Bacterial biofilm in salivary stones.

PURPOSE: To assess the susceptibility of salivary stones to bacterial biofilm formation, which may be involved in the development of salivary gland infection, and to investigate a relation between microbiological aspects and patient characteristics. METHODS: This prospective study comprises of 54 patients with sialolithiasis attended in Helsinki University Hospital during 2014-2016. A total of 55 salivary stones were removed, and studied for biofilm formation using fluorescence microscopy and sonication. The isolated organisms were quantified and identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. RESULTS: Biofilm formation was confirmed on the surface of 39 (70.9%) stones. A total of 96 microorganisms were isolated from 45 salivary stones (81.8%). Two or more organisms were isolated in 33 (73.3%) cases. The main isolates were Streptococcus mitis/oralis (n = 27; 28.1%), followed by Streptococcus anginosus (n = 10; 9.6%), Rothia spp. (n = 8; 8.3%), Streptococcus constellatus (n = 7; 7.3%), and Streptococcus gordonii (n = 6; 6.2%). In all patients showing pre-operative (12 cases) or peri-operative (three cases) drainage of pus, the presence of biofilm was detected in microscopy (p = 0.004). Four patients showed post-operative infection, and in three of them (75.0%), the presence of biofilm was detected. Increased number of pus drainage was found among patients with reflux symptoms or use of proton-pump inhibitors. CONCLUSIONS: Salivary stones are susceptible to bacterial biofilm formation, which could be related with the development and severity of the inflammation and the refractory nature of the disease. Sonication of salivary gland stones could be a useful method for finding the etiology of the chronic infection.

Impact of pre-operative antimicrobial treatment on microbiological findings from endocardial specimens in infective endocarditis.

Treatment of infective endocarditis (IE) should be initiated promptly. This might hamper the chances to identify the causative organism in blood cultures. Microbiological sampling of infected valve in patients undergoing surgery might identify the causative organism. The impact of pre-operative antimicrobial treatment on the yield of valve samples is not known. This study evaluated the impact of the duration of the pre-operative antibiotic treatment on valve culture and 16S rRNA PCR findings from resected endocardial samples. Patients meeting the modified Duke criteria of definite or possible IE and undergoing valve surgery due to IE during 2011-2016 were included from Southern Finland. Eighty-seven patients were included. In patients with shorter than 2 weeks of pre-operative antimicrobial treatment, PCR was positive in 91% (n = 42/46) and valve culture in 41% (n = 19/46) of cases. However, in patients who had 2 weeks or longer therapy before operation, PCR was positive in 53% (n = 18/34) and all valve cultures were negative. In 14% of patients, PCR had a diagnostic impact. In blood-culture negative cases (n = 13), PCR could detect the causative organism in ten patients (77%). These included five cases of Bartonella quintana, one Tropheryma whipplei, and one Coxiella burnetii. Long pre-operative antimicrobial treatment was shown to have a negative impact on microbiological tests done on resected endocardial material. After 2 weeks of therapy, all valve cultures were negative, but PCR was positive in half of the cases. PCR aided in diagnostic work-up, especially in blood culture negative cases.

Impact of short-incubation MALDI-TOF MS on empiric antibiotic therapy in bloodstream infections caused by Pseudomonas aeruginosa, Enterococcus spp. and AmpC-producing Enterobacteriaceae.

The impact of the short-incubation matrix-assisted laser desorption ionization time-of-flight (si-MALDI-TOF) mass spectrometry technique was evaluated in the treatment of bloodstream infections (BSIs) caused by Pseudomonas aeruginosa, Enterococcus spp., and Amp-C producing Enterobacteriaceae. A total of 124 bacteremia episodes were divided into 2 groups: i) si-MALDI-TOF group (n = 69) and ii) control group (n = 55). Identification by si-MALDI-TOF resulted in 12.8% increase in cases receiving appropriate antibiotic treatment within 48 h from blood culture draw. The importance of the rapid identification was emphasized in BSIs caused by enterococci (n = 62), where si-MALDI-TOF led to appropriate antibiotic treatment in 87.9% of cases (versus control group 65.5%, P = 0.036). Implementation of si-MALDI-TOF technology for microbial identification was associated with increased proportion of patients receiving effective antibiotic treatment within 48 h from blood culture draw. The effect was most significant in BSIs caused by enterococcal species and in a subgroup of immunosuppressed patients.

Quantitative N-glycoproteomics reveals altered glycosylation levels of various plasma proteins in bloodstream infected patients.

