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The red-complex bacteria Porphyromonas gingivalis and Tannerella forsythia together with Fusobacterium nucleatum are essential players in periodontitis. This study investigated the bacterial interplay with human periodontal ligament mesenchymal stromal cells (hPDL-MSCs) which act in the acute phase of periodontal infection. The capability of the bacteria to induce an inflammatory response as well as their viability, cellular adhesion and invasion were analyzed upon mono- and co-infections of hPDL-MSCs to delineate potential synergistic or antagonistic effects. The expression level and concentration of interleukin (IL)−6, IL-8 and monocyte chemoattractant protein (MCP)−1 were measured using qRT-PCR and ELISA. Viability, invasion, and adhesion were determined quantitatively using agar plate culture and qualitatively by confocal microscopy. Viability of P. gingivalis and T. forsythia but not F. nucleatum was preserved in the presence of hPDL-MSCs, even in an oxygenated environment. F. nucleatum significantly increased the expression and concentration of IL-6, IL-8 and MCP-1 in hPDL-MSCs, while T. forsythia and P. gingivalis caused only a minimal inflammatory response. Co-infections in different combinations had no effect on the inflammatory response. Moreover, P. gingivalis mitigated the increase in cytokine levels elicited by F. nucleatum. Both red-complex bacteria adhered to and invaded hPDL-MSCs in greater numbers than F. nucleatum , with only a minor effect of co-infections. Oral bacteria of different pathogenicity status interact differently with hPDL-MSCs. The data support P. gingivalis' capability to manipulate the inflammatory host response. Further research is necessary to obtain a comprehensive picture of the role of hPDL-MSCs in more complex oral biofilms. • F. nucleatum induces significant cytokine release by hPDL-MSCs. • P. gingivalis-F. nucleatum co-infection antagonizes cytokine production. • hPDL-MSCs preserve viability of red-complex bacteria, but not F. nucleatum. • Red-complex bacteria are more adhesive/invasive to hPDL-MSCs than F. nucleatum. [ABSTRACT FROM AUTHOR]

We evaluated the effect of chitosan gel on total oral bacteria, Porphyromonas gingivalis , Tannerella forsythia , and Treponema denticola , during orthodontic treatment with mini-implants. Thirty subjects with 52 orthodontic mini-implants were divided into three groups: one group was treated with chitosan gel, the other group with chlorhexidine gel, and the control group with placebo. The plaque of the orthodontic peri -mini-implant area was collected before and after gel treatment. The total oral bacteria and red-complex bacteria of P. pingivalis , T. forsythia , and T. denticola were determined with reverse transcription-quantitative PCR. Thirty-four orthodontic mini-implants (65.38%) appeared as healthy and showed no clinical signs of inflammation. The total number of bacteria was reduced after chitosan gel application. The highest decrease in the proportion of P. gingivalis was observed in the chlorhexidine gel application group, which showed a value of 70.86%, whereas the chitosan gel application showed a reduction of only 26.59%, and the control gel application showed the lowest reduction effect of only 2.55%. The difference in the reduction between gel application groups was significant (P < 0.05) for T. denticola and T. forsythia. The gel containing chitosan reduced the levels of total oral bacteria and red-complex bacteria. [ABSTRACT FROM AUTHOR]

