Complete genome sequence of a Staphylococcus condimenti isolated from a port catheter-associated bloodstream infection

Here, we describe the complete genome sequence of a Staphylococcus condimenti blood culture isolate from a catheter-related bloodstream infection in a male patient.

Superiority of manual disinfection using pre-soaked wipes over automatic UV-C radiation without prior cleaning

BACKGROUND

The efficacy of ultraviolet C (UV-C) radiation against a broad spectrum of micro-organisms has been demonstrated in several studies, but differences in the specific doses and the extent of microbial reduction were found. Furthermore, the conditions of laboratory tests differ greatly from reality, such that efficacy achieved in tests may not necessarily be assumed in reality. Consequently, it is important to investigate the effectiveness of UV-C in representative field trials. The aim was therefore to develop and establish a field test to evaluate automatic UV-C in comparison to manual disinfection.

METHODS

Before and after disinfection, samples were repeatedly collected from naturally highly contaminated surfaces using the swab technique to obtain representative data sets for disinfected and non-disinfected surfaces. Subsequently, the log reduction values (LRV) and the disinfection success were evaluated for UV-C radiation and full compliant manual disinfection using alcohol-based wipes.

RESULTS

Surfaces that are naturally contaminated with bacteria on a regular and nearly uniform basis have been identified as particularly suitable for field testing. Mean contamination was reduced from 23.3 to 1.98 cfu/cm2 (LRV 0.9) and 29.7 to 0.26 cfu/cm2 (LRV 1.2) for UV-C and manual disinfection, respectively. UV-C disinfection achieved 75.5% successful disinfected surfaces, whereas manual disinfection showed 98.1%.

CONCLUSIONS

Full compliant manual disinfection showed slightly higher LRVs and disinfection success than automatic UV-C disinfection. Successful, operator-independent UV-C disinfection still has the potential to improve disinfection performance in addition to manual disinfection.

Tolerance of clinical vancomycin-resistant Enterococcus faecium isolates against UV-C light from a mobile source

BACKGROUND

Admission to a room previously occupied by patients carrying environmentally robust pathogens implies an increased risk of acquiring those pathogens. Therefore, 'No-touch' automated room disinfection systems, including devices based on UV-C irradiation, are discussed to improve terminal cleaning. It is still unclear if clinical isolates of relevant pathogens behave differently under UV-C irradiation compared to laboratory strains used in the approval process of disinfection procedures. In this study we analysed the susceptibility of well characterized clonally divergent vancomycin-resistant enterococci (VRE) strains, including a linezolid-resistant isolate, against UV-C radiation.

METHODS

Susceptibility against UV-C of ten clonally divergent clinical isolates of VRE was determined in comparison to the commonly used test organism Enterococcus hirae ATCC 10541. Ceramic tiles contaminated with 105 to 106 colony forming units/25 cm² of the different enterococci were positioned at a distance of 1.0 and 1.5 m and irradiated for 20 s, resulting in a UV-C dose of 50 and 22 mJ/cm², respectively. Reduction factors were calculated after quantitative culture of the bacteria recovered from treated and untreated surfaces.

RESULTS

Susceptibility to UV-C varied considerably among the strains studied, with the mean value of the most robust strain being up to a power of ten lower compared to the most sensitive strain at both UV-C doses. The two most tolerant strains belonged to MLST sequence types ST80 and ST1283. The susceptibility of the laboratory strain E. hirae ATCC 10541 ranged between the most sensitive and most tolerant isolates for both irradiation doses. However, for UV-C dose of 22 mJ/cm², the reduction of the most tolerant isolate of ST1283 was statistically significantly lower compared to E. hirae ATCC 10541. The most susceptible strains belonged to the MLST sequence types ST117 and ST203.

CONCLUSIONS

These results indicate that UV-C doses reported in the literature are sufficient for the reduction of commonly used reference strains of enterococci but could be insufficient for the reduction of tolerant patient VRE-isolates in a hospital setting. Therefore, for future studies, the most tolerant clinical isolates should be used to validate automated UV-C devices or longer exposure times should be expected to ensure efficacy in the real world.

Long time persistence and evolution of carbapenemase-producing Enterobacterales in the wastewater of a tertiary care hospital in Germany

BACKGROUND

Worldwide observations revealed increased frequencies of multi-resistant Enterobacterales and resistance genes in hospital wastewater compared to any other type of wastewater. Despite the description of clonal lineages possibly adapted to hospital wastewater, little is known about long term persistence as well as evolution of these lineages.

METHODS

In this study, wastewater isolates of different Enterobacterales species from a tertiary care hospital were investigated with 2.5 years distance. Whole Genome Sequencing (WGS) and resistance gene identification were performed for E. coli, C. freundii, S. marcescens, K. pneumoniae, K. oxytoca, and E. cloacae isolates (n = 59), isolated in 2022 and compared with strains isolated from the same wastewater pipeline in 2019 (n = 240).

RESULTS

Individual clonal lineages with highly related isolates could be identified in all species identified more than once in 2022 that appear to persist in the wastewater drainage. A common motif of all persistent clonal lineages was the carriage of mobile genetic elements encoding carbapenemase genes with hints for horizontal gene transfer in persistent clones in this environment observed over the 2.5-year period. Multiple plasmid replicons could be detected in both years. In 2022 isolates bla_VIM-1 replaced bla_OXA-48 as the most common carbapenemase gene compared to 2019. Interestingly, despite a similar abundance of carbapenemase genes (>80% of all isolates) at both time points genes encoding extended spectrum β-lactamases decreased over time.

CONCLUSIONS

This data indicates that hospital wastewater continuously releases genes encoding carbapenemases to the urban wastewater system. The evolution of the resident clones as well as the reasons for the selection advantage in this specific ecological niche needs to be further investigated in the future.