Bloodstream infections are associated with high morbidity and mortality with rates varying from 10-25% and higher. Appropriate and timely onset of antibiotic therapy influences the prognosis of these patients. It requires the diagnostic accuracy which is not afforded by current gold standards such as blood culture. Moreover, the time from blood sampling to blood culture results is a key determinant of reducing mortality. No established biomarkers exist which can differentiate bloodstream infections from other systemic inflammatory conditions. This calls for studies on biomarkers potential of molecular profiling of plasma as it is affected most by the molecular changes accompanying bloodstream infections. N-glycosylation is a post-translational modification which is very sensitive to changes in physiology. Here we have performed targeted quantitative N-glycoproteomics from plasma samples of patients with confirmed positive blood culture together with age and sex matched febrile controls with negative blood culture reports. Three hundred and sixty eight potential N-glycopeptides were quantified by mass spectrometry and 149 were further selected for identification. Twenty four N-glycopeptides were identified with high confidence together with elucidation of the peptide sequence, N-glycosylation site, glycan composition and proposed glycan structures. Principal component analysis, orthogonal projections to latent structures-discriminant analysis (S-Plot) and self-organizing maps clustering among other statistical methods were employed to analyze the data. These methods gave us clear separation of the two patient classes. We propose high-confidence N-glycopeptides which have the power to separate the bloodstream infections from blood culture negative febrile patients and shed light on host response during bacteremia. Data are available via ProteomeXchange with identifier PXD009048.

Characterization of vB_SauM-fRuSau02, a Twort-Like Bacteriophage Isolated from a Therapeutic Phage Cocktail.

Staphylococcus aureus is a commensal and pathogenic bacterium that causes infections in humans and animals. It is a major cause of nosocomial infections worldwide. Due to increasing prevalence of multidrug resistance, alternative methods to eradicate the pathogen are necessary. In this respect, polyvalent staphylococcal myoviruses have been demonstrated to be excellent candidates for phage therapy. Here we present the characterization of the bacteriophage vB_SauM-fRuSau02 (fRuSau02) that was isolated from a commercial Staphylococcus bacteriophage cocktail produced by Microgen (Moscow, Russia). The genomic analysis revealed that fRuSau02 is very closely related to the phage MSA6, and possesses a large genome (148,464 bp), with typical modular organization and a low G+C (30.22%) content. It can therefore be classified as a new virus among the genus Twortlikevirus. The genome contains 236 predicted genes, 4 of which were interrupted by insertion sequences. Altogether, 78 different structural and virion-associated proteins were identified from purified phage particles by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The host range of fRuSau02 was tested with 135 strains, including 51 and 54 Staphylococcus aureus isolates from humans and pigs, respectively, and 30 coagulase-negative Staphylococcus strains of human origin. All clinical S. aureus strains were at least moderately sensitive to the phage, while only 39% of the pig strains were infected. Also, some strains of Staphylococcus intermedius, Staphylococcus lugdunensis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus saprophyticus and Staphylococcus pseudointer were sensitive. We conclude that fRuSau02, a phage therapy agent in Russia, can serve as an alternative to antibiotic therapy against S. aureus.

Staphylococcal protein Ecb impairs complement receptor-1 mediated recognition of opsonized bacteria.

Staphyloccus aureus is a major human pathogen leading frequently to sepsis and soft tissue infections with abscesses. Multiple virulence factors including several immune modulating molecules contribute to its survival in the host. When S. aureus invades the human body, one of the first line defenses is the complement system, which opsonizes the bacteria with C3b and attract neutrophils by release of chemotactic peptides. Neutrophils express Complement receptor-1 [CR1, CD35) that interacts with the C3b-opsonized particles and thereby plays an important role in pathogen recognition by phagocytic cells. In this study we observed that a fraction of S. aureus culture supernatant prevented binding of C3b to neutrophils. This fraction consisted of S. aureus leukocidins and Efb. The C-terminus of Efb is known to bind C3b and shares significant sequence homology to the extracellular complement binding protein [Ecb). Here we show that S. aureus Ecb displays various mechanisms to block bacterial recognition by neutrophils. The presence of Ecb blocked direct interaction between soluble CR1 and C3b and reduced the cofactor activity of CR1 in proteolytic inactivation of C3b. Furthermore, Ecb could dose-dependently prevent recognition of C3b by cell-bound CR1 that lead to impaired phagocytosis of NHS-opsonized S. aureus. Phagocytosis was furthermore reduced in the presence of soluble CR1 [sCR1). These data indicate that the staphylococcal protein Ecb prevents recognition of C3b opsonized bacteria by neutrophil CR1 leading to impaired killing by phagocytosis and thereby contribute to immune evasion of S. aureus.

