müllerian Inhibiting Substance (MIS), produced by testes during an embryonic critical period, is thought to induce regression of the Müllerian duct system, including the oviducts and uterus. In XX sex-reversed dogs, an apparent contradiction has been reported: The uterus persists in the presence of testes or ovotestes. The objective of this study is to determine whether testes of XX male and ovotestes of true hermaphrodite dogs produce MIS, and to examine the anatomy of Müllerian duct derivatives of affected dogs for evidence of regression. Gonadal samples were tested for MIS activity in a bioassay. The mean MIS activity score of XX males was similar to that of normal XY males and significantly greater than that of normal XX females. The mean MIS activity score of XX true hermaphrodites was intermediate between normal XX females and XY males. Within the true hermaphrodite group, ovotestes in which the proportion of testicular tissue was greater than or equal to 1/2 had higher MIS scores than those in which the proportion of testicular tissue was less than 1/2. XX males had a well-developed epididymis adjacent to each testis, but no oviducts. In true hermaphrodites, the oviduct regressed and an epididymis was present when greater than or equal to 1/2 of the adjacent ovotestis was testicular, and MIS activity in that gonad was high. A few ovotestes with intermediate levels of MIS activity had both an oviduct and an epididymis. Regression of the oviductal portion of the Müllerian duct system was positively correlated to the amount of testicular tissue and the MIS activity of the gonad, as would be predicted by Jost's original hypothesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diverse and atypical genotypes identified in Toxoplasma gondii from dogs in São Paulo, Brazil

The prevalence of Toxoplasma gondii in 118 unwanted dogs from S?o Paulo City, S?o Paulo State, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test and found in 42 (35.8%) dogs, with titers of 1:20 in 10, 1:40 in 6, 1:80 in 5, 1:160 in 5, 1:320 in 6, 1:640 in 7, and 1:1,280 or higher in 3. Hearts and brains of 36 seropositive dogs were bioassayed in mice, or cats, or both. Tissues from 20 seropositive dogs were fed to 20 T. gondii-free cats. Feces of cats were examined for oocysts. Toxoplasma gondii was isolated from 15 dogs by a bioassay in mice, from the brain alone of 1, from the heart alone of 4, and from both brains and hearts of 10. All infected mice from 5 of 15 isolates died of toxoplasmosis during primary infection. Four additional isolates were obtained by bioassay in cats. Genotyping of these 19 T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and a new SAG2 (an apicoplast marker Apico) revealed 12 genotypes. One isolate had Type III alleles at all 11 loci, and the remaining 18 isolates contained a combination of different alleles and were divided into 11 genotypes. The absence of Type II in Brazil was confirmed. The result supports previous findings that T. gondii population genetics is highly diverse in Brazil.     

Seasonal variations in lectin‐induced lymphocyte transformation in beagle dogs

Abstract

The lymphocyte stimulation test (LST) is an in vitro corollary of in vivo cell‐mediated immunity. We have analyzed LST results from 32 dogs covering a 16‐month time span. Two mitogens (plant lectins) were used in the LST, phytohemagglutinin (PHA) and concanavalin A (Con A) with comparable results. All dogs exhibited a seasonal variation in LST results using both mitogens. The dogs were either controls or were in one of five groups that received whole‐body gamma ray irradiation from a ⁶⁰CO source. There was little effect of irradiation except on the mean levels of oscillation. Few differences were noted among groups. The estimated mean times of peak activity in the LST ranged from July 19‐August 2 for PHA and from July 18‐August 15 for Con A. The times of peak of individual dogs for both mitogens were predominantly in the calendar quarter June 21 ‐September 20, and were, therefore, not randomly distributed throughout the year. The implications of these findings are discussed.     

