Potential bacteriophages to overcome bacterial infection of Alcaligenes faecalis in diabetic ulcer.

INTRODUCTION: Diabetes is a non-contagious disease, but it can cause various complications. One of the most common complications of diabetes is diabetic ulcers. Diabetic ulcers are infections that occur in the legs of diabetics due to the destruction of the deepest skin tissue. Recent studies have reported the presence of Alcaligenes faecalis with extensive drug resistance (XDR) properties as a cause of diabetic ulcers. Bacteriophages are known to have the ability to infect bacteria specifically so that they can be used as an alternative solution for treating diabetic ulcers. The purpose of this study was to determine the characteristics of bacteriophages capable of infecting Alcaligenes faecalis bacteria. MATERIAL AND METHODS: The method used is the spot test method, host range, and identification of nucleic acid types. RESULTS: The results showed that the 6 bacteriophages isolated, namely AFaV1, AFaV2, AFaV3, AFaV4, AFaV5, and AFaV6, had cloudy plaques with a diameter of ±3 mm. AFaV1, AFaV2, and AFaV4 isolates could infect all bacteria used; they were Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Meanwhile, bacteriophage isolates AFaV3, AFaV5, and AFaV6 could infect Klebsiella pneumoniae and Staphylococcus aureus bacteria only. The nucleic acid types of the 6 bacteriophage samples were dsDNA with band length > 1 Kb. CONCLUSIONS: The 6 isolates that were isolated had the ability to infect by forming a prophage that could inhibit the growth of Alcaligenes faecalis and other pathogenic bacteria in diabetic ulcers.

Construction of SHERLOCK-based sgRNA for SARS-CoV-2 Diagnostics from Indonesia.

Handling a pandemic requires high sensitivity, high specificity, simple, fast, and flexible tests. How- ever, conventional test methods (RT-PCR and Rapid Antigen) have weaknesses in test efficiency. Specific High sensitivity Enzymatic Reporter un-LOCKing (SHERLOCK), is a new technology that can detect nucleic acids even with limited sample preparation, but with high sensitivity, high spec- ificity, rapidly, and flexibly. The key to the specificity of the SHERLOCK diagnostic method is the single guide RNA (sgRNA). The purpose of this study was to analyze the design of the SHERLOCK sgRNA, which has optimum potential to be used as a Cas13a marker to recognize the spike protein gene of the Receptor Binding Domain of the SARS-CoV-2 strain from Indonesia. The method used was an in-silico approach using genomic and proteomic data and molecular docking. This study used a sample of 37 genomic data representing 86 types of SARS-CoV-2 spike protein mutations in Indonesia. Based on the docking candidate results, sgRNA8 has the lowest energy to bind to the viral protospacer target SARS-CoV-2 and a high melting point value at 70.3°C, indicating that the sgRNA8 chain is the optimal candidate for sgRNA.

In-silico analysis of recombinant protein vaccines based on the spike protein of Indonesian SARS-CoV-2 through a reverse vaccinology approach.

Objectives: This study aimed to produce a recombinant protein vaccine candidate based on an epitope of spike protein from Indonesian SARS-CoV-2 to provide immunogenicity and protection against future infection. Methods: A reverse vaccinology approach was used to identify potential vaccine candidates by screening the pathogen's genome through computational analyses. Results: Epitope vaccine candidates with the amino acid sequence of FKNHTSPDV were selected. This peptide is hydrophilic, does not induce autoimmune and allergic reactions, is antigenic, is classified as a stable protein, and is predicted to be present in the cell membrane. The selected epitope sequences were inserted into the plasmid vector pcDNA3.1(+) N-GST (thrombin). Inclusion of additional features of the gene encoding glutathione-S transferase, which can increase antigen expression and solubility, and the genes encoding NSP 1-4 proteins, which are essential in replication, added value to the produced recombinant protein. Conclusion: Recombinant protein vaccine candidates with the FKNHTSPDV epitope have parameters sufficient for production on a laboratory scale for further testing.

Effect of Phage-Antibiotic Synergism (PAS) in increasing antibiotic inhibition of bacteria caused of foodborne diseases.

