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Detection of a 640-bp deletion in the Aggregatibacter actinomycetemcomitans leukotoxin promoter region in isolates from an adolescent of Ethiopian origin.

Claesson R, Gudmundson J, Åberg CH, Haubek D, Johansson A - J Oral Microbiol (2015)

Bottom Line: The expression of the leukotoxin of Aggregatibacter actinomycetemcomitans is regulated by the leukotoxin promoter.A 530-bp deletion or an 886-bp insertion sequence (IS) element in this region has earlier been described in highly leukotoxic isolates.Here, we report on highly leukotoxic isolate with a 640-bp deletion, which was detected in an adolescent of Ethiopian origin.

View Article: PubMed Central - PubMed

Affiliation: Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden; rolf.claesson@odont.umu.se.

ABSTRACT
The expression of the leukotoxin of Aggregatibacter actinomycetemcomitans is regulated by the leukotoxin promoter. A 530-bp deletion or an 886-bp insertion sequence (IS) element in this region has earlier been described in highly leukotoxic isolates. Here, we report on highly leukotoxic isolate with a 640-bp deletion, which was detected in an adolescent of Ethiopian origin.

No MeSH data available.


Related in: MedlinePlus

Leukotoxicity of A. actinomycetemcomitans strains with different leukotoxin promoter types on cultures of PMA-differentiated THP-1 cells. Strains: 456A1 (novel), HK1651 (JP2), Y4 (non-JP2), and NCTC9710 (non-JP2). The THP-1 cells were exposed for 2 hours with 10% of a NaCl surface extract based on a bacterial density of OD 10 at 600 nm. Mean and standard deviations from two different experiments with four replicates in each are shown. (a) Cell lysis as a percentage of LDH release in relation to that of a triton-lysed control sample. (b) Viability as a percentage of neutral red uptake in relation to a plane control sample.
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Figure 0003: Leukotoxicity of A. actinomycetemcomitans strains with different leukotoxin promoter types on cultures of PMA-differentiated THP-1 cells. Strains: 456A1 (novel), HK1651 (JP2), Y4 (non-JP2), and NCTC9710 (non-JP2). The THP-1 cells were exposed for 2 hours with 10% of a NaCl surface extract based on a bacterial density of OD 10 at 600 nm. Mean and standard deviations from two different experiments with four replicates in each are shown. (a) Cell lysis as a percentage of LDH release in relation to that of a triton-lysed control sample. (b) Viability as a percentage of neutral red uptake in relation to a plane control sample.

Mentions: DNA was purified from one of the two isolates (456A1) with a DNA-purifying kit (Ready-To-Go Kit; GE Healthcare, Little Chalfont, UK) for further characterization. First, when the promoter region was sequenced as described (6), it was found to be associated with a 640-bp deletion, i.e., it lacked 640 bp as compared with strains with the full-length leukotoxin promoter (Fig. 1). In comparison with the 530-bp deletion in the leukotoxin promoter region in JP2 genotype strains, the additional 110 bp missing in the sequenced isolate (456A1) were located 108 bp upstream and 2 bp downstream from the site of the JP2 genotype–associated deletion. Although isolate 456A1 carried a different leukotoxin promoter than JP2 genotype strains, it was found to have leukotoxicity similar to that of the JP2 genotype of A. actinomycetemcomitans (strain HK1615), when leukotoxic activity was determined as described (6) (Fig. 3).


Detection of a 640-bp deletion in the Aggregatibacter actinomycetemcomitans leukotoxin promoter region in isolates from an adolescent of Ethiopian origin.

Claesson R, Gudmundson J, Åberg CH, Haubek D, Johansson A - J Oral Microbiol (2015)

Leukotoxicity of A. actinomycetemcomitans strains with different leukotoxin promoter types on cultures of PMA-differentiated THP-1 cells. Strains: 456A1 (novel), HK1651 (JP2), Y4 (non-JP2), and NCTC9710 (non-JP2). The THP-1 cells were exposed for 2 hours with 10% of a NaCl surface extract based on a bacterial density of OD 10 at 600 nm. Mean and standard deviations from two different experiments with four replicates in each are shown. (a) Cell lysis as a percentage of LDH release in relation to that of a triton-lysed control sample. (b) Viability as a percentage of neutral red uptake in relation to a plane control sample.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400299&req=5

Figure 0003: Leukotoxicity of A. actinomycetemcomitans strains with different leukotoxin promoter types on cultures of PMA-differentiated THP-1 cells. Strains: 456A1 (novel), HK1651 (JP2), Y4 (non-JP2), and NCTC9710 (non-JP2). The THP-1 cells were exposed for 2 hours with 10% of a NaCl surface extract based on a bacterial density of OD 10 at 600 nm. Mean and standard deviations from two different experiments with four replicates in each are shown. (a) Cell lysis as a percentage of LDH release in relation to that of a triton-lysed control sample. (b) Viability as a percentage of neutral red uptake in relation to a plane control sample.
Mentions: DNA was purified from one of the two isolates (456A1) with a DNA-purifying kit (Ready-To-Go Kit; GE Healthcare, Little Chalfont, UK) for further characterization. First, when the promoter region was sequenced as described (6), it was found to be associated with a 640-bp deletion, i.e., it lacked 640 bp as compared with strains with the full-length leukotoxin promoter (Fig. 1). In comparison with the 530-bp deletion in the leukotoxin promoter region in JP2 genotype strains, the additional 110 bp missing in the sequenced isolate (456A1) were located 108 bp upstream and 2 bp downstream from the site of the JP2 genotype–associated deletion. Although isolate 456A1 carried a different leukotoxin promoter than JP2 genotype strains, it was found to have leukotoxicity similar to that of the JP2 genotype of A. actinomycetemcomitans (strain HK1615), when leukotoxic activity was determined as described (6) (Fig. 3).

Bottom Line: The expression of the leukotoxin of Aggregatibacter actinomycetemcomitans is regulated by the leukotoxin promoter.A 530-bp deletion or an 886-bp insertion sequence (IS) element in this region has earlier been described in highly leukotoxic isolates.Here, we report on highly leukotoxic isolate with a 640-bp deletion, which was detected in an adolescent of Ethiopian origin.

View Article: PubMed Central - PubMed

Affiliation: Division of Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden; rolf.claesson@odont.umu.se.

ABSTRACT
The expression of the leukotoxin of Aggregatibacter actinomycetemcomitans is regulated by the leukotoxin promoter. A 530-bp deletion or an 886-bp insertion sequence (IS) element in this region has earlier been described in highly leukotoxic isolates. Here, we report on highly leukotoxic isolate with a 640-bp deletion, which was detected in an adolescent of Ethiopian origin.

No MeSH data available.


Related in: MedlinePlus