Phenotypic Variation in Clinical S. aureus Isolates Did Not Affect Disinfection Efficacy Using Short-Term UV-C Radiation

Pigmentation, catalase activity and biofilm formation are virulence factors that cause resistance of Staphylococcus aureus to environmental stress factors including disinfectants. In recent years, automatic UV-C room disinfection gained greater importance in enhanced disinfection procedures to improve disinfection success in hospitals. In this study, we evaluated the effect of naturally occurring variations in the expression of virulence factors in clinical S. aureus isolates on tolerance against UV-C radiation. Quantification of staphyloxanthin expression, catalase activity and biofilm formation for nine genetically different clinical S. aureus isolates as well as reference strain S. aureus ATCC 6538 were performed using methanol extraction, a visual approach assay and a biofilm assay, respectively. Log₁₀ reduction values (LRV) were determined after irradiation of artificially contaminated ceramic tiles with 50 and 22 mJ/cm² UV-C using a commercial UV-C disinfection robot. A wide variety of virulence factor expression was observed, indicating differential regulation of global regulatory networks. However, no direct correlation with the strength of expression with UV-C tolerance was observed for either staphyloxanthin expression, catalase activity or biofilm formation. All isolates were effectively reduced with LRVs of 4.75 to 5.94. UV-C disinfection seems therefore effective against a wide spectrum of S. aureus strains independent of occurring variations in the expression of the investigated virulence factors. Due to only minor differences, the results of frequently used reference strains seem to be representative also for clinical isolates in S. aureus.

Development of an artificial synovial fluid useful for studying Staphylococcus epidermidis joint infections

Staphylococcus epidermidis is a major causative agent of prosthetic joint infections (PJI). The ability to form biofilms supports this highly selective pathogenic potential. In vitro studies essentially relying on phenotypic assays and genetic approaches have provided a detailed picture of the molecular events contributing to biofilm assembly. A major limitation in these studies is the use of synthetic growth media, which significantly differs from the environmental conditions S. epidermidis encounters during host invasion. Building on evidence showing that growth in serum substantially affects S. epidermidis gene expression profiles and phenotypes, the major aim of this study was to develop and characterize a growth medium mimicking synovial fluid, thereby facilitating research addressing specific aspects related to PJI. Using fresh human plasma, a protocol was established allowing for the large-scale production of a medium that by biochemical analysis matches key characteristics of synovial fluid and therefore is referred to as artificial synovial fluid (ASF). By analysis of biofilm-positive, polysaccharide intercellular adhesion (PIA)-producing S. epidermidis 1457 and its isogenic, PIA- and biofilm-negative mutant 1457-M10, evidence is provided that the presence of ASF induces cluster formation in S. epidermidis 1457 and mutant 1457-M10. Consistent with the aggregative properties, both strains formed multilayered biofilms when analyzed by confocal laser scanning microscopy. In parallel to the phenotypic findings, expression analysis after growth in ASF found upregulation of genes encoding for intercellular adhesins (icaA, aap, and embp) as well as atlE, encoding for the major cell wall autolysin being responsible for eDNA release. In contrast, growth in ASF was associated with reduced expression of the master regulator agr. Collectively, these results indicate that ASF induces expression profiles that are able to support intercellular adhesion in both PIA-positive and PIA-negative S. epidermidis. Given the observation that ASF overall induced biofilm formation in a collection of S. epidermidis isolates from PJI, the results strongly support the idea of using growth media mimicking host environments. ASF may play an important role in future studies related to the pathogenesis of S. epidermidis PJI.

The giant staphylococcal protein Embp facilitates colonization of surfaces through Velcro-like attachment to fibrillated fibronectin

Staphylococcus epidermidis causes some of the most hard-to-treat clinical infections by forming biofilms: Multicellular communities of bacteria encased in a protective matrix, supporting immune evasion and tolerance against antibiotics. Biofilms occur most commonly on medical implants, and a key event in implant colonization is the robust adherence to the surface, facilitated by interactions between bacterial surface proteins and host matrix components. S. epidermidis is equipped with a giant adhesive protein, extracellular matrix-binding protein (Embp), which facilitates bacterial interactions with surface-deposited, but not soluble fibronectin. The structural basis behind this selective binding process has remained obscure. Using a suite of single-cell and single-molecule analysis techniques, we show that S. epidermidis is capable of such distinction because Embp binds specifically to fibrillated fibronectin on surfaces, while ignoring globular fibronectin in solution. S. epidermidis adherence is critically dependent on multivalent interactions involving 50 fibronectin-binding repeats of Embp. This unusual, Velcro-like interaction proved critical for colonization of surfaces under high flow, making this newly identified attachment mechanism particularly relevant for colonization of intravascular devices, such as prosthetic heart valves or vascular grafts. Other biofilm-forming pathogens, such as Staphylococcus aureus, express homologs of Embp and likely deploy the same mechanism for surface colonization. Our results may open for a novel direction in efforts to combat devastating, biofilm-associated infections, as the development of implant materials that steer the conformation of adsorbed proteins is a much more manageable task than avoiding protein adsorption altogether.

A usually harmless bacterium called Staphylococcus epidermidis lives on human skin. Sometimes it makes its way into the bloodstream through a cut or surgical procedure, but it rarely causes blood infections. It can, however, cause severe infections when it attaches to the surface of a medical implant like a pacemaker or an artificial replacement joint. It does this by forming a colony of bacteria on the implant’s surface called a biofilm, which protects the bacteria from destruction by the immune system or antibiotics.

Understanding how Staphylococcus epidermidis implant infections start is critical to preventing them. This information may help scientists develop infection-resistant implants or new treatments for implant infections. Scientists suspect that Staphylococcus epidermidis attaches to implants by binding to a human protein called fibronectin, which coats medical implants in the human body. Another protein on the surface of the bacteria, called Embp, facilitates the connection. But why the bacteria attach to fibronectin on implants, and not fibronectin molecules in the bloodstream, is unclear.