Changes in plasma protein levels as an early indication of a bloodstream infection.

Blood culture is the primary diagnostic test performed in a suspicion of bloodstream infection to detect the presence of microorganisms and direct the treatment. However, blood culture is slow and time consuming method to detect blood stream infections or separate septic and/or bacteremic patients from others with less serious febrile disease. Plasma proteomics, despite its challenges, remains an important source for early biomarkers for systemic diseases and might show changes before direct evidence from bacteria can be obtained. We have performed a plasma proteomic analysis, simultaneously at the time of blood culture sampling from ten blood culture positive and ten blood culture negative patients, and quantified 172 proteins with two or more unique peptides. Principal components analysis, Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) and ROC curve analysis were performed to select protein(s) features which can classify the two groups of samples. We propose a number of candidates which qualify as potential biomarkers to select the blood culture positive cases from negative ones. Pathway analysis by two methods revealed complement activation, phagocytosis pathway and alterations in lipid metabolism as enriched pathways which are relevant for the condition. Data are available via ProteomeXchange with identifier PXD005022.

Complement Factor H Binds to Human Serum Apolipoprotein E and Mediates Complement Regulation on High Density Lipoprotein Particles.

The alternative pathway of complement is an important part of the innate immunity response against foreign particles invading the human body. To avoid damage to host cells, it needs to be efficiently down-regulated by plasma factor H (FH) as exemplified by various diseases caused by mutations in its domains 19-20 (FH19-20) and 5-7 (FH5-7). These regions are also the main interaction sites for microbial pathogens that bind host FH to evade complement attack. We previously showed that inhibition of FH binding by a recombinant FH5-7 construct impairs survival of FH binding pathogens in human blood. In this study we found that upon exposure to full blood, the addition of FH5-7 reduces survival of, surprisingly, also those microbes that are not able to bind FH. This effect was mediated by inhibition of complement regulation and subsequently enhanced neutrophil phagocytosis by FH5-7. We found that although FH5-7 does not reduce complement regulation in the actual fluid phase of plasma, it reduces regulation on HDL particles in plasma. Using affinity chromatography and mass spectrometry we revealed that FH interacts with serum apolipoprotein E (apoE) via FH5-7 domains. Furthermore, binding of FH5-7 to HDL was dependent on the concentration of apoE on the HDL particles. These findings explain why the addition of FH5-7 to plasma leads to excessive complement activation and phagocytosis of microbes in full anticoagulated blood. In conclusion, our data show how FH interacts with apoE molecules via domains 5-7 and regulates alternative pathway activation on plasma HDL particles.

Accurate and rapid identification of Candida spp. frequently associated with fungemia by using PCR and the microarray-based Prove-it Sepsis assay.

The rapid identification of microbes responsible for bloodstream infections (BSIs) allows more focused and effective therapies and outcomes. DNA sequence-based methods offer an opportunity for faster, accurate diagnosis and for effective therapy. As our objective of the study, the ability of the Prove-it Sepsis platform, already proven as a rapid PCR- and microarray-based assay for the majority of sepsis-causing bacteria, was extended to also rapidly identify clinically relevant yeasts in blood culture. The performance characteristics of this extended platform are described. We found that the extended diagnostic Prove-it Sepsis platform was found to be highly accurate when analyzing primary isolates, spiked blood cultures, nucleic acid extracts from a retrospective blood culture data set, and primary blood cultures. Comparison of the blood culture results from the Prove-it Sepsis platform with those from conventional culture-based methods or by gene sequencing demonstrated a sensitivity of 99% and a specificity of 98% for fungal targets (based on analysis of a total of 388 specimens). Total assay time was 3 h from DNA extraction to BSI diagnosis. These results extend the performance characteristics of the Prove-it platform for bacteria to the easy, rapid, and accurate detection and species identification of yeasts in positive blood cultures. Incorporation of this extended and rapid diagnostic platform into the tools for clinical patient management would allow possibly faster identification and more focused therapies for BSIs.

Cefuroxime as a prophylactic preoperative antibiotic in septoplasty. A double blind randomized placebo controlled study.

