Objective To study biological characteristics of R5 tropic human immunodeficiency virus (HIV)-1 strains in different disease stage. Methods Primary clinical viruses were isolated from fresh peripheral blood mononuclear cells (PBMC) using co-culture methods; meanwhile, viral co receptor usage and infectivity were tested using flow cytometry on GHOST (3) cell lines,which expressed CD4 receptor and CC ehemokine receptor 5 (CCR5) or CXCR4 eoreceptor; to identified CCR5 tropic viruses(R5 tropic strains). Viral replication kinetics was detected in PBMCs. Plasma viral load was measured using an HIV-1 nucleotide fluorescence quantification assay kit. Results There were 22 individuals with HIV-1 subtype B' infection, in which 11 were CD4>0. 2 × 109/L and 11 were CD4≤0. 2 × 109/L. All isolated viruses used CCR5 coreceptor and therefore were HIV-1 R5 tropic strains. The infectivity of R5 tropic strains isolated from patients with CD4≤0.2 × 109/L was (7.392 7 ± 4. 584 2) % ; while the infectivity of R5 tropic strain from patients with CD4>0. 2 × 109/L was (2. 613 6 ± 1. 610 5)%. There were significant statistical difference(t= 3. 262, P<0.05). The possibility of viral replication became strong after the day 7 post-infection. There was a significant difference of viral replication between two groups in the day 7,10, 15 post-infection(t value was 3. 771, 2. 509 and 2. 260 respectively, P<0. 05). The possibility of viral replication was higher in CD4≤0.2 ×109/L group than that of CD4>0.2 × 109/L group. The logarithm of viral load was (5. 606 8 ± 0. 815 1 ) copies/mL in CD4≤0.2 × 109/L group and (4. 729 8 ± 0. 431 6) copies/mL in CD4> 0.2 × 109/L group. There was a significant difference between two groups(t = 3. 771 ; P<0.05). Conclusion Viral infection and replication are enhanced during progression of disease, even if viral coreceptor usage do not switch from CCR5 to CXCR4.

A type of entomopathogenic fungus of soil in Citrus grandis 'tomentosa' production base was isolated and identified with morphological and molecular biological methods, including pathogenesis, spore characteristic and ITS sequence analysis were conducted. The results showed that eighteen entomopathogenic fungi strains were isolated from the Tenebrio molitor infected in the soil samples, which were identified as Metarhizium anisopliae var. anisopliae. Based on results above, we concluded that there was quantity of Metarhizium resources in this area. These provided the useful information for controlling some pests of C. grandis by using these strains of fungus.
Animals ; Citrus ; parasitology ; Metarhizium ; isolation & purification ; physiology ; Pest Control, Biological ; methods ; Soil Microbiology