INTRODUCTION: Food contaminated with pathogenic bacteria is one of the most harmful things that can even threaten human life. Over time, these pathogenic bacteria are increasingly resistant to antibiotics. Continuous use of synthetic preservatives will also have an adverse effect. This study was conducted to evaluate the synergy of bacteriophage and antibiotics in increasing antibiotics inhibition to the bacteria that cause foodborne disease. METHODOLOGY: The test was performed by plaque assay and paper disc diffusion on NA medium in the same petri dish. The combination was incubated for 24 hours at 37ºC. An antibiotic inhibition on a non-bacteriophage test showed cefadroxil could only inhibit P21B bacteria. RESULTS: Cefadroxil inhibition in the PAS test showed that these antibiotics could inhibit some other foodborne disease bacteria (Salmonella spp., Staphylococcus aureus, and Escherichia coli). The inhibitory observed from the clear zone located around the disc paper. CONCLUSION: These results provide useful information to reduce the risk of antibiotic resistance in humans and foods.

Antihyperglycaemic and tissue-repair effects of Myrmeleon formicarius extract in streptozotocin-induced diabetic mice.

OBJECTIVES: In this study, we aimed to investigate the effects of oral administration of Myrmeleon formicarius (antlion) extract on liver and kidney histology in streptozotocin-induced diabetic mice. METHODS: Twenty-four mice received a single intraperitoneal injection of streptozotocin and were then divided into six groups. Untreated diabetic mice served as the negative control group, and glibenclamide-treated mice served as the positive control group. Mice in the other four groups, namely T1, T2, T3, and T4 groups, received M. formicarius (antlion) extract at 2.5, 5, 7.5, and 10 mg/kg, respectively. Permanent thin sections were used to examine liver and kidney histology. RESULTS: The most appropriate antihyperglycaemic dosage of the M. formicarius extract was 10 mg/kg for 2 days. Histological examination of the liver and kidneys showed that the antlion extract at 10 and 5 mg/kg exhibited significant tissue-repair effects. CONCLUSION: M. formicarius (antlion) extract can not only reduce blood glucose levels but also repair hyperglycaemia-induced tissue damage.

Genomic diversity of large-plaque-forming podoviruses infecting the phytopathogen Ralstonia solanacearum.

The genome organization, gene structure, and host range of five podoviruses that infect Ralstonia solanacearum, the causative agent of bacterial wilt disease were characterized. The phages fell into two distinctive groups based on the genome position of the RNA polymerase gene (i.e., T7-type and ϕKMV-type). One-step growth experiments revealed that ϕRSB2 (a T7-like phage) lysed host cells more efficiently with a shorter infection cycle (ca. 60 min corresponding to half the doubling time of the host) than ϕKMV-like phages such as ϕRSB1 (with an infection cycle of ca. 180 min). Co-infection experiments with ϕRSB1 and ϕRSB2 showed that ϕRSB2 always predominated in the phage progeny independent of host strains. Most phages had wide host-ranges and the phage particles usually did not attach to the resistant strains; when occasionally some did, the phage genome was injected into the resistant strain's cytoplasm, as revealed by fluorescence microscopy with SYBR Gold-labeled phage particles.

The involvement of the PilQ secretin of type IV pili in phage infection in Ralstonia solanacearum.

PilQ is a member of the secretin family of outer membrane proteins and specifically involved in type IV secretion. Here we report the effects of pilQ mutation in Ralstonia solanacearum on the host physiology including susceptibility to several phage types (Inoviridae, Podoviridae and Myoviridae). With three lines of cells, namely wild type, ΔpilQ and pilQ-complemented cells, the cell surface proteins, twitching motility and sensitivity to phages were compared. SDS-PAGE analysis revealed that the major TFP pilin (PilA) was specifically lost in pilQ mutants and was recovered in the complemented cells. Drastically inactivated twitching motility in pilQ mutants was recovered to the wild type level in the complemented cells. Several phages of different types including those of Inoviridae, Podoviridae, and Myoviridae that infect wild type cells could not form plaques on pilQ mutants but showed infectivity to pilQ-complemented cells. These results indicate that PilQ function is generally required for phage infection in R. solanacearum.