Hormonal changes in spontaneous and aglépristone-induced parturition in dogs

To increase our understanding of the endocrine changes associated with parturition in dogs, plasma concentrations of progesterone (P4), 15-ketodihydroprostaglandin F(2alpha) (PGFM), estradiol-17-beta (E2beta), cortisol, ACTH, prolactin (PRL), LH, and FSH were measured in six spontaneously whelping bitches and in six bitches in which parturition was induced with the progesterone-receptor blocker aglépristone on day 58 of pregnancy. Expulsion of pups in the induced group took place in the presence of P4 concentrations that were still elevated. PGFM concentrations increased before parturition in both groups, but levels were lower in the induced bitches. PGFM levels reached a maximum in both groups during parturition and quickly decreased in the spontaneously whelping group after parturition, but remained elevated in the induced group. In both groups, cortisol concentrations reached similar maximum levels during the last 30 h before the onset of expulsion. During the 3 days postpartum, cortisol concentrations were higher in the induced group. The highly variable ACTH concentrations did not differ significantly throughout the study within or between groups. In both groups, E2beta concentrations decreased and PRL concentrations increased between the late gestational period and the 30-h period before parturition. Concentrations of both LH (spontaneously whelping group) and FSH (both groups) decreased between late gestation and the postpartum period. The results of this study illustrate the hormonal changes around parturition in the bitch, and reveal that aglépristone-induced parturition is associated with still incomplete luteolysis, an altered PGFM profile, and elevated postpartum cortisol concentrations as compared with spontaneously whelping dogs.     

The performance of dogs in detecting α-ionone in the vapor phase

Summary Concentration-response functions for-ionone were established for four German shepherds (Figs. 3 and 4). The dogs were tested in a three choice behavioral apparatus (Fig. 2), and trained, by a restricted operant procedure, to establish an approach-avoidance discrimination between odor and air. Odorant concentrations were presented from an olfactometer calibrated by gas chromatography. Minimum detectable concentrations fell within the range 4.0×10^4.5–4.0×10^6.5 molecules/cm³. Concentration-response curves for three of the dogs show a clear double reversal in slope which is statistically significant and which divides the curve into a slowly descending upper limb, best fitted by a parabolic function, and a rapidly descending lower limb, best fitted by a cubic function (Figs. 5 and 6). There is evidence that this division might reflect a dual receptor mechanism. When performance during testing stabilized for a given concentration and the concentration was then lowered by a certain magnitude, the new performance level depended markedly on that magnitude. No evidence was found to suggest that adaptation to the test odor influenced performance. As defined by a differential threshold fraction (Flow/Flow) one dog's ability to discriminate between differences in flow rate fell in the range 0.12–0.08.We thank the U.S. Air Force, Air Force Office of Scientific Research for their generous support of this work (Grant No. 73-2425 to D.G.Moulton).-ionone was donated by Givaudan Inc. (Dr. J. Dorsky). We also thank Mr. Paul Phillips for able technical assistance and Dr. T. Burlingame for gas chromatographic measurements.     

Frequency of antibodies to Toxoplasma gondii in stray dogs of Oaxaca, México

We studied the frequency of antibodies against Toxoplasma gondii in stray dogs in the city of Oaxaca, Mexico through the evaluation of 154 sera by indirect ELISA. A frequency of 61.7% was found; it was higher in males (45 of 65, 69.2%) than in females (49 of 89, 55.0%), although this difference was not statistically significant. An increase in frequency was observed with age, the lowest being among animals younger than 1 yr (4 of 20, 20.0%) and the highest in dogs older than 7 yr (21 of 25, 84.0%). This is the first study in dogs of this region of Mexico and revealed high T. gondii transmission and evidence of early exposure in animals that are in close contact with contaminated water or raw meat, or both. Further studies are needed in order to understand the role of T. gondii infection in public health.     

Microsporum canis en gatos dermatológicamente sanos en Temuco,Chile

BackgroundMicrosporum canis is the most common cause of feline dermatophytosis and the most pathogenic fungus isolated from the skin and hair of healthy cats. Cats are considered to be the natural reservoir and infection sourse of this disease in human and domestic animals.AimsKnowing the M. canis frequency in the dermatological healthy cat population of Temuco city, Chile.MethodsFifty cat samples were collected irrespective sex or race. Cats' ages were between 2 months and 12 years old, and the animals were treated at the Veterinary Clinical Hospital of the Universidad Católica de Temuco, or in three private clinics from this city. Tissue and hair samples were collected using two sampling techniques: hair extracting tweezers and the Mariat & Tapia method. For the clinical diagnosis, the Wood's lamp was used. Hairs were microscopically observed followed by a culture using Sabouraud agar and Lactrimel agar. M.canis was isolated in 30 cats (60%).ResultsThere were no statistically significative differences when parameters such as age, sex and race were taking into account. Differences between the use of Sabouraud agar and Lactrimel agar were not registered. It was determined that the Mariat & Tapia method was able to detect more dermatophytes than the collecting tweezers method. These differences were statistically significative.ConclusionsThe percentage of M. canis isolation obtained in this work remarks the role of healthy cats in the transmission of these dermatophytes to humans and other animals.     

