Sucrose, Lactose, and Xylitol Exposures Affect Biofilm Formation of Streptococcus mutans

Abstract Objective: To determine the level of biofilm formation of S. mutans after being exposed to 5% sucrose, 8% lactose, or 1% xylitol. Material and Methods: This research was a laboratory-based experimental study with post-test only control group design. S. mutans was grown in test tubes containing tryptose soy broth (TSB) medium supplemented with 1% glucose. They were incubated at 37° C for 24 hours to grow the biofilms. The culture was then exposed to 5% sucrose, 8% lactose or 1% xylitol, incubated for 24 hours at 37° C, and examined using ELISA at a wavelength of 625 nm. The statistical analysis was performed using a one-way analysis of variance followed by the least significant difference test (a=0.05). Results: There were some differences in the biofilm formation of S. mutans after exposure to 5% sucrose, 8% lactose, or 1% xylitol (p<0.05). An LSD test indicated significant differences among the biofilm formations after exposure to 5% sucrose and 8% lactose and between 5% sucrose and 1% xylitol. In comparison, there were no significant differences (p>0.05) between 8% lactose and 1% xylitol. Conclusion: Sucrose, lactose and xylitol can form biofilms and the formation of lactose biofilms is the same as xylitol.

Prevalence and genotype distribution of hepatitis B virus among migrant workers in Lombok Island, Indonesia

To examine the potential risk of hepatitis B virus (HBV) spread in Indonesia by migrant workers, based on the molecular characteristics of HBV strains. Methods: Sera collected from migrant workers traveling to their destination countries (pre-migrant workers) and those returning to Indonesia (post-migrant workers) were screened for HBsAg by ELISA, followed by HBV DNA detection by PCR and (sub) genotype/subtype determination according to surface region and whole genome sequencing. Results: Of 87 pre-migrant workers, 15 (17.24%) were HBsAgpositive, whereas 15 (12.10%) of 124 post-migrant workers were HBsAg seropositive. HBV genotype analysis based on the S region showed that HBV-B3/adw2 was predominant (96.15%, 25/26) whereas 3.85% (1/26) of isolates were HBV-C3/adrq+. Whole genome sequencing of selected strains and phylogenetic tree analysis identified subgenotype B7 in three samples previously categorized as subgenotype B3 based on S region analysis, supporting a recent argument that subgenotypes B5/B7/B8/B9 could be considered as a quasi-subgenotype of B3. Conclusions: A high prevalence of HBsAg carriers was detected among migrant workers from Lombok Island, with no significant difference in prevalence between before and after returning to Indonesia. All strains were classified into genotypes common in Indonesia, and the results suggested that migrant workers are not a risk factor for HBV transmission into Indonesia.

Antiviral activity of the dichloromethane extracts from Artocarpus heterophyllus leaves against hepatitis C virus

Objective To determine anti-viral activities of three Artocarpus species: Artocarpus altilis, Artocarpus camansi, and Artocarpus heterophyllus (A. heterophyllus) against Hepatitis C Virus (HCV). Methods Antiviral activities of the crude extracts were examined by cell culture method using Huh7it-1 cells and HCV genotype 2a strain JFH1. The mode of action for anti-HCV activities was determined by time-of-addition experiments. The effect on HCV RNA replication and HCV accumulation in cells were analyzed by quantitative reverse transcription-PCR and western blotting, respectively. Results The dichloromethane (DCM) extract of A. heterophyllus exhibited strong anti-HCV activity with an inhibitory concentration (IC

Differential distribution of hepatitis C virus subtypes in Asia: comparative study among Thailand, Indonesia, the Philippines and Japan.

Hepatitis C virus (HCV) is currently classified into at least six major genotypes, each of which is further divided into a number of subtypes. It has been reported that prevalence of each subtype varies among different geographical regions of the world and that severity of liver disease and sensitivity to interferon treatment varies with different subtypes. The purpose of this study was to determine and compare the prevalence of each subtype among HCV isolates in different areas in Asia such as southern (Hat Yai) and northern (Chiang Mai) parts of Thailand, Indonesia (Surabaya), the Philippines (Manila) and Japan (Kobe). Sera were obtained from various groups of patients and tested for antibodies against HCV using second and/or third generation ELISA kits. RNA was extracted from anti-HCV-positive sera and reverse-transcribed into cDNA. The cDNA-preparations were subjected to nested PCR to amplify NS5B and 5'-untranslated region (5'UTR) sequences. Amplified fragments were sequenced and subtypes of the isolates were determined based on sequence similarities with reported sequences. In Chiang Mai and Hat Yai, Thailand, HCV-3a, HCV-1a and HCV-1b were common in various populations. HCV type 6 variants were commonly found among blood donors and drug addicts in Chiang Mai, but not in Hat Yai. In Surabaya, Indonesia, HCV-2a was frequently detected in blood donors, but less frequently in patients with chronic liver disease. In blood donors, HCV-1a, HCV-1b and HCV-1d were more strongly associated with elevation of serum aminotransferase levels than HCV-2a. HCV-1a was significantly more common in patients on maintenance hemodialysis than in blood donors or patients with chronic liver disease. HCV-1d was detected exclusively in Indonesia. Another unique subtype HCV-3g was found also in Indonesia, though less frequently than HCV-1d. In the Philippines, a vast majority of the isolates were either HCV-1a or HCV-1b. Thus, HCV subtype prevalence varies among different regions of Asia.