In addition, whether polyclonal Tregs or antigen-specific Tregs a

In addition, whether polyclonal Tregs or antigen-specific Tregs are used will influence the dose. Of note, studies using antigen-specific Tregs showed that lower numbers were able to achieve the LY2109761 supplier same functional efficacy as larger numbers of polyclonal Tregs [86, 87]. Finally, whether a single injection or multiple injections are required

is a matter of debate and may be determined in a Phase II efficacy study, where patient outcomes should also be measured and an in-depth patient monitoring planned. The use of molecular diagnostic tools can help to assess the increased expression of biomarkers of operational tolerance in patients receiving cellular therapy and whether these can be used as surrogate end-points of efficacy [101-103]. The same approach can be used selleck inhibitor to define whether or not the patients have decreased expression of biomarkers of acute rejection [104, 105].

Furthermore, phenotypic analysis of patient PBMCs, using flow cytometric analysis, can determine whether or not the number of Tregs has increased or the composition of the T cell compartment has changed as a result of the intervention [106]. Using the same analysis, the cytokine profile of the cells that have been phenotyped can be analysed to establish their plasticity. Finally, lymphocyte compartments can be monitored after specific interventions, as has been shown useful when associating expansion of lymphocyte

subsets, in this case naive B cells, in peripheral blood of patients in whom better outcomes were noted [107]. In spite of the potential concerns and controversies outlined with regard to Treg isolation and expansion protocols and the optimal clinical protocol, clinical Pomalidomide nmr trials are under way to test the therapeutic potential of Tregs. Beneficial effects of Treg infusions on allograft survival were first reported in bone marrow transplantation models in which donor Tregs reduced the incidence of GVHD. The first human trial using Treg cell therapy by Trzonkowski et al. [108] involved two patients. The first patient had chronic GVHD 2 years post-bone marrow transplantation. After receiving 0·1 × 106/kg FACS purified ex-vivo-expanded Tregs from the donor, the symptoms subsided and the patient was withdrawn successfully from immunosuppression without evidence of recurrence. The second patient had acute GVHD at 1 month post-transplantation, which was treated with several infusions of expanded donor Tregs. Despite initial and transitory improvement, the disease progressed and resulted ultimately in the patient’s death. This was the first report to show that adoptive transfer of Tregs is well tolerated and thus was a major breakthrough.

It could, therefore, be hypothesized

that P gingivalis m

It could, therefore, be hypothesized

that P. gingivalis modulate T-cell development and function in ways that promotes Th17-mediated inflammation Doxorubicin supplier over a Th1-dependent cell-mediated immune response, which is thought to promote clearance of P. gingivalis [60]. Numerous Th17 cells can be observed in periodontitis lesions [93] and can function as an osteoclastogenic subset that links T-cell activation to inflammatory bone loss [98, 99]. On the other hand, Th1 cells are thought to play a protective role in periodontitis [100], although some studies have attributed destructive effects to Th1 cells [101]. Overall, more research is warranted to better understand the roles of T-cell subsets in periodontitis and the biological relevance of their modulation by P. gingivalis in the context of its role as a keystone pathogen. In inflammatory conditions associated with bacterial communities, traditional concepts of pathogen selleck kinase inhibitor and commensal have become obsolete. This is well illustrated by periodontal disease where P. gingivalis can remain quiescent for long periods of time before (and after)

expressing pathogenicity through manipulation of the host response and disruption of homeostasis. Conversely, organisms usually considered commensals, such as S. gordonii, can act as accessory pathogens and elevate the pathogenicity of P. gingivalis. Commensal organisms can also act as pathobionts, i.e. following homeostasis breakdown and initiation of inflammation, these commensals-turned pathogens can propagate and amplify destructive periodontal inflammation. In this regard, a recent study identified a bacterium (designated NI1060) in the murine oral cavity that selectively accumulates in damaged periodontal tissue and causes inflammatory

bone loss by activating the intracellular PRR Nod1 [102]. NI1060 appears to thrive over under inflammatory conditions, apparently because it can readily procure nutrients derived from tissue breakdown in an inflammatory environment. NI1060, moreover, contributes to the exacerbation of inflammation by inducing neutrophil-specific chemokines, thereby augmenting neutrophil infiltration in the periodontal tissue [102]. Other commensals (NI440 and NI968) dominate exclusively in healthy sites and do not behave as periodontal pathobionts [102]. The notion that there are pathobionts that can opportunistically contribute to periodontitis is consistent with recent metagenomic studies showing a strong association of previously underappreciated bacteria (including the gram-positive Filifactor alocis and Peptostreptococcus stomatis and other species from the genera Prevotella, Megasphaera, Selenomonas, and Desulfobulbus) with periodontitis [8, 103, 104]. Moreover, as the bacterial biomass increases with increasing periodontal inflammation, the ecological shift from health to disease involves the emergence of newly dominant community members as opposed to the appearance of novel species [8].

