Fecal microbiota in patients with ankylosing spondylitis: Correlation with dietary factors and disease activity.

BACKGROUND: We investigated the characterization of the gut microbiome in Chinese patients with ankylosing spondylitis (AS) and healthy controls (HCs) and to explore the association ofbacteria communities with dietary factors and disease activity. METHODS: 16S ribosomal RNA gene sequencing was performed on fecal DNA isolated from stool samples in consecutive cross-sectional cohorts. Alpha and beta diversities were assessed using QIIME, and comparisons were performed using one-way ANOVA, Student's t-test, and SKN multiple range comparisons to examine differences between groups and a correlation network analysis was performed. RESULTS: We investigated 207 samples from 103 AS patients and 104 HCs. Alpha diversity was not significant difference in AS compared with HCs. For the community structure, Bacteroidetes was the most represented class. Megamonas, Dorea, and Blautia were significantly greater in AS than in HCs, whereas the abundance of Lachnospira, Ruminococcus, and Clostridium_XlVb was significantly lower in AS than in HCs. In addition, Specific gut microbiome was significantly correlated with disease activity and dietary factors. CONCLUSIONS: Our results suggest that the human gut microbiome of AS patients was clearly different from that of HCs and bacteria communities are associated with dietary factors and disease activity.

The association of HLA-B27 and Klebsiella pneumoniae in ankylosing spondylitis: A systematic review.

Ankylosing spondylitis (AS) is a chronic inflammatory arthritis of unknown origin. Its autoimmune origin has been suggested but never proven. Several reports have implicated K. pneumoniae as a triggering or perpetuating factor in AS; and the HLA-B27 antigen has also been found in association with AS. But there is no satisfactory explanation of why the presence of HLA-B27 predisposes to AS and the precise role played by K. pneumoniae in the disease has not yet been clarified. However, various studies have shown that the results of molecular, immunological, and microbiological studies could establish the link between K. pneumoniae infections and HLA-B27 in the aetiopathogenesis of AS. In this review, we have examined the evidence linking the interaction between K. pneumoniae infections and HLA-B27 in AS, and tried to exploit the possible mechanisms by which K. pneumoniae infections might induce pathologic processes to develop novel diagnostic criteria. Finally, we have also summarized some dietary regimens that could be helpful in the therapeutic management of AS patients.

Seroprevalence and genetic characterization of Toxoplasma gondii in cancer patients in Anhui Province, Eastern China.

BACKGROUND: Recent studies have indicated the predominance of Toxoplasma gondii genotype Chinese 1 in animals in China. However, little is known of the genetic features of the parasite in humans. This study aims to determine the prevalence of anti-T. gondii antibodies based on which the genetic character of the parasite was identified in cancer patients in China. METHODS: A total of 1014 serum samples with malignant neoplasms were collected from six tertiary-care hospitals (HAUCM, APH, HAMU, XAH, FHH and HBMC) from January, 2012 to August, 2013. Antibodies against T. gondii were examined by enzyme-linked immunosorbent assay (ELISA). Blood samples were subsequently used for PCR assay to detect T. gondii DNA (gra6). The DNA positive samples were subjected to genotyping using a multiplex multilocus nested PCR-RFLP at 10 loci, including sag1, sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1 and apico. Samples from the patients were anonymous and only data with regard to age and gender was available at sample collection. RESULTS: Overall, 8.38% (85/1014) of the examined patients showed positive antibodies against T. gondii. Among them, 61 (6.02%) were seropositive only for IgG, 16 (1.58%) were only for IgM, and 8 (0.79%) were found to be positive for both IgG and IgM. The seroprevalence of antibodies to Toxoplasma ranged from 5.8% to 11.0%, without regional difference (χ(2) = 4.764, P = 0.445). No significant differences of the positive rates of T. gondii infection were noted in genders (male, 8.96%; female, 7.45%) (χ(2) = 0.707, P = 0.400) and in ages (χ(2) = 1.172, P = 0.947). Of 1014 DNA samples, 36 (3.55%) were positive for T. gondii by nested PCR at gra6 locus and nine gave rise to complete genotyping results. All samples with achieved PCR-RFLP genotyping showed a common genetic character of type Chinese 1 (ToxoDB#9). CONCLUSION: Seroprevalence of toxoplasmosis in immunosuppressed individuals is rarely reported in China and we presented a positive rate of 8.38% in cancer patients. Toxoplasma genomic DNA genotyping demonstrated a common genetic character of Chinese 1, indicating a possible pathogenic origin of animals in human infection.