Association between ocular toxoplasmosis and APEX1 and MYD88 polymorphism.

Ocular toxoplasmosis (OT) is the most common form of posterior uveitis, and in some countries, it is the most frequent cause of visual impairment. Studies demonstrate that the polymorphism in genes involved with the immune response can be related both to the occurrence and to the recurrence of OT. Thus, the present study aimed to analyze the association between OT and the polymorphism of the APEX1 (rs1130409) and MyD88 (rs7744) genes. The studied sample consisted of 48 volunteers with OT and 96 asymptomatic volunteers, but positive for anti - T. gondii IgG (control group). Blood collection was performed for serological analysis (ELISA) and DNA extraction. Genotyping of the polymorphism was performed using real-time PCR. To analyze the association between gene polymorphism and OT, logistic regression was performed. The results showed no association between the MYD88 gene polymorphism and the development of OT. However, a significant association was found between OT and APEX1 gene polymorphism, indicating that individuals expressing polymorphic (GG) or heterozygous (GT) alleles are more likely to develop the disease (P-value = 0.02 and 0.03 respectively). These results suggest that APEX1 (rs1130409) polymorphism is a risk factor for the occurrence of ocular toxoplasmosis in the studied population.

Seroprevalence and risk factors for human toxoplasmosis in northeastern Brazil

Toxoplasmosis is one of the most prevalent parasitic infections in humans, causing severe clinical complications in immunocompromised patients or in foetuses. Estimates on the toxoplasmosis seroprevalence in human populations vary widely, even within the same region. This study aimed to estimate the prevalence of Toxoplasma gondii infection in the municipality of Santa Cruz, State of Rio Grande do Norte, Brazil, and identify the risk factors for toxoplasmosis. T. gondii IgG antibodies were measured in 66.2% of the studied population. The factors associated with infection were as follows: age above 45 years (OR = 7.4; 95% CI = 3.7-14.8); illiteracy (OR = 2.8; 95% CI = 1.6-5.0); the presence of more than three cats in the home (OR 2.0; 95% CI = 1.2-3.5); no water tank (OR = 2.0; 95% CI = 1.4-3.1); and consumption of raw or unpasteurized milk (OR = 2.0; 95% CI = 1.3-3.0). The risk factors identified were predominantly related to the ingestion of oocysts. This study may contribute to public health knowledge of toxoplasmosis and the definition of control programs, particularly for pregnant women from regions similar to the area studied.

Ploidy manipulation and polyploid detection in the white shrimp Litopenaeus vannamei (Boone 1931) (Decapoda, Penaeidae).

Ploidy manipulation has been rarely used in the genetic improvement of cultured marine shrimps. Although polyploid induction has been proven to be successful in Penaeids, including the species Litopenaeus vannamei, the methodology still requires some improvements. In the present work, different thermal shock treatments on ploidy manipulation were tested and a protocol for detecting polyploid individuals was also established. Fertilized eggs were treated by cold (10°C) and heat (38°C) thermal shocks for 8, 12, 15, 18, 20, and 22 min to induce polyploidy. Nuclear measurements within distinct treatments revealed a significant deviation in relation to the mean diameter of nuclei in the control individuals. Triploid and tetraploid metaphases were observed within treated individuals, confirming the increase of interphasic nuclear diameter. The cold thermal shock was more efficient than the hot ones, besides leading to a higher and more homogeneous hatchery rate. A mean number of three nucleoli per nucleus were observed in diploid individuals, while treated samples usually presented up to five nucleoli per nucleus. The standardization of protocols to obtain and detect polyploid products allows further utilization of such methods on a commercial scale in order to evaluate the performance of polyploid individuals in the genetic improvement of L. vannamei.