Objective To evaluate the adhesion of selected bacterial strains incl. expression of important virulence factors at dentin and titanium SLA surfaces coated with layers of serum proteins. Methods Dentin- and moderately rough SLA titanium-discs were coated overnight with human serum, or IgG, or human serum albumin (HSA). Thereafter, Porphyromonas gingivalis, Tannerella forsythia, or a six-species mixture were added for 4 h and 24 h. The number of adhered bacteria (colony forming units; CFU) was determined. Arg-gingipain activity of P. gingivalis and mRNA expressions of P. gingivalis and T. forsythia proteases and T. forsythia protease inhibitor were measured. Results Coating specimens never resulted in differences exceeding 1.1 log10 CFU, comparing to controls, irrespective the substrate. Counts of T. forsythia were statistically significantly higher at titanium than dentin, the difference was up to 3.7 log10 CFU after 24 h (p = 0.002). No statistically significant variation regarding adhesion of the mixed culture was detected between surfaces or among coatings. Arg-gingipain activity of P. gingivalis was associated with log10 CFU but not with the surface or the coating. Titanium negatively influenced mRNA expression of T. forsythia protease inhibitor at 24 h (p = 0.026 uncoated, p = 0.009 with serum). Conclusions The present findings indicate that: a) single bacterial species ( T. forsythia ) can adhere more readily to titanium SLA than to dentin, b) low expression of T. forsythia protease inhibitor may influence the virulence of the species on titanium SLA surfaces in comparison with teeth, and c) surface properties ( e.g. material and/or protein layers) do not appear to significantly influence multi-species adhesion. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the mechanism by which periodontitis affects the inflammatory response and systemic insulin resistance in the white adipose and liver tissues in an obese rat model. The obese model was generated by feeding rats a high fat diet. The periodontitis model was induced by ligatures and injection of “red complex”, which consisted of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, for two weeks. When compared with rats without periodontitis, fasting glucose levels and homeostasis model assessment index were significantly increased in rats with periodontitis, suggesting that periodontitis promotes the development of insulin resistance in obese rats. Gene and protein expression analysis in white adipose and liver tissue revealed that experimental periodontitis stimulated the expression of inflammatory cytokines, such as tumor necrosis factors-alpha, interleukin-1 beta, toll-like receptor 2 and toll-like receptor 4. Signals associated with inflammation and insulin resistance, including nuclear factor- B, c-Jun amino-terminal kinase and extracellular-signal regulated kinase were significantly activated in the white adipose tissue from obese rats with periodontitis compared to obese rats without periodontitis. Taken together, these findings suggest that periodontitis plays an important role in aggravating the development of local white adipose inflammation and systemic insulin resistance in rat models. [ABSTRACT FROM AUTHOR]

Objectives The objective of the present study was to clarify the lysine-specific proteolytic activity derived from periodontal pathogens responsible for Forsythia detaching factor (FDF) modification. Design The activity responsible for FDF modification in Tannerella forsythia and Porphyromonas gingivalis were evaluated by colorimetric assay using Ac-Arg-Ala-Lys-p-nitroaniline as a substrate. FDF modification in T. forsythia and P. gingivalis were evaluated by Western blotting using recombinant FDF (rFDF) as a substrate. Furthermore, the activity in GCF of 20 patients with periodontitis and 10 healthy subjects was also evaluated by colorimetric assay. Bacteria in subgingival plaque were detected using polymerase chain reaction. Results The activity of both bacteria in colorimetric assay were 21.35 unit ( P. gingivalis ) and 3.61 unit ( T. forsythia ), respectively. Western blot analysis revealed that P. gingivalis was found to efficiently degrade rFDF and T. forsythia partially cleaved rFDF. The activity in GCF from patients with periodontitis (clinically healthy sites: CH, deep bleeding sites: DB and deep non-bleeding sites: DNB) was significantly higher than those from healthy subjects (healthy sites: H). Among the patients with periodontitis, the activity from CH was significantly lower than those from DB and DNB. T. forsythia was detected in 68.4% of DNB, in 78.4% of DB and in none of CH. P. gingivalis was detected in 63.2% of DNB, in 84.0% of DB and in 10.5% of CH. No bacterium was detected in healthy subjects. Conclusion The lysine-specific proteolytic activity responsible for FDF modification correlates with the presence of major periodontal pathogens. [ABSTRACT FROM AUTHOR]

Background Unique phosphodihydroceramides containing phosphoethanolamine and glycerol have been previously described in Porphyromonas gingivalis . Importantly, they were shown to possess pro-inflammatory properties. Other common human bacteria were screened for the presence of these lipids, and they were found, amongst others, in the oral pathogen Tannerella forsythia . To date, no detailed study into the lipids of this organism has been performed. Methods Lipids were extracted, separated and purified by HPTLC, and analyzed using GC-MS, ESI–MS and NMR. Of special interest was how T. forsythia acquires the metabolic precursors for the lipids studied here. This was assayed by radioactive and stable isotope incorporation using carbon-14 and deuterium labeled myo -inositol, added to the growth medium. Results T. forsythia synthesizes two phosphodihydroceramides (Tf GL1, Tf GL2) which are constituted by phospho- myo -inositol linked to either a 17-, 18-, or 19-carbon sphinganine, N -linked to either a branched 17:0(3-OH) or a linear 16:0(3-OH) fatty acid which, in Tf GL2, is, in turn, ester-substituted with a branched 15:0 fatty acid. T. forsythia lacks the enzymatic machinery required for myo -inositol synthesis but was found to internalize inositol from the medium for the synthesis of both Tf GL1 and Tf GL2. Conclusion The study describes two novel glycolipids in T. forsythia which could be essential in this organism. Their synthesis could be reliant on an external source of myo -inositol. General significance The effects of these unique lipids on the immune system and their role in bacterial virulence could be relevant in the search for new drug targets. [ABSTRACT FROM AUTHOR]

