Characteristics and outcome of 16 periprosthetic shoulder joint infections.

PURPOSE: Shoulder arthroplasties are increasingly performed, but data on periprosthetic joint infections (PJI) in this anatomical position are limited. We retrospectively investigated the characteristics and outcome of shoulder PJI after primary arthroplasty from 1998 to 2010 in a single centre. METHODS: Periprosthetic joint infection was defined as periprosthetic purulence, presence of sinus tract or microbial growth. A Kaplan-Meier survival method was used to estimate relapse-free survival of prosthesis. RESULTS: From 1,571 primary shoulder prostheses, we evaluated 16 patients with a PJI at different stages, i.e, early (n = 4), delayed (n = 6) and late (n = 6) infections. The median patient age was 67 (range 53-86) years, and 69 % were females. The most commonly isolated microorganism was Propionibacterium acnes in 38 % of patients (monobacterial in four and polymicrobial in two patients). In 14 of the 16 patients, surgical interventions consisting of debridement and implant retention (6 patients), exchange (7) and explantation (1) were performed. Four patients had a relapse of infection with P. acnes (n = 3) or Bacteroides fragilis (n = 1). The relapse-free survival of the prosthesis was 75 % (95 % confidence interval 46-90 %) after 1 and 2 years, 100 % in six patients following the treatment algorithm for hip and knee PJI and 60 % in 10 patients not followed up. All but one of the relapses were previously treated without exchange of the prosthesis. CONCLUSIONS: As recommended for hip and knee PJI, we suggest treating shoulder PJI with a low-grade infection by microorganisms such as P. acnes with an exchange of the prosthesis. Cohort studies are needed to verify our results.

[Antimicrobial resistance among E. coli in urinary specimens: prevalence data from three laboratories in Zurich between 1985 and 2010]. / Antibiotikaresistenzen von E.coli in Urinproben: Prävalenzdaten dreier Laboratorien im Raum Zürich von 1985 bis 2010.

Urinary tract infections in women are common. Drug resistance among Escherichia coli, the most frequent uropathogen, has increased worldwide. In a prevalence study we investigated the local antibiotic susceptibility of this microorganism in urinary specimens of three laboratories in Zurich. Resistance rates against trimethoprim-sulfamethoxazole 2010 were 28%, 16% against quinolones and 16% against amoxicillin/clavulanic acid. Resistance prevalence for nitrofurantoin and fosfomycin were low with 3,6%, resp. 0,7%. The rate of extended-spectrum beta-lactamase-producing E. coli has rapidly increased to 4,3% in 2010. Based on this data and according to the international guidelines for the treatment of uncomplicated cystitis, therapy with trimethoprim-sulfamethoxazole and quinolones are no longer recommended. Nitrofurantoin and Fosfomycin are an appropriate choice. Microbiological testing is advised.

Road factors and bicycle-motor vehicle crashes at unsignalized priority intersections.

In this study, the safety of cyclists at unsignalized priority intersections within built-up areas is investigated. The study focuses on the link between the characteristics of priority intersection design and bicycle-motor vehicle (BMV) crashes. Across 540 intersections that are involved in the study, the police recorded 339 failure-to-yield crashes with cyclists in four years. These BMV crashes are classified into two types based on the movements of the involved motorists and cyclists: • type I: through bicycle related collisions where the cyclist has right of way (i.e. bicycle on the priority road); • type II: through motor vehicle related collisions where the motorist has right of way (i.e. motorist on the priority road). The probability of each crash type was related to its relative flows and to independent variables using negative binomial regression. The results show that more type I crashes occur at intersections with two-way bicycle tracks, well marked, and reddish coloured bicycle crossings. Type I crashes are negatively related to the presence of raised bicycle crossings (e.g. on a speed hump) and other speed reducing measures. The accident probability is also decreased at intersections where the cycle track approaches are deflected between 2 and 5m away from the main carriageway. No significant relationships are found between type II crashes and road factors such as the presence of a raised median.

Characteristics and outcome of 27 elbow periprosthetic joint infections: results from a 14-year cohort study of 358 elbow prostheses.

