Complete genome sequences of Lactococcus lactis D1_2, a bacterium with antimicrobial properties isolated from peat soil.

Lactococcus lactis is a beneficial lactic acid bacterium commonly studied for its probiotic properties and role in dairy production. Here, we present a complete genome of Lactococcus lactis D1_2, isolated from peat swamp forests. To discover the potential antimicrobial properties, the complete genome of the strain was sequenced and analyzed.

Phenotypic Characterization and Comparative Genomic Analysis of Novel Salmonella Bacteriophages Isolated from a Tropical Rainforest.

Salmonella infections across the globe are becoming more challenging to control due to the emergence of multidrug-resistant (MDR) strains. Lytic phages may be suitable alternatives for treating these multidrug-resistant Salmonella infections. Most Salmonella phages to date were collected from human-impacted environments. To further explore the Salmonella phage space, and to potentially identify phages with novel characteristics, we characterized Salmonella-specific phages isolated from the Penang National Park, a conserved rainforest. Four phages with a broad lytic spectrum (kills >5 Salmonella serovars) were further characterized; they have isometric heads and cone-shaped tails, and genomes of ~39,900 bp, encoding 49 CDSs. As the genomes share a <95% sequence similarity to known genomes, the phages were classified as a new species within the genus Kayfunavirus. Interestingly, the phages displayed obvious differences in their lytic spectrum and pH stability, despite having a high sequence similarity (~99% ANI). Subsequent analysis revealed that the phages differed in the nucleotide sequence in the tail spike proteins, tail tubular proteins, and portal proteins, suggesting that the SNPs were responsible for their differing phenotypes. Our findings highlight the diversity of novel Salmonella bacteriophages from rainforest regions, which can be explored as an antimicrobial agent against MDR-Salmonella strains.

The Complex Mechanism of the Salmonella typhi Biofilm Formation That Facilitates Pathogenicity: A Review

Salmonella enterica serovar Typhi (S. typhi) is an intracellular pathogen belonging to the Enterobacteriaceae family, where biofilm (aggregation and colonization of cells) formation is one of their advantageous traits. Salmonella typhi is the causative agent of typhoid fever in the human body and is exceptionally host specific. It is transmitted through the fecal-oral route by consuming contaminated food or water. This subspecies is quite intelligent to evade the innate detection and immune response of the host body, leading to systemic dissemination. Consequently, during the period of illness, the gallbladder becomes a harbor and may develop antibiotic resistance. Afterwards, they start contributing to the continuous damage of epithelium cells and make the host asymptomatic and potential carriers of this pathogen for an extended period. Statistically, almost 5% of infected people with Salmonella typhi become chronic carriers and are ready to contribute to future transmission by biofilm formation. Biofilm development is already recognized to link with pathogenicity and plays a crucial role in persistency within the human body. This review seeks to discuss some of the crucial factors related to biofilm development and its mechanism of interaction causing pathogenicity. Understanding the connections between these things will open up a new avenue for finding therapeutic approaches to combat pathogenicity.

A Multianalyte Electrochemical Genosensor for the Detection of High-Risk HPV Genotypes in Oral and Cervical Cancers.

Infection with high-risk human papillomavirus (HPV) is a major risk factor for oral and cervical cancers. Hence, we developed a multianalyte electrochemical DNA biosensor that could be used for both oral and cervical samples to detect the high-risk HPV genotypes 16 and 18. The assay involves the sandwich hybridization of the HPV target to the silica-redox dye reporter probe and capture probe, followed by electrochemical detection. The sensor was found to be highly specific and sensitive, with a detection limit of 22 fM for HPV-16 and 20 fM for HPV-18, between the range of 1 fM and 1 µM. Evaluation with oral and cervical samples showed that the biosensor result was consistent with the nested PCR/gel electrophoresis detection. The biosensor assay could be completed within 90 min. Due to its simplicity, rapidity, and high sensitivity, this biosensor could be used as an alternative method for HPV detection in clinical laboratories as well as for epidemiological studies.

Biocontrol capability of bacteriophages against soft rot disease caused by Dickeya chrysanthemi

Aims@#This study aims to evaluate the effectiveness of bacteriophages isolated from Klang and Penang, Malaysia against Dickeya chrysanthemi that causes soft rot disease.@*Methodology and results@#Basic characterization such as dextrose test, citrate test, lactose fermentation test and ornithine test were carried out on D. chrysanthemi. Activity of bacteriophages against D. chrysanthemi was evaluated using spot test. Double agar overlay assay was performed to purify and enumerate the quantify of bacteriophages.Bacteriophages were also checked for its effectiveness in controlling soft rot on post-harvested vegetables: potato (Solanum tuberosum), cucumber (Cucumis sativus) and apple (Malus domestica). Results showed that D. chrysanthemiable to utilize citrate and dextrose as the source of energy, which indicated that D. chrysanthemi inclined to choose fruits and vegetables containing citrate and dextrose as the target of attack. Clear zone observed on the bacterial lawn (spot test) indicated the ability of the bacteriophages to infect and lyse D. chrysanthemi. All the bacteriophages studied herein reached the highest concentration on day 3 and were monovalent.@*Conclusion, significance and impact of study@#All the isolated bacteriophages were able to restrain the spreading of soft rot caused by D. chrysanthemi either work alone or as cocktail. This study provides information for the formulation development of bacteriophage against soft rot disease cause by D. chrysanthemi. Furthermore, this study reveals the potential of locally isolated bacteriophages against the D. chrysanthemi and paving the application of phage treatment on agriculture products that are not limited to potatoes, cucumber and apple.

Rapid multi sample DNA amplification using rotary-linear polymerase chain reaction device (PCRDisc).

Multiple sample DNA amplification was done by using a novel rotary-linear motion polymerase chain reaction (PCR) device. A simple compact disc was used to create the stationary sample chambers which are individually temperature controlled. The PCR was performed by shuttling the samples to different temperature zones by using a combined rotary-linear movement of the disc. The device was successfully used to amplify up to 12 samples in less than 30 min with a sample volume of 5 µl. A simple spring loaded heater mechanism was introduced to enable good thermal contact between the samples and the heaters. Each of the heater temperatures are controlled by using a simple proportional-integral-derivative pulse width modulation control system. The results show a good improvement in the amplification rate and duration of the samples. The reagent volume used was reduced to nearly 25% of that used in conventional method.