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Objective: To determine the correlation between intraoperative changes of electrocochleography (ECochG) responses and traumatic cochlear implant insertions as well as postoperative hearing loss. Methods: ECochG, radiological, and audiological data were collected prospectively in a cochlear implant recipient with otosclerosis and assumed cochlear trauma during electrode insertion. A systematic review was conducted within PubMed-NCBI, EMBASE, and the Cochrane Library using the terms “Cochlear implant” and “Electrocochleography.” Original studies that evaluated intraoperative ECochG responses and postoperative hearing loss were selected and analyzed. Results: The case report revealed a drop of intra- and extracochlear ECochG signals during electrode insertion. The postoperative computed tomography scan suggested a scalar dislocation. There was no measurable hearing 4 weeks after surgery. Within the database search, nine articles met the inclusion criteria. All were case series reports (range from 2 to 36 subjects) with a total of 173 subjects. Due to the heterogeneous data, a meta-analysis was unfeasible. Conclusions: In concordance with some findings in the literature, the presented case report suggests that a drop of intra- and extracochlear ECochG signals during the insertion of the electrode array is associated with cochlear trauma and postoperative hearing loss in some cases. However, the literature is inconclusive regarding the correlation between intraoperative changes of the ECochG signals and postoperative hearing preservation. More studies investigating the correlation are needed to provide sufficient data.

Multiport laparoscopy is the gold-standard approach for cholecystectomy, and single-port laparoscopy has been developed to further reduce its invasiveness. A specific robotic single-port platform (da Vinci single-site, Intuitive Surgical Inc., Sunnyvale, CA, USA) has been released in 2011, which could technically facilitate single-site cholecystectomy. Current data show its feasibility; however, detailed short- and long-term analyses of costs and comparisons relative to multiport laparoscopy are not available to date. Patients who underwent robotic single-site cholecystectomy for benign, clinically noninflammatory disease between 2011 and 2015 were matched for disease, age, gender, BMI, ASA classification, diagnosis, and elapsed year of surgery to a cohort of multiport cholecystectomies. Demographic, perioperative, and long-term data were collected retrospectively and analyzed. Perioperative and long-term costs including re-operations due to the primary procedure until February 2017 were compared across both cohorts. 99 patients who underwent robotic single-site cholecystectomy were matched to 99 patients with multiport cholecystectomy. A higher rate of outpatient procedures in the robotic cohort (31.3 vs. 17.2%, p = 0.0305) was found, and demographic parameters and perioperative clinical outcomes were similar. Perioperative costs were significantly higher for the robotic single-site patients (6158.0 vs. 4288.0 USD, p

Pharmacokinetic characteristics of benzylpenicillin and its benzylpenicilloyl (BPO)-derivatives were studied in serum and milk of health cows, using a classical biological assay ( Sarcina lutea test) and a competitive ELISA for BPO detection. The plasma level and passage into milk was determined after intramuscular administration of penethamate-hydroiodide and benzylpenicillin-procaine. In serum of cows receiving penethamate hydroiodide, BPO seemed to persist for a rather long time; the reason for this observation was not clarified. The effect of local (intramammary) application of penicillin G was followed with milk from cows having healthy and mastitic quarters. In all cases, it was found that BPO was not excreted any longer than active penicillin G in milk. In a further survey, 1015 bulk milk samples from two large dairy regions were examined with the ELISA and a biological assay using Bacillus stearothermophilus var. calidolactis . None of the samples showed detectable BPO or antibiotic residues. It is concluded that milk containing inactive penicillin derivatives, like BPO, is not an important source to cause allergies.

Purpose: The optimal duration of concomitant antibiotic therapy after surgical intervention for implant-free chronic osteomyelitis is unknown. No randomized data exist. Available recommendations are based on expert's opinion. We evaluated the duration of post-surgical antibiotic treatment related to remission of chronic osteomyelitis. Methods: This was a retrospective single-centre study at Geneva University Hospitals with a minimal follow-up of two years after treatment. We used multivariate logistic regression analysis with exclusion of pediatric cases and of implant-related chronic osteomyelitis. Results: A total of 49 episodes of implant-free chronic osteomyelitis in 49 adult patients were studied. The median number of surgical interventions was two (range, 1-10). The median duration of post-debridement antibiotic treatment was eightweeks (range, 4-14weeks). Thirty-nine patients (80%) were in remission after a minimal follow-up of twoyears. In multivariate logistic regression analysis, one week of intravenous therapy had the same remission as two to threeweeks (0.2, 0.1-1.9) or ≥ 3weeks (0.3, 0.1-2.4). More than sixweeks of total antibiotic treatment equalled ≤ six weeks (0.8, 0.1-5.2). Conclusions: In chronic osteomyelitis in adults, a post-debridement antibiotic therapy beyond six weeks, or an IV treatment longer than one week, did not show enhanced remission incidences. Prospective randomized trials are required to confirm this observation