Ticks (Acari: Ixodidae) associated with domestic dogs in Franca region,São Paulo,Brazil

Ticks on 140 domestic dogs from both urban and rural areas of Franca region in São Paulo state were identified with 102 dogs from urban areas and 38 from rural areas. Of urban dogs, 27.5% were infested exclusively by Rhipicephalus sanguineus ticks. Of the rural dogs, 36.8% were infested with the following tick species: R. sanguineus, Boophilus microplus, Amblyomma ovale and A. cajennense. Mixed infestations included a dog hosting A. cajennense and A. ovale and another with B. microplus and R. sanguineus. The most intense infestations were detected on urban dogs. Hemolymph tests of these ticks performed to detect rickettsial or Borrelia bacteria yielded negative results.     

LRRK2 mutation in familial Parkinson’s disease in a Taiwanese population: clinical, PET, and functional studies

Pathogenic mutations in leucine-rich repeat kinase 2 (LRRK2) cause autosomal-dominant familial Parkinson’s disease (PD). We performed clinical, imaging, and molecular functional studies in one family with the R1441H and six families with the G2385R variants of Lrrk2. To determine the contribution of these variants to familial PD in Taiwanese, we screened 32 Taiwanese or ethnic Chinese patients with familial PD for four pathogenic substitutions (R1441H, I2012T, I2020T, and G2019S) and one susceptibility polymorphism (G2385R). The frequencies of R1441H and G2385R were 3.7% and 22.2%, respectively. G2019S, I2012T, and I2020T were not detected. The clinical phenotypes and [¹⁸F]-dopa PET findings for subjects with R1441H or G2385R resembled those of patients with idiopathic PD; however, their lymphoblastoid cell lines showed increased apoptosis following exposure to a proteosome inhibitor. Thus, LRRK2 mutations are rare in Taiwanese with familial PD. Further study is needed to identify causative genes or unique biomarkers for familial PD.     

Virulence factors in food,clinical and reference Enterococci: A common trait in the genus?

The occurrence of several virulence traits (cytolysin, adhesins and hydrolytic enzymes) was investigated in a collection of 164 enterococci, including food and clinical isolates (from human and veterinary origin), as well as type and reference strains from 20 enterococcal species. Up to fifteen different cyl genotypes were found, as well as silent cyl genes. The occurrence of the cyl operon and haemolytic potential seems to be widespread in the genus. A significant association of this virulent trait with clinical isolates was found (p < 0.05). High levels of incidence were also observed for genes encoding surface adhesins (esp, efaA(fs), efaA(fm)), agg and gelE, irrespectively of species allocation and origin of strains. Although gelE behaves as silent in the majority of the strains, gelatinase activity predominates in clinical isolates, whereas lipase and DNase were mainly detected in food isolates pointing to their minor role as virulence determinants. No hyaluronidase activity was detected for all strains. Numerical hierarchic data analysis grouped the strains in three main clusters, two of them including a total of 50 strains with low number of virulence determinants (from 2 to 7) and the other with 114 strains with a high virulence potential (up to 12 determinants). No statistical association was found between virulence clusters and species allocation (p > 0.10), strongly suggesting that virulence determinants are a common trait in the genus Enterococcus. Clinical strains seem to be significantly associated with high virulence potential, whereas food, commensal and environmental strains harbour fewer virulence determinants (p < 0.01). A high level of relative diversity in virulence patterns was observed (Shannon's index varies from 0.95 to 1.0 among clusters), reinforcing the strain-specific nature of the association of virulence factors. Although a low risk seems to be associated with the use of enterococci in long-established artisanal cheeses, screening of virulence traits and their cross-synergies must be performed, particularly for commercial starters, probiotic strains and products to be used by high risk population groups.     

Heterogeneity in β0 thalassemia from Algeria: Genetic,clinical and molecular studies

Summary Six Algerian patients with ⁰ thalassemia are presented, in addition to the two patients already reported (Godet et al., 1977). Family studies indicate that all the patients had homozygous thalassemia characterized by absence of globin chain synthesis in peripheral blood. The clinical severity varies from one family to the other and within the same family, from typical Cooley's anemia to thalassemia intermedia and appears to be related to the child death rate observed in each family. The / biosynthetic ratio was 0.36–0.40 in seven patients and 0.2 in the most seriously affected patient. The mRNA content in peripheral reticulocytes was less than 1.5% of mRNA in seven patients and 13.3% in one patient. These results indicate that Algerians homozygous for thalassemia are heterozygous at the clinical, biochemical and molecular levels.