Now, Khan, Aslan et al. show that Embp forms a Velcro-like bond with fibronectin on the surface of implants. In the experiments, Khan and Aslan et al. used powerful microscopes to create 3-dimensional images of the interactions between Embp and fibronectin. The experiments showed that Embp's attachment site is hidden on the globe-shaped form of fibronectin circulating in the blood. But when fibronectin covers an implant surface, it forms a fibrous network, and Embp can attach to it with up to 50 Velcro-like individual connections. These many weak connections form a strong bond that withstands the force of blood pumping past.

The experiments show that the fibrous coating of fibronectin on implants makes them a hotspot for Staphylococcus epidermidis infections. Finding ways to block Embp from attaching to fibronectin on implants, or altering the form fibronectin takes on implants, may help prevent these infections. Many bacteria that form biofilms have an Embp-like protein. As a result, these discoveries may also help scientists develop prevention or treatment strategies for other bacterial biofilm infections.

Integration of Sequencing and Epidemiologic Data for Surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections in a Tertiary-Care Hospital

BACKGROUND

The ongoing coronavirus disease 2019 pandemic significantly burdens hospitals and other healthcare facilities. Therefore, understanding the entry and transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for effective prevention and preparedness measures. We performed surveillance and analysis of testing and transmission of SARS-CoV-2 infections in a tertiary-care hospital in Germany during the second and third pandemic waves in fall/winter 2020.

METHODS

Between calendar week 41 in 2020 and calendar week 1 in 2021, 40%, of all positive patient and staff samples (284 total) were subjected to full-length viral genome sequencing. Clusters were defined based on similar genotypes indicating common sources of infection. We integrated phylogenetic, spatial, and temporal metadata to detect nosocomial infections and outbreaks, uncover transmission chains, and evaluate containment measures' effectiveness.

RESULTS

Epidemiologic data and contact tracing readily recognize most healthcare-associated (HA) patient infections. However, sequencing data reveal that temporally preceding index cases and transmission routes can be missed using epidemiologic methods, resulting in delayed interventions and serially linked outbreaks being counted as independent events. While hospital-associated transmissions were significantly elevated at a moderate rate of community transmission during the second wave, systematic testing and high vaccination rates among staff have led to a substantial decrease in HA infections at the end of the second/beginning of the third wave despite high community transmissions.

CONCLUSIONS

While epidemiologic analysis is critical for immediate containment of HA SARS-CoV-2 outbreaks, integration of genomic surveillance revealed weaknesses in identifying staff contacts. Our study underscores the importance of high testing frequency and genomic surveillance to detect, contain and prevent SARS-CoV-2-associated infections in healthcare settings.

High burden and diversity of carbapenemase-producing Enterobacterales observed in wastewater of a tertiary care hospital in Germany

Hospitals are one of the main reservoirs of multi-resistant Enterobacterales (MRE). As MRE are resistant to the most frequently used antibiotics, therapy for patients with MRE infections is challenging. It has been previously described that MRE from hospital wastewater can pass into municipal wastewater and even surface water. In this study, we investigated the diversity and epidemiology of MRE in the wastewater of a large tertiary care hospital. Wastewater samples were collected for a four-day period and tested for the presence of Enterobacterales resistant to 3rd gen. cephalosporins. Representative isolates were further characterized by whole genome sequencing. In 120 β-glucuronidase-producing isolates, 68 Escherichia coli and, interestingly, also 52 Citrobacter freundii were identified. In 120 β-glucosidase-producing isolates 45 Serratia marcescens, 34 Klebsiella oxytoca, 32 Enterobacter cloacae and 9 Klebsiella pneumoniae were observed. For all species various MLST sequence types and different clusters of resistance genes were determined, showing a great diversity within the different Enterobacterales, further corroborated by clonal analysis performed by cgMLST. The most prominent clone was wastewater associated E. coli ST635, which accounted for 47.1% of all E. coli isolates. Interestingly, 45.6% of E. coli, 88.5% of C. freundii, 95.6% of S. marcescens, 91.2% of K. oxytoca, 96.9% of E. cloacae and 88.9% of K. pneumoniae isolates carried a carbapenemase gene, indicating a high burden with carbapenemase-producing Enterobacterales. Comparison with clinical isolates from the same hospital displayed few clonal matches. One wastewater isolate of K. pneumoniae was identified to be closely related compared to a clone that had been introduced into the hospital during an outbreak four years earlier. One E. coli isolate was identified as identical to an isolate from a patient, with inpatient stay during the sampling period. The data obtained in this study highlight the problem of antibiotic resistance of Enterobacterales in hospital wastewater. In particular, the clustered occurrence of carbapenemase genes is of great concern and underscores the problem of increasingly scarce antibiotic options against these bacteria.

Host factors abolish the need for polysaccharides and extracellular matrix-binding protein in Staphylococcus epidermidis biofilm formation