, 1999), and purulent conjunctivitis (Poulou et al , 2008) A low

, 1999), and purulent conjunctivitis (Poulou et al., 2008). A low-level Selleck PLX-4720 resistance of E. hermannii

against amoxicillin and ticarcillin by its production of β-lactamase (HER-1) has also been described (Fitoussi et al., 1995; Beauchef-Havard et al., 2003). Isolation of E. hermannii from contaminated soils at an oil refinery suggests that this organism has an environmental habitat and can survive under adverse environmental conditions (Hernandez et al., 1998). However, the association of this organism with oral infections has not been reported thus far. Some strains of E. hermannii are also known to yield false-positive results in serological tests directed against E. coli O157:H7, Yersinia enterocolitica serotype O:9, Brucella melitensis, Brucella abortus, Vibrio cholerae O1, and Salmonella group N (O:30). This is because the lipopolysaccharides of these bacteria contain perosamine as a common antigenic O-chain (Perry & Bundle, 1990; Rice et al., 1992; Godfroid et al., 1998; Reeves & Wang, 2002; Munoz et al., 2005). In this report, we have determined some of Roscovitine concentration the pathogenic properties of a clinical isolate of E. hermannii obtained from an infected root canal of a persistent apical periodontitis lesion (Chavez de Paz, 2007; Yamane et al., 2009). Random

insertion mutagenesis using the EZ-Tn5™〈KAN-2〉 transposon revealed that a gene cluster encoded in the wzt (a gene for an ATPase domain protein Wzt) of the ATP-binding cassette (ABC)-type transporter (Davidson & Chen, 2004) in the perosamine biosynthesis system could be involved in the biofilm formation by this organism. A clinical strain capable of producing viscous materials was isolated from a persistent apical periodontitis lesion. The isolate was designated as YS-11 and was the primary strain used in this study. YS-11 was 3-mercaptopyruvate sulfurtransferase identified in our laboratory as E. hermannii by 16S rRNA gene sequencing. The nucleotide sequence of the 16S rRNA gene [DNA Data Bank of Japan (DDBJ) accession: AB377402; http://www.ddbj.nig.ac.jp] was identical

to that of E. hermannii GTC347 (DDBJ accession: AB273738). This was confirmed by PCR amplification of a bla gene encoding E. hermannii class A β-lactamase (HER-1) using the methodology as detailed elsewhere (Beauchef-Havard et al., 2003). The nucleotide sequence obtained from YS-11 (DDBJ accession: AB479111) showed 100% similarity to E. hermannii blaHER-1 (EMBL accession: AF311385). Stock cultures of YS-11 and E. hermannii ATCC33650 (a reference strain for E. hermannii) were grown on trypticase soy agar (BBL Microbiology Systems, Cockeysville, ND) supplemented with 0.5% yeast extract (Difco Laboratories, Detroit, MI) (TSAY) or grown in a trypticase soy broth supplemented with 0.5% yeast extract (TSBY). Bacterial cultures were grown aerobically at 37 °C in an incubation chamber.

Periapical bone loss associated with endodontic infection was sig

Periapical bone loss associated with endodontic infection was significantly more severe in OPN-deficient mice compared with wild-type 3 weeks after infection, and was associated with increased areas of inflammation. Expression of cytokines associated with bone loss, interleukin-1α (IL-1α) and RANKL, was increased 3 days after infection. There was little effect of OPN deficiency on the adaptive immune response to these infections, as there was no effect of genotype on the ratio of bacteria-specific immunoglobulin G1 and G2a in the serum of infected