Breakthrough candidemia (BTC) on fluconazole was associated with non-susceptible Candida spp. and increased mortality. This nationwide FUNGINOS study analyzed clinical and mycological BTC characteristics.A 3-year prospective study was conducted in 567 consecutive candidemias. Species identification and antifungal susceptibility testing (CLSI) were performed in the FUNGINOS reference laboratory. Data were analyzed according to STROBE criteria.43/576 (8%) BTC occurred: 37/43 (86%) on fluconazole (28 prophylaxis, median 200 mg/day). 21% BTC vs. 23% non-BTC presented severe sepsis/septic shock. Overall mortality was 34% vs. 32%. BTC was associated with gastrointestinal mucositis (multivariate OR 5.25, 95%CI 2.23-12.40, p 0.001) and graft-versus-host-disease (6.25, 1.00-38.87, p = 0.05), immunosuppression (2.42, 1.03-5.68, p = 0.043), and parenteral nutrition (2.87, 1.44-5.71, p = 0.003). Non-albicans Candida were isolated in 58% BTC vs. 35% non-BTC (p = 0.005). 63% of 16 BTC occurring after 10-day fluconazole were non-susceptible (Candida glabrata, Candida krusei, Candida norvegensis) vs. 19% of 21 BTC (C. glabrata) following shorter exposure (7.10, 1.60-31.30, p = 0.007). Median fluconazole MIC was 4 mg/l vs. 0.25 mg/l (p 0.001). Ten-day fluconazole exposure predicted non-susceptible BTC with 73% accuracy.Outcomes of BTC and non-BTC were similar. Fluconazole non-susceptible BTC occurred in three out of four cases after prolonged low-dose prophylaxis. This implies reassessment of prophylaxis duration and rapid de-escalation of empirical therapy in BTC after short fluconazole exposure.

Clinical experience suggests that a high proportion of orthopaedic infections occur in persons with diabetes.We reviewed several databases of adult patients hospitalized for orthopaedic infections at Geneva University Hospitals from 2004 to 2014 and retrieved 2740 episodes of infection.Overall, diabetes was noted in the medical record for 659 (24%) of these cases. The patients with, compared with those without, diabetes had more than five times more foot infections (274/659 [42%] vs 155/2081 [7%]; p0.01) and a significantly higher serum C-reactive protein level at admission (median 96 vs 70 mg/L; p0.01). Diabetic patients were older (median 67 vs 52 years; p0.01), more often male (471 [71%] vs 1398 [67%]; p = 0.04), and had more frequent polymicrobial infections (219 [37%] vs 353 [19%]; p0.01), including more gram-negative non-fermenting rods (90 [15%] vs 168 [9%]; p0.01). Excluding foot infections from these analyses did not change the statistically significant differences. Diabetes was present in 17% of all infected orthopaedic patients without foot involvement. In Geneva canton, the overall prevalence of diabetes is estimated at 5.1%, while we have found that the prevalence is 13% in our hospitalized adults.Diabetes is present in 24% of all adult patients hospitalized for surgery for an orthopaedic infection, a prevalence that is several times higher than for the general population and twice as high as that for the population of hospitalized patients. Compared with non-diabetics, patients with diabetes have significantly more infections that are polymicrobial, including gram-negative non-fermenting rods.