Introduction. Staphylococcus epidermidis is predominant in implant-associated infections due to its capability to form biofilms. It can deploy several strategies for biofilm development using either polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA) and/or proteins, such as the extracellular matrix-binding protein (Embp).Hypothesis/Gap Statement. We hypothesize that the dichotomic regulation of S. epidermidis adhesins is linked to whether it is inside a host or not, and that in vitro biofilm investigations in laboratory media may not reflect actual biofilms in vivo.Aim. We address the importance of PIA and Embp in biofilm grown in 'humanized' media to understand if these components play different roles in biofilm formation under conditions where bacteria can incorporate host proteins in the biofilm matrix.Methodology. S. epidermidis 1585 WT (deficient in icaADBC), and derivative strains that either lack embp, express embp from an inducible promotor, or express icaADBC from a plasmid, were cultivated in standard laboratory media, or in media with human plasma or serum. The amount, structure, elasticity and antimicrobial penetration of biofilms was quantified to describe structural differences caused by the different matrix components and growth conditions. Finally, we quantified the initiation of biofilms as suspended aggregates in response to host factors to determine how quickly the cells aggregate in response to the host environment and reach a size that protects them from phagocytosis.Results. S. epidermidis 1585 required polysaccharides to form biofilm in laboratory media. However, these observations were not representative of the biofilm phenotype in the presence of human plasma. If human plasma were present, polysaccharides and Embp were redundant for biofilm formation. Biofilms formed in human plasma were loosely attached and existed mostly as suspended aggregates. Aggregation occurred after 2 h of exposing cells to plasma or serum. Despite stark differences in the amount and composition of biofilms formed by polysaccharide-producing and Embp-producing strains in different media, there were no differences in vancomycin penetration or susceptibility.Conclusion. We suggest that the assumed importance of polysaccharides for biofilm formation is an artefact from studying biofilms in laboratory media void of human matrix components. The cell-cell aggregation of S. epidermidis can be activated by host factors without relying on either of the major adhesins, PIA and Embp, indicating a need to revisit the basic question of how S. epidermidis deploys self-produced and host-derived matrix components to form antibiotic-tolerant biofilms in vivo.

Growth of Cutibacterium acnes is common on osteosynthesis material of the shoulder in patients without signs of infection

Background and purpose - Cutibacterium acnes, formerly known as Propionibacterium acnes, is often isolated from deep tissues of the shoulder. It is recognized as an important causative agent of foreign-material associated infections. However, the incidence and significance of its detection in tissues from patients without clinical evidence for infection is unclear. We assessed the incidence of C. acnes colonization of osteosynthesis material in asymptomatic patients, and evaluated the short-term outcome in relation to the microbiological findings. Patients and methods - We microbiologically analyzed osteosynthesis material of 34 asymptomatic patients after surgery on the clavicle. Material obtained from 19 asymptomatic patients after osteosynthesis of the fibula served as a control group. Patients were clinically followed up for 3-24 months after removal of the osteosynthesis material. Results - Bacteria were recovered from devices in 29 of 34 patients from the clavicle group. 27 of 29 positive samples grew C. acnes. Isolation of C. acnes was more common in male than in female patients. No bacterial growth was observed on foreign material from patients in the fibula group. All patients remained asymptomatic at follow-up. Interpretation - Growth of C. acnes is common on osteosynthesis material of the shoulder, especially in males. Samples were positive irrespective of clinical signs of infection. Therefore, detection of C. acnes in this clinical setting is of questionable clinical significance. The high positivity rate in asymptomatic patients discourages routine sampling of material in cases without clinical evidence for infection.

The metalloprotease SepA governs processing of accumulation-associated protein and shapes intercellular adhesive surface properties in Staphylococcus epidermidis

The otherwise harmless skin inhabitant Staphylococcus epidermidis is a major cause of healthcare-associated medical device infections. The species' selective pathogenic potential depends on its production of surface adherent biofilms. The Cell wall-anchored protein Aap promotes biofilm formation in S. epidermidis, independently from the polysaccharide intercellular adhesin PIA. Aap requires proteolytic cleavage to act as an intercellular adhesin. Whether and which staphylococcal proteases account for Aap processing is yet unknown. Here, evidence is provided that in PIA-negative S. epidermidis 1457Δica, the metalloprotease SepA is required for Aap-dependent S. epidermidis biofilm formation in static and dynamic biofilm models. qRT-PCR and protease activity assays demonstrated that under standard growth conditions, sepA is repressed by the global regulator SarA. Inactivation of sarA increased SepA production, and in turn augmented biofilm formation. Genetic and biochemical analyses demonstrated that SepA-related induction of biofilm accumulation resulted from enhanced Aap processing. Studies using recombinant proteins demonstrated that SepA is able to cleave the A domain of Aap at residue 335 and between the A and B domains at residue 601. This study identifies the mechanism behind Aap-mediated biofilm maturation, and also demonstrates a novel role for a secreted staphylococcal protease as a requirement for the development of a biofilm.

First report of Escherichia coli co-producing NDM-1 and OXA-232

Recently Gram-negative bacteria co-producing multiple carbapenemases have emerged in different parts of the world. We report the first isolation of an Escherichia coli strain co-producing the carbapenemases NDM-1 and OXA-232.

Sub-inhibitory tigecycline concentrations induce extracellular matrix binding protein Embp dependent Staphylococcus epidermidis biofilm formation and immune evasion

Biofilm-associated Staphylococcus epidermidis implant infections are notoriously reluctant to antibiotic treatment. Here we studied the effect of sub-inhibitory concentrations of penicillin, oxacillin, vancomycin, daptomycin, linezolid and tigecycline on S. epidermidis 1585 biofilm formation, expression of extracellular matrix binding protein (Embp) and potential implications for S. epidermidis - macrophage interactions. Penicillin, vancomycin, daptomycin, and linezolid had no biofilm augmenting effect at any of the concentrations tested. In contrast, at sub-inhibitory concentrations tigecycline and oxacillin exhibited significant biofilm inducing activity. In S. epidermidis 1585, SarA is a negative regulator of giant 1 MDa Embp, and down regulation of sarA induces Embp-dependent assembly of a multi-layered biofilm architecture. Dot blot immune assays, confocal laser scanning microscopy, and qPCR showed that under biofilm inducing conditions, tigecycline augmented embp expression compared to the control grown without antibiotics. Conversely, expression of regulator sarA was suppressed, suggesting that tigecycline exerts its effects on embp expression through SarA. Tigecycline failed to induce biofilm formation in embp transposon mutant 1585-M135, proving that under these conditions Embp up-regulation is necessary for biofilm accumulation. As a functional consequence, tigecycline induced biofilm formation significantly impaired the up-take of S. epidermidis by mouse macrophage-like cell line J774A.1. Our data provide novel evidence for the molecular basis of antibiotic induced biofilm formation, a phenotype associated with inherently increased antimicrobial tolerance. While this could explain failure of antimicrobial therapies, persistence of S. epidermidis infections in the presence of sub-inhibitory antimicrobials is additionally propelled by biofilm-related impairment of macrophage-mediated pathogen eradication.