mice. Furthermore, EGFR inhibitor there was no difference in the expression of cytokines associated with T helper type 1/type2 balance: IL-12, IL-10 and interferon-γ. In infected tissues, neutrophil infiltration into the lesion area was slightly increased in OPN-deficient animals 3 days after infection: this was confirmed by a significant increase in expression of neutrophil elastase in OPN-deficient samples at this time-point. We conclude that OPN has a protective effect on polymicrobial infection, at least partially because of alterations in phagocyte recruitment and/or persistence at the sites of infection, and that this molecule

has a potential therapeutic role in polymicrobial infections. Endodontic infections are typically polymicrobial infections of the dental root canal system.1,2 Bacterial species gain access to this space through defects in the tooth structure, often advanced caries or stress-related cracks and fissures. The associated inflammatory response at the apex of the root results in loss of Ceritinib molecular weight the surrounding peri-apical bone. These infections, together with periodontitis, are unusual in combining bone resorption with a polymicrobial infection. The inflammatory response to these infections has been best characterized in the mouse system, and involves a robust activation of the innate immune system. The resultant bone loss is much more severe in animals with impaired neutrophil3,4 or macrophage5 function. The role of the adaptive immune system in these infections is less clear – mice lacking the classic Teicoplanin T helper type 1 (Th1) cytokines interleukin-12

(IL-12) and interferon-γ (IFN-γ) have comparable susceptibility to endodontic infections to wild-type mice,6 whereas IL-10-deficient mice are significantly more susceptible to infection-associated bone loss.7 Osteopontin (OPN) is a secreted phosphoprotein with various roles in the immune responses. It is made by T cells and macrophages, and binds to a series of integrins, as an intact protein or as proteolytically cleaved fragments.8 Its activities associated with immune/inflammatory responses include regulation of Th1/Th2 balance,9 enhancement of dendritic cell function10 and regulation of IL-17 production.11 It is also important in the regulation of the innate immune response, enhancing the accumulation of neutrophils and macrophages at sites of injury.

tuberculosis-specific antigens, may lead to the identification of

tuberculosis-specific antigens, may lead to the identification of antigens useful as new vaccine candidates or those mediating pathogenesis in TB. The availability of complete genome sequences

of mycobacterial species and comparisons between them have allowed the identification of 11 genomic RD in M. tuberculosis, each region encompassing 1.9 to 12.7 kb genomic DNA, which are deleted/absent in all vaccine strains of Mycobacterium bovis BCG (16). In recent years, the focus has been on studying the cellular immune responses induced by the proteins encoded by genes predicted in these RDs of M. tuberculosis with the hope of identifying new antigens useful in the diagnosis of, and/or vaccine formulations against, TB (17–21). However, learn more it is thought that these M. tuberculosis-specific genomic regions may also be responsible, at least in part, for the pathogenesis of M. tuberculosis (22–24). One of the ways to differentiate between antigens

that mediate protection and those mediating pathogenesis is to study the proinflammatory Th1 and Th2 cytokine responses induced by them, using cell populations containing lymphocytes and monocytes/macrophages (13). In this study, we explored the Th1, Th2 and proinflammatory cytokine responses of PBMC from pulmonary TB patients in an attempt to identify the RDs of M. tuberculosis that differentially mediate the protective and pathologic responses in TB. For comparison purposes, preparations containing complex mycobacterial antigens were also included in the study. The complex mycobacterial antigens used were selleck inhibitor whole-cell killed M. tuberculosis H37Rv and M. bovis BCG (25, 26), MT-CF and MT-CW (27). MT-CF

and MT-CW were produced under NIH contract HHSN266200400091C/ADB contract NO-AI40092 (Tuberculosis Vaccine Testing and Research Materials Contract) and kindly provided by Dr J. T. Belisle (Colorado State University, Fort Collins, CO, USA). In addition, synthetic peptides (25-mers overlapping neighboring peptides by 10 amino acids) covering the sequence of putative proteins encoded by genes predicted in the genomic regions of RD1, RD4, RD5, RD6, RD7, RD9, RD10, RD11, RD12, RD13 and RD15 were designed based click here on the amino acid sequence deduced from the nucleotide sequences of the respective genes (Table 1) (16). These peptides were commercially synthesized by Thermo Hybaid GmBH (Ulm, Germany) using fluonerylmethoxycarbonyl chemistry, as described previously (27, 28). Stock concentrations (5 mg/mL) of the peptides were prepared in normal saline (0.9%) by vigorous pipetting, and the working concentrations were prepared by further dilution in tissue culture medium RPMI-1640, as described previously (29, 30). Heparinized venous blood was obtained from 17 pulmonary TB patients (10 men and 7 women) aged 28–87 (median, 37) years attending the Allergy and Respiratory Diseases Hospital, Tuberculosis Centre, Kuwait.