Summary Objectives To assess the risk factors for recurrence of septic arthritis with an emphasis on the duration of antibiotic treatment, to gather data for a prospective study on an optimized antibiotic treatment in adults with septic arthritis. Methods This was a retrospective single-center study conducted for the period 1996–2008. Results A total of 169 episodes of septic arthritis in 157 adult patients (median age 63 years; 65 females) were included. In 21 episodes (21/169, 12%), arthritis recurred after the end of antibiotic treatment. Multivariate analysis showed that Gram-negative infection (odds ratio (OR) 5.9, 95% confidence interval (CI) 1.4–25.3), immune suppression (OR 5.3, 95% CI 1.3–22.0), and lack of surgical intervention were associated with recurrence. The size of the infected joint, the number of surgical drainages (OR 1.3, 95% CI 1.0–1.7), arthrotomy vs. arthroscopic drainage (OR 0.5, 95% CI 0.2–1.8), duration of antibiotic therapy (OR 1.0, 95% CI 0.95–1.05), and duration of intravenous antibiotic therapy (OR 1.0, 95% CI 1.0–1.0) were not. Seven days of intravenous therapy had the same success rate as 8–21 days (OR 0.4, 95% CI 0.1–1.7) and >21 days (OR 1.1, 95% CI 0.4–3.1). Fourteen days or less of total antibiotic treatment had the same outcome as 15–28 days (OR 0.4, 95% CI 0.1–2.3) or >28 days (OR 0.4, 95% CI 0.1–1.6). Conclusions In this retrospective study of adults with septic arthritis, the duration of antibiotic therapy, or an early switch from intravenous to oral administration, did not statistically influence the risk of recurrence. Due to study limitations, the data cannot be used directly for antibiotic therapy recommendations for septic arthritis. Prospective randomized trials are warranted to optimize the antibiotic treatment of septic arthritis.

OBJECTIVES: In the treatment of prosthetic joint infections (PJI), the benefit of antibiotic therapy for more than 6 weeks after surgery is uncertain. We compared PJI cure rates according to the duration of antibiotics, 6 versus 12 weeks. METHODS: A prospective observational non-randomized study in Geneva University Hospitals 1996-2007. RESULTS: A total of 144 PJI (62 hip arthroplasties, 62 knee arthroplasties, and 20 hip hemiarthroplasties) were included with a prolonged follow-up ranging from 26 to 65 months. Surgical treatment included 60 debridements with implant retention, 10 one-stage exchanges of the prosthesis, 57 two-stage exchanges, and 17 Girdlestone procedures or knee arthrodeses. Seventy episodes (49%) received 6 weeks antibiotic therapy and 74 episodes, 12 weeks. Cure was achieved in 115 episodes (80%). Cure rate did not change according to the duration of intravenous antibiotics (>8 days, 8-21 days, >21 days) (Kruskal-Wallis-test; p = 0.37). In multivariate analysis, none of the following parameters was statistically significantly associated with cure: two-stage exchange (odds ratio 1.1,95%CI 0.2-4.8); number of debridements (0.9, 0.4-1.9); six weeks antibiotherapy (2.7, 0.96-8.3); duration of intravenous course (1.0, 0.96-1.03); sinus tract (0.6, 0.2-1.7); or MRSA infection (0.5, 0.2-1.5), although implant retention showed a tendency for less cure (0.3, 0.1-1.1). CONCLUSIONS: Following surgery for treatment of PJI, antibiotic therapy appears able to be limited to a 6-week course, with one week of intravenous administration. This approach needs confirmation in randomized trials.

Objectives The value of non-bone microbiological cultures in the diagnosis of osteomyelitis with sinus tract is not clear. We aimed to establish the concordance between deep sinus tract cultures and bone cultures in cases of osteomyelitis with a cutaneous fistula. Methods This was a non-randomized, prospective diagnostic trial at the Orthopedic Service of the University Hospital of Geneva. Each patient with osteomyelitis with a cutaneous sinus tract had four microbiological samples taken: two consecutive sinus tract cultures with bone contact at different times (samples A-1 and A-2), surgical bone biopsy performed through the sinus tract (sample B), and a surgical bone biopsy performed through an uninfected area outside the sinus tract (sample C), the latter considered as the ‘gold standard'. Results One hundred and forty-one patients with 154 episodes of osteomyelitis were included in the study. When both sinus tract cultures yielded the same microorganism (86.4%), the concordance between both samples A and sample C was 96%. In the case of identical sinus tract culture infections, sensitivity was 91%, specificity 86%, and accuracy 90%. The accuracy in monomicrobial infections (50%) was higher than in polymicrobial infections (94.3% vs. 78.9%, respectively; p =0.02). Conclusions In cases of monomicrobial osteomyelitis with sinus tract, two concordant tract cultures with bone contact accurately predict the pathogen.