Impact of cardiovascular risk factors and related comorbid conditions and medical therapy reported at baseline on the treatment response to tadalafil 5 mg once-daily in men with lower urinary tract symptoms associated with benign prostatic hyperplasia: an integrated analysis of four randomised, double-blind, placebo-controlled, clinical trials

PURPOSE

The influence of cardiovascular risk factors/comorbidities on response to oral once-daily tadalafil 5 mg was explored in men with lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH).

METHODS

This post hoc analysis pooled data from four double-blind studies in which 1498 men with > 6-mo history of LUTS/BPH were randomised and received either once-daily placebo (n = 746) or tadalafil 5 mg (n = 752) for 12 weeks. Descriptive statistics were reported for changes in total International Prostate Symptom Score (IPSS), IPSS voiding and storage subscores, and IPSS quality-of-life (QoL) index. Treatment group differences by baseline clinical and cardiovascular factors and medical therapies were examined using analysis of covariance.

RESULTS

Tadalafil was effective in men with LUTS/BPH and cardiovascular risk factors/comorbidities except for patients receiving > 1 antihypertensive medication. Placebo-adjusted least squares (LS) mean improvements in total IPSS were -1.2 (95% CI: -2.5 to -0.0) in men taking > 1 antihypertensive medication vs. -3.3 (95% CI: -4.4 to -2.1) in men taking one medication (interaction p = 0.020). In addition, placebo-adjusted LS mean improvements in total IPSS were -0.2 (95% CI, -2.1 to 1.7) in men who reported use of diuretics vs. -2.8 (95% CI, -3.7 to -1.9) in men who reported taking other antihypertensive medications vs. -2.3 (95% CI, -3.2 to -1.5) in men who reported not using any antihypertensive drug (p-value for interaction = 0.053).

CONCLUSIONS

Once-daily tadalafil 5 mg improved LUTS/BPH, regardless of severity, in men with coexisting cardiovascular risk factors/comorbidities, except for patients with history of > 1 drug for arterial hypertension. Use of diuretics may contribute to patients' perception of a negated efficacy of tadalafil on LUTS/BPH. Comorbidities should be considered when choosing the optimal medicine to treat men with LUTS/BPH.

Emergence of daptomycin non-susceptibility in colonizing vancomycin-resistant Enterococcus faecium isolates during daptomycin therapy

Infections due to vancomycin-resistant enterococci (VRE) are of significant importance in high-risk populations, and daptomycin is a bactericidal antibiotic to treat multidrug-resistant VRE in these patients. The emergence of daptomycin non-susceptibility invasive VRE during daptomycin therapy is a major clinical issue. Here the hypothesis was tested that systemic daptomycin therapy also induces the emergence of daptomycin non-susceptible (DNS-) isolates in colonizing VRE populations. 11 vancomycin-resistant Enterococcus faecium strain pairs recovered from rectal swabs were available for analysis. All initial isolates exhibited daptomycin MICs within the wild type MIC distribution of E. faecium (MIC≤4 mg/L). In follow-up isolates from five patients a 4-16-fold daptomycin MIC increase was detected. All patients carrying DNS-VRE received daptomycin (14-28 days) at 4 mg/kg body weight, while two patients in whom no DNS-VRE emerged were only treated with daptomycin for 1 and 4 days, respectively. Comparative whole genome sequencing identified DNS-VRE-specific single nucleotide polymorphisms (SNP), including mutations in cardiolipin synthase (Cls), and additional SNPs in independent genes potentially relevant for the DNS phenotype. Mutations within cls were also identified in three additional, colonizing DNS-VRE. Of these, at least one strain was transmitted within the hospital. In none of the VRE isolates tested, pre-existing or de novo mutations in the liaFSR operon were detected. This is the first report documenting the emergence of DNS-VRE in colonizing strains during daptomycin treatment, putting the patient at risk for subsequent DNS-VRE infections and priming the spread of DNS-VRE within the hospital environment.

An 18 kDa scaffold protein is critical for Staphylococcus epidermidis biofilm formation

Virulence of the nosocomial pathogen Staphylococcus epidermidis is crucially linked to formation of adherent biofilms on artificial surfaces. Biofilm assembly is significantly fostered by production of a bacteria derived extracellular matrix. However, the matrix composition, spatial organization, and relevance of specific molecular interactions for integration of bacterial cells into the multilayered biofilm community are not fully understood. Here we report on the function of novel 18 kDa Small basic protein (Sbp) that was isolated from S. epidermidis biofilm matrix preparations by an affinity chromatographic approach. Sbp accumulates within the biofilm matrix, being preferentially deposited at the biofilm–substratum interface. Analysis of Sbp-negative S. epidermidis mutants demonstrated the importance of Sbp for sustained colonization of abiotic surfaces, but also epithelial cells. In addition, Sbp promotes assembly of S. epidermidis cell aggregates and establishment of multilayered biofilms by influencing polysaccharide intercellular-adhesin (PIA) and accumulation associated protein (Aap) mediated intercellular aggregation. While inactivation of Sbp indirectly resulted in reduced PIA-synthesis and biofilm formation, Sbp serves as an essential ligand during Aap domain-B mediated biofilm accumulation. Our data support the conclusion that Sbp serves as an S. epidermidis biofilm scaffold protein that significantly contributes to key steps of surface colonization. Sbp-negative S. epidermidis mutants showed no attenuated virulence in a mouse catheter infection model. Nevertheless, the high prevalence of sbp in commensal and invasive S. epidermidis populations suggests that Sbp plays a significant role as a co-factor during both multi-factorial commensal colonization and infection of artificial surfaces.

