Microbiology Indonesia

The Effect of Pili Protein of Klebsiella pneumoniae 65,5 kDa on Enhanced IFN- Gamma Levels in Mice Liver

2018-08-09T01:32:01+00:00

Klebsiella pneumoniae develops antibiotic resistance by producing enzymes such as Extended-Spectrum Beta-Lactamase and Carbapenemase. Antibiotic resistance causes K. pneumoniae to have less antibiotic activity and more virulence factors. Capsule polysaccharides, lipopolysaccharide, Outer Membrane Protein, siderophores, and pili are all virulence factors in K. pneumoniae. This study aims to demonstrate the possibility of a host immunological response to the pili protein K. pneumoniae 65.5 kDa by injecting it into mice and measuring the levels of IFN-gamma cytokines in the mice's liver. This study used mice liver samples taken from 21 mice aged 6-8 weeks in the experimental investigation with a randomized post-test only controlled group design. Phosphate buffer saline was given to KI, pili protein antigen 65.5 kDa + Freunds' adjuvant was given to K2, and Freunds' adjuvant was given to K3. IFN-gamma concentration was measured using the sandwich ELISA method. The average concentration of IFN-gamma in the mice liver in this study was 247.68±47.67 pg m 'L ', 163.19±13.63 pg m'L', and 182.41 ±41.70 pg m'L'. The p-value of the Welch ANO VA test was 0.005 (p < 0.05), hence the Post Hoc Games-Howell test was used. The Games-Howell test showed a statistically significant difference in the mean value of IFN-gamma in KI compared to K2 and K3 of 0.007 and 0.046, respectively. There was no statistically significant difference between K2 and K3 with a p-value of 0.511. These findings revealed that intraperitoneal injection of Klebsiella pneumoniae pili protein 65.5 kDa did not increase IFN-gamma levels in the mice liver.

In Silico Study of Splicing Variations on Angiotensin-Converting Enzyme 2 (ACE2) and Its Effects on Infection from SARS-CoV-2

2021-07-30T06:28:08+00:00

Several factors can influence SARS-CoV-2 infection. Alternative Splicing is thought to correlate with the differences of affinity value for interactions with the SARS-CoV-2 spike protein so that the infection may be influenced. This phenomenon can be happened by generating various kinds of protein expression variations with different isoform variants. So far, the difference in interaction affinity with the SARS-CoV-2 spike protein in Alternative Splicing has not been widely reported. Therefore, this study aimed to determine the isoform resulting from Alternative Splicing in the ACE2 transcript and its effect on SARS-CoV-2 infection. Molecular docking was used to determine the binding affinity between ACE2 proteins isoforms and SARS-CoV-2 spike protein. The 3D protein model of ACE2 isoforms obtained from the database was validated by evaluating the model quality of each ACE2 isoform. Based on docking results, there are variations in the docking scores of 8 isoform variants. However, there was no interaction between the ACE2_205 variant and SARS-CoV-2 spike protein while ACE2_206 and ACE2_207 showed a lower docking score than the other variants. In addition, essential residues in the interaction of each variant were also analyzed. Q42 and A384 are residues on the ACE2 protein that appear in interactions in more than two variants. These results indicate the possibility that splicing variations can cause differences in a person's level of susceptibility to SARS-CoV-2 infection, especially in the ACE2_205 variant that cannot interact with the SARS-CoV-2 spike protein.

Supplementation of Sucrose and n-source in Culture Medium Towards Bacteriocin Production of Lactic Acid Bacteria Isolated from Ampel Bamboo Shoot (Bambusa vulgaris) Pickle

2021-07-08T04:28:09+00:00

Study on the use of sucrose in media for LAB from bamboo shoot is limited. The aim of this study was to determine the effect of sucrose in the culture medium to produce bacteriocins of LAB isolated from Ampel bamboo shoot pickle under different fermentation conditions. Fermentation of bamboo shoot was done in 2.5% of salt concentration at 15oC for 5 days (condition A) and in 5.0% of salt concentration at 30oC for 4 days (condition B). Isolation of LAB from the brine water of bamboo shoot fermentation yielded 35 isolates consisting of 16 isolates from condition A and 19 isolates from condition B. Antimicrobial activity analysis showed that all the isolates had antimicrobial activity against pathogenic bacteria (E. coli FNCC 0091, L. monocytogenes FNCC 0156 and S. aureus FNCC 0047). All isolates were grown in MRS-B media supplemented with sucrose as a carbon source and yeast extract and peptone as nitrogen source. The inhibitory activity of bacteriocin was between 13-3274 mm2 ml-1. The highest inhibition was found from isolate B16 grown in MRS-B supplemented with 2% sucrose against S. aureus FNCC 0047 (3274.99 mm2 ml-1). Thirteen showed bacteriocin production after inoculated in MRS-B with a combination of carbon and nitrogen source. From the 32 isolates in the present study, only 4 isolates A14, A17, A18 and B9 showed bacteriocin inhibitory activity against all the indicator pathogens E. coli FNCC 0091, L. monocytogenes FNCC 0156 and S. aureus FNCC 0047.

Antibacterial Potential of Kepok Sobo Londo Banana Peel (Musa paradisiaca L.) Against Diarrhea Causing Bacteria Enterohemorrhagic Escherichia coli

2021-05-05T02:20:33+00:00

The administration of excessive doses of antibiotics and frequency of diarrhea outbreaks caused by Enterohemorrhagic E. coli (EHEC) need to be reexamined, and one of it measures is considering the potency of local plants, such as kepok sobo londo banana. This study is conducted to examine the antibacterial potential of kepok sobo londo banana peel extract (Musa paradisiaca L.) through its inhibitory activity on the growth of EHEC. Thebacterial isolates were molecularly identified using specific primers encoding EHEC virulence genes, namely stx1 and eae, respectively. Banana peel samples were extracted by maceration method and tested for phytochemicals using GC-MS. Antibacterial testing was carried out using the agar well diffusion method, as well as MIC and MBC assay. The data from GC-MS analysis results in the identification of main antibacterial compounds contained in the extract, namely fatty acids, tannin alkaloids, and phenols, respectively. The results of the antibacterial assay using agar well diffusion method for inhibition of EHEC bacteria by kepok sobo londo banana peel extract were found to be greatest at a concentration of 28% which is considered as intermediate inhibitory power. Obtained MIC dan MBC value of extract occurred at concentration of 17% and 22%, respectively against EHEC.