Elbow arthroplasty is increasingly performed in patients with rheumatic and post-traumatic arthritis. Data on elbow periprosthetic joint infection (PJI) are limited. We investigated the characteristics and outcome of elbow PJI in a 14-year cohort of total elbow arthroplasties in a single centre. Elbow prosthesis, which were implanted between 1994 and 2007 at Schulthess Clinic in Zurich, were retrospectively screened for infection. PJI was defined as periprosthetic purulence, the presence of sinus tract or microbial growth. A Kaplan-Meier survival method and Cox proportional hazard analysis were performed. Of 358 elbow prostheses, PJI was identified in 27 (7.5%). The median patient age (range) was 61 (39-82) years; 63% were females. Seventeen patients (63%) had a rheumatic disorder and ten (37%) had osteoarthritis. Debridement and implant retention was performed in 78%, followed by exchange or removal of the prosthesis (15%) or no surgery (7%).The relapse-free survival (95% CI) was 79% (63-95%) after 1 year and 65% (45-85%) after 2 years. The outcome after 2 years was significantly better when patients were treated according to the algorithm compared to patients who were not (100% vs. 33%, p <0.05). In 21 patients treated with debridement and retention, the cure rate was also higher when the algorithm was followed (100% vs. 11%, p <0.05). The findings of the present study suggest that the treatment algorithm developed for hip and knee PJI can be applied to elbow PJI. With proper patient selection and antimicrobial therapy, debridement and retention of the elbow prosthesis is associated with good treatment outcome.

25 anys de l’inici de la reforma de l’atenció primària pediàtrica al CAP Canteres / No disponible

No disponible

[Sensitivity of bacteria to antibiotics (Zurich, 2000)]. / Die Empfindlichkeit von Bakterien gegen Antibiotika (Zürich, 2000).

This paper describes the frequency of susceptibility of Gram-negative and Gram-positive bacteria against antibacterial agents. Data are based on all susceptibility tests performed at the Department of Medical Microbiology of the University of Zurich in 2000. The evaluation of the results from 1987 to 2000 shows that susceptibilities against the antimicrobial agents tested have not markedly changed with the following exceptions: 7% of Staphylococcus aureus are resistant against methicillin, 8% of pneumococci have a reduced susceptibility to penicillin, 1% is resistant to penicillin, and 10% are resistant to macrolides. 9% of group A streptococci are resistant to macrolides. Quinolone resistance is markedly high in the medical practice with 10% of E. coli strains and 32% of Campylobacter sp. Strains of Klebsiella pneumoniae and E. coli producing extended spectrum betalactamases are isolated occasionally. Of all strains of Mycobacterium tuberculosis isolated from clinical specimens in 2000, 4% were multi-drug resistant. The tables may be a help for the physician in his decision for a "calculated chemotherapy" of bacterial infections.

Infection of a hip prosthesis by Actinomyces naeslundii.

We present the case of a 77-year-old woman who developed an Actinomyces naeslundii infection of a hip prosthesis. The isolate grew well aerobically with 5% CO(2). Possible diagnostic problems may arise in the microbiological laboratory because aerobic growth is not sufficiently accounted for in some of the traditional identification schemes and commercial test kits. Therefore, besides presenting an unusual pathogen in this setting, this report focuses on possible diagnostic problems in the microbiological laboratory.

Low specificity of the bacterial index for the diagnosis of bacterial pneumonia by bronchoalveolar lavage.

The bacterial index (BI) as defined by the sum of log10 colony-forming units (cfu) of microorganisms per milliliter of bronchoalveolar lavage (BAL) fluid, i.e., a multiplication of the single cfu/ml, has been used to distinguish between polymicrobial pneumonia (BI> or =5) and colonization (BI<5). Since many false-positive results are to be expected using this parameter, the diagnostic value of the BI was studied prospectively by obtaining bacteriologic cultures of BAL fluid in 165 consecutive unselected patients. In 27 cases the diagnosis of bacterial pneumonia was established on clinical criteria. In 133 patients pneumonia could be excluded, and in five patients the diagnosis remained unclear. Using a cut-off of > or = 10(5) cfu/ml BAL fluid, sensitivity and specificity for the diagnosis of pneumonia were 33% (9/27) and 99% (132/133), respectively. Sensitivity was mainly influenced by prior treatment with antibiotics, being 70% (7/10) in untreated and 12% (2/17) in treated patients. Applying the BI methodology at a cut-off of > or =5, however, resulted in an unacceptably high rate of 16 additional false-positive results, thus lowering the specificity to 87% (116/133; P<0.0001) while increasing the sensitivity to only 41% (11/27; P = 0.77). In conclusion, given the high rate of false-positive results, the methodology of the BI is of doubtful value for the diagnosis of bacterial pneumonia by BAL in an unselected patient group. By applying the absolute number of cfu/ml BAL fluid, however, positive bacteriologic cultures of BAL fluid are highly specific for the diagnosis of pneumonia. Their sensitivity is limited by previous antibiotic therapy.