Biofilm formation is a key phenotype allowing the otherwise harmless skin commensal S. epidermidis to establish chronic implant-associated infections, affecting millions of patients worldwide. S. epidermidis biofilm assembly relies on the production of an extracellular matrix that serves as glue to stabilize the multilayered bacterial architecture. Here we identified novel 18 kDa Small basic protein (Sbp) as a key component of the extracellular matrix that promotes pivotal steps of bacterial biofilm formation in vitro. Importantly, Sbp is deposited specifically at the interface between biofilm and substrate, as well as in larger humps interspersed within the bacterial cell architecture, thereby forming a proteinaceous biofilm scaffold. This localization enables Sbp to foster stable S. epidermidis interactions with an artificial surface and also contributes to S. epidermidis cell aggregation mechanisms, i.e., polysaccharide intercellular adhesin (PIA) and accumulation associated protein (Aap). In fact, by demonstrating direct Sbp-Aap interactions we provide the first evidence supporting the idea that specific molecular interactions between S. epidermidis and matrix components are involved in S. epidermidis biofilm accumulation. In conclusion, we here show that Sbp promotes key phenotypic features important for S. epidermidis to evolve as an opportunistic pathogen.

Structural basis of Staphylococcus epidermidis biofilm formation: mechanisms and molecular interactions

Staphylococcus epidermidis is a usually harmless commensal bacterium highly abundant on the human skin. Under defined predisposing conditions, most importantly implantation of a medical device, S. epidermidis, however, can switch from a colonizing to an invasive life style. The emergence of S. epidermidis as an opportunistic pathogen is closely linked to the biofilm forming capability of the species. During the past decades, tremendous advance regarding our understanding of molecular mechanisms contributing to surface colonization has been made, and detailed information is available for several factors active during the primary attachment, accumulative or dispersal phase of biofilm formation. A picture evolved in which distinct factors, though appearing to be redundantly organized, take over specific and exclusive functions during biofilm development. In this review, these mechanisms are described in molecular detail, with a highlight on recent insights into multi-functional S. epidermidis cell surface proteins contributing to surface adherence and intercellular adhesion. The integration of distinct biofilm-promoting factors into regulatory networks is summarized, with an emphasis on mechanism that could allow S. epidermidis to flexibly adapt to changing environmental conditions present during colonizing or invasive life-styles.

Continuation and effectiveness of tadalafil once daily during a 6-month observational study in erectile dysfunction: the EDATE study

AIMS

This was the first observational study evaluating treatment continuation, effectiveness and tolerability of tadalafil 5 mg once daily (TAD-OaD) in patients who chose and paid for treatment of erectile dysfunction (ED) in routine clinical practice.

METHODS

Men ≥ 18 years with ED, treated previously with phosphodiesterase type 5 (PDE5)-inhibitor on-demand (PRN) or treatment-naïve, were enrolled at 59 sites. For patients prescribed TAD-OaD at baseline (T1), change in erectile function (IIEF-EF and GAQ) was documented after 1-3 (T2) and 4-6 (T3) months. The primary outcome was the probability to switch/discontinue from TAD-OaD, estimated by Kaplan-Meier (KM) product-limit method. Changes in IIEF-EF were evaluated using a mixed model for repeated measures adjusting for patient baseline characteristics.

RESULTS

Of 975 men enrolled (median age 56.8 years, 33.7% with previous PDE5-inhibitor use), 778 were prescribed TAD-OaD, 135 TAD-PRN and 62 sildenafil or vardenafil PRN. During the 6-month longitudinal observation, 107 patients (13.8% of 778) switched or discontinued TAD-OaD-treatment. KM-rates (95%CI) for continuing TAD-OaD at 2, 4 and 6 months were 94.0% (92.3, 95.7), 88.3% (85.9, 90.6) and 86.3% (83.7, 88.9), respectively. The 25th percentile of time to switch/discontinuation of TAD-OaD was estimated as 31.1 weeks (lower 95%CI 30.3 weeks). At T3, IIEF-EF scores had increased by 7.1 (LSmean; 95%CI 5.8, 8.5) points; 91.3% of patients reported improved erections. The most frequently reported AE was headache (10 patients; 1.3%); no new/unexpected safety signals were observed.

CONCLUSION

Under routine conditions, and when patients were involved in treatment decision-making, more than 86% of men starting/switching to tadalafil once daily (OaD) at baseline continued tadalafil OaD treatment for ≥ 6 months.

Electret Model for the Collective Behaviour of Biological Systems

It is suggested that several basic properties of biological systems, such as muscular motions, active transport of energy, etc., may be described in terms of a dynamical model possessing metastable ferroelectric states. The model is based on the observation that confi-gurationally unstable anions, in particular O2-, can lead to ferroelectric phase transitions. Due to the highly variable electronic polarizability of such ions a fourth-order potential is generated which can be the origin of three types of solitary excitations: elastic 'pulse' solitons, ferroelectric 'kink' (or domain-wall) solitons and periodic (coherent) solitary waves. Their possible relation to biological phenomena is discussed.

Polar-Soft-Mode-Driven Structural Phase Transition in SrTiO3

The structural phase transition of SrTiO3 at 105 K, which has been believed to be independent of the ferroelectric soft mode [Phys. Rev. 177, 858 (1969)], is shown, on the contrary, to be driven by the same long-wavelength polar instability. Isotope replacement of 16O by 18O is predicted to cause an increase in the structural phase transition temperature by 3.8 K. In both isotopic cases, dynamical polarizability-induced ferroelastic-type cluster formation takes place above the structural phase transition, which is intrinsic and a consequence of electron-lattice driven mode-mode coupling. Distinct length and time scales are identified. The precursor domains are evidence that order-disorder effects coexist with displacive dynamics.

