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GidA, a tRNA Modification Enzyme, Contributes to the Growth, and Virulence of Streptococcus suis Serotype 2.

Gao T, Tan M, Liu W, Zhang C, Zhang T, Zheng L, Zhu J, Li L, Zhou R - Front Cell Infect Microbiol (2016)

Bottom Line: Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity.This is consistent with the phenotypes of the mutant.Our findings provide new insight into the regulatory function of GidA in bacterial pathogens.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China; Veterinary Medicine Laboratory, Institute of Animal Husbandry and Veterinary Science, Hubei Academy of Agricultural ScienceWuhan, China; Wuhan Chopper Biology Co., Ltd.Wuhan, China.

ABSTRACT
Glucose-inhibited division protein (GidA), is a tRNA modification enzyme functioning together with MnmE in the addition of a carboxymethylaminomethyl group to position 5 of the anticodon wobble uridine of tRNA. Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity. Moreover, the gidA deletion mutant (ΔgidA) displayed reduced mortality and bacterial loads in mice, reduced ability of adhesion to and invasion in epithelial cells, and increased sensitivity to phagocytosis. The iTRAQ analysis identified 372 differentially expressed (182 up- and 190 down-regulated) proteins in ΔgidA and SC-19. Numerous DNA replication, cell division, and virulence associated proteins were downregulated, whereas many capsule synthesis enzymes were upregulated by gidA disruption. This is consistent with the phenotypes of the mutant. Thus, GidA is a translational regulator that plays an important role in the growth, cell division, capsule biosynthesis, and virulence of SS2. Our findings provide new insight into the regulatory function of GidA in bacterial pathogens.

No MeSH data available.


Related in: MedlinePlus

Characterization of gidA mutant. (A) SC-19 and ΔgidA mutant cultured overnight at 37°C on TSA plates. (B) Bacterial cell density was measured spectrometrically at 600 nm, and separate aliquots of the bacterial suspensions were serially diluted and plated to determine CFU numbers per milliliter. Data were collected at the indicated times. (C) Transmission electron micrographs of bacteria; the bars represent 400 nm (***p < 0.001). (D) Microplate showing hemolytic activity of the supernatants collected from SC-19 and ΔgidA mutant grown in CDM. Absorption was measured at 550 nm to determine suilysin production (***p < 0.001). CDM was used as negative control.
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Figure 2: Characterization of gidA mutant. (A) SC-19 and ΔgidA mutant cultured overnight at 37°C on TSA plates. (B) Bacterial cell density was measured spectrometrically at 600 nm, and separate aliquots of the bacterial suspensions were serially diluted and plated to determine CFU numbers per milliliter. Data were collected at the indicated times. (C) Transmission electron micrographs of bacteria; the bars represent 400 nm (***p < 0.001). (D) Microplate showing hemolytic activity of the supernatants collected from SC-19 and ΔgidA mutant grown in CDM. Absorption was measured at 550 nm to determine suilysin production (***p < 0.001). CDM was used as negative control.

Mentions: The colonies sensitive to spectinomycin and resistant to erythromycin were selected as candidates of gidA deletion mutants, which were confirmed by PCR (Figure 1A), RT-PCR (Figure 1B), and Western blot analysis (Figure 1C). The colonies of ΔgidA appeared smaller than those of SC-19 when cultured on TSA plates overnight (Figure 2A). The growth curves showed that ΔgidA grew slower in the CDM than SC-19 (Figure 2B). However, no obvious difference in CFU counts was observed during the initial 3 h of growth. TEM revealed that the mean capsule was significantly thicker in ΔgidA (118 ± 5 nm) than in SC-19 (54 ± 3 nm; p < 0.001; Figure 2C).


GidA, a tRNA Modification Enzyme, Contributes to the Growth, and Virulence of Streptococcus suis Serotype 2.

Gao T, Tan M, Liu W, Zhang C, Zhang T, Zheng L, Zhu J, Li L, Zhou R - Front Cell Infect Microbiol (2016)

Characterization of gidA mutant. (A) SC-19 and ΔgidA mutant cultured overnight at 37°C on TSA plates. (B) Bacterial cell density was measured spectrometrically at 600 nm, and separate aliquots of the bacterial suspensions were serially diluted and plated to determine CFU numbers per milliliter. Data were collected at the indicated times. (C) Transmission electron micrographs of bacteria; the bars represent 400 nm (***p < 0.001). (D) Microplate showing hemolytic activity of the supernatants collected from SC-19 and ΔgidA mutant grown in CDM. Absorption was measured at 550 nm to determine suilysin production (***p < 0.001). CDM was used as negative control.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4835480&req=5

Figure 2: Characterization of gidA mutant. (A) SC-19 and ΔgidA mutant cultured overnight at 37°C on TSA plates. (B) Bacterial cell density was measured spectrometrically at 600 nm, and separate aliquots of the bacterial suspensions were serially diluted and plated to determine CFU numbers per milliliter. Data were collected at the indicated times. (C) Transmission electron micrographs of bacteria; the bars represent 400 nm (***p < 0.001). (D) Microplate showing hemolytic activity of the supernatants collected from SC-19 and ΔgidA mutant grown in CDM. Absorption was measured at 550 nm to determine suilysin production (***p < 0.001). CDM was used as negative control.
Mentions: The colonies sensitive to spectinomycin and resistant to erythromycin were selected as candidates of gidA deletion mutants, which were confirmed by PCR (Figure 1A), RT-PCR (Figure 1B), and Western blot analysis (Figure 1C). The colonies of ΔgidA appeared smaller than those of SC-19 when cultured on TSA plates overnight (Figure 2A). The growth curves showed that ΔgidA grew slower in the CDM than SC-19 (Figure 2B). However, no obvious difference in CFU counts was observed during the initial 3 h of growth. TEM revealed that the mean capsule was significantly thicker in ΔgidA (118 ± 5 nm) than in SC-19 (54 ± 3 nm; p < 0.001; Figure 2C).

Bottom Line: Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity.This is consistent with the phenotypes of the mutant.Our findings provide new insight into the regulatory function of GidA in bacterial pathogens.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China; Veterinary Medicine Laboratory, Institute of Animal Husbandry and Veterinary Science, Hubei Academy of Agricultural ScienceWuhan, China; Wuhan Chopper Biology Co., Ltd.Wuhan, China.

ABSTRACT
Glucose-inhibited division protein (GidA), is a tRNA modification enzyme functioning together with MnmE in the addition of a carboxymethylaminomethyl group to position 5 of the anticodon wobble uridine of tRNA. Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity. Moreover, the gidA deletion mutant (ΔgidA) displayed reduced mortality and bacterial loads in mice, reduced ability of adhesion to and invasion in epithelial cells, and increased sensitivity to phagocytosis. The iTRAQ analysis identified 372 differentially expressed (182 up- and 190 down-regulated) proteins in ΔgidA and SC-19. Numerous DNA replication, cell division, and virulence associated proteins were downregulated, whereas many capsule synthesis enzymes were upregulated by gidA disruption. This is consistent with the phenotypes of the mutant. Thus, GidA is a translational regulator that plays an important role in the growth, cell division, capsule biosynthesis, and virulence of SS2. Our findings provide new insight into the regulatory function of GidA in bacterial pathogens.

No MeSH data available.


Related in: MedlinePlus