[Sensitivity of bacteria to therapeutic drugs (Zurich 1996)]. / Die Empfindlichkeit von Bakterien gegen Chemotherapeutika (Zürich, 1996).

This paper describes the frequency of susceptibility of Gram-negative and Gram-positive bacteria against antibacterial agents. The data are based on all susceptibility tests performed in 1996 at the Department of Medical Microbiology of the University of Zurich and at the private medical laboratory "medica" in Zurich. The evaluation of the results from 1975 to 1996 shows that susceptibilities against the antimicrobial agents tested have not changed markedly in this period with few exceptions. The tables may be a help for the physician in his decision for a "calculated chemotherapy" of bacterial infections.

Molecular epidemiology of Mycobacterium tuberculosis strains isolated from patients in a human immunodeficiency virus cohort in Switzerland.

From 1989 to 1995, 46 patients infected with the human immunodeficiency virus were diagnosed with tuberculosis at the University Hospital in Zurich. Using the IS6110 insertion sequence as a genetic marker, restriction fragment length polymorphism analyses were done for 52 Mycobacterium tuberculosis isolates. We have found a large degree of IS6110 polymorphism, ranging from 1 to 16 copies. For isolates from patients from whom multiple isolates had been available, the IS6110 pattern remained virtually stable over a period of up to 4 years, as well as during emerging drug resistance. In none of the cases was a reinfection of a patient with another strain detected. For isolates from 10 patients we detected identical patterns which could be associated with four clusters. In one of these, the strains exhibited a low IS6110 copy number (four bands), and the strains were further analyzed by hybridizing with (i) the polymorphic GC-rich repetitive sequence (PGRS) and (ii) the 36-bp direct-repeat (DR) cluster sequence. One of these isolates had a different pattern with the PGRS as well as with the DR sequence and could therefore be safely excluded from that cluster. These findings point to the importance of applying more than one genetic criterion in the molecular biological study of strain relatedness.

In vitro activity of cefpirome against microorganisms isolated in haematology, oncology and intensive care units in Switzerland.

The in vitro activity of cefpirome, a new parenteral fourth-generation cephalosporin, was investigated in the 5 university hospitals of Switzerland, and compared to 9 other antibiotics mainly used in hospitals, such as ceftazidime, ceftriaxone, cefotaxime, piperacillin, imipenem, gentamicin, vancomycin, ciprofloxacin and ofloxacin. A total number of 992 strains collected only from intensive care units and haematology-oncology units were tested by microdilution according to NCCLS. Cefpirome showed an excellent activity against all Enterobacteriaceae (MIC90 = 4 mg/l), methicillin-susceptible staphylococci (MIC90 = 1 mg/l), Streptococcus pneumoniae (MIC90 = 0.25 mg/l) and Haemophilus influenzae (MIC90 = 0.12 mg/l) isolates. Its activity was superior to that of third-generation cephalosporins against cephalosporinase-depressed mutants of Enterobacter cloacae and Citrobacter freundii isolates (MIC90 > 32 mg/l for third-generation cephalosporins vs 4 mg/l for cefpirome). The MICs of cefpirome of 3 strains of Klebsiella spp. with an extended-spectrum-beta-lactamase were lower (MIC90 = 2 mg/l) than those of third-generation cephalosporins (MICs90 > 32 mg/l). Against Pseudomonas aeruginosa cefpirome was as active as ceftazidime. The activity of cefpirome was poor against methicillin-resistant staphylococci, enterococci and nosocomial Gram-negative bacteria such as Stenotrophomonas maltophilia.

[Tips and requests by microbiologists]. / Ratschläge und Wünsche des Mikrobiologen.

Useful results of microbiological examinations can only be expected, when the specimens submitted to the laboratory are taken correctly. This overview shows appropriate and inappropriate specimens. Hints are given for a 'calculated antimicrobial chemotherapy'. A brief outline shows which bacteria should be tested for susceptibility to antimicrobial agents due to variable sensitivity.

Prospective evaluation of a semiquantitative dip slide method compared with quantitative bacterial cultures of BAL fluid.

