Search PubMed⌕ Search

Biomedical subjects

V Brade

Publications and source records attributed to V Brade.

At least 37 records · Page 2Linked to original sources
PubMed2000

Risk of Pseudomonas aeruginosa cross-colonisation in patients with cystic fibrosis within a holiday camp--a molecular-epidemiological study.

OBJECTIVE: A study on the molecular epidemiology of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) from Germany (N = 18) and Israel (N = 12) is presented. The aim is to provide an answer to the question as to whether or not social contact outside the hospital environment involves a potential risk for person-to-person spread of this pathogen. METHODS: Sputa from German and Israeli patients were obtained while these were attending a holiday camp in Israel. The sputum samples were analysed with regard to Pseudomonas aeruginosa. Strains dissimilar in macroscopic appearance and/or antibiotic resistance patterns were genotyped using pulsed-field gel electrophoresis after digestion of genomic DNA with restriction endonuclease Spel. The genetic polymorphism of DNA fragment patterns of all strains (N = 146) was studied for their overall relatedness using a fingerprint software system. RESULTS: Most of the German patients (77.7%) were colonised persistently by a unique clonal type during the four-week screening period. Isolates obtained from Israeli patients displayed a very close clonal relationship and a higher antibiotic resistance as a result of preceding epidemic spread of certain clones before the camp. Additionally, isolates showing identical PFGE patterns were demonstrated once in a single male Israeli patient and in one female German patient, suggesting previous cross-colonisation. CONCLUSION: The occurrence of person-to-person spread through social contact in patients with CF is supported by our findings, but remains a rare event outside the hospital environment, provided appropriate hygienic measures are applied.

Adult↗
PubMed2000

[Prospective detection of important bacterial pathogens in pyoderma and their in vitro antibiotic susceptibility].

BACKGROUND AND OBJECTIVE: For rational therapeutic recommendations the spectrum and resistance of bacteria in skin diseases were investigated. PATIENTS/METHODS: Within 4 months 911 swabs of dematoses possibly caused by bacteria were taken prospectively (481 outpatients, 430 inpatients) and the material cultured on standard media. The positive cultures including resistance screening of 210 swabs of 168 outpatients and of 175 swabs of 85 inpatients could be evaluated, the remaining cultures were sterile. RESULTS: Staphylococcus aureus was the most frequent pathogen (outpatient 67%, inpatient 61% of all positive cultures), followed by streptococci (groups A and B; 25%). In patients Pseudomonas aeruginosa was the most common pathogen in leg ulcers and between the toes (45% and 70% respectively). 13% of the Staphylococcus aureus isolates were resistant to tetracyclines and erythromycin; one strain proved to be methicillin resistant. CONCLUSIONS: Cephalosporins (I. generation), penicillins with beta-lactamase-inhibitors, and to a lesser extent isoxazoyl-penicillin and clindamycin can be recommended for the treatment of skin infections. Oral quinolones are suited for infections with gram-negative bacteria (such as bewteen the toes). The indications for systemic antibiotic therapy of leg ulcers should be restricted.

Bacterial Infections↗
PubMed2000

[Epidemiology and therapy of bacterial infections in geriatrics].

As the elderly segment of our population expands, there is an increase of therapeutic problems considering this age group. The elderly patient is generally susceptible to infections because of the decline in host defense mechanisms that occurs with aging, and the underlying chronic diseases of these patients. Increasing numbers of elderly people are being treated in hospitals and are additionally at particular risk of acquiring nosocomial infections with antibiotic-resistant organisms. This article focuses on the epidemiological considerations, risk factors, types of infections that occur in elderly patients, and the guidelines for empiric therapy. The most common infections of the elderly are respiratory tract infection, urinary tract infection, and skin and soft tissue infection. Empirical therapy should be broader in spectrum for elderly patients since the variety of infecting bacteria tends to be greater and the choice of antimicrobial therapy must be based on risk stratification (age, medical illnesses, and severity of presentation). Many additional aspects, e.g., route of administration, drug pharmacokinetics and pharmacodynamics, drug toxicity and drug-drug interactions, compliance, and multiple underlying diseases (e.g., renal failure) must be considered in the rational selection of antibiotic regimen.