Objective Epidemiological, biological and clinical links between periodontal and cardiovascular diseases are now well established. Several human studies have detected bacterial DNA corresponding to periodontal pathogens in cardiovascular samples. Intraplaque hemorrhage has been associated with a higher risk of atherosclerotic plaque rupture, potentially mediated by neutrophil activation. In this study, we hypothesized that plaque composition may be related to periodontal pathogens. Methods Carotid culprit plaque samples were collected from 157 patients. Macroscopic characterization was performed at the time of collection: presence of blood, lipid core, calcification and fibrosis. Markers of neutrophil activation released by carotid samples were quantified (myeloperoxidase or MPO, cell-free DNA and DNA-MPO complexes). PCR analysis using specific primers for Porphyromonas gingivalis , Aggregatibacter actinomycetemcommitans , Treponema denticola , Prevotella intermedia and Tannerella forsythia was used to detect DNA from periodontal pathogens in carotid tissues. In addition, bacterial lipopolysaccharide (LPS) and Immunoglobulins G against T. forsythia were quantified in atherosclerotic carotid conditioned medium. Results Intraplaque hemorrhage was present in 73/157 carotid samples and was associated with neutrophil activation, reflected by the release of MPO, cell-free DNA and MPO-DNA complexes. LPS levels were also linked to intraplaque hemorrhage but not with the neutrophil activation markers. Seventy-three percent of the carotid samples were positive for periodontal bacterial DNA. Furthermore, hemoglobin levels were associated with the detection of T. forsythia and neutrophil activation/inflammation markers. Conclusion This study suggests a potential role of periodontal microorganisms, especially T. forsythia , in neutrophil activation within hemorrhagic atherosclerotic carotid plaques. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Forsythia detaching factor (FDF) is a virulence factor of Tannerella forsythia detected as a mixture of the 60-kDa form of FDF and the 28-kDa C-terminal fragment (FDFc). The objective of the present study was to clarify the proteolytic activity of gingival crevicular fluid (GCF) from patients with periodontitis and healthy subjects using recombinant FDF (rFDF) as substrate. Design: Eleven patients with periodontitis and 6 healthy subjects were recruited. Modification of rFDF and subsequent production of rFDFc by proteolytic activity of GCF was determined by Western blotting. Proteolytic activity of GCF was evaluated using an Ac-Arg-Ala-Lys-p-nitroaniline substrate. Correlation analysis between two different sets of variables was performed. Variables used in this analysis were proteolytic activity, clinical parameters, relative band density of rFDFc and those of rFDF. Results: Proteolytic activity in GCF was significantly higher in patients with periodontitis than in healthy subjects. Production of rFDFc was determined by treatment of rFDF with GCF from patients with periodontitis and with GCF from healthy subjects. Correlations between clinical parameters and proteolytic activity in GCF were significantly positive. On the other hand, correlations between relative band density of rFDFc or rFDF on Western blot and cleaving activity or clinical parameters were significantly negative. Conclusion: The detected extend of GCF-activity generating rFDFc from rFDF and/or even further degrading rFDF correlates with severity of periodontitis. [Copyright &y& Elsevier]

