Role of host immunity and HBx among inactive chronic hepatitis B patients in a highly endemic region.

The hepatitis B virus (HBV) infection has a wide range, from fulminant hepatitis to inactive chronic hepatitis B (ICB) infection. The present study evaluated critical factors in the outcomes of HBV infection in a highly endemic region of Iran (approximately 12% HBV positive). The expression of seven genes involved in host immunity (Foxp3, T-bet, ROR-γt, AKT, CREB, IL-28/or IFN-λ2, and IL-28R) and HBx for viral activities were evaluated using real-time PCR, TaqMan method. A total of 58 subjects were randomly chosen, including 28 ICB and 30 healthy controls (HCs) from the Esfandiar district, South Khorasan province, Iran. The expression index of Foxp3 and ROR-γt was moderately up-regulated in ICBs but did not statistically significant. T-bet expression in ICB patients was significantly higher than in HCs (p = 0.004). Furthermore, evaluating two signalling pathways in Th activation and cell survival showed that the CREB pathway was significantly up-regulated in ICB patients compared to HCs (p = 0.006), but the AKT did not differ. In innate immune responses, the IL-28/or IFN-λ2 expression in ICB patients was significantly higher than in the HCs (p = 0.02). Surprisingly, only one ICB patient disclosed HBx expression, which shows deficient virus activity in these patients. The ICB condition seems to result from host immune pressure on HBV activities, up-regulation of T-bet and IFN-λ. The high expression of CREB may prevent Kupffer's pro-inflammatory reactions in the liver. Whereas the absence of HBx expression in ICB patients and, consequently, the inactivity of HBV may also confirm such immune pressure.

Comparison of four methods for isolation of Yersinia enterocolitica from raw and pasteurized milk from northern Iran.

Four methods for isolation of Yersinia enterocolitica from raw and pasteurized milk from northern Iran were compared. Three hundred and ten raw milk samples were collected from tanks on their arrival at various central dairies, and 40 pasteurized milk samples were collected from tanks on their arrival at a manufacturing plant. Each sample was examined for the presence of Y. enterocolitica by (1) direct culture; (2) enrichment in double-strength buffered peptone water at 4 degrees C for 1 month; (3) enrichment in modified Rappaport medium at room temperature for 72 h after a preenrichment in double-strength peptone water at 4 degrees C for 1 month; and (4) enrichment in a medium containing sucrose, tris (hydroxymethyl) aminomethane, sodium azide, and ampicillin at 28 degrees C for 48 h after a preenrichment in double-strength peptone water at 4 degrees C for 1 month. All samples and enrichments were spread on MacConkey agar plus calcium chloride and Tween 80, Yersinia selective agar, and Hektoen medium plus ampicillin. Five samples (1.6%) of raw milk but no pasteurized milk samples were positive for Y. enterocolitica. No Y. enterocolitica were recovered by methods 1 or 2. Y. enterocolitica were recovered from 2 samples by method 3 followed by culture on Yersinia selective agar, and from 5 samples by method 4 followed by culture on Hektoen medium plus ampicillin. The isolates were biotype 1A or 1B, serotype O:7-13 or O:9 and phage type Xo or Xz. All isolates were resistant to ampicillin and amoxicillin, and sensitive to tetracycline, streptomycin, chloramphenicol, and trimethoprim-sulfamethoxazole.