Aged↗
PubMed2000

New colorimetric microdilution method for in vitro susceptibility testing of Borrelia burgdorferi against antimicrobial substances.

A newly developed colorimetric microdilution method was used to analyze the activity of 12 antimicrobial agents against nine Borrelia burgdorferi isolates, including all three genospecies pathogenic for humans. In addition, in vitro antimicrobial resistance patterns of Borrelia valaisiana and Borrelia bissettii tick isolates were investigated. The applied test system is based upon color changes that occur in the presence of phenol red and result from the accumulation of nonvolatile acid produced by actively metabolizing spirochetes. After 72 h of incubation, minimal inhibitory concentrations (MICs) were determined from the decrease of absorbance by software-assisted calculation of growth curves. MIC values were lowest for azlocillin (MIC, < or = 0.125 microg/ml), ceftriaxone (MIC range, < or = 0.015-0.06 microg/ ml), and azithromycin (MIC range, < or = 0.015-0.06 microg/ml). Whereas tobramycin (MIC range, 8-64 microg/ml) exhibited little activity, spectinomycin (MIC range, 0.25-2 microg/ml) showed in vitro antimicrobial activity against Borrelia burgdorferi. The MICs of penicillin G for Borrelia afzelii isolates were ten times higher than those for Borrelia burgdorferi, Borrelia valaisiana, and Borrelia bissettii isolates (P<0.05) and 100 times higher than those for isolates belonging to the genospecies Borrelia garinii (P < 0.05). Further significant differences with respect to the MIC values of the other antimicrobial agents tested were not noted. The colorimetric microdilution method offered the advantages of reliability, reproducibility, and convenience and could handle large numbers of isolates and antibiotics.

Anti-Bacterial Agents↗
PubMed2000

Comparison of two laboratory methods for the determination of serum resistance in Borrelia burgdorferi isolates.

A growth inhibition assay (GIA) and an immunofluorescence test detecting deposited complement components C6 and C9 were compared for their ability to classify Borrelia isolates with respect to their resistance to non-immune human serum (NHS). In both assays a total of 34 Borrelia isolates of all three human pathogenic genospecies were tested. Interestingly, 95% of the serum-sensitive or intermediate serum-sensitive isolates belonged to the genospecies B. burgdorferi s. s. and B. garinii, whereas most B. afzelii isolates (83%) proved serum-resistant. Consequently, a strong correlation between the assignment of the isolates to the different genospecies and their degree of serum sensitivity was seen. These findings were supported strongly by the quantitative analysis of the deposited complement components and the location of the terminal complement complex on the bacterial surface as detected by means of immunoelectron microscopy. The GIA displayed an obvious lack of sensitivity to slow growing isolates, whereas the IFA allowed classification of all Borrelia isolates. Discrimination between serum-sensitive and serum-resistant isolates in the IFA was the most specific provided that the detection of C6 and C9 was incorporated into the final classification of isolates. Accordingly, both assays, turned out to be effective and reliable tools for the investigation of borrelial serum sensitivity. The IFA, however, is regarded as superior to the GIA owing to the obvious ease of performance and its rapid capability for the classification of even very slow growing isolates.

Borrelia burgdorferi Group↗
PubMed2000

Colorimetric in vitro susceptibility testing of penicillins, cephalosporins, macrolides, streptogramins, tetracyclines, and aminoglycosides against Borrelia burgdorferi isolates.

