Effects of CCR2 and CCRS polymorphisms on HIV-1 infection in Thai females

Polymorphisms in CCR2 and CCR5 genes reportedly affect HIV-1 transmission and disease progression in HIV-1-infected individuals. In the study presented here, we examined the effects of CCR2 and CCR5 polymorphisms on HIV-1 transmission in 74 Thai females who were exposed to HIV but seronegative (ESN) and in 347 HIV-seropositive females. We found that the combination of 2 non-synonymous substitutions, CCR2 V64I and CCR5 G316A, tended to occur more frequently in ESN females (2 of 74) than in HIV-1 infected females (1 of 347) (P = 0.08). This suggested that non-synonymous substitution in the CCR5 gene also affects HIV-1 transmission in an Asian population in which the CCR5-Delta32 is very rare.     

Erythrocyte binding preference of avian influenza H5N1 viruses

Five erythrocyte species (horse, goose, chicken, guinea pig, and human) were used to agglutinate avian influenza H5N1 viruses by hemagglutination assay and to detect specific antibody by hemagglutination inhibition test. We found that goose erythrocytes confer a greater advantage over other erythrocyte species in both assays.     

HIV infection and risk factors among Bangkok prisoners,Thailand: a prospective cohort study

Background  

Incarceration has been associated with HIV infection among injection drug users. However, data on HIV risk factors of the inmates during incarceration are rarely reported from Thailand.     

Characteristic of HIV-1 in V3 loop region based on seroreactivity and amino acid sequences in Thailand

The third variable (V3) domain of the envelop (env) protein has been used for determining genetic subtype and phenotypic characteristics of human immunodeficiency virus type 1 (HIV-1) isolates. Based on the seroreactivity of the HIV-1 subtype by V3 peptide binding enzyme immunoassay (EIA) of 351 samples obtained in 1998 from HIV-1 infected individuals and AIDS patients, we found that 283 (80.6%) were subtype E, 20 (5.7%) were subtype B, 28 (8.0%) were cross-reactive between both types and 20 (5.7%) were non-typeable. The degree of seroreactivity of HIV-1 subtype E decreased significantly when the amino acid at the crown of the V3 loop was substituted from a GPGQ motif to GPGR motif. Interestingly, AIDS patients who had V3 sequences of subtype E as GPGR motif had a stronger immunoreactivity to GPGQ motif peptides than to GPGR motif peptides, in contradiction for their proviral sequences. The results suggested that mutations in the V3 loop may lead to a changed immunoreactivity that makes HIV-1 mutants unrecognizable or allow escape from the primary immune response by means of neutralizing sensitivity. In connection with vaccine development, it should be pointed out that the combination of V3 sequencing and peptide EIA could provide a novel approach to obtain a primarily infected virus sequence as a target for a preventive AIDS vaccine.     

A rapid,simple, and sensitive loop-mediated isothermal amplification method to detect toxigenic Vibrio cholerae in rectal swab samples

Loop-mediated isothermal amplification (LAMP) method was designed for clinical diagnosis of Vibrio cholerae carrying the ctxA gene. The detection limits of the method were 5 fg of purified genomic DNA/reaction and 0.54 CFU/reaction. The method was applied to rectal swab samples from cholera patients and healthy volunteers (19 subjects each) and yielded the same results as the “gold standard” culture method, while the polymerase chain reaction-based method failed to detect V. cholerae in 8 of the positive samples. Direct application of this LAMP method without precultivation enabled the rapid detection of 5 asymptomatic carriers from rectal swabs of 21 household contacts of cholera patients. This LAMP method could be a sensitive, specific, inexpensive, and rapid detection tool for V. cholerae carrying the ctxA gene in the clinical laboratory and in the field.