BACKGROUND The HLA (human leukocyte antigen) molecules that present pathogen-derived epitopes to T cells are highly diverse. Correspondingly, many pathogens such as HIV evolve epitope variants in order to evade immune recognition. In contrast, another persistent human pathogen, Mycobacterium tuberculosis, has highly conserved epitope sequences. This raises the question whether there is also a d...

Gram stains were performed on strains of Actinomyces bovis, Actinomyces viscosus, Arthrobacter globiformis, Bacillus brevis, Butyrivibrio fibrisolvens, Clostridium tetani, Clostridium thermosaccharolyticum, Corynebacterium parvum, Mycobacterium phlei, and Propionibacterium acnes, using a modified Gram regimen that allowed the staining process to be observed by electron microscopy (J. A. Davies,...

Studies of the effect of bacteria on neoplasms are among the oldest approaches to the problem of cancer therapy. In 1868, Busch (2) reported tem porary clinical improvement in two patients with sarcoma who developed concurrent erysipelas. Subsequent studies, identifying streptococci and other micro-organisms involved in tumor destruc tion, ascribed their effect to a toxic bacterial prod uct (3)...

Electrochemical measurement of respiratory chain activity allows rapid and reliable screening for antibiotic susceptibility in microorganisms. Chronoamperometry and chronocoulometry of suspensions of aerobically cultivated E. coli combined with the non-native oxidant potassium hexacyanoferrate(III) (ferricyanide) yield signals for reoxidation of the reduction product ferrocyanide that are much ...

The recently reported identification, within the transcription terminator Rho of Clostridium botulinum (Cb-Rho), of a prion-like domain functionally similar to that of a yeast prion-forming protein, along with the amyloidogenicity conferred by it on Cb-Rho, represent findings of extraordinary scientific relevance (Yuan and Hochschild, 2017). In this respect, another recent study has shown that ...

Aspartate kinase (AK) is an enzyme which is tightly regulated through feedback control and responsible for the synthesis of 4-phospho-L-aspartate from L-aspartate. This intermediate step is at an important branch point where one path leads to the synthesis of lysine and the other to threonine, methionine and isoleucine. Concerted feedback inhibition of AK is mediated by threonine and lysine and...

The cloning, expression and characterization of three cellulosomal pectinolytic enzymes viz., two variants of PL1 (PL1A and PL1B) and PL9 from Clostridium thermocellum was carried out. The comparison of the primary sequences of PL1A, PL1B and PL9 revealed that these proteins displayed considerable sequence similarities with family 1 and 9 polysaccharide lyases, respectively. PL1A, PL1B and PL9 ...

Glioblastoma (GBM) is a highly aggressive primary brain tumor that is especially difficult to treat. The tumor's ability to withstand hypoxia leads to enhanced cancer cell survival and therapy resistance, but also yields a microenvironment that is in many aspects unique within the human body, thus offering potential therapeutic opportunities. The spore-forming anaerobic bacterium Clostridium no...

BACKGROUND Clostridium chauvoei causes blackleg, an acute disease associated with high mortality in ruminants. The apparent primary port of entry is oral, during grazing on pasture contaminated by spores. Cases of blackleg can occur year after year on contaminated pastures. A method to determine the prevalence of C. chauvoei spores on pasture would be useful.The standard method for C. chauvoei ...

We examined the oxidation and esterification of palmitate and the hydrolysis and oxidation of intramuscular lipids in isolated soleus muscles at rest and during tetanic contractions (2-40 tetani/min). Muscles were pulsed with [14C]palmitate to prelabel all intramuscular lipid pools. Muscles remained at rest or were then stimulated to contract at 2, 8, 20, or 40 tetani/min (30 min) in the presen...