Lack of Serotype Antigen in A. actinomycetemcomitans

Aquino

Eur J Clin Microbiol Infect Dis

et al. 2011

This study investigated a large population of individuals positive for A. actinomycetemcomitans and performed a two way analysis assessing the relation between the different serotypes of the bacterium and periodontal conditions. The serotypes analysis (serotypes a, b, c, d, e, f) showed that out of the 204 selected individuals positive for A. actinomycetemcomitans, 152 were positive for a single serotype, 27 showed a variable mixed infection and 25 individuals were not positive for any of the serotypes tested. Serotypes a, b and c were largely found (98%), and serotype c was the most prevalent. Serotypes d, e, and f were either not detected or relatively rare. It was also verified that in non-periodontitis individuals, serotypes a and c were more prevalent (p<0.05); in individuals with mild or moderate/severe chronic periodontitis serotype c was also more common (p<0.05); and aggressive periodontitis subjects showed high prevalence of both serotypes b and c (p<0.05). In conclusion, our study showed that serotype c was the most prevalent in both diseased and healthy subjects. Aggressive periodontitis subjects were not exclusively associated with A. actinomycetemcomitans serotype b. Non-typeable strains were either not detected or were relatively infrequent, and serotypes d and f were not detected in the examined Brazilian population.

Section: Resultsmentioning

confidence: 99%

“…An interesting investigation related to non-serotypeable strains of A. actinomycetemcomitans was performed by Kanasi et al [19]. They hypothesized that non-serotypeable strains represent new serotypes or have altered expression of serotype-specific polysaccharide antigen (S-PA).…”

Section: Discussionmentioning

confidence: 99%

Aggregatibacter actinomycetemcomitans serotypes infections and periodontal conditions: a two-way assessment

Aquino

Eur J Clin Microbiol Infect Dis

et al. 2011

“…In the last case (S23A/I23C), the two strains in the pair were isolated from the subject at the same time point, but displayed different serological reactivity to serotyping by immunodiffusion (Table 1). The presence of serotype b specific gene cluster in S23A and I23C was confirmed by PCR [25]. Henceforth, the strains from each individual will be referred to as “paired strains”.…”

Section: Methodsmentioning

confidence: 87%

“…A number of studies have reported nonserotypeable clinical isolates of A. actinomycetemcomitans [25], [43]. The nonserotypeable strains may be expressing serotype antigens not included in the sets of antisera used in the immunodiffusion assay (e.g., serotype f).…”

Section: Discussionmentioning

confidence: 99%

Genomic Stability of Aggregatibacter actinomycetemcomitans during Persistent Oral Infection in Human

et al. 2013

The genome of periodontal pathogen Aggregatibacter actinomycetemcomitans exhibits substantial variations in gene content among unrelated strains primarily due to the presence or absence of genomic islands. This study examined the genomic stability of A. actinomycetemcomitans during its persistent infection in the same host. Four pairs of A. actinomycetemcomitans strains, each pair isolated from an individual over time (0–10 years), were examined for their gains/losses of genes by whole genome sequencing, comparative genomic hybridization by microarray and PCR analysis. Possible effects due to genomic changes were further assessed by comparative transcriptome analysis using microarrays. The results showed that each pair of strains was clonally identical based on phylogenetic analysis of 150 core genes. A novel 24.1-Kb plasmid found in strain S23A was apparently lost in the sibling strain I23C. A 353-bp inversion affecting two essential genes of the serotype-specific gene cluster was found in the serotype antigen-nonexpressing strain I23C, while the same gene cluster was intact in the serotype-expressing sibling strain S23A. A 2,293-bp deletion affecting a gene encoding oxaloacetate decarboxylase and its neighbor region was found in strain SCC2302 but not in the sibling strain AAS4a. However, no evidence of gains or losses of genomic islands was found in the paired strains. Transcriptome profiles showed little or no difference in the paired strains. In conclusion, the genome of A. actinomycetemcomitans appears to be relatively stable during short-term infection. Several types of genomic changes were observed in the paired strains of A. actinomycetemcomitans recovered from the same subjects, including a mutation in serotype-specific gene cluster that may allow the bacteria to evade host immune response.

J Clinic Periodontology

“…These variants could be correctly assigned to the known six serotypes using the PCR method (Kanasi et al. ). When studies using PCR and identifying all six serotypes were considered, the prevalence of non‐serotypeable strains was generally lower than 3% (van der Reijden et al.…”

Section: Discussionmentioning

confidence: 99%

Aggregatibacter actinomycetemcomitans serotypes, the JP2 clone and cytolethal distending toxin genes in a Thai population

Bandhaya

Saraithong

Likittanasombat

et al. 2012