The spectrum of antibiotic susceptibility of Borrelia burgdorferi has been only partially defined. In the present study the effectiveness of 12 antimicrobials, belonging to six different antibiotic classes have been tested against Borrelia burgdorferi s.s. (N=3), Borrelia garinii (N=3), Borrelia afzelii (N=3), Borrelia valaisiana (N=1), and Borrelia bissettii (N=1) isolates. These isolates were analysed by a new standardised colorimetric minimal inhibitory concentration (MIC) method based upon colour changes that result from actively metabolizing spirochaetes after 72 h of incubation. Piperacillin (MIC90: 0.08 mg/l), ceftriaxone (MIC90: 0. 04 mg/l), cefotaxime (MIC90: 0.15 mg/l), azithromycin (MIC90: 0.015 mg/l), roxithromycin (MIC90: 0.05 mg/l) and quinupristin/dalfopristin (MIC90: 0.12 mg/l) gave the lowest MIC values. Minimal inhibibitory activity of amoxycillin (MIC90: 1.04 mg/l), cefixime (MIC90: 1.33 mg/l), cefoperazone (MIC90: 0.83 mg/l) tetracycline (MIC90: 0.29 mg/l) and minocycline (MIC90: 0.30 mg/l) was slightly lower, whereas borrelia were resistant to amikacin (MIC90: >128 mg/l). Mean minimal borreliacidal concentrations (MBCs) were representatively determined for piperacillin (MBC: 1.8 mg/l), ceftriaxone (MBC: 2.0 mg/l), azithromycin (MBC: 0.82 mg/ml), roxithromycin (MBC: 1.8 mg/l), quinupristin/dalfopristin (MBC: 5.0 mg/l), minocycline (MBC: 5.8 mg/l), and amikacin (MBC: >128 mg/l) by using conventional subculture for three weeks in combination with dark-field microscopy. B. garinii proved to be the most susceptible of the genospecies tested. Our study showed excellent in vitro antimicrobial activity of all classes of antibiotics tested, except the aminoglycosides and hence their suitability for therapy of Lyme disease.

Aminoglycosides↗
PubMed2000

Colonization with superantigen-producing Staphylococcus aureus is associated with increased severity of atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with colonization of the skin with Staphylococcus aureus known to produce toxins with superantigen (SAg) activity. Besides T-cell activation these toxins induce T-cell skin homing in vitro. This may contribute to the observed induction or enhancement of skin inflammation. OBJECTIVE: The aim of this study was to determine whether colonization with SAg-producing S. aureus isolates modulates the intensity of AD. If so, it was of interest whether this may be primarily due to the toxins' effects as SAgs or as allergens. METHODS: In AD patients, healthy controls, and atopic controls SAg production by S. aureus isolated from skin or mucous membranes was investigated and correlated to the severity of the disease. Total IgE, SAg-specific IgE, and T-cell activation and recirculation markers were analysed and correlated with SAg production. RESULTS: Fifty-seven percent of S. aureus strains isolated from AD patients produced SAgs. This frequency was higher compared to healthy controls (33%). SAg production by S. aureus was correlated with a significantly higher scoring of AD (SCORAD index, 58 +/- 19 in SAg-producing vs 41 +/- 7 in non-SAg-producing germs; P < 0.05). However, the severity of the disease was not associated with sensitization against the SAgs staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB). Furthermore, SAg production by S. aureus was inversely correlated with total IgE concentration (P < 0.05) and positively correlated with T-cell activation (as measured by HLA-DR and CD69 expression) and the expression of the T-cell skin homing phenotype cutaneous lymphocyte-associated antigen. CONCLUSION: SAg production by S. aureus is suggested to be associated with an increased severity of atopic dermatitis. Since SAg production was found neither exclusively in AD patients nor in all patients, other pathogenic factors may be additionally effective.

Adult↗
PubMed1999

Prevalence of antibodies against the human granulocytic ehrlichiosis agent in Lyme borreliosis patients from Germany.

