Enhanced phagocytosis of encapsulated Escherichia coli strains after exposure to sub-MICs of antibiotics is correlated to changes of the bacterial cell surface

Raponi, Giammarco; Keller, Nathan; Overbeek, B. P.; Rozenberg-Arska, M.; Kessel, Kok P. M. van; Verhoef, J.

doi:10.1128/aac.34.2.332

Cited by 38 publications

(24 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…22 A link between encapsulation and enhanced phagocytic uptake after exposure to sub-inhibitory antibiotics in E. coli was also reported. 18 Taken together, these data indicate a common response to sub-inhibitory concentrations of antibiotics across different bacterial species as well as antibiotics with different modes of action. However, ampicillin exposure resulted in a smaller reduction in capsule compared to penicillin and erythromycin.…”

Section: Cps Type Percent Survivalmentioning

confidence: 91%

“…Since capsule is an important virulence factor in immune system evasion 17 and a previous study showed a correlation between capsule alteration after antibiotic exposure and enhanced phagocytosis in E. coli, 18 we hypothesized that changes in capsule could contribute to enhanced phagocytosis of the ST-17 strain. To test this, we examined the GBS cultures after exposure to antibiotics using a capsule stain (Figs.…”

Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

See 1 more Smart Citation

Differing mechanisms of surviving phagosomal stress among group BStreptococcusstrains of varying genotypes

et al. 2016

View full text Add to dashboard Cite

Group B Streptococcus (GBS), a leading cause of neonatal sepsis and meningitis, asymptomatically colonizes up to 30% of women and can persistently colonize even after antibiotic treatment. Previous studies have shown that GBS resides inside macrophages, but the mechanism by which it survives remains unknown. Here, we examined the ability of 4 GBS strains to survive inside macrophages and then focused on 2 strains belonging to sequence type (ST)-17 and ST-12, to examine persistence in the presence of antibiotics. A multiple stress medium was also developed using several stressors found in the phagosome to assess the ability of 30 GBS strains to withstand phagosomal stress. The ST-17 strain was more readily phagocytosed and survived intracellularly longer than the ST-12 strain, but the ST-12 strain was tolerant to ampicillin unlike the ST-17 strain. Exposure to sub-inhibitory concentrations of ampicillin and erythromycin increased the level of phagocytosis of the ST-17 strain, but had no effect on the ST-12 strain. In addition, blocking acidification of the phagosome decreased the survival of the ST-17 strain indicating a pHdependent survival mechanism for the ST-17 strain. Congruent with the macrophage experiments, the ST-17 strain had a higher survival rate in the multiple stress medium than the ST-12 strain, and overall, serotype III isolates survived significantly better than other serotypes. These results indicate that diverse GBS strains may use differing mechanisms to persist and that serotype III strains are better able to survive specific stressors inside the phagosome relative to other serotypes.

show abstract

Section: Cps Type Percent Survivalmentioning

confidence: 91%

Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

Differing mechanisms of surviving phagosomal stress among group BStreptococcusstrains of varying genotypes

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Beyond an inhibitory effect on the growth rate in vitro (12), sub-MICs may alter the bacterial cell wall and thus increase the susceptibility of the bacteria to the immune system (8,15,17,22,30), change the expression of bacterial exoenzymes (10,13), and also change the outcome of experimental infections in animals. Zak and Kradolfer (35) have shown in a mouse model that one-third of the MIC of ampicillin in peritoneal fluid is enough to prevent a regrowth of E. coli and Staphylococcus aureus up to 18 h after the injection.…”

Section: Discussionmentioning

confidence: 99%

Postantibiotic sub-MIC effects of vancomycin, roxithromycin, sparfloxacin, and amikacin

