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Articles by issue : Vol 10, No 1 (2016): March 2016
6
Articles
Detection of Hepatitis B Virus X Gene Mutation from Local Clinical Samples

ARTARINI, ANITA, JESSICA, HANARY G, KARTIKASARI, RADEN RINI, RIANI, CATUR, RETNONINGRUM, DEBBIE S

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

Hepatitis B virus (HBV) belongs to the Hepadnaviridae family and it infects hepatocytes, which is the most common cell in liver. HBV infection is distinguished into acute and chronic infection based on the duration of infection. Chronic infection of HBV exists more than six months and it can develop into liver cirrhosis and hepatocellular carcinoma (HCC). The development of chronic HBV infection is affected by viral particle load, genotype and subgenotype, as well as its association with HBV X gene mutation. The aim of this study is to determine the genotype and subgenotype based on X gene, and to detect its mutation. The X gene in DNA samples was amplified with nested PCR, which produced two fragments with size of 469bp and 395bp. The DNA sequencing results of the amplified product were analyzed by BLAST program to determine their HBV genotype and subgenotype based on the X gene sequences. The analysis showed that patients were infected mainly by HBV subgenotype B3, which are common in Indonesia. The obtained HBx gene sequences were aligned with HBx gene sequences from database to determine the genotype, subgenotype and amino acid substitution. In this study, we described the presence of known HCC-related HBx mutant, i.e. V5L, A47T, I127T and K130M/V131I, as well as new HBx mutant, i.e. G22S and A85T. The presence of HBx T118N mutant was detected at the highest percentage and occurred from samples with high HBV DNA titer. 

High Prevalence of Occult Hepatitis B Infection (OBI) and its Molecular Characteristics among Pregnant Women in Surabaya, Indonesia

MEILANI, MEILANI ( School of Medicine Airlangga University ) , UTSUMI, TAKAKO, JUNIASTUTI, JUNIASTUTI, AMIN, MOCHAMAD, SOETJIPTO, SOETJIPTO, HAYASHI, YOSHITAKE, LUSIDA, MARIA INGE ( Institute of Tropical Disease Airlangga University )

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

Perinatal transmission is the predominant mode of hepatitis B virus (HBV) transmission in countries where HBV infection is endemic. Newborns of HBV infected mothers have a high risk (up to 90%) of chronicity through perinatal transmission. HBsAg serology screening has been recommended to pregnant women, to prevent perinatal HBV infection. However, at present HBV DNA can be detected in serum with negative HBsAg (OBI - occult hepatitis B infection). The aim of this study was to determine the prevalence of occult hepatitis B infection (OBI) in pregnant women in Surabaya, Indonesia and its virological characteristics. A total of 50 HBsAg-negative and anti-HBc-positive sera were tested for anti-HBs and HBeAg. HBV DNA was isolated from these samples, analyzed by polymerase chain reaction (PCR) and sequenced. HBV DNA was detected in 9 (18%) samples, based on part of the S gene sequence. HBV/B3-adw2 was found predominant in 7 (77.7%) samples, HBV/B9-ayw1 in 1 (11.1%) sample, and HBV/C7-adrq+ in 1 (11.1%) sample. Three samples had mutations (Q129H, T131N, M133S, T140I, T126I) in the ‘a’ determinant region, which may play a role in the undetectability of the virus by the common HBsAg detection kit. The prevalence of OBI in pregnant women from Surabaya is high, but still in line with the general population in Asia. Application of anti-HBc antibody or HBV DNA detection in screening would be very beneficial and prevent perinatal transmission from OBI pregnant women.

