Differential Staining of Bacteria: Capsule Stain

Breakwell, Donald P.; Moyes, Rita B.; Reynolds, Jackie

doi:10.1002/9780471729259.mca03is15

Cited by 23 publications

(20 citation statements)

References 5 publications

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“…We determined whether N. musculi produces a capsule by using two biochemical tests, India ink and alcian blue staining, that are widely used to detect capsulated organisms ( 43 ). After India ink treatment, N. musculi cells (smooth and rough variants) were surrounded by a clear halo against a dark background, which is indicative of capsulated organisms ( Fig.…”

Section: Resultsmentioning

confidence: 99%

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A Natural Mouse Model for Neisseria Colonization

Powell

Weyand

et al. 2018

Infect Immun

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Commensals are important for the proper functioning of multicellular organisms. How a commensal establishes persistent colonization of its host is little understood. Studies of this aspect of microbe-host interactions are impeded by the absence of an animal model. We have developed a natural small animal model for identifying host and commensal determinants of colonization and of the elusive process of persistence. Our system couples a commensal bacterium of wild mice, Neisseria musculi, with the laboratory mouse. The pairing of a mouse commensal with its natural host circumvents issues of host restriction. Studies are performed in the absence of antibiotics, hormones, invasive procedures, or genetic manipulation of the host. A single dose of N. musculi, administered orally, leads to long-term colonization of the oral cavity and gut. All mice are healthy. Susceptibility to colonization is determined by host genetics and innate immunity. For N. musculi, colonization requires the type IV pilus. Reagents and powerful tools are readily available for manipulating the laboratory mouse, allowing easy dissection of host determinants controlling colonization resistance. N. musculi is genetically related to human-dwelling commensal and pathogenic Neisseria and encodes host interaction factors and vaccine antigens of pathogenic Neisseria. Our system provides a natural approach for studying Neisseria-host interactions and is potentially useful for vaccine efficacy studies.

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Section: Resultsmentioning

confidence: 99%

“… N. meningitidis capsulated strain 8013 and unencapsulated strain FAM2 and N. musculi AP2365 T were suspended in India ink (BD Diagnostic) and spread as thin films on a microscope slide ( 43 ). After the films were allowed to air dry, the bacteria were counterstained with crystal violet (Gibson) for 1 min.…”

Section: Methodsmentioning

confidence: 99%

A Natural Mouse Model for Neisseria Colonization

Powell

Weyand

et al. 2018

Infect Immun

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“…This capsule is not shown in Figure 1 . Bacterial capsules are composed of high-molecular-weight polysaccharides and/or polypeptides, and are associated with virulence and biofilm formation [ 10 ]. The capsule protects the cell from desiccation and engulfment by macrophages and prevents attachment of bacteriophages on the cell surface [ 11 ].…”

Section: Resultsmentioning

confidence: 99%

Review on SERS of Bacteria

Mosier‐Boss¹

2017

Biosensors

113

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Surface enhanced Raman spectroscopy (SERS) has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

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“…Phase contrast microscopy was used to visualize sporulating cells. India ink (Becton Dickinson Microbiology Systems, Sparks, MD, United States) exclusion methods were employed by mixing 7 μl culture and 3 μl India Ink followed by wet-mounting 5 μl onto a glass slide for visualization ( Breakwell et al, 2009 ). DIC imaging was used to visualize capsule.…”

Section: Methodsmentioning

confidence: 99%

A Dual Role for the Bacillus anthracis Master Virulence Regulator AtxA: Control of Sporulation and Anthrax Toxin Production

Dale

Raynor

et al. 2018

Front. Microbiol.

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Bacillus anthracis is an endemic soil bacterium that exhibits two different lifestyles. In the soil environment, B. anthracis undergoes a cycle of saprophytic growth, sporulation, and germination. In mammalian hosts, the pathogenic lifestyle of B. anthracis is spore germination followed by vegetative cell replication, but cells do not sporulate. During infection, and in specific culture conditions, transcription of the structural genes for the anthrax toxin proteins and the biosynthetic operon for capsule synthesis is positively controlled by the regulatory protein AtxA. A critical role for the atxA gene in B. anthracis virulence has been established. Here we report an inverse relationship between toxin production and sporulation that is linked to AtxA levels. During culture in conditions favoring sporulation, B. anthracis produces little to no AtxA. When B. anthracis is cultured in conditions favoring toxin gene expression, AtxA is expressed at relatively high levels and sporulation rate and efficiency are reduced. We found that a mutation within the atxA promoter region resulting in AtxA over-expression leads to a marked sporulation defect. The sporulation phenotype of the mutant is dependent upon pXO2-0075, an atxA-regulated open reading frame located on virulence plasmid pXO2. The predicted amino acid sequence of the pXO2-0075 protein has similarity to the sensor domain of sporulation sensor histidine kinases. It was shown previously that pXO2-0075 overexpression suppresses sporulation. We have designated pXO2-0075 “skiA” for “sporulation kinase inhibitor.” Our results indicate that in addition to serving as a positive regulator of virulence gene expression, AtxA modulates B. anthracis development.

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Differential Staining of Bacteria: Capsule Stain

Cited by 23 publications

References 5 publications

A Natural Mouse Model for Neisseria Colonization

A Natural Mouse Model for Neisseria Colonization

Review on SERS of Bacteria

A Dual Role for the Bacillus anthracis Master Virulence Regulator AtxA: Control of Sporulation and Anthrax Toxin Production

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