Adenovirus type 5 (Ad5) is one of the vaccine vectors, including the COVID-19 vaccine. Pre-existing immunity to Ad5 may suppress the immunogenicity and efficacy of adenovirus vectored vaccine. The neutralizing antibodies are directed specifically toward seven hypervariable regions (HVR) of hexon proteins located on the outer surface of the capsid. This study aims to design an Ad5 vector that may circumvent anti-Ad5 immunity by designing a chimera Ad5 vector with the sequence of Ad26 HVR (Ad5HVR26) using in silico approach. Substitution of the Ad5 HVR DNA sequence may affect the alternative splicing process of adenovirus mRNA, which then influence the protein product. The splice site prediction of Ad5HVR26 chimera vector was found at HVR5, 6, and 7. The codon change in the splice site was performed to decrease the possibility of incorrect splicing, while retaining the original amino acid sequence. The HVR substitution in chimera vector Ad5HVR26 may also affect the interaction of hexon in the capsid. The HVR2 and HVR4 hexon proteins individually interact with other hexon proteins and IX protein. Thus, two designs of the Ad5HVR26 chimera vector were created in this research. The first design was the Ad5 chimera vector with complete substitution of HVR hexon by Ad26 sequence, with codon modification on the splice site. The second design was Ad5HVR26 chimera vector without the HVR2 and HVR4 substitution to maintain the hexon protein interaction with the capsid proteins. Production of the designed vectors are needed to prove the reduction of vector neutralization by pre-existing immunity.
Cases of food poisoning often occur due to food contamination caused by pathogenic bacteria. One of the pathogenic bacteria is Vibrio parahaemolyticus which is found in seafood. Thus, a fast, accurate and specific detection method is needed. The purpose of this study was to quickly detect Vibrio parahaemolyticus bacteria in seafood samples targeting the ToxR gene using Real Time PCR. In a previous study, gradient PCR was used to optimize ideal annealing temperature ranges from 53-62°C and revealed that 58°C produced the best outcomes for the ToxR primer with a size of 171 base pairs. Real-Time PCR was utilized to amplify, specify, and test for sensitivity under the ideal conditions from the PCR Gradient. The confirmation results show that the primer pairs could amplify ToxR of Vibrio parahaemolyticus with the amount of concentration as much as 50 ng/µL with Ct 10,69 and 10,32 and melting curve at temperature 82,18°C and 82,23°C. This primer pair can also distinguish non-target bacteria with different Ct and melting curve temperature. The sensitivity assay for this primer can amplify DNA templates at concentration 0,0032 ng/µL. Shrimp samples that are contaminated artificially can still be detected at Ct 13,02 and Ct 13,09. Based on these results, it can be concluded that Real Time PCR with ToxR primer can be applied to develop a detection kit for Vibrio parahaemolyticus in seafood.
This study investigates the effect of fermentation using lactic acid bacteria and yeast as starters on the formation of flavonoid compounds and the antioxidant activity of cacao beans. The fermentation process were divided into 4 groups: F1: spontaneous fermentation, F2: fermentation using Lactic Acid Bacteria (LAB), F3: fermentation using yeast and F4: fermentation using LAB and yeast. The extraction process was done using ethanol. Flavonoid content was analysis using spectrophotometer assay. The antioxidant activity was analyzed by 1,1-difenil-2-pikrilhidrazil (DPPH) method. All ethanol extract samples of fermented cacao beans contained alkaloids, polyphenols, flavonoids, and tannins. The flavonoid compounds from ethanol extract of cacao beans in F1 is 4.35 ± 0.20 mg/L, F2 (5.64 ± 0.05), F3 (5.37 ± 0.17), and F4 (5.99 ± 0.23 mg/L). The antioxidant activity of cacao bean fermentation extracts using starter were increase compared to the spontaneous fermentation extract (F1). The antioxidant activity in F2 increased to 46.45 ± 2.00%, F3 (49.05 ± 0.58%), and F4 (50.33 ± 0.43%), while the antioxidant activity of F1 was 42.31 ± 0.66%. IC50 value as the ability of the extract to reduce 50% DPPH radical on the ethanol extract of cacao beans from spontaneous fermentation (F1) was 141.67 mg/L. The IC50 value of the fermented cacao bean extract with the addition of starter was obtained at F2 at 109.30 mg/L, F3 (97.51), and F4 is 88.15 mg/L.
Antimicrobial resistance in bacteria has become a leading global public health issue. Staphylococcus sp. has an efficient mechanism to deal with antimicrobial agents that make them hard to treat in hospital-acquired and community-acquired infections. This study was conducted due to limited data about multidrug resistance and extensively drug resistance in Staphylococcus sp. in Indonesia. This study was a descriptive retrospective study using a cross-sectional design to get the prevalence and antimicrobial susceptibility of S. haemolyticus, S. aureus, and S. epidermidis. The data was secondary data extracted from WHONET 2022 software. This study’s data were from bacteria from samples sent to UKK LMK FKUI, Jakarta from 2017 to 2021 for routine diagnostic. In this study, we found that the prevalence of methicillin-resistant S.aureus was 24,9%, methicillin-resistant S.epidermidis was 65,5%, and methicillin-resistant S.haemolyticus was 86,8%. The prevalence of MDR S.aureus is less than S.epidermidis and S.haemolyticus, respectively. MDR S.haemolyticus was consistently above 85% each year, while S.epidermidis was above 50% and S.aureus was below 50%. XDR Staphylococcus was only found in S.aureus and S.haemolyticus, i.e. three and seven XDR isolates of S.aureus and S.haemolyticus respectively during 2017-2021. Although we could not find any pan-resistant isolates from all samples, we found methicillin-resistant S.aureus and S.haemolyticus isolates that were also resistant to vancomycin and linezolid. S.haemolyticus dan S. epidermidis were an important coagulase-negative Staphylococcus species that can’t be neglected due to the high percentage of MDR and the discoveries of XDR in S.haemolyticus so that they have the potential to disseminate resistance plasmids to the more virulent bacteria. Therefore we need to control the use of antimicrobial agent to prevent this resistance.
Antimicrobial resistance is one of the top 10 global health threats. The hospital wastewater (HWW) potentially becomes the reservoir and dissemination of antibiotic resistance gene (ARG) and bacterial pathogens. In Indonesia, the protocol to monitor the ARGs form HWW has not been established. This study aimed to detect the presence and find the relative abundance of P. aeruginosa and aadA2 genes from Dr. RSUPN. Cipto Mangungkusumo (RSCM) inlet and outlet wastewater through qPCR assay. The primers used were supported by Resistomap. The study revealed that the qPCR assay was able to detect the Ct value of P. aeruginosa and aadA2. The aadA2 gene was found in all waste water samples, meanwhile P. aeruginosa was only found in some of inlet samples. aadA2 had the highest relative abundance and this gene’s mobility uses plasmids and integrons that potentially enhance the acquired antimicrobial resistance (AMR) mechanism. This study implicated that qPCR assay was capable to detect pathogenic bacteria and ARG, and ARG could be released to the environment even though the wastewater samples have been proceeded in wastewater treatment plants (WWTP). The qPCR assay can be used as the method to monitor the AMR status in a hospital and the spreading potency to the environment using the HWW.
