Comparative analysis of intestinal parasitic infections of outpatients in Guangxi medical university affiliated hospital in 2005 and 2013.

OBJECTIVE: To understand the hospital's status and trends of intestinal parasitic infections and to provide a reference for prevention. METHODS: Stool samples were treated by acid-ether centrifugation; iodine staining and direct-smearing were performed; intestinal parasites were examined under a microscope; characteristics of parasitic infections in population were analyzed using the descriptive epidemiological method. RESULTS: 10 kinds of parasites were detected; the infection rate of clonorchissinensis was the highest, followed by B. hominis, hookworm, whipworm and roundworm in order (x(2) = 131.188, 1261.928, 129.386, P < 0.01); The overall infection rates in 2013 and 2005 were 37.08% and 41.07% respectively, and the infection rate in 2013 was lower than that in 2005 (x(2) = 20.5003, P < 0.01); All the infection rates of clonorchissinensis, hookworm, whipworm and roundworm in 2013 were lower than those in 2005 (x(2) = 18.275, 45.449, 34.855, 12.435, P < 0.01); Both in 2005 and 2013, the male infection rate was higher than that in female (x(2) = 12.859, 24.924, P < 0.01); For male, the infection rate of clonorchissinensis was the highest, followed by B. hominis (x(2) = 313.621, 104.409, P < 0.01); for female, the infection rate of B. hominis was the highest, followed by clonorchissinensis (x(2) = 95.293, 43.357, P < 0.01). For male, the age group of 41~ had the highest infection rate of clonorchissinensis in 2005 (x(2) = 5.734, P < 0.05), and the age groups of 31~ and 41~ had the highest infection rate of clonorchissinensis in 2013 (x(2) = 8.908, P < 0.01); for female, both in 2005 and 2013, the age group of 21~, 31~, 41~ and 51~ had the highest infection rate of clonorchissinensis (x(2) = 6.508, 5.145, P < 0.05). There was no difference in male infection rate of B. hominis in 2005 (x(2) = 10.134, P > 0.05); in 2013, the age group of 0~ had the highest infection rate (x(2) = 3.825, P < 0.05); for women, it was the highest in the age groups of 11~, 21~ and 31~ in 2005 (x(2) = 10.459, P < 0.01), 0~ and 11~ in 2013 (x(2) = 53.669, P < 0.01). For Hookworm infection in male, the highest infection rate was found in the age group of 11~ 21~ and 61~ in 2005 (x(2) = 4.547, P < 0.05), 61~ and ≥ 71~ in 2013 (x(2) = 4.843, P < 0.05); for female, the highest infection rate was found in the age groups of 51~ and 61~ both in 2005 and 2013 (x(2) = 5.709, 5.958, P < 0.05). CONCLUSION: In Nanning city, although there was a decline in the infection rate of intestinal parasites of attenders compared with 8 years ago, the infection rate was still high and intestinal parasites were various; The infection rate of geohelminthes had been reduced to a low level; Clonorchissinensis and B. hominis were still the insect species with the highest infection rate.

[PCR-based genotype classification of Blastocystis hominis isolates from college students of Guangxi].

Fifty-three Blastocystis hominis isolates were separated from the fecal specimens of carriers in college students from Guangxi and cultivated in vitro, and the genetic DNA was extracted. All the isolates were genotyped by PCR using seven pairs of known sequence-tagged site (STS) primers. The results showed there were five subtypes in the 53 isolates. Subtype 3 was the most popular one (32.1%, 17/53), followed by subtype 7 (9.4%, 5/53). Subtypes 1 (7.6%, 4/53), 4 (7.6%, 4/53), and 6 (1.9%, 1/53) were detected, while subtypes 2 and 5 were not detected. The genotypes of the other 22 isolates were unknown which were negative to all the STS primers.

[Relationship between morphology and pathogenicity of Blastocystis hominis trophozoites].