RATIONALE: The duration of antibiotic therapy in critically ill patients with sepsis can result in antibiotic overuse, increasing the risk of developing bacterial resistance. OBJECTIVES: To test the hypothesis that an algorithm based on serial measurements of procalcitonin (PCT) allows reduction in the duration of antibiotic therapy compared with empirical rules, and does not result in more adverse outcomes in patients with severe sepsis and septic shock. METHODS: In patients randomly assigned to the intervention group, antibiotics were stopped when PCT levels had decreased 90% or more from the initial value (if clinicians agreed) but not before Day 3 (if baseline PCT levels were /=1 microg/L). In control patients, clinicians decided on the duration of antibiotic therapy based on empirical rules. MEASUREMENTS AND MAIN RESULTS: Patients assigned to the PCT group had 3.5-day shorter median duration of antibiotic therapy for the first episode of infection than control subjects (intention-to-treat, n = 79, P = 0.15). In patients in whom a decision could be taken based on serial PCT measurements, PCT guidance resulted in a 4-day reduction in the duration of antibiotic therapy (per protocol, n = 68, P = 0.003) and a smaller overall antibiotic exposure (P = 0.0002). A similar mortality and recurrence of the primary infection were observed in PCT and control groups. A 2-day shorter intensive care unit stay was also observed in patients assigned to the PCT group (P = 0.03). CONCLUSIONS: Our results suggest that a protocol based on serial PCT measurement allows reducing antibiotic treatment duration and exposure in patients with severe sepsis and septic shock without apparent harm.

Zygomycosis are rare fungal infections occurring mainly in immunocompromised patients. To date only 160 cases have been published in transplant recipients. We report four new cases of zygomycosis in transplant recipients illustrating the large clinical spectrum of this infection: one disseminated infection with heart involvement and one rhinocerebral infection with dissemination in two Bone Marrow Transplantation recipients, one cutaneous infection in a liver and one pulmonary infection in a kidney recipient. All cases, except the cutaneous infection that was accessible to surgical resection and a systemic antifungal treatment, were fatal. In transplant recipients cumulating risk factors for zygomycosis, a high index of suspicion is required. Early diagnosis and combining surgery with systemic amphotericin-B are mandatory to improve survival rates.

It remains controversial whether combination therapy, given empirically or as definitive treatment, for Pseudomonas aeruginosa bacteremia is associated with a better outcome than monotherapy. The aim of the present study was to compare the rates of survival among patients who received either combination therapy or monotherapy for P. aeruginosa bacteremia. We assembled a historical cohort of 115 episodes of P. aeruginosa bacteremia treated with empirical antipseudomonal therapy between 1988 and 1998. On the basis of susceptibility testing of the bacteremic P. aeruginosa isolate, we defined categories of empirical treatment, including adequate combination therapy, adequate monotherapy, and inadequate therapy, as well as corresponding categories of definitive therapy. Neither the adequacy of the empirical treatment nor the use of combination therapy predicted survival until receipt of the antibiogram. However, the risk of death from the date of receipt of the antibiogram to day 30 was higher for both adequate empirical monotherapy (adjusted hazard ratio [aHR], 3.7; 95% confidence interval [CI], 1.0 to 14.1) and inadequate empirical therapy (aHR, 5.0; 95% CI, 1.2 to 20.4) than for adequate empirical combination therapy. Compared to adequate definitive combination therapy, the risk of death at 30 days was also higher with inadequate definitive therapy (aHR, 2.6; 95% CI, 1.1 to 6.7) but not with adequate definitive monotherapy (aHR, 0.70; 95% CI, 0.30 to 1.7). In this retrospective analysis the use of adequate combination antimicrobial therapy as empirical treatment until receipt of the antibiogram was associated with a better rate of survival at 30 days than the use of monotherapy. However, adequate combination antimicrobial therapy given as definitive treatment for P. aeruginosa bacteremia did not improve the rate of survival compared to that from the provision of adequate definitive monotherapy.

All patients positive for methicillin-resistant Staphylococcus aureus (MRSA) at the University Hospitals of Geneva, Switzerland, between 1989 and 1997 (N = 1771) were included in a cohort study to evaluate the consequences of delayed containment of a hospital-wide outbreak occurring during a 4-year absence of MRSA control measures. The effects of efforts to control both the MRSA reservoir and the number of bacteraemic patients were assessed. Intensive infection control measures were initiated in 1993 and included patient screening, on-site surveillance, contact isolation, a computerized alert system, and hospital-wide promotion of hand hygiene. An increase in the rate of new MRSA-infected or -colonized patients was observed between 1989 and 1994 (from 0.05 to 0.60 cases per 100 admissions), which subsequently decreased to 0.24 cases in 1997 (P

Recurrence of osteomyelitis by the same bacterial strain is well known. We report three patients with a second episode of osteomyelitis at the same site caused by different strains of bacteria from the original. Formerly infected and altered bone surface might present a region of diminished resistance for a new infection.