First-line pemetrexed (P) for the treatment of hormone refractory prostate cancer (HRPC): A phase I/II study

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Background: Evaluation of maximum tolerated dose (MTD), efficacy and toxicity of pemetrexed as first-line treatment in HRPC. Methods: Patients (pts) with metastatic and/or unresectable HRPC and progression received P monotherapy 500 mg/m2 i.v. d1 q21d-cycle for 6 cycles with VitB12 and folate supplementation until progression or dose-limiting toxicity. Corticosteroids were given 8 mg p.o. 3 d around P infusion. The primary outcome measure was PSA (serological) response (PSAr), defined as = 50% decline from baseline, confirmed at least 3 wks later. If no metastatic disease, baseline PSA > 5 ng/mL was required. Results: Patient characteristics: 12 pts were treated; median age was 67 yrs (61–76), median baseline PSA 138.6 ng/ml (9.4–2662), median Karnofsky status 95 (80–100). Cycles: A total of 55 treatment cycles was administered with a median of 5 cycles (1–6) per pt. Due to dose limiting toxicities (DLT) during the first cycle in 2/6 pts, P dose was reduced to 400 mg/m2 d1 q21d-cycle for the following 6 pts. One pt experienced a DLT during his first cycle with P 400 mg/m2. Dose needed to be reduced in 3/12 pts, treatment discontinuation occurred in 6/12 pts. Adverse Effects: 6 of 12 (50%) pts experienced a total of 18 grade 3 events according to CTC criteria, including neutropenia, anemia and pain. 4 of 12 (33%) pts experienced a total of 7 grade 4 events, mainly neutropenia and leucopenia. 1 death occurred after one dose of P 500 mg/m2; relationship to P could not be ruled out. Response: 11/12 pts were evaluable for response. On 500 mg/m2 1 pt showed serological response, 1 partial tumor-response in metastatic lymph-node disease was seen. Overall, 7 patients remained serologically stable (63.6%), 3 PSA progressions (27.3%) were seen. Stable serological status could be maintained for 3–43 wks. Conclusions: P 400 mg/m2 was determined the recommended dose for a potential phase II, with an acceptable toxicity profile in this patient population. Serological stability could be achieved in > 60% of patients for up to 43 wks. However, as no confirmed PSA response was achieved with P 400 mg/m2, in a potential phase II a schedule with P 400 mg/m2 but higher dose-density should be pursued as a first-line approach in pts with HRPC.

No significant financial relationships to disclose.

[Metabolic syndrome and erectile dysfunction. Epidemiologic associations and pathogenetic links]

There is abundant evidence for the association between erectile dysfunction (ED) and the traditional atherosclerotic risk factors, such as dyslipidemia, hypertension, glucose intolerance, and obesity, that make up the metabolic syndrome. Recent findings have demonstrated a linear relationship between the number of these risk factors and the prevalence of ED. There is also growing evidence that endothelial dysfunction characterized by decreased bioavailability of nitrogen monoxide (NO) and a proinflammatory, prothrombotic, and proliferative phenotype is the common pathogenetic pathway linking ED to peripheral vascular diseases. Since ED often occurs several years before any clinical manifestation of systemic cardiovascular disease, ED should be seen as a warning of early atherosclerotic disease and an opportunity for doctor and patient to initiate preventive measures.

[Radiotherapy of urothelial carcinomas of the urinary bladder]

Radiotherapy of bladder cancer is a locally effective therapeutic approach. It is increasingly becoming part of the multimodal protocols aimed at the preservation of both organ and organ function. In this context, it is an alternative to cystectomy. The addition of chemotherapy to radiotherapy enhances the curative potential of this non-surgical approach and may be useful especially in older, multimorbid patients. If chemotherapy can not be applied, the use of radiotherapy alone is reasonable, although in advanced tumors the results are disappointing. After the transurethral resection of bladder cancer, postoperative radiotherapy should be considered in muscle-invasive cancer as well as when other negative prognostic factors occur. The prerequisites for an effective, minimally toxic, state of the art radiotherapy are a subtle treatment-planning procedure and an accurate delivery of the radiation.

[Radiochemotherapy of urothelial carcinoma]

Radical cystectomy is the current standard therapy for muscle invasive or locally advanced transitional cell carcinoma of the bladder. Organ-preserving monotherapeutic alternatives (e.g. transurethral resection, radiotherapy) do not lead to similar cure rates. In selected cases, a trimodal approach using transurethral resection and combined radio- and chemotherapy can be as efficient as cystectomy.

Phase diagram of an asymmetric spin ladder

We investigate an asymmetric zigzag spin ladder with different exchange integrals on both legs using bosonization and renormalization group approaches. When the leg exchange integrals and frustration both are sufficiently small, renormalization group analysis shows that the Heisenberg critical point flows to an intermediate-coupling fixed point with gapless excitations and a vanishing spin velocity. When they are large, a spin gap opens and a dimer liquid is realized. Here, we find a continuous manifold of Hamiltonians with dimer product ground states, interpolating between the Majumdar-Ghosh and sawtooth spin-chain model.