To contribute to the discussion of whether or not human granulocytic ehrlichiosis (HGE) occurs in midwestern Germany, sera from individuals with different risk categories for tick exposure were retrospectively examined by means of an immunofluorescence assay. The seroreprevalence for the HGE agent accounted for 5.5% of the 270 patients tested. Specific antibodies were detected more often in patients with early Lyme infection than in patients with stage III disease or in asymptomatic individuals seropositive for Lyme disease. Investigation of 50 patients with an active or recent syphilis infection revealed no cross-reactivity between Treponema pallidum antibodies and the HGE agent. The prevalence of HGE antibodies (13.1%) among 76 Lyme borreliosis patients from this urban area was significantly higher (P < 0.05) than that in the control groups (2.6%). The findings indicate that concomitant or serial infections with Borrelia burgdorferi and the HGE agent or closely related organisms may be a common occurrence in tick-exposed patients from Germany.

Adult↗
PubMed1999

Mycobacterium malmoense infections in immunocompetent patients.

While Mycobacterium malmoense infections were originally restricted to northern Europe, there has been an increasing number of reports of cases of infection in other countries. Two cases of infections due to Mycobacterium malmoense in immunocompetent patients in Germany are presented. In both cases a presumptive diagnosis of tuberculosis was established initially. Mycobacterium malmoense was cultured after a long incubation period (6-8 weeks). The patients were successfully treated with a triple regimen consisting of rifampicin, ethambutol and clarithromycin. The epidemiology and difficulties in diagnosis of Mycobacterium malmoense infection are discussed.

Adult↗
PubMed1999

Lyme arthritis in a 12-year-old patient after a latency period of 5 years.

Lyme arthritis (LA) may be confused with other rheumatic diseases, particularly in the absence of a history of erythema migrans (EM). We report the case of a 12-year-old patient who developed a large effusion of the right knee joint. The titer for antinuclear antibodies was 1:80 and the test for rheumatoid factor was negative. Investigations for antibody response to Borrelia burgdorferi demonstrated remarkable elevation of IgG antibody and no specific IgM response. These results were confirmed by immunoblotting reactivity with the bands p83/100, p58, p43, p41, p39, OspA, p30, OspC, p21, and p17. We subsequently learned that the child had suffered a tick bite followed by an EM 5 years earlier and had been treated with trimethoprim/sulfamethoxazole at that time. The patient now was given intravenous ceftriaxone, 2 g daily for 14 days. In the absence of clinical improvement 3 weeks later a knee joint aspiration was performed which resulted in a positive polymerase chain reaction (PCR) test for B. burgdorferi DNA (OspA) in the synovial fluid. The patient fully recovered 2 months later without further treatment. The case indicates that the latency period between EM and onset of LA may last up to 5 years. In addition to serologic test methods, analysis of synovial fluid using PCR may be decisive for making the final diagnosis of LA.

Antibodies, Bacterial↗
PubMed1999

Molecular characterization of rpoB mutations conferring cross-resistance to rifamycins on methicillin-resistant Staphylococcus aureus.

Mutations of the rpoB gene conferring resistance to rifampin were analyzed in 40 methicillin-resistant Staphylococcus aureus isolates obtained from six countries. Interestingly, the majority of clinical isolates showed multiple mutations within rpoB. The amino acid substitution 481His-->Asn was the most prevalent one, capable of conferring low-level resistance on its own. Cross-resistance to rifampin, rifabutin, and rifapentine was demonstrated for all mutants identified. The level of resistance to rifamycins correlated with both the mutation position and type of amino acid substitution.

Amino Acid Sequence↗
PubMed1999

Rapid detection of epidemic strains of methicillin-resistant Staphylococcus aureus.

