Levels of Genetic Variants Among Symptomatic Blastocystis Subtypes and their Relationship to Mucosal Immune Surveillance in the Precancerous Colons of Experimentally Infected Rats.

PURPOSE: The relationship between the genetic diversity of Blastocystis and immune surveillance in precancerous colons with blastocystosis is still under investigation. This study aimed to identify the genetic Blastocystis variants among 54 symptomatic human isolates and their relationship to mucosal immune surveillance in the precancerous polyps of experimentally infected rats. METHODS: Polymerase chain reaction and high-resolution melting (PCR/HRM) curves discriminated human symptomatic Blastocystis isolates into subtypes (STs)/intrasubtypes, which were orally administered to rats to induce experimental infection. Then, the mucosal immune responses of the infected colons were evaluated in relation to polyp formation through immunostaining to identify mucus MUC2 and determine mucosal immune cell (goblet, lymphocyte and mast) counts, secretory IgA levels and parasitic intestinal invasion. RESULTS: ST1, ST3, and ST4 were found in 18.5% (10/54), 54.7% (29/54), and 27.8% (15/54) of the samples, respectively. Then, the HRM curve discriminated ST3 into the wild, mutant, and heterozygous [17/54 (31.5%), 5/54 (9.3%), and 7/54 (12.9%)] intrasubtypes. ST1 and ST4 had no genetic variations. Precancerous polyps were detected in the colons of 40.5% of the infected rats. ST1 constituted 14.7% of these cases, while the wild, mutant, and heterozygous intrasubtypes of ST3 showed polyps in 12.9%, 5.5%, and 5.5% of cases, respectively. Only 1.9% of the polyps were related to ST4. MUC2 showed weak immunostaining in 44.5% of the infected colons, and 38.9% were polyp inducers. Low goblet cell numbers and high interepithelial lymphocyte counts were significantly associated with polyp formation, particularly with ST1 and wild ST3. Among the polyp inducers, high numbers of mast cells were detected in wild ST3 and ST4, while a low number was found with heterozygous ST3. The level of secretory IgA was low in polyp-inducing STs. Most of the results were statistically significant. CONCLUSION: Immunosurveillance showed a potential relationship between ST1 and the ST3 intrasubtypes and precancerous polyps. This relationship may provide insight into the prevention and/or development of new immunotherapeutic strategies to combat colorectal cancer.

Predominance of Giardia lamblia assemblage A among iron deficiency anaemic pre-school Egyptian children.

Intestinal parasites and nutritional deficiency can coexist and influence each other. This study aimed to clarify the association between Giardia genotypes and presence of iron deficiency anaemia (IDA) among pre-school Egyptian children. Two groups (IDA and non-anaemic) of giardiasis children (44/group) were selected according to their recovery response after treatment of giardiasis. Each group included 24 and 20 gastrointestinal symptomatic and asymptomatic, respectively. Giardia human genotypes were performed by intergenic spacer (IGS) gene based polymerase chain reaction (PCR) with high-resolution melting curve (HRM). PCR/HRM proved that Tms of assemblage A and B ranged from 79.31 ± 0.29 to 84.77 ± 0.31. In IDA patients, assemblages A and B were found among 40/44 (90.9 %) and 4/44 (9.1 %), respectively, while in non-anaemic patients, assemblages A and B were found in 10/44 (22.7 %) and 32/44 (72.7 %), respectively, beside two (4.6 %) cases had mixed infection. The difference was statistically significant. No significant relation was found between symptomatic or asymptomatic assemblages and IDA as assemblage A was found in 21/24 (87.5 %) and 19/20 (95 %) of symptomatic and asymptomatic, respectively, while 3/24 (12.5 %) and 1/20 (5 %) of assemblage B were symptomatic was asymptomatic, respectively. A significant relation was found between assemblage A subtypes distribution among IDA patients as AI and AII were detected on 23 (52.3 %) and 16 (36.4 %) of patients, respectively, while one case (2.3 %) had mixed infection. In conclusion, assemblage A is predominant among IDA giardiasis children suggesting its role in enhancing the occurrence of IDA while B has a protective role.

SEROPREVALENCE OF TOXOPLASMA GONDII INFECTION AND ITS AS- SOCIATED RISK FACTORS IN NEUROPSYCHIATRIC PATIENTS IN JAZAN PROVINCE, SAUDI ARABIA.

Toxoplasma gondii has worldwide distribution in nearly one-third of the human population. It is a neurotropic protozoan parasite so a potential role of T. gondii infection for some neuropsychiatric disorders was postulated. Patients with psychiatric disorders had high toxoplasmosis se- roprevalence. Limited information about toxoplasmosis seroprevalence in psychiatric patients was known in southern area of Saudi Arabia. The current cross sectional case control study aims at determination of the prevalence of T. gondii IgG & IgM in neuropsychiatric patients in Jazan Province. A total of 162 neuropsychiatric patients from Al-Amal hospital for psychiatric health and 162 subjects without neuropsychiatric manifestations from Jazan General Hospital, Jazan City, KSA. were enrolled in the study. Psychiatric diagnosis was based on the International Classification of Diseases-10 (ICD-10 classification). Serological analysis for latent toxoplasmosis (IgG) and active toxoplasmosis (IgM) was done using Enzyme Linked Immunosorbent Assay (ELISA). Investigations for the association with socio-demographic, clinical and behavioral characteristics in psychiatric patients were also done. The serofrequency of IgG antibodies among neuropsychiatric patients was significantly higher than that of the controls (35.8% vs 14.8%) P = 0.0022. OR 3.2 with 95% CI= (1.4952 to 6.8774). However; serofrequency of toxoplasma IgM antibody between neuro-psychiatric patients and controls was not statistically significant (P > 0.05).,Bivariate and multivariate analysis for socio-demographics and possible associated risk factors showed that contact to cats and/or dogs, eating under cooked meat, and contact to soil were significantly higher in neuropsychiatric patients than controls.