BACKGROUND: Prophylactic antibiotics are often used in septoplasty. However, the number of controlled studies, especially randomized double blind placebo controlled studies on the effect of antibiotics in septum surgery, is very low. The PURPOSE OF THE PRESENT STUDY was to investigate if intravenous cefuroxime given as preoperative antimicrobial prophylaxis 30 minutes prior to surgery diminishes the risk of infection after septoplasty during the first postoperative month among patients with normal immune function. METHODS: This study was a double-blind placebo controlled randomized study and patients were randomized to either an antibiotic prophylaxis-group or placebo-group. RESULTS: In the antibiotic-group, the infection rate was 2.2% (2/92) and in the placebo-group 8.3% (8/96), which is not statistically different. All three deep incisional SSI (septal abscess) occurred in the placebo-group. The preoperative crusting or purulent secretion, or Staphylococcus aureus in the bacterial swab increased the risk of postoperative infection significantly. CONCLUSIONS: We recommend the use of one dose of 1500 mg intravenous cefuroxime prior to septoplasty in patients having crusts or purulent secretion in the nasal cavities or if the operation is expected to be prolonged.

Clinical spectrum of bacteraemic Fusobacterium infections: from septic shock to nosocomial bacteraemia.

BACKGROUND: Fusobacterium species are anaerobic bacteria that relatively rarely cause sepsis with a variable clinical presentation. METHODS: We reviewed the records of 52 consecutive patients who had Fusobacterium bacteraemia over a 10-y period. RESULTS: The clinical pictures could be classified into 4 groups: (1) patients who had Lemierre's syndrome with Fusobacterium necrophorum sepsis and internal jugular vein thrombosis, n = 5 (10%); (2) previously healthy patients who had F. necrophorum sepsis without any signs of macroscopic vascular thrombosis (but 5 of them had abscesses), n = 14 (27%); (3) women who had puerperal infections, n = 6 (12%); and (4) patients who were on average older than the patients in the previous groups, who had cardiovascular, pulmonary, neoplastic, or other underlying diseases, n = 27 (52%). Of these latter 27 patients, 23 had nosocomial Fusobacterium nucleatum bacteraemia presenting as a febrile illness associated with chemotherapy or instrumentation. CONCLUSIONS: Patients with chronic underlying diseases are more likely to be infected with F. nucleatum than F. necrophorum. F. nucleatum bacteraemia may present as a febrile illness without severe symptoms. F. necrophorum caused sepsis mainly in previously healthy individuals. These infections may be accompanied with a jugular vein thrombosis characteristic of Lemierre's syndrome and septic shock. However, F. necrophorum infections present more frequently without any apparent venous thrombosis and may be accompanied by abscesses.

Characterization of infecting strains and superantigen-neutralizing antibodies in Staphylococcus aureus bacteremia.

Staphylococcus aureus superantigens (SAgs) are highly potent T cell mitogens. Antibodies against non-enterotoxin gene cluster (non-egc) SAgs are common in healthy adults, whereas neutralizing antibodies against egc SAgs are rare. We investigated the infecting S. aureus strains and the anti-SAg antibody response during S. aureus bacteremia (SAB). This prospective clinical study (www.clinicaltrials.gov, NCT00548002) included 43 injection drug users (IDUs) and 44 group-matched nonaddicts with SAB. spa genotypes and SAg gene patterns (multiplex PCR) of the S. aureus isolates were determined. The neutralizing capacities of sera obtained at the acute phase and the convalescent phase of SAB were tested against the SAg cocktail of the respective infecting strain and a panel of recombinant SAgs. The lineages CC59 and CC30 were more prevalent among bacteremia strains from IDUs than among strains from nonaddicts. SAg gene patterns in isolates from IDUs and nonaddicts were similar. At the acute phase of bacteremia, IDUs had more neutralizing antibodies against non-egc SAgs than did nonaddicts. Antibody titers frequently increased during infection. In contrast, there were no neutralizing antibodies against egc SAgs at disease onset and such antibodies were not induced by SAB. SAB triggers an antibody response only against non-egc SAgs. Preimmunization in IDU patients is probably due to previous exposure to the infecting strain.

Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

BACKGROUND: Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine. CONCLUSIONS/SIGNIFICANCE: Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

Nosocomial candidaemia in a Finnish tertiary care centre during 1987-2004.