Fifty methicillin-resistant Staphylococcus aureus (MRSA) initial isolates obtained from patients hospitalized in the orthopedic clinic of the Frankfurt University Hospital and 150 methicillin-sensitive Staphylococcus aureus (MSSA) isolates were investigated in this study to determine whether the Slidex Staph-Kit is capable of differentiating between MRSA and MSSA owing to its unique performance characteristics. The Slidex Staph-Kit is a combined latex hemagglutination test designed to detect clumping factor, protein A, and a specific surface immunogen for S. aureus. Clumping factor-positive strains cause erythrocytes sensitized with fibrinogen to hemagglutinate, thereby resulting in visible red clumps. S. aureus strains deficient in clumping factor agglutinate latex particles sensitized with specific antibodies against surface proteins of S. aureus, thereby resulting in visible white clumps. Our results demonstrate that white clumping has a 99% specificity as well as a 98% positive predictive value for MRSA. Clumping factor-negative MRSA, which have been reported to occur in several countries, are epidemic in the Frankfurt area and account for 80% of all MRSA initial isolates in the orthopedic clinic of the Frankfurt University Hospital. Genotyping of all MRSA isolates by macrorestriction analysis of chromosomal DNA revealed that 83% of clumping factor-negative MRSA are closely related to the "southern-German" epidemic strain. This is the first study demonstrating the Slidex Staph-Kit's capability for identifying epidemic clumping factor-negative S. aureus strains as methicillin resistant even prior to antimicrobial susceptibility testing.

Agglutination Tests↗
PubMed1999

[Pathogen detection in blood culture. Contamination, colonization or infection].

Sepsis is a severe and life-threatening disease that requires a rapid and reliable diagnosis. The detection of microorganisms in blood culture and the results of in vitro anti-microbial susceptibility testing are prerequisites for a directed and cost-effective antimicrobial therapy. Microbiological results are difficult to interpret if contamination of the blood culture with colonizing or environmental germs cannot be ruled out. The source of contamination is predominantly inappropriate withdrawal of blood. Occasionally, contamination of blood cultures occurs in the laboratory. A potentially relevant blood culture result is already indicated by the isolated pathogen itself. In addition, a short time between the collection of blood and the isolation of the microorganism as well as the detection of the same pathogen in several blood cultures even more suggest a clinically relevant result.

Bacteriological Techniques↗
PubMed1998

Growth inhibitory and bactericidal efficacy of sera from Lyme borreliosis patients on B. burgdorferi strains.

Two B. afzelii strains EB1 and FEM1, classified in normal human sera (NHS) as serum-resistant, and an intermediate serum-sensitive B. burgdorferi s.s. strain 297, were tested in regard of their serum sensitivity in immune sera (IS) of patients at all stages of Lyme borreliosis by a growth inhibition assay (GIA). Fifty-four per cent (13/24) of the tested IS were GIA positive, while the sera of patients in stage III disease inhibited the growth more frequently than did the patients with sera of stage II or stage I disease. Growth inhibition was predominantly directed against strain FEM1 (12/24), less against strain EB1 (4/24) and strain 297 (2/24). A growth inhibiting effect on two strains was only detectable for two IS and merely one stage III serum inhibited all three strains. Positive results in the GIA required fresh serum and resulted in the killing of the borreliae. The detection of the deposited complement components C3 and C9 on the surfaces of the inhibited strains by means of immunofluorescence assays confirmed the role of complement. In Westernblot analyses of strain FEM1, it was striking that GIA-positive IS reacted 3- to 5-fold more often with proteins of molecular masses of 48.9-, 38.6-, 27.5-, 25-, 23.1- (OspC), 21.7-, and 16-kDa, than did GIA-negative IS. Furthermore, two proteins of approximately 20- and 31.2-kDa reacted exclusively with GIA-positive IS. Antibodies reacting with these proteins could play a role in the growth inhibition of NHS-resistant borrelial strains, OspC.

Antigens, Bacterial↗
PubMed1998

Serologic evidence for tick-borne pathogens other than Borrelia burgdorferi (TOBB) in Lyme borreliosis patients from midwestern Germany.