Odenholt-Tornqvist

Löwdin

Cars

1992

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The sub-MIC effects (SMEs) and the postantibiotic sub-MIC effects (PA SMEs) of vancomycin, roxithromycin, and sparfloxacin for Streptococcus pyogenes and Streptococcus pneumoniae and of amikacin for Escherichia coli and Pseudomonas aeruginosa were investigated. A postantibiotic effect was induced by exposing strains to 10x the MIC of the antibiotic for 2 h in vitro. After the induction, the exposed cultures were washed to eliminate the antibiotics. Unexposed controls were treated similarly. Thereafter, the exposed cultures (PA SME) and the controls (SME) were exposed to different subinhibitory concentrations (0.1, 0.2, and 0.3 x the MIC) of the same drug and growth curves for a period of 24 h were compared. In general, the PA SMEs were much more pronounced than the SMEs. However, for amikacin and E. coli the SME of 0.2 and 0.3 x the MIC also had an initial bactericidal effect. The longest PA SMEs were demonstrated for the combinations with the most pronounced killing during the induction and for the combinations which exhibited the longest PAEs.In the early 1940s, the dosage schedules devised for penicillin therapy were based on the assumption that drug concentrations must be maintained above the MIC. This assumption was based on previous experiments with the sulfonamides (1, 26). However, a few years after the introduction of penicillin, it was shown both in animal experiments and in clinical studies that a discontinuous penicillin therapy was as effective as a continuous one, even if the concentrations in serum had fallen under the MIC (4, 26, 28). At that time, Eagle et al. showed, both in vitro and in a thigh infection model in mice, that there was a lag phase before regrowth of bacteria after a first challenge of penicillin (5, 6). This concept aroused new interest in the 1970s and was named the postantibiotic effect (PAE) (3,14,33). The PAE has been extensively studied both in vitro and in vivo and has been cited as one explanation for the success of intermittent dosing regimens (3, 32). However, in most antibioticbacterium combinations the sum of the time that the drug concentration is above the MIC and the PAE does not cover the whole dosing interval. Also, in the in vivo situation, a suprainhibitory concentration of a drug will always be followed by subinhibitory concentrations (sub-MICs).We have shown earlier that subinhibitory antibiotic concentrations may have different effects on bacteria exposed previously to suprainhibitory antibiotic concentrations (postantibiotic sub-MIC effect [PA SME]), compared with the effects on bacteria not previously exposed to antibiotics (sub-MIC effect [SME]) (18,20). In most of the investigated combinations with P-lactam antibiotics, we found a pronounced difference in time between the PA SME and the SME, with two exceptions. In the combinations with no PAE, neither a PA SME nor an SME was found, and in the combination of imipenem with Pseudomonas aeruginosa, both a long PA SME and an SME were seen (20).The aim of this study was to investigate the occurrence of PA SME...

show abstract

“…The development of fluorochromes to detect oxidative bursts due to phagocytosis (17,251,281) increased the number of studies with different microbes such as Borrelia burgdorferi (17), Staphylococcus spp. (128,196), Escherichia coli (70,271), Bordetella pertussis (299), Cryptococcus neoformans (48), Salmonella (272), and yeasts (90,96,114).…”

Section: General Applications Of Flow Cytometry To Microbiologymentioning

confidence: 99%

Applications of Flow Cytometry to Clinical Microbiology

Alvarez-Barrientos¹,

Arroyo²,

Cantón³

et al. 2000

Clinical Microbiology Reviews

161

112

View full text Add to dashboard Cite

Enhanced phagocytosis of encapsulated Escherichia coli strains after exposure to sub-MICs of antibiotics is correlated to changes of the bacterial cell surface

Cited by 38 publications

References 22 publications

Differing mechanisms of surviving phagosomal stress among group BStreptococcusstrains of varying genotypes

Differing mechanisms of surviving phagosomal stress among group BStreptococcusstrains of varying genotypes

Postantibiotic sub-MIC effects of vancomycin, roxithromycin, sparfloxacin, and amikacin

Applications of Flow Cytometry to Clinical Microbiology

Contact Info

Product

Resources

About