Six hundred and eighty-six fresh fecal specimens were collected from outpatients (663 well-formed feces and 23 watery feces) during March 2011 to March 2012. All specimens were examined microscopically by direct smear and iodine stained method. B. hominis obtained from the human positive fecal specimens were cultured in LES medium, and inoculated into the abdominal cavity of 10 female mice of 6-8-week old. The abdominal fluid was examined with same methods. 103 of 686 patients were positive (80 well-formed feces and 23 watery feces). Micro-scopically, the granular form and vacuolated form of B. hominis trophozoites could be easily identified by direct smear and iodine staining in well-formed fecal specimens, showing ovoid in shape and about (13.2 +/- 0.2) microm in size. The trophozoites cultured in LES medium showed similar feature. But in the watery fecal specimens and mice ascites specimen, they were amorphous containing more granules. And their average size was (28.0 +/- 0.3) microm which was larger than the former. Moreover, the ameba form of B. hominis trophozoites was also detected in the 23 watery fecal specimen and mice ascites specimen. The trophozoites of B. hominis were varying in shape and size depending on their living environment.

[Expressions and significance of IL-17 and IL-23 in intestinal mucosa of mice infected with Blastocystis hominis].

OBJECTIVE: To study the expressions of interleukin-17 (IL-17) and interleukin-23 (IL-23) in the intestinal mucosa of BABL/C mice infected with Blastocystis hominis. METHODS: A total of 30 BABL/C mice were randomly divided into different groups: an experimental group, an immunosuppressant group and a normal group. Each mouse of the experimental group and immunosuppressant group was administered intraperieneally with dexamethasone (2 mg, gd, for 5 days) and one of the control group was given physiological saline (0.2 ml). In the experimental group, each mouse was infected with Blastocystis hominis (107 parasites per 0.5 ml) by the intragastric infusion method; in the immunosuppressant group and normal group, the mice were fed with equal physiological saline. On the fifth day post-infection, the duodenum, jejunum, ileum and colon of the mice of the 3 groups were taken out for the tissue section. The pathological changes of bowel mucosa were determined by HE staining, and the expressions of IL-17 and IL-23 in different parts of bowel mucosa were determined by immunohistochemistry assay. RESULTS: The pathological examinations showed intestinal mucosa had various degrees of inflammatory changes. The expressions of IL-17 and IL-23 in the intestinal mucosa of the mice in the experimental group was significantly higher than those in the immunosuppressant group or normal group (both P < 0.05). The expressions of IL-17 and IL-23 in the intestinal mucosa of the mice in the immunosuppressant group were similar to those in the normal group (P > 0.05). The expression of IL-17 in the duodenum or jejunum or colon of the mice was significantly higher than that in the ileum in the experimental group (P < 0.05). The expression of IL-23 in the duodenum or jejunum of the mice was significantly higher that that in the ileum or colon in the experimental group (P < 0.05). CONCLUSIONS: IL-17 and IL-23 are highly expressed in the intestinal mucosa of the mice infected with Blastocystis hominis. IL-23 may also be involved in the immunomodulatory effects of Blastocystis hominis infection, which plays a mutual regulatory role with IL-17.

[A preliminary study on preservation methods of Blastocystis hominis].

OBJECTIVE: To observe the effect of different cryoprotective agents and temperature factors on the viability of Blastocystis hominis so as to explore the ideal method for preservation of B. hominis. METHODS: B. hominis agents were obtained from a patient's fecal specimen. Having washed by normal saline and divided into tubes, the samples were cryopreserved in -20 degrees C refrigerator or in -196 degrees C liquid nitrogen with 10% DMSO, 40% glycerol and 15% ethylene glycol respectively. The thawed B. hominis agents were then used for culture. By trypan blue staining and microscopy, the viability and proliferation of those resuscitative cells were investigated. RESULTS: B. hominis survived for 3 weeks at 18 degrees C-20 degrees C while less than 1 week at 4 degrees C-6 degrees C. When stored in -20 degrees C refrigerator or liquid nitrogen with cryoprotective agents, they survived for more than 3 months. The cryopreservation with 40% glycerol at -196 degrees C for 6 months resulted in 41.7% viability of the revivified cells. Cleavage cells were easily observed after culturing for 72 hours. CONCLUSION: Preserving B. hominis in liquid nitrogen with 40% glycerol is an optimal cryopreservation protocol.