Phenotypic switch to persister state confers resistance to vancomycin in methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is known to cause many hospital acquired infections and is difficult to treat. While susceptible to attack by vancomycin antibiotic, clinical observations suggest that MRSA may also be resistant to the last-resort antibiotic for MRSA treatment. However, little is known about the underlying mechanisms that confer vancomycin resistance to MRSA.   … More Phenotypic switch to persister state confers resistance to vancomycin in methicillin-resistant Staphylococcus aureus

Growth curves provide important information about a microorganism

Microbial growth experiments are often under-appreciated in research, but they provide important information about each species and strain of microorganism prior to their use for more advanced studies.   Specifically, while growth experiments had been conducted for many of the common microorganisms important to biotechnology and bioengineering, many subspecies or strains of the same species … More Growth curves provide important information about a microorganism

Single molecule experiments typically pertain to hundreds to thousands of molecules

Single molecule experiment is one of the important trends in research over the past decade. However, what are defined as single molecule experiments are typically not experiments interrogating a single molecule (except for imaging of a DNA molecule in bacteria). Rather, single molecule experiments typically revolve around hundreds to thousands of molecules.   Specifically, schematic … More Single molecule experiments typically pertain to hundreds to thousands of molecules

Mass spectra of microorganisms could not be used in phylogenetic analysis

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been shown to be effective in rapid analysis of bacterial cell samples for microbial identification. Specifically, the technique relies on the generation of a mass spectrum fingerprint for individual microbes, which when compared to a reference database of mass spectra of known microorganisms, provide the capability … More Mass spectra of microorganisms could not be used in phylogenetic analysis

Visualizing mutational events in bacteria

A recent article in Science, Vol. 359, Issue 6381, pp. 1283-1286 (Link) visualized mutational events in bacterial cells at the single cell level using a combination of microfluidics cellular assays and fluorescent readout. The research opens up our understanding of how mutations are potentiated and propagated from parent to daughter cells. Furthermore, it reveals more … More Visualizing mutational events in bacteria

Understanding Earth complement of viruses

Article in Nature, Vol. 536, Issue 7617, pp. 425-430, “Uncovering Earth’s virome”   Summary of article: A vector-based metagenomics approach combined with bioinformatics analysis was used to uncover the subset of viruses present on human body surfaces and freshwater habitats. The study’s experiment design does not fit the grandiose nature of the paper’s title. Additionally, … More Understanding Earth complement of viruses

When does stationary phase occur during growth on solid agar?

Microbial growth occurs over four stages: (i) lag, (ii) exponential, (iii) stationary and (iv) death. Specifically, during lag phase, the cells synthesize enzymes and other metabolic machinery for coping with growth in a new environment and nutrient source. After enzyme synthesis is complete, the cells subsequently enter exponential growth where cells multiply rapidly through mitosis. … More When does stationary phase occur during growth on solid agar?

High precision sequencing of 16S rRNA gene

Article in PeerJ, “A method for high precision sequencing of near full-length 16S rRNA genes on an Illumina MiSeq”   Summary of article: A tag sequencing method utilizing the Ilumina MiSeq platform was shown to be useful in sequencing, in high precision, near full length 16S rRNA gene, which is important for phylogenetic purposes, particularly … More High precision sequencing of 16S rRNA gene

Lack of new antibiotics targeting Gram-negative bacteria

Bacteria can in general be classified into Gram-positive and Gram-negative bacteria. Specifically, Gram-positive bacteria is characterized by a single membrane with a thick peptidoglycan layer on the outer cell envelope. On the other hand, a double phospholipid bilayer membrane constitutes the cell envelope of Gram-negative bacteria, where a thin peptidoglycan layer is interspersed between the … More Lack of new antibiotics targeting Gram-negative bacteria

Modification of cell surface prevents the attachment of phage to bacteria

Different methods are utilized by bacterial cells for defending against bacteriophages. For example, the CRISPR-Cas system retains a molecular memory of previous phage attack on the cells and uses it to prevent subsequent infection by the same phage. Another approach involves the synthesis of DNA intercalating agents that binds to the newly synthesized DNA of … More Modification of cell surface prevents the attachment of phage to bacteria