Abstract: Objective: The purpose of the present study was to characterize the collagenolytic activity in a sonicated extract of Tannerella forsythia and to investigate the activation of proMMMP-2 and -9 by the T. forsythia extract. Methods: The T. forsythia extract was incubated with type I collagen. The cleaved products were then analyzed by SDS-PAGE using the method of Laemmli. We studied the effects of cysteine, DTT, CaCl2, and various proteinase inhibitors on collagenolytic activity. A HT1080 cell culture supernatant containing proMMP-2 and -9 was incubated with the T. forsythia extract and analyzed for the activation of proMMP-2 and -9 by gelatin zymography. Results: The T. forsythia extract degraded type I collagen. Cysteine increased the collagenolytic activity of the extract, and 5mM CaCl2 was required for this activity. The collagenolytic activity of T. forsythia was inhibited by N-ethylmaleimide, iodoacetamide, iodoacetic acid, EDTA, and leupeptin, but not by PMSF, E-64, TLCK, or TPCK. When proMMP-2 and -9 were incubated with the T. forsythia extract, gelatinases with the relative molecular masses of MMP-2 and -9 were produced. Conclusion: The present study suggests that T. forsythia extract is able to degrade type I collagen and activate proMMP-2 and -9. [Copyright &y& Elsevier]

Abstract: The periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia are strongly associated with periodontal disease and are highly prevalent in humans with periodontitis. Porphyromonas and Tannerella spp. have also been isolated from the oral cavity of cats. The oral microflora in animals was compared with those in humans in earlier studies, but no studies are available on the comparison of the oral microflora from pets and their respective owners. The aim of this study was to determine the presence of these bacteria in the oral microflora of cats and their owners, since animal to human transmission, or vice versa, of oral pathogens could have public health implications. This study investigated the prevalence of Porphyromonas gulae, P. gingivalis, and T. forsythia in the oral microflora of cats and their owners, using culture and polymerase chain reaction (PCR). All Porphyromonas isolates from cats (n =64) were catalase positive, whereas the Porphyromonas isolates from owners (n =7) were catalase negative, suggesting that the isolates from cats were P. gulae whereas those from the owners were P. gingivalis. T. forsythia was recovered from both cats (n =63) and owners (n =31); the proportion of T. forsythia relative to the total CFU was higher in cats with periodontitis than in cats without periodontal disease. Genotyping of T. forsythia isolates (n =54) in six cat/owner couples showed that in one cat/owner couple the T. forsythia isolates (n =6) were identical. These T. forsythia isolates were all catalase positive, which led us to hypothesize that transmission from cats to owners had occurred and that cats may be a reservoir of T. forsythia. [Copyright &y& Elsevier]

Abstract: Accumulated evidence points to Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia as three major etiologic agents of chronic periodontitis. Epithelial cells and macrophages play a major role in the host response to periodontopathogens, and the secretion of inflammatory mediators and matrix metalloproteinases (MMPs) by these host cells is believed to contribute to periodontal tissue destruction. The aim of this study was to investigate the inflammatory response of a macrophage/epithelial cell co-culture model following mono or mixed infections with the above three periodontopathogens. An in vitro co-culture model composed of epithelial-like transformed cells (HeLa cell line) and macrophage-like cells (phorbol myristic acid-differentiated U937 monocytic cell line) was challenged with whole cells or lipopolysaccharides (LPS) of P. gingivalis, T. denticola, and T. forsythia, individually and in combination. Following stimulation, the production of interleukin-1 beta (IL-1β), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), regulated on activation normal T cell expressed and secreted (RANTES), prostaglandin E2 (PGE2), and MMP-9 were quantified by enzyme-linked immunoassays. We observed that mono or mixed infections of the co-culture model induced the secretion of IL-1β, IL-6, IL-8, PGE2, and MMP-9. P. gingivalis and T. forsythia induced an increase in RANTES secretion, whereas T. denticola alone or in combination resulted in a significant decrease in RANTES levels. All LPS challenges induced an increase in chemokine, MMP-9, and PGE2 production. No synergistic effect on the production of cytokines, chemokines, PGE2, and MMP-9 was observed for any of the bacterial or LPS mixtures tested. This study supports the view that P. gingivalis, T. denticola, and T. forsythia may induce high levels of pro-inflammatory mediators and MMP-9 in periodontal lesions, thus contributing to the progression of periodontitis. [Copyright &y& Elsevier]