Background. It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. Methods. We investigated temporal trends in annual incidence densities (events per 100 000 patient-days) of nosocomial BSIs caused by methicillin-resistant Staphylococcus aureus (MRSA), ARB other than MRSA, and ASB in 7 ARB-endemic and 7 ARB-nonendemic hospitals between 1998 and 2007. Results. 33 130 nosocomial BSIs (14% caused by ARB) yielded 36 679 microorganisms. From 1998 to 2007, the MRSA incidence density increased from 0.2 to 0.7 (annual increase, 22%) in ARB-nonendemic hospitals, and from 3.1 to 11.7 (annual increase, 10%) in ARB-endemic hospitals (P = .2), increasing the incidence density difference between ARB-endemic and ARB-nonendemic hospitals from 2.9 to 11.0. The non-MRSA ARB incidence density increased from 2.8 to 4.1 (annual increase, 5%) in ARB-nonendemic hospitals, and from 1.5 to 17.4 (annual increase, 22%) in ARB-endemic hospitals (P < .001), changing the incidence density difference from −1.3 to 13.3. Trends in ASB incidence densities were similar in both groups (P = .7). With annual increases of 3.8% and 5.4% of all nosocomial BSIs in ARB-nonendemic and ARB-endemic hospitals, respectively (P < .001), the overall incidence density difference of 3.8 increased to 24.4. Conclusions. Increased nosocomial BSI rates due to ARB occur in addition to infections caused by ASB, increasing the total burden of disease. Hospitals with high ARB infection rates in 2005 had an excess burden of BSI of 20.6 per 100 000 patient-days in a 10-year period, mainly caused by infections with ARB. Funding Agencies|Netherlands Organization of Scientific Research|VICI NWO 918.76.611|Oxford National Institute for Health Research Biomedical Research Centre||Novartis||3M||Roche||Optimer Pharmaceuticals||Cepheid||bioMerieux||Astellas||Basilea||Bayer||Pfizer||Gilead||MSD||Oxoid||Wyeth||Siemens||Bruker

BACKGROUND: The incidence of fungal infections, including those due to Aspergillosis species has continued to increase in recent years. Invasive aspergillosis remains an important cause of morbidity and mortality, despite therapeutics interventions. PATIENTS AND METHODS: We reported five cases of invasive pulmonary aspergillosis treated with voriconazole failing to respond to conventional treatments. RESULTS: The clinical and radiological resolution of pulmonary aspergillosis reported in these cases following therapy with voriconazole is remarkable, considering the infections had proved refractory to standard antifungal therapies. Long-term therapy (in two cases > or = 1 year, in one case 6 months) was very well tolerated by patients who were unable to tolerate other antifungal agents. CONCLUSION: Therapy with voriconazole offers a new therapeutic option for otherwise difficult-to-treat infections and the potential to significantly improve the management of Aspergillosis infections.

The efficacies of imipenem when directed against methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains of Staphylococcus aureus were compared with those of oxacillin and vancomycin in a subcutaneous rat model, using chronically infected tissue cages. At three weeks after inoculation, stable chronic infections were established with average bacterial counts exceeding 10(6) cfu/mL tissue cage fluid for both strains. Intraperitoneal administration (twice a day for 7 days) of imipenem (80 mg/kg) or oxacillin (200 mg/kg) produced peak levels of 23 or 45 mg/L and through levels of < 0.1 and 5.7 mg/L, respectively. The therapeutic regimens of either imipenem (P < 0.001) or oxacillin (P < 0.02) administered for 7 days led to significant reductions in bacterial counts in the tissue cage fluids of animals chronically infected with MSSA. In contrast, imipenem was not effective against chronic MRSA tissue cage infections, despite the relatively low MIC of the infecting strain and the use of high dose (120 mg/kg) therapy. In-vitro susceptibility testings of MRSA performed before and after imipenem therapy demonstrated the emergence of a highly resistant subpopulation.

Paecilomyces lilacinus is a rare cause of endophthalmitis and there are few reports of it in the literature. Herein we report a patient with P. lilacinus endophthalmitis who was treated with the new triazole, voriconazole, for 4 months, with a good clinical evolution. This treatment appears to be a valuable new therapeutic option but requires further clinical confirmation.