We studied the epidemiology of nosocomial candidaemia by assessing the incidence and outcome of illness and causative species in a large Finnish tertiary care centre during 1987-2004. A total of 364 episodes were observed; annual incidence varied between 0.26 per 10,000 patient-d in 2000 and 0.59 in 1989. The most common species were C. albicans (65%), C. parapsilosis (13%), and C. glabrata (9%). The proportion of C. albicans decreased from 71% during 1987-1992 to 58% during 1999-2004, and C. glabrata increased from 3% to 14%, respectively. The proportion of intensive care patients increased from 27% during 1987-1992 to 44% by 1999-2004, associated with neonates and surgical patients. The 1-month case fatality ranged from 30% to 33%. Nosocomial candidaemias did not increase, but the distribution of Candida spp. changed. Mortality remained high. The observed changes may reflect differences in prevention strategies that need to be explored for further improvements in prevention.

Expression of Pls (plasmin sensitive) in Staphylococcus aureus negative for pls reduces adherence and cellular invasion and acts by steric hindrance.

BACKGROUND: The methicillin-resistant Staphylococcus aureus (MRSA) surface protein Pls (plasmin sensitive) reduces adhesion to host proteins and cellular invasiveness by an unknown mechanism that requires Pls expression. Here, we tested the effect of Pls expression using different pls-negative backgrounds. METHODS: Three pls-negative strains (the methicillin-susceptible Staphylococcus aureus strains Cowan I and 6850 and the MRSA strain ST239-635/93, which harbors staphylococcal cassette chromosome [SCC] mec type III) were transformed. Constructs used were full-length pls (pPLS4), pls-DeltaLPDTG (no sortase motif; pPLS5), and pls-DeltaSD (no serine-aspartic acid [SD] repeats; pPLS6). Adherence, invasiveness, gene expression, and surface expression were quantified by photometry, flow cytometry, real-time reverse-transcription polymerase chain reaction, and a modified enzyme-linked immunosorbent assay, respectively. RESULTS: In Pls-expressing strains (those with pPLS4), adherence to immobilized fibronectin (Fn) and binding of soluble Fn was reduced by approximately 20% and approximately 25%, respectively. Invasion of 293 cells and EA.hy 926 cells was reduced by up to 85%. Surprisingly, transcription of fnbA and spa was up-regulated, but transcription of clfA and hla was down-regulated. Pls and Fn-binding protein (FnBP) surface expression was increased. Competition with purified FnBPA, but not with Pls, reduced invasiveness by approximately 90%. The invasiveness of 6850 (pPLS5) and of 6850 (pPLS6) was reduced by only approximately 20% and approximately 15%, respectively. CONCLUSION: Expression of cell wall-anchored Pls reduces adherence and invasiveness independently of the MRSA/SCCmec background. This occurs despite early up-regulation of fnbA transcription and FnBP surface expression. Thus, Pls acts by steric hindrance rather than another mechanism.

Factor H binding as a complement evasion mechanism for an anaerobic pathogen, Fusobacterium necrophorum.

Fusobacterium necrophorum subspecies funduliforme is an obligate anaerobic Gram-negative rod causing invasive infections such as the life-threatening Lemierre's syndrome (sore throat, septicemia, jugular vein thrombosis, and disseminated infection). The aim of our study was to understand if and how F. necrophorum avoids C activation. We studied 12 F. necrophorum subsp. funduliforme strains isolated from patients with sepsis. All strains were resistant to serum killing after a 1-h incubation in 20% serum. The bacteria bound, at different levels, the C inhibitor factor H (fH). Binding was ionic and specific in nature and occurred via sites on both the N terminus and the C terminus of fH. Bound fH remained functionally active as a cofactor for factor I in the cleavage of C3b. Interestingly, patients with the most severe symptoms carried strains with the strongest ability to bind fH. An increased C3b deposition and membrane attack complex formation on the surface of a weakly fH-binding strain was observed and its survival in serum at 3.5 h was impaired. This strain had not caused a typical Lemierre's syndrome. These data, and the fact that fH-binding correlated with the severity of disease, suggest that the binding of fH contributes to virulence and survival of F. necrophorum subsp. funduliforme in the human host. Our data show, for the first time, that an anaerobic bacterium is able to bind the C inhibitor fH to evade C attack.

Methicillin-sensitive Staphylococcus aureus bacteraemia and endocarditis among injection drug users and nonaddicts: host factors, microbiological and serological characteristics.