This is likely to be the result of the thorough sampling of a hig

This is likely to be the result of the thorough sampling of a highly restricted portion of sequence space that is revealed by PCR amplification using a forward primer specific for IGHV6-1. selleck In contrast, the relatively low proportion of clonally related sequences seen in this study suggests that the IgE response, in parasitized individuals, may be highly diverse. The varying proportions of clonally related sequences seen in association with different IgG subclasses may also point to varying levels of diversity in these responses, although analysis is confounded by the unequal numbers of different IgG subclass transcripts obtained from different individuals.

Certainly, the high proportion of clonally related IgG4 sequences suggests a lack of diversity which might be expected if this subclass response was restricted to the minor set of the most persistent antigens. Further insights into the IgE anti-parasite response come from analysis of somatic point mutations, and to better interpret our observations of mutations in IgE sequences, we amplified IgG-associated VDJ gene sequences, using IgG subclass-specific reverse PCR primers. The mean mutation levels seen in these 886 unique IgG sequences varied substantially between subclasses and correlated with the position of the constant region

genes within the constant region gene locus (IgG3 < IgG1 < IgG2 < IgG4). Although unexpected, this is in accord with the reports of low-affinity IgG3 being seen early in a response RAD001 mw [25], and high-affinity IgG4 emerging after long periods of persistent antigen stimulation [28]. These studies are consistent with the concept that B cells only switch to IgG4 after multiple rounds of cell division, during which the VDJ sequences accumulate high numbers of mutations [29]. On the other hand, it does not imply that IgG class-switching progresses inevitably by a series of sequential downstream steps, for cells

may switch to IgG4 both directly from IgM and indirectly via other constant region genes, as is also known to occur in the IgE response [30, 31]. Interestingly, despite IgE also being associated with persistent stimulation, and the IGHE gene being downstream of SPTLC1 the IGHG genes, the level of mutation in IgE sequences was similar to that of IgG1 and IgG2 sequences and was significantly less than that of IgG4 sequences. The average number of mutations seen in the IgE-associated VDJ gene sequences was 23.0, which is substantially higher than we previously reported for IgE sequences from individuals with atopic dermatitis, whose mean mutation counts were 14.7 and 15.7 [13, 27]. Higher counts have been seen in individuals with seasonal rhinitis and allergy to grass pollen [32], with a reported median count of 21. While an average of 19.

The systematic review by Richter et al 48 assessed the effects of

The systematic review by Richter et al.48 assessed the effects of pioglitazone in the treatment of type 2 diabetes. The relevant outcomes for these guidelines are mortality (kidney disease) and morbidity (nephropathy). Overall the evidence for a positive patient-oriented outcome for the use of pioglitazone was considered not to be convincing. Three studies were identified that included endpoints relevant to the assessment of kidney disease namely, Hanefeld et al.,49 Matthews et al.50 and Schernthaner et al.51 The Hanefeld et al.49 study compared pioglitazone plus sulfonyl urea with metformin plus sulphonyl urea over 12 months in 649 people with type 2 diabetes with

a history of poorly controlled PLX-4720 cost diabetes. The pioglitazone treatment resulted in a 15% reduction in the urinary ACR compared with a 2% increase in the metformin group with both treatments giving clinically equivalent glycaemic control. The Matthews et al.50 study compared pioglitazone plus metformin with glicazide plus metformin in 630 people with poorly managed type 2 diabetes over 12 months. The pioglitazone treatment gave a 10% reduction in the ACR compared

with a 6% increase in the glicazide Roscovitine solubility dmso group with no significant difference in HbA1c. The Schernthaner et al.51 study included 1199 people with type 2 diabetes inadequately treated by diet alone (HbA between 7.5% and 11%) and aged between 35–75 years from 167 centres located across 12 European countries. Pioglitazone treatment resulted in a 19% decrease in ACR compared with 1% in the metformin group. Blood pressure was not statistically different between groups. The results