BACKGROUND: Quantitative bacteriologic workup of BAL fluid (BALF) has evolved as a sensitive and specific technique for the diagnosis of bacterial pneumonia. Conventional quantitative cultures are expensive, time-consuming, and often unavailable on a 24-h basis. Therefore, we evaluated a dip slide method for the semiquantitative measurement of bacterial cultures in BALF specimens and compared the results with those from conventional quantitative cultures. METHODS: Fifty BALF specimens from 45 patients with suspected pulmonary infection were examined prospectively with both methods. We compared the microbiologic results of conventional quantitative cultures with those of the dip slide method that is commercially available for blood cultures. Cost-effectiveness analysis of both methods was performed. RESULTS: In 37 BALF specimens, 64 bacterial strains were detected with both techniques. The dip slide method and conventional cultures showed a high correlation with respect to the colony counts of the individual organisms per milliliter BALF (r=0.935; p= 0.0001) and the sum of colony counts in individual patients (r=0.947; p=0.0001). Although five strains were not detected by the dip slide technique, the diagnostic accuracy was not influenced. In 13 BALF samples, there was no growth of bacteria with both techniques. While the diagnostic yield of both methods was similar, the dip slide technique was 44 to 66% less expensive than conventional cultures. CONCLUSIONS: The examination of BALF with a clip slide method is highly comparable to conventional quantitative culture techniques, less expensive, and can be used independently of a specialized microbiology laboratory on a 24-h basis.

[Effectiveness of triple therapy to eradicate H. pylori in patients after failed therapy with omeprazole/amoxicillin]. / Wirksamkeit der Tripeltherapie zur Eradikation von H. pylori bei Therapieversagern mit Omeprazol/Amoxicillin.

Helicobacter pylori (H. pylori) eradication rates with omeperazole/amoxicillin range from 0-90%. The best regimen for retreatment after failure of omeprazole/amoxicillin has not been established so far. The aim of this prospective study was to evaluate the efficacy of triple therapy with bismuth, tetracycline and ornidazole in eradicating H. pylori after failure of omeprazole/amoxicillin. 79 duodenal ulcer patients with H. pylori infection were treated with oral omeprazole (40 mg bid) and amoxicillin solute (750 mg tid) for 10 days. Eradication rate was 28/79 (35%) and was distinctly lower in smokers (> 10 cigarettes/day) vs nonsmokers (10/49 [20%] vs 18/30 [60%], p < 0.001). 37 patients with persistent H. pylori infection in whom omeprazole/amoxicillin had failed agreed to retreatment with triple therapy. Persistence of H. pylori was confirmed by histology (3 antral and 2 gastric body biopsies; H&E, Giemsa), urease test (CLO) and/or H. pylori culture. Patients smoking > 10 cigarettes/day were classified as smokers. Retreatment consisted of oral bismuth-subcitrate 4 x 120 mg/d for 28 days (day 1-28), tetracycline 4 x 500 mg/d and ornidazole 3 x 500 mg/d for 10 days (day 1-10). Control endoscopy was done 30 days after the end of treatment. Criteria for H. pylori eradication was negative urease test, culture and histology. 34/37 patients (6 females/28 males; 39 [23-64] years) completed the study (24/34 smokers, 10/34 nonsmokers). 3/37 patients dropped out because of side effects (n = 1) or incompliance (n = 2). H. pylori subcultures for resistance testing were possible in 32/34 patients: H. pylori was metronidazole-sensitive in 11/32 (1 female, 10 males; 38 [24-55] years; 9 smokers, 2 nonsmokers) and metronidazole-resistant (minimal inhibitory concentration for metronidazole > 8 mg/ml) in 21/32 (5 females, 16 males; 40 [23-64] years; 13 smokers, 8 nonsmokers). The overall H. pylori eradication rate of the triple therapy was 27/34 (79%). H. pylori was eradicated in 19/24 (79%) smokers and in 8/10 (80%) nonsmokers. Eradication rate for metronidazole-sensitive H. pylori was 11/11 (100%) vs 14/21 (67%) for metronidazole-resistant H. pylori (p = 0.012). Triple therapy is effective and safe in eradicating H. pylori in patients after failure of omeprazole/amoxicillin. Smoking had no negative effect on the eradication rate of the triple therapy after failure of omeprazole/amoxicillin. Eradication failures were due to metronidazole-resistance.

Antimicrobial susceptibilities and serotypes of invasive Streptococcus pneumoniae strains in Switzerland.

