Limits...
Salmonella enterica serovar Typhimurium slows down to dodge antibiotics.

Sedwick C - PLoS Biol. (2014)

View Article: PubMed Central - PubMed

Affiliation: Freelance Science Writer, San Diego, California, United States of America.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Tm.'s response to antibiotic treatment, Kaiser and colleagues studied the course of infection in C57BL/6 mice... The authors' experiments showed that high doses of ciprofloxacin treatment quickly (within three hours) eradicated bacteria from the animals' gut lumen... The antibiotic also quickly reduced bacterial levels within a pouchlike region of the gut called the cecum, and within the lymph node associated with that tissue (the cecum draining lymph node, or cLN)... But within two hours of treatment initiation, the rate of bacterial killing in cecal tissue and the cLN was observed to drop precipitously... As a result, viable S... Kaiser et al. theorized that these bacteria could be responsible for disease relapse... In support of this idea, they found that S... Further experiments showed that, following ciprofloxacin treatment, viable bacteria were found specifically inside “classical” dendritic cells, but not in another cLN cell type, the interstitial dendritic cells... Tm. numbers in ciprofloxacin-treated cLN also changed in concert with the size of the classical dendritic cell population, the authors hypothesized that bacteria living inside dendritic cells form a reservoir that can reinstate infection upon withdrawal of the antibiotic... Tm. also acquires tolerance through slow growth rates, Kaiser et al. constructed a population dynamics–based simulation for cLN bacterial growth and compared its predictions to data from actual infections... Tm. cells in the cLN... Ultimately, the authors concluded that such slow-growing cells, living within classical dendritic cells, are responsible for relapses in complicated S... Tm. somehow avoids digestion and—whether because of a change induced by phagocytosis or simply because of inherent variations within the bacterial population—a few of the bacteria slow their growth enough to resist the effects of antibiotic treatment... This led Kaiser and colleagues to investigate whether compounds that enhance immune activity could also improve bacterial clearance by ciprofloxacin... Indeed, they found that immune activators such as lipopolysaccharide and CpG dinucleotides reduced bacterial loads in the cLN of ciprofloxacin-treated mice.

Show MeSH
Image of a cecum draining lymph node (cLN) from a mouse infected with S. Tm. and treated for two days with ciprofloxacin. Green fluorescence marks the “classical” dendritic cells present in the cLN.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3928048&req=5

pbio-1001794-g001: Image of a cecum draining lymph node (cLN) from a mouse infected with S. Tm. and treated for two days with ciprofloxacin. Green fluorescence marks the “classical” dendritic cells present in the cLN.


Salmonella enterica serovar Typhimurium slows down to dodge antibiotics.

Sedwick C - PLoS Biol. (2014)

Image of a cecum draining lymph node (cLN) from a mouse infected with S. Tm. and treated for two days with ciprofloxacin. Green fluorescence marks the “classical” dendritic cells present in the cLN.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3928048&req=5

pbio-1001794-g001: Image of a cecum draining lymph node (cLN) from a mouse infected with S. Tm. and treated for two days with ciprofloxacin. Green fluorescence marks the “classical” dendritic cells present in the cLN.

View Article: PubMed Central - PubMed

Affiliation: Freelance Science Writer, San Diego, California, United States of America.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Tm.'s response to antibiotic treatment, Kaiser and colleagues studied the course of infection in C57BL/6 mice... The authors' experiments showed that high doses of ciprofloxacin treatment quickly (within three hours) eradicated bacteria from the animals' gut lumen... The antibiotic also quickly reduced bacterial levels within a pouchlike region of the gut called the cecum, and within the lymph node associated with that tissue (the cecum draining lymph node, or cLN)... But within two hours of treatment initiation, the rate of bacterial killing in cecal tissue and the cLN was observed to drop precipitously... As a result, viable S... Kaiser et al. theorized that these bacteria could be responsible for disease relapse... In support of this idea, they found that S... Further experiments showed that, following ciprofloxacin treatment, viable bacteria were found specifically inside “classical” dendritic cells, but not in another cLN cell type, the interstitial dendritic cells... Tm. numbers in ciprofloxacin-treated cLN also changed in concert with the size of the classical dendritic cell population, the authors hypothesized that bacteria living inside dendritic cells form a reservoir that can reinstate infection upon withdrawal of the antibiotic... Tm. also acquires tolerance through slow growth rates, Kaiser et al. constructed a population dynamics–based simulation for cLN bacterial growth and compared its predictions to data from actual infections... Tm. cells in the cLN... Ultimately, the authors concluded that such slow-growing cells, living within classical dendritic cells, are responsible for relapses in complicated S... Tm. somehow avoids digestion and—whether because of a change induced by phagocytosis or simply because of inherent variations within the bacterial population—a few of the bacteria slow their growth enough to resist the effects of antibiotic treatment... This led Kaiser and colleagues to investigate whether compounds that enhance immune activity could also improve bacterial clearance by ciprofloxacin... Indeed, they found that immune activators such as lipopolysaccharide and CpG dinucleotides reduced bacterial loads in the cLN of ciprofloxacin-treated mice.

Show MeSH