BACKGROUND: Endocarditis has been associated with lower mortality and fewer complications among injection drug users (IDUs) than nonaddicts in Staphylococcus aureus bacteraemia (SAB). The better prognosis of IDUs has not been clarified but it has generally been explained by younger age and other host factors. In this study, bacterial strains, their virulence factors, and host immune responses were compared among IDUs and nonaddicts with SAB, including those with and without endocarditis. METHODS: A total of 430 consecutive adult patients with methicillin-sensitive SAB were followed prospectively for 3 months. All 44 IDUs were included, and 44 nonaddicts as controls for them. According to the modified Duke criteria, 20 patients in both groups had endocarditis. For each addict without endocarditis, an age and sex matched nonaddict was selected as a control. S. aureus isolates were assigned a genotype by PFGE, Panton-Valentine leukocidin (PVL), staphylokinase (SAK), protease, and haemolysin production. Acute and convalescent sera were tested for antibodies to alpha-haemolysin (ASTA) and teichoic acid (TAA). RESULTS: There were no differences between IDUs and nonaddicts with SAB in the proportion of patients with a deep infection (98% vs 86%, P=0.06) or a thromboembolic complication (30% vs 14%, P=0.12). Endocarditis among IDUs was not associated with any specific strains, and only the FIN-4 strain was observed more often in IDUs than in nonaddicts (21% vs 5%, P=0.03). The majority of isolates (98%) were PVL negative, and there were no differences in the numbers of SAK, protease and haemolysin production among strains between IDUs and nonaddicts. However, haemolytic properties were found more frequently in strains from IDUs without endocarditis than those with endocarditis (88% vs 47%, P=0.007). IDUs displayed more often elevated TAA titers than nonaddicts, especially in endocarditis at acute phase (33% vs 5%, P=0.04) and at convalescent phase (50% vs 10%, P=0.01). The ASTA titer was more frequently initially positive among IDUs without endocarditis than with endocarditis (44% vs 6%, P=0.01). CONCLUSIONS: Characterization of the bacterial strains and their virulence factors, and host immune responses did not reveal significant differences between IDUs and nonaddicts with similar clinical picture of SAB. Serological tests were not helpful in identifying patients with endocarditis.

Tuberculosis of the head and neck in Finland.

CONCLUSION: Tuberculosis is a rare disease that can mimic a neck malignancy. It should be taken into consideration when evaluating a patient with a neck mass, especially when the patient has come from an area of high endemic incidence. Another risk group comprises older people with dormant tuberculosis. OBJECTIVES: We wanted to find out the incidence of head and neck tuberculosis in Finland and to define the factors that should make one suspect it. PATIENTS AND METHODS: This was a retrospective analysis of patients who were diagnosed with tuberculosis in the Department of Otolaryngology, Helsinki University Central Hospital (population base c.a. 1,000,000) during 1996-2005. All the patients with culture- or PCR-positive tuberculosis were included. RESULTS: During 1996-2005, 63 patients were diagnosed with head and neck tuberculosis, the average incidence being 0.6/100,000 per year. The age of the patients varied between 3 and 94 years (mean 47 years). The mean age of patients who were of Finnish extraction (37 patients) was 62 years and that of immigrants (26 patients) was 27 years. Forty-four (70%) patients were female and 19 (30%) male. The majority of patients presented with a neck mass without symptoms of general infection such as fever or fatigue.

Comparison of bacterial adherence to polylactides, silicone, and titanium.

CONCLUSIONS: Less bacterial adherence occurred on uncoated polylactide and silicone than on uncoated titanium surfaces. Albumin coating was an effective method to inhibit bacterial adherence to all these surfaces. As regards bacterial adherence, polylactides are at least as safe implant materials as silicone and titanium. OBJECTIVES: We compared adherence of Staphylococcus aureus and Pseudomonas aeruginosa to four implant materials and studied the inhibitory effect of albumin on adherence. The aims were to discover any differences between materials and to study the effectiveness of albumin coating. MATERIALS AND METHODS: Eight plates of polylactide A and B, silicone, and titanium were exposed to S. aureus and P. aeruginosa. Four of these plates were uncoated and four were coated with albumin. A total of 64 plates were included in the study. The bacteria were stained with acridine orange, and 10 photomicrographs of each plate allowed quantification of the surface area covered with bacteria. RESULTS: The most adherence occurred on titanium without coating. Albumin coating of the surface significantly reduced bacterial adherence to each material. Differences between materials with albumin coating were relatively small. Of the bacteria, P. aeruginosa had the greater capacity to adhere to a surface.