Utilization of the Bacteria Bacillus pumilus and Citrobacter youngae as Flotation Bioreagents in the Microflotation of Chalcopyrite, Pyrite, and Silica

SANWANI, EDY, HIDAYATI, DITA, CHAERUN, SITI KHODIJAH

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

Until presently, relatively toxic and expensive chemical reageants are routinely used in the flotation of sulfide and oxide minerals. To establish a more environmentally friendly flotation process, alternative flotation reagents have been explored extensively by using microbes and their metabolic products such as biosurfactants or EPS (extracellular polymeric substances) as high molecular weight biosurfactants. Hence, the present work focused on the application of the mixotrophic bacteria capable of both producing biosurfactants and oxidizing iron-sulfur (herein Bacillus pumilus strain SKC-2 and Citrobacter youngae strain SKC-4) as flotation bioreagents in the microflotation of chalcopyrite, pyrite and silica. Laboratory microflotation tests using both bacterial strains as bioreagents were evaluated as a function of conditioning time, pH and bacterial cell concentration. Experimental evidence indicated that the chalcopyrite recoveries could be achived using both bacterial strains but its better recovery was obtained with the bacterium Citrobacter youngae as bioreagents. The findings of this study thus suggest the possible application of these bacterial strains as flotation bioreagents in order for establishing a more eco-friendly mineral processing.

ITA registration form and back cover

Helianti, Is ( 1. BPPT 2. Indonesian Society for Microbiology )

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

Heterologous Expression of α-Amylase from Saccharomycopsis fibuligera R64 and its Tyr401Trp Mutant in Pichia pastoris

AMALIA, RIEZKI, ISMAYA, WANGSA TIRTA ( Dexa Laboratories of Molecular Sciences ) , PUSPASARI, FERNITA, HASAN, KHOMAINI, SUBROTO, TOTO, NATALIA, DESSY, SOEMITRO, SOETIJOSO

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

α-Amylase from Saccharomycopsis fibuligera R64 is a non-adsorbing raw-starch degrading enzyme, a unique characteristic. This character is difficult to explain in the absence of its three-dimensional structure. Here we discuss the expression of a-amylase from Saccharomycopsis fibuligera in Pichia pastoris and the effect of site directed mutagenesis on its activity. A model based on the structure of its homologs suggested mutation of codon of Tyr401 into that of a Trp residue. An activity study using whole cells P. pastoris showed similar substrate degradation rates by cells carrying either the native or mutant amylase encoding gene. However, the purified enzyme of the mutant strain showed faster starch hydrolysis.

Comparison of Microbial Pattern Causing Urinary Tract Infection in Female Out- and Hospitalized Patients in Jakarta

ROSANA, YEVA, OCVIYANTI, DWIANA, KARUNIAWATI, ANIS, AKHMAD, SYADZA RHIZKY PUTRI

Microbiology Indonesia Vol 10, No 1 (2016): March 2016
Publisher : Indonesian Society for microbiology

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Abstract

Urinary Tract Infection (UTI) is an infection in any part of the urinary system. Women are 3 times more likely to have UTI than men. The UTI accounts for 15% infection cases in outpatients and 24% cases in hospitalized patients. Although the most common cause of UTI is certain bacteria, but it was not easy to choose the appropriate antimicrobial therapy. Strategy for choosing empiric antimicrobial treatments for UTI in female out- and hospitalized patients should be based on the pattern of the causative organisms. The aim of this study was to understand the microbial pattern causing UTI in female out- and hospitalized patients in Jakarta. The UTI -1 causative microorganisms were obtained from urine culture containing 100,000 cfu/mL . Twenty nine microorganisms were found as the causative agents of UTI in 317 pregnant women who came to six Community Health Centres (Puskesmas) in Jakarta: Makassar; Pulogadung, Cakung, Pasar Rebo, Duren Sawit, and Kramat Jati for antenatal care. Twenty nine microorganisms were isolated from 114 urine samples of female hospitalized patients who were diagnosed of UTI. The samples were obtained from the Microbiology Laboratory Clinic of FKUI-RSCM. The most common microorganisms causing UTI in female out- and hospitalized patients were Gram negative bacteria. In female outpatients, Klebsiella sp was the most common causative bacteria (31%), followed by Escherichia coli (24.1%). In female hospitalized patients, Escherichia coli was the most common causative bacteria (30%), followed by Candida sp (24.1%) and Klebsiella pneumonia (6.8%). There was more variation in the pattern of UTI causative organisms in hospitalized female patients in comparison to that of the outpatients. Candida sp. was only found in hospitalized UTI patients but not in outpatients.