Abstract: Aims. – Erythromycin (ERY) and spiramycin (SPI) are the most frequently prescribed macrolides by dentists. However, the emergence of resistant anaerobic subgingival bacteria imposes an increased vigilance. This study aims to compare these macrolides efficacy on principal periopathogens. Materials and methods. – Twenty adult patients with aggressive periodontitis were selected and a total of 60 samples were taken from subgingival flora. Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Peptostreptococcus micros and Actinobacillus actinomycetemcomitans were isolated according to J. Slots''s rapid identification method. The susceptibilities to ERY and SPI were studied using disk diffusion susceptibility test and minimum inhibitory concentration test (MIC test). Results. – The efficiency variability of ERY and SPI on the 50 isolated anaerobic periopathogens was present either interindividually (between different patients) and intra-individually (within the same patient). While 68% of the tested anaerobic bacteria were sensitive to SPI (22% resistant), only 54% were sensitive to ERY (34% resistant). Although moderate, the efficacy of SPI seemed more regular in general than ERY: it''s variation coefficient (40%) is lower than the ERY one (53%). The 7 A. actinomycetemcomitans tested showed all a high resistance. Conclusion. – In a general way, the spectre of activity of SPI is stacked in that of ERY. However, this study shows a better and regular activity of SPI on the main tested periopathogens. These results are in favour of the use of SPI in periodontology when penicillins and doxycycline are not useful because specific problems are identified (allergy, pregnancy…). [Copyright &y& Elsevier]

Abstract: We report the discovery of natural competence in Tannerella forsythia and its application to targeted chromosomal mutagenesis. Keeping T. forsythia in a biofilm throughout the procedure allowed efficient DNA uptake and allelic replacement. This simple method is cost-effective and reproducible compared with the conventional protocols using broth culture and electroporation. [Copyright &y& Elsevier]

• PDT has the ability to reduce hyperplastic index scores in OTGE. • PDT assisted in bacterial reduction in OTGE. • PDT has the ability to modulate immune response. The aim of the present clinical trial is to evaluate the clinical, bacterial, and immunological outcomes of photodynamic therapy (PDT) in adolescent patients with orthodontic treatment-induced gingival enlargement (OTGE). A total of 26 adolescent patients, 16 girls and 10 boys, of mean age 16.8 years, undergoing fixed orthodontic treatment for at least 6 months (mean duration in months, 8.3 ± 1.9) and presenting with GE were included in the clinical trial. All patients undergoing fixed orthodontic treatment with clinical diagnosis of OTGE were divided into two groups: Patients receiving full-mouth periodontal debridement (FMPD) 'Group-FMPD' and 'Group-PDT' included participants receiving methylene blue-assisted PDT in the selected area along with FMPD. Clinical periodontal assessments included the evaluation of plaque scores (PS), bleeding on probing (BOP), probing depth (PD) and hyperplastic index (HI). The total bacterial counts of Porphyromonas gingivalis (P. gingivalis), Treponema denticola (T. denticola), and Tannerella forsythia (T. forsythia) were estimated and expressed as log CFU/mL of each bacteria. Cytokines including interleukin (IL)-1β and IL-6 were analyzed using enzyme-linked immunosorbent assay (ELISA) kit. The mean percentage of PS and BOP statistically significantly reduced with both FMPD and PDT from baseline to 4 weeks (p < 0.05). Although mean PD significantly reduced in both the groups at all time points, there was significantly higher reduction with PDT as compared to FMPD at 2 weeks post treatment (p < 0.05). Inter-group comparison showed PDT demonstrated significantly higher HI at 2- and 4-weeks post treatment (p < 0.05). The mean log CFU/mL of P. gingivalis and T. forsythia showed statistically significantly higher reduction with PDT than FMPD (p < 0.05) at both 2-and 4-weeks follow-up. T. denticola reported significantly reduced levels at 2 weeks follow-up period only with PDT (p < 0.05). No statistically significant difference appeared when both treatment modalities were compared with one another (p > 0.05). Four weeks after periodontal treatment, IL-6 significantly reduced with PDT compared to FMPD (p < 0.05). PDT assisted in reducing bacterial counts and improving hyperplastic index in OTGE. [ABSTRACT FROM AUTHOR]