In 1993 and 1994, 10 microbiological laboratories in Switzerland collected 351 strains of Streptococcus pneumoniae from invasive infections. Susceptibilities to the main representatives of the chemical classes were as follows: penicillin, 93%; chloramphenicol, 92%; erythromycin, 94%; sulfamethoxazole-trimethoprim, 86%; tetracycline, 92%; vancomycin, 100%. Forty-three strains showed resistance to one agent, and 35 strains showed resistance to two or more antimicrobial agents simultaneously; i.e., 22% of the strains were resistant to at least one antimicrobial agent. Four strains (1%) were fully resistant to penicillin, whereas 21 strains (6%) showed reduced susceptibility. Of these 25 strains not fully susceptible to penicillin, 10 were resistant to one, 3 were resistant to two, and 8 were resistant to three additional antimicrobial agents. Of the quinolones, sparfloxacin was the most active substance, with an MIC at which 90% of the strains are inhibited of 0.5 mg/liter. The most common serotypes were types 6 (13.6% of isolates), 7 (10.5%), 19 (10.5%), 14 (9.1%), and 1 (8.5%) as well as 3 and 23 (8.0% each). Reduced susceptibility to penicillin was found mainly among serotypes 6, 14, 19, and 23. The currently available 23-valent pneumococcal vaccine covers 320 (91%) of the pneumococci isolated. Regional differences within Switzerland with regard to serotypes and antimicrobial resistance were not observed.

Soft tissue infections of the upper extremities with special consideration of abscesses in parenteral drug abusers. A prospective study.

Despite surgical advances and new antibiotics, upper extremity infections continue to present a serious problem. Soft tissue infections of the upper extremities were prospectively examined to elucidate incidence, cause, bacterial pathogens involved, and treatment. Special attention was paid to infections associated with parenteral drug abuse. During an 18-month period all patients over 16 years of age presenting for treatment of an established infection were included in the study. Conservative treatment consisted of immobilization and antibiotics. Radical débridement with removal of all necrotic tissue was the guideline for operative care. In addition, for both regimens a penicillinase-resistant antibiotic was administered. A total of 415 patients (271 men and 144 women; mean age 36.7 +/- 14.5 years) were enrolled into the study, 55 of whom were parenteral drug abusers; 45 of these were HIV-reactive. Infections of fingers (excluding paronychia), paronychia and abscesses at injection sites were the most common diagnoses. Operative and conservative treatment were performed in 285 and 130 patients respectively. Staphylococcus and streptococcus species were the predominant organisms recovered from 212 specimens of pus. Anaerobic bacteria and yeasts were of minor importance. Therefore, a penicillinase-resistant antibiotic is a good initial choice.

Comparison of BacT/Alert blood culture bottles with lytic media for culture of peritoneal dialysis fluid.

A comparison was made between the Septi-Chek "Release" system containing saponins, standard BacT/Alert blood culture bottles and FAN BacT/Alert blood culture bottles for culturing CAPD fluids. Seventy-seven CAPD effluent specimens were tested. No differences could be found. Therefore, lytic agents are not necessary when dialysates are cultured in blood culture media.

Assignment of Actinomyces pyogenes-like (CDC coryneform group E) bacteria to the genus Actinomyces as Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov.

In a previous study the authors reported the characterization of some facultatively anaerobic, Gram-positive, non-sporeforming rods which were found in mixed cultures from various infectious processes, including patients with otitis, empyema, perianal abscesses and decubitus ulcers. Phenotypically these organisms closely resembled Actinomyces pyogenes although their precise taxonomic position remained unknown. In the present investigation the authors have determined the 16S rRNA gene sequences of some representative strains of the Actinomyces pyogenes-like bacteria and report the results of a comparative sequence analysis. On the basis of the results of the present and earlier findings two new Actinomyces species, Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov. are proposed. The type strains are DSM 9169T and DSM 9168T, respectively.

[sensitivity of bacteria to chemotherapeutic agents (Zurich, 1993)]. / Die Empfindlichkeit von Bakterien gegen Chemotherapeutika (Zürich, 1993).

This paper describes the incidence of Gram-negative and Gram-positive bacteria susceptible to antibacterial agents. The data are based on all susceptibility tests performed at the Department of Medical Microbiology of the University of Zurich. The evaluation of the results from 1987 to 1993 shows that susceptibilities against the antimicrobial agents tested have not changed markedly in this period with few exceptions. The tables may be of help to the physician in his decision for a 'calculated chemotherapy' of bacterial infections.