The CovS/CovR Acid Response Regulator Is Required for Intracellular Survival of Group B Streptococcus in Macrophages

Cumley, Nicola; Smith, Laurence; Anthony, Mark; May, Robin C.

doi:10.1128/iai.05443-11

Cited by 61 publications

(76 citation statements)

References 51 publications

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“…1A). At 24 hr, the ST-23 strain had the greatest ability to survive inside the macrophages followed by the strains belonging to STs 17,19, and 12, which had the lowest ability to survive (Fig. 1B).…”

Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

“…Taken together, these data suggest that diverse strains of GBS use different mechanisms to survive phagosomal stress. Since the ST-12 strain survived H 2 O 2 stress significantly better than the ST-17 strain and GBS was previously shown to prevent the induction of ROS production in the macrophage during infection, 19 we hypothesized that the ST-17 strain would have an enhanced ability to inhibit ROS production. To test this, we examined the production of ROS in placental macrophages every 30 min for 2 hr after GBS infection.…”

Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

“…This pH requirement is congruent with a previous study that found the CovR/S acid response regulator was needed for intracellular survival. 19 When comparing the individual effect of different phagosomal stressors on each of the strains, the ST-17 strain survived better in low pH and CuCl 2 but the ST-12 strain survived better under H 2 O 2 and NO stress. Taken together, these results suggest that different GBS strains use different mechanisms to survive inside the phagosome.…”

Section: Cps Type Percent Survivalmentioning

confidence: 99%

“…19 Briefly, stationary phase cultures were washed in PBS, then resuspended in 0.1M sodium phosphate buffer pH 7.5 alone or buffer with the indicated stressor at a final concentration of approximately 1£10 6 cells/ml. Cultures were incubated for 1 hr at 37 C then diluted and plated on THA to count viable bacteria.…”

Section: Gbs Survival In Synthetic Multiple Stress Mediummentioning

confidence: 99%

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

et al. 2016

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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.

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Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

Section: Gbs Genotypes Differ In Level Of Phagocytosis By Macrophagesmentioning

confidence: 99%

Section: Cps Type Percent Survivalmentioning

confidence: 99%

Section: Gbs Survival In Synthetic Multiple Stress Mediummentioning

confidence: 99%

See 2 more Smart Citations

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

et al. 2016

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“…To measure the susceptibility of S. suis to oxidative stress, we conducted H 2 O 2 -sensitivity assays according to the method reported by Cumley et al (2012) with minor modifications. Briefly, overnight-grown bacteria were diluted 100-fold into fresh THY and grown to early stationary phase at 37 uC with vigorous shaking.…”

Section: Methodsmentioning

confidence: 99%

The two-component system Ihk/Irr contributes to the virulence of Streptococcus suis serotype 2 strain 05ZYH33 through alteration of the bacterial cell metabolism

et al. 2012

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Host–pathogen interactions in bacterial meningitis

et al. 2016

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Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host–pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host–pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood–brain and blood–cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.

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The CovS/CovR Acid Response Regulator Is Required for Intracellular Survival of Group B Streptococcus in Macrophages

Cited by 61 publications

References 51 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

The two-component system Ihk/Irr contributes to the virulence of Streptococcus suis serotype 2 strain 05ZYH33 through alteration of the bacterial cell metabolism

Host–pathogen interactions in bacterial meningitis

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