• A-PDT does not have any effect on pain scales. • A-PDT significantly reduced periodontal pathogens in pericoronitis. • A-PDT may help to reduce some amount of proinflammation in pericoronitis. We evaluated the efficacy of antimicrobial photodynamic therapy (A-PDT) in the reduction of pain intensity and performed cytokine profiling and measurement of microbiological parameters in patients with acute pericoronitis. Sixty patients with age range 14–19 years were randomized into two groups: 'A-PDT group' which received additional A-PDT with conventional protocol, and 'conventional protocol group' (CPG) without A-PDT. Present pain intensity (PPI) were investigated using McGill Pain Questionnaire (MPQ) and Visual Analogue Scale (VAS). Gingival crevicular fluid were sampled to evaluate the levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) and quantified using enzyme-linked immunosorbent assay. Microbial plaque was collected to evaluate total counts of Porphyromonas gingivalis and Tannerella forsythi a expressed as log colony forming unit (CFU)/mL. Level of pain intensity, cytokine profiling and microbial load were assessed at baseline (B0), and post treatment F 7 (Day 7) and F 14 (Day 14). A total of 59 patients (30 CPG and 29 A-PDT) completed the clinical trial. Present pain intensity scores statistically significantly reduced from B 0 to F 7 in both treatment groups (p < 0.05). For VAS, both groups showed statistically significant reduction in pain scores at F 14 only when compared with baseline (p < 0.05). There was no inter-group significant difference at any time point for either pain scores (p > 0.05). Only TNF-α showed statistically significant reduction with A-PDT compared to CPG at both F 7 and F 14. CPG group showed significant reduction for only T. forsythia at both follow-up points. The microbial counts for P. gingivalis and T. forsythia significantly reduced in A-PDT groups compared to CPG group at both F 7 and F 14. The results of this study indicate that A-PDT may be a reliable treatment option in pericoronitis for the reduction of TNF-α and microbial load. However, A-PDT does not have any effect in the reduction of pain. [ABSTRACT FROM AUTHOR]

The ability to recover components of their own cell wall is a common feature of bacteria. This was initially recognized in the Gram-negative bacterium Escherichia coli , which recycles about half of the peptidoglycan of its cell wall during one cell doubling. Moreover, E. coli was shown to grow on peptidoglycan components provided as nutrients. A distinguished recycling enzyme of E. coli required for both, recovery of the cell wall sugar N -acetylmuramic acid (MurNAc) of the own cell wall and for growth on external MurNAc, is the MurNAc 6-phosphate (MurNAc 6P) lactyl ether hydrolase MurQ. We revealed however, that most Gram-negative bacteria lack a murQ ortholog and instead harbor a pathway, absent in E. coli, that channels MurNAc directly to peptidoglycan biosynthesis. This "anabolic recycling pathway" bypasses the initial steps of peptidoglycan de novo synthesis, including the target of the antibiotic fosfomycin, thus providing intrinsic resistance to the antibiotic. The Gram-negative oral pathogen Tannerella forsythia is auxotrophic for MurNAc and apparently depends on the anabolic recycling pathway to synthesize its own cell wall by scavenging cell wall debris of other bacteria. In contrast, Gram-positive bacteria lack the anabolic recycling genes, but mostly contain one or two murQ orthologs. Quantification of MurNAc 6P accumulation in murQ mutant cells by mass spectrometry allowed us to demonstrate for the first time that Gram-positive bacteria do recycle their own peptidoglycan. This had been questioned earlier, since peptidoglycan turnover products accumulate in the spent media of Gram-positives. We showed, that these fragments are recovered during nutrient limitation, which prolongs starvation survival of Bacillus subtilis and Staphylococcus aureus. Peptidoglycan recycling in these bacteria however differs, as the cell wall is either cleaved exhaustively and monosaccharide building blocks are taken up (B. subtilis) or disaccharides are released and recycled involving a novel phosphomuramidase (MupG; S.aureus). In B. subtilis also the teichoic acids, covalently bound to the peptidoglycan (wall teichoic acids; WTAs), are recycled. During phosphate limitation, the sn-glycerol-3-phosphate phosphodiesterase GlpQ specifically degrades WTAs of B. subtilis. In S. aureus , in contrast, GlpQ is used to scavenge external teichoic acid sources. Thus, although bacteria generally recover their own cell wall, they apparently apply distinct strategies for breakdown and reutilization of cell wall fragments. This review summarizes our work on this topic funded between 2011 and 2019 by the DFG within the collaborative research center SFB766. [ABSTRACT FROM AUTHOR]