were considered to be consistent with previous studies that troglitazone but not metformin or glibenclamide reduced urinary albumin excretion rate. The systematic review by Richter et al.52 assessed the effects of rosiglitazone in the treatment of type 2 diabetes. The study by Lebovitz et al.53 was identified as including an outcome measure relevant to kidney disease. The study examined the use of rosiglitazone as a monotherapy in 493 people with type 2 diabetes over a 7 month period. Urinary albumin excretion was decreased significantly compared with the placebo. For the subgroup of people with microalbuminuria, both doses of rosiglitazone gave a reduction 3-mercaptopyruvate sulfurtransferase in ACR from baseline of around 40%. Only a small percentage of patients were receiving antihypertensive therapy which the authors suggested indicates the effect to be a result of improved glycaemic control or a different effect of rosiglitazone. The measurement of urinary ACR was a secondary prospective outcome of the study of 203 people with type 2 diabetes by Bakris et al.54 comparing rosiglitazone with glyburide in a randomized controlled trial. RSG significantly reduced ACR from baseline and strongly correlated with changes in blood pressure and little relation to changes in FPG or HbA1c.

, Osaka, Japan) The recombinant cofilin-1 with MBP (cofilin-MBP)

, Osaka, Japan). The recombinant cofilin-1 with MBP (cofilin-MBP), as well as MBP alone, was purified from the bacterial see more cell lysate by histidine-Ni+ affinity purification as described previously (19). Western blotting was carried out as follows. In 1DE-WB, 5 μg cofilin-MBP or MBP alone as a control was separated by 12.5% SDS-PAGE, and then transferred onto a nitrocellulose membrane. After blocking with PBS containing 1% BSA and 0.1% Tween 20 for 2

hr and washing in PBS with 0.1% Tween 20 for 5 min three times, the membrane was incubated with each of the serum samples for 2 hr. The serum samples, diluted at 1:100 with PBS containing 1% BSA and 0.1% Tween 20, were incubated with 2000 μg/ml bacterial lysate containing non-recombinant pMAL-eHis products for 2 hr at room temperature in advance. The membrane was then washed five times in PBS with 0.1% Tween 20, and the bound antibodies were reacted with horseradish peroxidase-conjugated goat anti-human IgG (Zymed Laboratories, San Francisco, CA, USA) Epacadostat diluted at 1:3000 with PBS containing 1% BSA and 0.1% Tween 20 for 1 hr. The bound antibodies were visualized with diaminobenzidine. In 2DE-WB, the PBMC proteins, separated by 2DE as described above, were transferred onto a nitrocellulose membrane. The procedures afterward were similar to those

in 1D-WB without the preclearance by incubation with the bacterial lysate. We first detected autoAgs/autoAbs by 2DE and the subsequent WB using each of 10 serum samples from five patients (BD5, BD6, BD7, BD8 and BD10, randomly selected from the 30 BD patients) and from five healthy donors. The results of WB in all the five BD patients and a representative result from the healthy group are shown in Figure 1. We detected a total of 17 protein spots that reacted to at least one of the five serum samples from the patients with BD, but did not react to any of the serum samples from the healthy group. The positions

of the 17 spots on the 2DE gel are shown in Figure 2 and the reactivities of the protein spots to each of the five serum samples are summarized in Table 2. The proteins detected here would C-X-C chemokine receptor type 7 (CXCR-7) be candidate autoAgs in BD and the detection of multiple autoAgs here indicates that autoimmunity is a common phenomenon in BD as pointed out previously. We next tried to identify the 17 proteins by mass spectrometry and protein database searching. We thus successfully identified eight out of the 17 protein spots (spot no. 2, 3, 4, 6, 8, 9, 14 and 17). The profiles of the identified proteins and representative data of the protein identification are shown in Table 3 and Figure 3. One of the nine identified proteins is enolase-1, which has been reported to be autoantigenic in BD in our previous study (3). This indicates that our screening here is reliable. Three of the eight proteins were identified as actin-like proteins. The others included vimentin, a tubulin-like protein, Rho-GDI-β and cofilin-1.