Magnetic polyoxometalates: anisotropic antiferro- and ferromagnetic exchange interactions in the pentameric cobalt(II) cluster

The ground-state properties of the pentameric Co(II) cluster [Co(3)W(D(2)O)(2)(CoW(9)O(34))(2)](12-) were investigated by combining magnetic susceptibility and low-temperature magnetization measurements with a detailed inelastic neutron scattering (INS) study on a fully deuterated polycrystalline sample of Na(12)[Co(3)W(D(2)O)(2)(CoW(9)O(34))(2)].46D(2)O. The encapsulated magnetic Co(5) unit consists of three octahedral and two tetrahedral oxo-coordinated Co(II) ions. Thus, two different types of exchange interactions are present within this cluster: a ferromagnetic interaction between the octahedral Co(II) ions and an antiferromagnetic interaction between the octahedral and the tetrahedral Co(II) ions. As a result of the single-ion anisotropy of the octahedral Co(II) ions, the appropriate exchange Hamiltonian to describe the ground-state properties of the Co(5) spin cluster is anisotropic and is expressed as H = -2 summation operator(i= x,y,z)J(1)(i)[S(1)(i)S(2)(i) + S(2)(i)S(3)(i)] + J(2)(i)[S(1)(i)S(5)(i) + S(2)(i)S(5)(i) + S(2)(i)S(6)(i) + S(3)(i)S(6)(i)], where J(1)(i) are the components of the exchange interaction between the octahedral Co(II) ions and J(2)(i) are the components of the exchange interaction between the octahedral and tetrahedral Co(II) ions (see Figure 1d). The study of the exchange interactions in the two structurally related polyoxoanions [Co(4)(H(2)O)(2)(PW(9)O(34))(2)](10)(-) and [Co(3)W(H(2)O)(2)(ZnW(9)O(34))(2)](12)(-) allowed an independent determination of the ferromagnetic exchange parameters J(1)(x) = 0.70 meV, J(1)(y) = 0.43 meV, and J(1)(z) = 1.51 meV (set a) and J(1)(x) = 1.16 meV, J(1)(y) = 1.16 meV and J(1)(z) = 1.73 meV (set b), respectively. Our analysis proved to be much more sensitive to the size and anisotropy of the antiferromagnetic exchange interaction J(2). We demonstrate that this exchange interaction exhibits a rhombic anisotropy with exchange parameters J(2)(x) = -1.24 meV, J(2)(y) = -0.53 meV, and J(2)(z) = -1.44 meV (set a) or J(1)(x) = -1.19 meV, J(1)(y) = -0.53 meV, and J(1)(z) = -1.44 meV (set b). The two parameter sets reproduce in a satisfactory manner the susceptibility, magnetization, and INS properties of the title compound.

Primary treatment of condylomata acuminata with viable bacillus Calmette-Guerin

PURPOSE

Condylomata acuminata or genital warts are caused by human papillomavirus. Prevalence data show that infection rates are increasing. To our knowledge we report the first successful primary treatment of genital warts with topical bacillus Calmette-Guerin (BCG) and provide long-term followup in a group of adjuvant treated patients with recurrent condylomata acuminata.

MATERIALS AND METHODS

In 10 consecutive men viable BCG was directly applied to the condylomata acuminata lesions once weekly for 6 weeks. In nonresponding patients another course of 9 applications was administered for 3 weeks.

RESULTS

A complete response was achieved in 6 of the 10 men after 1 or 2 treatment cycles. All responding patients are disease-free at a median followup of 9.2 months (range 4 to 12). One patient achieved partial regression of the lesions and in 3 the condylomata did not disappear. Side effects were rare and mild. Long-term followup in 6 adjuvant treated patients with rapidly recurrent condylomata acuminata showed no further recurrence after topical BCG in 5 at a median of 30.8 months (range 29 to 50).

CONCLUSIONS

Topical application of viable BCG has therapeutic activity as adjuvant and primary treatment for penile condylomata acuminata with negligible side effects. Long-term followup implies the prevention of recurrent disease.

Fatal basilar artery thrombosis after chemotherapy for testicular cancer

We report a 31-year-old patient with a pT3N2M1 seminoma who received cisplatin-based chemotherapy. During the second course of chemotherapy, the patient suffered a thrombosis of the basilar artery. He died 14 h after hospital admission. Cerebrovascular events related to cisplatin-based chemotherapy are rare, however, these potentially fatal events should be kept in mind when treating patients with testicular cancer.

Value of acute-phase proteins in the differential diagnosis of acute scrotum

OBJECTIVES

The evaluation of patients with an acute scrotum is primarily based on physical examination, imaging studies, as well as blood and urine tests. However, the differential diagnosis may be difficult in some cases. In a retrospective study, we investigated the value of acutephase proteins in serum and plasma from patients with an acute scrotum.

METHODS

A total of 104 patients (epididymitis n=52, testicular tumor n=17, testicular torsion n = 11, other conditions n = 24) with an acute scrotum were included in this study. In all patients the acute-phase proteins C-reactive protein (CRP), haptoglobin, alpha1-acid glycoprotein and transferrin in serum as well as fibrinogen in plasma were determined by turbidimetric analysis. The results were compared to the clinical findings, routine blood and urine tests and ultrasound.

RESULTS

Patients with an epididymitis showed at least a 4-fold elevation of CRP except for 2 cases (median 63.2 mg/l). In these patients, the sensitivity of CRP was 96.2%, the specificity 94.2%, the negative predictive value 94.2% and the positive predictive value 94.3%. Patients with a testicular tumor had no significant elevation of CRP (median 9 mg/l) as well as those with a testicular torsion (median 5 mg/l) except for 1 patient. The difference between patients with epididymitis and those with noninflammatory conditions was statistically significant (p<0.001, Kruskal-Wallis test and Tukey-Kramer test). The remaining parameters (haptoglobin, fibrinogen, a1-acid glycoprotein, transferrin, white blood count, body temperature and ultrasound) were less sensitive and specific.

CONCLUSIONS

Acute-phase proteins (especially C-reactive protein) are helpful in differentiating epididymitis from noninflammatory conditions like testicular torsion or tumor. Turbidimetric analysis of these proteins is rapid, easy and inexpensive.