Genotyping of Toxoplasma gondii isolates from chickens from India

The present study was undertaken to isolate and genotype Toxoplasma gondii from free-range chickens (Gallus domesticus) from villages in Maharashtra and Tamil Nadu states of central and south India, respectively. Blood, heart, and brain from a total of 741 chickens were examined for T. gondii infection. Antibodies to T. gondii, as assayed with the modified agglutination test (MAT >or = 1:5) were found in 133 (17.9%) chickens. Hearts and brains of 186 chickens were bioassayed in mice. Additionally, hearts and/or brains of most of the seronegative (MAT < 1:5) chickens were fed to 20 T. gondii-free cats, while 32 seropositive chickens (MAT 1:5) were fed to 3 cats. T. gondii was not isolated from any of the chickens by mouse bioassay. Five of the cats that were fed seronegative chickens shed oocysts, while isolates were not obtained from any of the other cats fed seropositive chickens. These five isolates, along with the two that were previously isolated in India through cat bioassay, were genetically analyzed. Genotyping using the SAG 2 locus indicated that two isolates were type II and five were type III. Microsatellite analysis revealed allelic differences between and within the lineages. This is the first report of genetic characterization of any T. gondii isolate from India.     

Aerobic bacterial flora from dead-in-shell chicken embryos from Nigeria

Dead-in-shell chicken embryos from two commercial hatcheries in Anambra State of Nigeria were investigated for isolation of aerobic bacteria. For this purpose, 79 pooled samples containing 632 dead-in-shell chicken embryos were cultured. From these samples, 23 isolates of Escherichia coli and 25 isolates of Staphylococcus aureus were recorded. Other bacterial species isolated included Micrococcus sp. (fifteen isolates), Klebsiella sp. (thirteen isolates), Pseudomonas sp. (nine isolates), and Proteus sp. (seven isolates). Salmonella, Streptococcus, and Mycoplasma spp. could not be isolated. A high incidence of pathogenic strains of bacteria from dead-in-shell chicken embryos was observed. This suggests that the isolates may have contributed to the embryonic mortality and reduced hatchability recorded in the farms investigated.     

素材来自生产 灵感源于交流——广西大学韦平教授专访

2008年9月29日上午,借"中国畜牧兽医学会禽病学分会第十四次学术研讨会"在扬州落幕的空隙,广西大学教授、广西养禽与禽病研究所所长韦平来到<中国家禽>编辑部参观指导.此间,本刊就广西黄鸡产业的现状及存在问题、禽免疫抑制病及加强交流对科研工作的重要性等话题对韦教授进行了专访.本文择其精华刊发.     

Isolation of Giardia from a llama and from sheep.

Giardia cysts were detected in feces of a domestic llama (Lama glama) and in feces of lambs (Ovis aries) from Wisconsin, U.S.A. All of the animals examined were immature, and they had recent histories of poor condition and passing unformed or semiformed, pale stools. Giardia cysts from both host species were excysted in vitro, and the trophozoites were cultivated axenically. Furthermore, Giardia cysts from both sources were shown to produce infection in Mongolian gerbils (Meriones unquiculatus). The finding of Giardia in the llama represents a new host recorded for this parasite. Also, this is the first report of Giardia-infected sheep from the Western Hemisphere.     

Live foals produced from sperm-injected oocytes derived from pregnant mares

Recently, in vitro fertilization (IVF) in the horse has met with less than anticipated results. Various problems associated with equine IVF include: (1) the inability to collect large numbers of good quality oocytes, (2) the alteration of the zona pellucida associated with in vitro maturation of equine oocytes, and (3) the improper preparation of equine sperm cells for IVF of these oocytes. Therefore, this study was conducted to achieve fertilization via sperm injection of equine oocytes and to produce live offspring from this IVF procedure. Oocytes were collected by transvaginal ultrasound-guided oocyte retrieval procedures from early pregnant mares of mixed breeds (day 14 to day 70 of pregnancy) and were matured in vitro and subjected to intracytoplasmic sperm injection (ICSI). Injected oocytes were then cultured for 48 hours in either TCM-199 or P-1 medium (glucose and phosphate-free medium) supplemented with 15% fetal bovine serum. Cleavage rates for embryos cultured in the two culture media were different (47% vs. 63% in TCM-199 and P-1, respectively). Also, four Grade 1 embryos were surgically transferred into the oviducts of four recipient mares (one embryo/mare) at 48 hours post-ICSI, with three pregnancies (75%) developing as ultrasonically demonstrated by the presence of an embryonic vesicle in the uterine body by day 16 post-ICSI. On June 23rd one live filly was born after 328 days of gestation and subsequently, a second healthy filly was born after 319 days of gestation. To our knowledge, this is the first report of live foals resulting from in vitro fertilization (via ICSI) of in vitro matured oocytes recovered from pregnant mares using an efficient, repeatable transvaginal ultrasound-guided procedure.     

Seroprevalence of Toxoplasma gondii antibodies from wild canids from Brazil

The prevalence of anti-Toxoplasma gondii antibodies was evaluated by the indirect immunofluorescent-antibody test in serum of 57 wild canids from three different species: Lycalopex gymnocercus, Cerdocyon thous and Dusicyon vetulus from the northeast, southeast and southern regions of Brazil. The prevalence was 35.1%, with 20 of the 57 canids demonstrating antibodies anti-T. gondii at dilutions of 1:16 in 2, 1:32 in 4, 1:64 in 2, 1:128 in 2, 1:256 in 6, 1:512 in 2 and 1:2048 in 2 animals. None of the D. vetulus were positive. Among the L. gymnocercus 11 (91.7%) of the 12 samples were positive and among C. thous 9 (60%) of the 15 had antibodies anti-T. gondii.     

Genetic diversity of Toxoplasma gondii isolates from chickens from Brazil

Until recently, Toxoplasma gondii was considered clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. In the present study, we retyped 151 free range chicken isolates from Brazil including 117 newly isolated samples from 11 geographically areas (Alagoas, Bahia, Ceará, Maranh?o, Paraná, Pernambuco, Rio de Janeiro, Rio Grande do Norte, S?o Paulo, Sergipe, and Rondonia) and 34 previously reported isolates from the very north (Pará) and the very south (Rio Grande do Sul). Ten PCR-RFLP markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico were used to genotype all isolates. Overall analysis of 151 T. gondii isolates revealed 58 genotypes. Half (29/58) of these genotypes had single isolate and the other half of the genotypes were characterized with two or more isolates. Only 1 of 151 isolates was clonal Type I strain and 5 were clonal Type III strains. Two isolates had mixed infections. Clonal Type II strain was absent. One strain was Type II at all loci, except BTUB. The results confirm high genetic diversity of T. gondii isolates from Brazil.