mansoni schistosomes, combined with a preliminary analysis of the

mansoni schistosomes, combined with a preliminary analysis of the S. mansoni Actin 1.1 (SmAct1.1) promoter sequence (23). Expression of luciferase driven by the SmAct 1.1 promoter was only transient. The authors suggest that the loss of expression over time was probably not because of the loss of plasmid, because transfected parasites that were no longer expressing the luciferase remained PCR positive for luciferase DNA for 8 weeks learn more following electroporation. This finding is similar to that reported by Yuan et al. (24). These results also indicated that the electroporation protocol described was either insufficient to deliver the transgene to the germline or that the transgene was not

integrated at high frequency to be able to be detected in transgenic F1 parasites. Most of the aforementioned strategies for the introduction of transgenes into parasitic helminths result in transient, nonheritable expression of the gene of interest. For many gene expression and functional studies, this may be sufficient; however, for other types of studies such as the investigation into cellular and molecular aspects of the host immune response to the parasite, heritable expression is required. Whilst techniques for transgenesis in the free-living nematode Caenorhabditis elegans have been established for decades, heritable transgene expression in parasitic worms is still in its

infancy, although significant inroads are being made into achieving this. It is unlikely that transfection with plasmid-based constructs, as Roscovitine described in many of the reports above, will result in chromosomal integration of transgenes. However, a way forward to achieve this aim is to use gene therapy-type approaches utilizing retroviruses (e.g. gamma retroviruses or lentiviruses),

retrotransposons or transposons, which enhance the likelihood of development of heritable, transgenic lines of schistosomes. This is particularly likely if germline cells can be targeted for transduction. In addition, retroviruses or transposons can be used to transfer gene cassettes for the production of siRNAs, thereby combining a powerful knock-down technology with an efficient delivery system offering the possibility for heritable RNAi targeting specific host cell genes (25,26). Together with colleagues, 3-mercaptopyruvate sulfurtransferase we have made the first attempts down this track and reported the use of retroviruses and transposons to transduce schistosomes (27,28). In Kines et al., we produced replication incompetent Moloney murine leukaemia virus (MMLV) virions that were pseudotyped with vesicular stomatitis virus glycoprotein (VSVG) carrying a luciferase reporter gene. Virions co-cultured with schistosomes interacted with the tegument of the worms and immunofluorescence studies indicated that the retroviral capsid and RNA genome were released within the surface cells.

Raad et al (1992) showed that sonication improved

the ef

Raad et al. (1992) showed that sonication improved

the efficiency of identifying catheter-related infections. A study by Yűcel et al. also suggests that biofilms on CVCs lead to catheter-related bloodstream infections, because antimicrobial-treated CVCs resulted in a reduction in these infections (Yűcel et al.,2004). It is not yet clear whether specific catheters are less likely to lead to colonization and infection (Safdar & Maki, 2005), but further investigation of the link between biofilms and device-related infection is needed. Recently dental implants have been a focus of study for oral biofilms that may eventually lead to peri-implantitis with loss of the supporting bone and ultimately failure of the implant. Organisms associated with peri-implantitis are similar to those found in PF-02341066 datasheet periodontitis but also include etiological involvement of actinomycetes, S. aureus, coliforms, or Candida spp. (Pye et al., 2009; Heitz-Mayfield & Lang, 2010). So far, only a few

studies have used molecular techniques like checkerboard hybridization or pyrosequencing to study the microflora of failing implants, indicating distinct species associated with peri-implantitis (Shibli et al., 2008; Kumar et al., 2012). More systematic epidemiological studies are necessary for the development HDAC cancer of standardized diagnostic and therapeutic strategies. Criterion 3 indicates that BAI are localized and not systemic. Systemic signs and symptoms may occur, but they may

also be a function of planktonic cells or microbial products being shed from the biofilm at the original focus of during infection (Costerton et al., 1999; Parsek & Singh, 2003). Immune complex-mediated inflammation leading to tissue damage around biofilms also dominates in some biofilm infections such as P. aeruginosa lung infection in CF patients (Høiby et al., 1986; Bjarnsholt et al., 2009a). The fourth criterion addresses another tenet of biofilms: infections with planktonic bacteria are typically treated successfully with the appropriate antibiotics where the microorganism is found susceptible in vitro, whereas BAI are recalcitrant to antibiotic therapy or at least tolerant to higher antibiotic doses compared with planktonic cells of the same isolate. Although a BAI may show some response to conventional antibiotic therapies, it will not be eradicated and therefore recurs at a subsequent point. One example is the intermittent colonization of the lower respiratory tract with P. aeruginosa that sooner or later leads to chronic lung infection in CF. Intermittent colonization by P. aeruginosa can be eradicated by early aggressive antibiotic therapy in contrast to the chronic infection, which is treated by maintenance therapy (i.e. chronic suppressive antibiotic therapy).