The seroprevalence of antibodies against the human granulocytic ehrlichiosis agent (HGE) and Babesia microti was retrospectively determined in 76 Lyme borreliosis patients and in 44 asymptomatic individuals with a positive borreliosis serology, in comparison to 100 healthy blood donors from the Rhein-Main area. Additionally, seroreactivity for tick-borne encephalitis virus (TBEV) was investigated. For antibody detection, commercially available immunofluorescence assays (MRL Diagnostics, USA) and a TBEV-ELISA (Immuno, Germany) were used. In the control group, the positivity rate for anti-Borrelia burgdorferi (IgG/IgM) and anti-Babesia microti-antibodies in the population of the Rhein-Main area (Midwestern Germany) may be estimated at 15% and 8%, respectively. Examination for both HGE and TBEV demonstrated seroreactivity (IgG) in 1% of tested individuals. Specific anti-HGE IgG and/or IgM antibodies were more often discovered in cases of early Borrelia infection (stage I: 13.6%, stage II: 18.4%) than in patients with stage III disease (0%) or in seropositive but asymptomatic patients (6.8%). Investigation for TBEV revealed seroreactivity for IgG in 13% of these cases. No TBEV-IgM was found. Interestingly, the prevalence of anti-HGE and anti-TBEV antibodies among Lyme borreliosis patients and seropositive patients without active Lyme disease symptoms was significantly higher than that in the control group of healthy blood donors (p < 0.05). Likewise, antibody titers reflecting a recent infection with Babesia microti could be demonstrated more often in patients with Lyme borreliosis stage I or II (p < 0.05). Analysis of 50 samples from patients with florid or recent syphilis infection revealed no crossreactivity between Babesia microti, HGE and Treponema pallidum. Our findings suggest that concomitant or serial infection due to TOBB may be common in tick exposed patients from the Rhein-Main area and in European countries in general. Hence, in addition to TBEV, human babesiosis and HGE should always be considered by European physicians in the differential diagnosis of acute febrile illness following a tick bite.

Animals↗
PubMed1998

Two cases of chronic arthritis of the forearm due to Mycobacterium tuberculosis.

In the absence of coexisting active pulmonary disease, tuberculosis is frequently not considered in the differential diagnosis of chronic inflammation of the joints. The cases of two immigrant patients with tuberculous arthritis involving the forearm are reported. In both cases non-specific arthritis or trauma was suspected, resulting in a delay between the onset of symptoms and institution of specific therapy of 21 and 24 months, respectively. Diagnosis was achieved by histological and microbiological examination of synovial biopsy material. Polymerase chain reaction for Mycobacterium tuberculosis complex was positive in only one patient. Treatment consisted of antituberculosis chemotherapy, surgical synovectomy, and debridement of the affected joints. These cases serve as a reminder that, although rare, tuberculosis can cause chronic arthritis.

Adult↗
PubMed1998

[Methicillin-reistant Staphylococcus aureus: risk factors for infection-colonization and clonal heterogeneity in intensive care units].

PURPOSE: The aim of this study was to determine the risk factors associated with colonisation/infection by methicillin-resistant Staphylococcus aureus (MRSA) and to demonstrate the chain of infections by genotyping of all MRSA isolates. METHODS: A total of 6143 microbiological samples from 1753 patients was obtained at a surgical ICU of Frankfurt University hospital during 1995. RESULTS: MRSA was detected in 1.6% of patients and three members of staff (3.3%). Typing of these 31 MRSA-strains (first isolates) by macrorestriction analysis of chromosomal DNA revealed nine different genotypes. More than 60% of all isolates belonged to one type that was confirmed to be closely related to the "South Germany" epidemic strain. A strong correlation between severity of underlying disease and length of hospitalisation on the one hand and detection of MRSA on the other could be demonstrated. Detection of MRSA was significantly more common in patients with adult respiratory distress syndrome (ARDS), sepsis, kidney failure, prolong respiratory treatment and in patients with prolonged phases of haemodynamic instability. It appeared that the mortality rate of MRSA-infected patients was higher (28.6%) than the mortality rate of all patients (6.5%). CONCLUSION: Following of a strict hygiene regime is important to prevent clonal spread of MRSA and especially to protect immunocompromised patients from complicating infections.

Adult↗