Postdoctoral fellow KP Smith discusses how to use "time to positivity" information in interpreting the meaning of blood cultures. His blog article is titled: "Predictive Value of Blood Culture Time to Positivity."
We have been taking advantage of Addgene for years. About to deposit about twenty plasmids form Yoon-Suk Kang's bioreporter tool kit. Assembling plasmid maps in SnapGene. Thank you, Addgene!
Apramycin scaffold exploration using novel glycochemistry and SAR studies to enhance activity against Acinetobacter baumannii and other multidrug-resistant Gram-negative pathogens.
KP Smith Speaking tomorrow at Harvard Antimicrobial Resistance Laboratory Network as well as Broad Institute collaborator, Alejandro Pironti
Congratulations to postdoctoral fellow, Yoon-Suk Kang, on acceptance of his manuscript in Infection and Immunity. The manuscript is titled: "Brucella neotomae recapitulates attributes of zoonotic human disease in a murine infection model." One of my favorite figures are images of tdTomato-labeled Brucella detected by confocal microscopy replicating in the middle of a liver granulomas visualized by counterstaining with H&E. In contrast to wild type organisms, virB4 mutant bacteria are found as single cells in sinusoids presumably within Kuffpfer cells. Wild type bacteria are found at high levels in mouse thymus at all time points examined; virB4 mutant bacteria are undetectable in thymus. B. neotomae induces a Th-1 immune response. More information in the manuscript.
Excel and Powerpoint have been banned for figure preparation. Converted my lab over to GraphPad Prism. A very well designed graphing and statistics program. Love several features including the ability to apply standard dimension formats for charts, and wand tool to covert charts to exact format used previously. Application of statistics to data is facile, also a wand tool to apply the same statistics to multiple tables. Grateful to Assay and Drug Development Technology for their requirement (recommendation?) to use this or similar programs in figure preparation. Powerpoint never worked well for figure preparation and conversion to vector-graphics format, for use with illustrator was a nightmare. Now we just start out using a freeware vector graphics program or Adobe Illustrator directly. Greatly speeds up manuscript preparation.
P.S. I have no financial relationship with GraphPad Prism, but it is a good product so therefore my endorsement!
Evaluation of apramycin activity against methicillin-resistant, methicillin-sensitive, and vancomycin-intermediate Staphylococcus aureus clinical isolates. Now online, congrats to Kat Truelson, see previous post.
BIDMC news release on Thea's antimicrobial synergy paper:
"Bacteria—especially Gram-negative strains—are becoming increasingly resistant to current antibiotic drugs, and the development of new classes of antibiotics has slowed. Faced with these challenges, investigators are studying the potential of combination therapy, in which two or more drugs are used together to increase or restore the efficacy of both drugs against a resistant bacterial pathogen. Now new research indicates that such synergy may work even when bacteria become resistant to colistin, which is considered a treatment agent of last resort.
The findings are especially promising because recent evidence indicates the potential for rapid worldwide spread of colistin resistance. “For an infected patient, if the multidrug-resistant Gram-negative bacterial pathogen is resistant to colistin, then there is a big problem,” said senior author James Kirby, MD, Director of the Clinical Microbiology Laboratory at BIDMC.
In their Antimicrobial Agents and Chemotherapy study, Kirby and his colleagues Thea Brennan-Krohn, MD and Alejandro Pironti, PhD screened 19 different antibiotics for synergy with colistin. The team discovered several combinations where synergy was present and infections with resistant pathogens could potentially be treated with the combination therapy.
Of particular interest, colistin demonstrated high rates of synergy with linezolid, fusidic acid, and clindamycin, which are protein synthesis inhibitor antibiotics that individually have no activity against Gram-negative bacteria. “It was remarkable to see two drugs, each of which is inactive on its own against these bacteria, inhibiting them in combination,” notes Brennan-Krohn. “These findings suggest that colistin retains sub-lethal activity against colistin-resistant bacteria, which may enable drugs like linezolid to reach their targets.”
“Faced with highly resistant pathogens, clinicians often currently treat with multiple antibiotics without knowing the benefit the combinations may provide,” said Kirby. “This study now provides some scientific underpinning for these choices and direction for future investigation.” He added that combination therapy may also allow clinicians to use lower effective doses of colistin and other drugs, which would help avoid toxicities associated with the medications as well as slow the development of antibiotic resistance.
This work was funded in part with Federal funds from the National Institute of Allergy and Infectious Diseases, the National Institutes of Health, and the Department of Health and Human Services."
Kirby Lab Blog