Background. No guidelines exist concerning treatment of asymptomatic bacteriuria in renal transplant recipients (RTR). Because of scarce clinical symptoms and fear of complications, such episodes are frequently treated based on subjective criteria without clear clinical benefit, with the risk of selecting resistant pathogens. Methods. We retrospectively analysed the outcome of 334 asymptomatic Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) bacteriuria that occurred in 77 RTR later than 1 month post-transplantation. We distinguished: Type I, high-grade bacteriuria with pyuria; Type II, high-grade bacteriuria without pyuria; Type III, low-grade bacteriuria with pyuria and Type IV, low-grade bacteriuria without pyuria. Results. None of the 334 episodes was followed by acute rejection or chronic pyelonephritis. One hundred and one (30%) episodes were treated [32 (62%) Type I, 38 (45%) Type II, 13 (36%) Type III and 18 (11%) Type IV]. Evolution to symptomatic urinary tract infection (UTI) was similar between treated and untreated episodes (0/101 versus 4/233, P = 0.32). The four UTI resolved favourably without further complication upon treatment. Persistent asymptomatic bacteriuria occurred in 45 (46%) treated episodes (2 Type I, 27 Type II, 8 Type III and 9 Type IV), with selection of resistant pathogen in 35 cases (78%). Spontaneous bacterial clearance occurred in 138 (59%) untreated episodes (15 Type I, 23 Type II, 9 Type III and 91 Type IV). Negative control cultures tended to be more frequent in treated Type I (P = 0.09) and in untreated Type II episodes (P = 0.08). Conclusion. Restricting antibiotic treatments for asymptomatic low-grade bacteriuria and high-grade bacteriuria in the absence of pyuria, occurring later than 1 month posttransplantation, might be safe in RTR

International audience; Propionibacterium acnes is the most frequent anaerobic pathogen found in spondylodiscitis. A documented case required microbiological proof of P. acnes with clinical and radiological confirmation of inflammation in a localized region of the spine. Microbiological samplings were obtained by surgery or aspiration under radiological control. Twelve males and 17 females (median age, 42 years) with spondylodiscitis due to P. acnes were diagnosed within the last 15 years. Three patients were immunosuppressed. All patients reported back pain as the main symptom, and most were afebrile. Three patients had a peripheral neurological deficit, one a motor deficit, and two a sensory deficit attributable to the infection; and six patients had an epidural abscess. The most frequent risk factor was surgery, which was present in the history 28 of 29 (97%) patients. The mean delay between spinal surgery and onset of disease was 34 months, with a wide range of 0-156 months. Osteosynthesis material was present in twenty-two cases (76%). In 24 (83%) patients, additional surgery, such as débridement or spondylodesis, was performed. Previous osteosynthesis material was removed in 17 of the 22 (77%) patients where it was present. Total cure was reported in all patients, except one, after a mean duration of antibiotic therapy of 10.5 weeks (range, 2-28 weeks). In conclusion, spondylodiscitis due to P. acnes is an acute infection closely related to previous surgery. The most prominent clinical feature is pain, whereas fever is rare, and the prognosis is very good.

BACKGROUND: Pseudomonas aeruginosa is an uncommon cause of community-acquired bacteremia among patients without severe immunodeficiency. Because tension exists between the need to limit unnecessary use of anti-pseudomonal agents and the need to avoid a delay in appropriate therapy, clinicians require better guidance regarding when to cover empirically for P. aeruginosa. We sought to determine the occurrence of and construct a model to predict P. aeruginosa bacteremia upon hospital admission. METHODS: A retrospective study was conducted in 4 tertiary care hospitals. Microbiology databases were searched to find all episodes of bacteremia caused by gram-negative rods (GNRs) ≤ 48 h after hospital admission. Patient data were extracted from the medical records of 151 patients with P. aeruginosa bacteremia and of 152 randomly selected patients with bacteremia due to Enterobacteriaceae. Discriminative parameters were identified using logistic regression, and the probabilities of having P. aeruginosa bacteremia were calculated. RESULTS: P. aeruginosa caused 6.8% of 4114 unique patient episodes of GNR bacteremia upon hospital admission (incidence ratio, 5 cases per 10,000 hospital admissions). Independent predictors of P. aeruginosa bacteremia were severe immunodeficiency, age >90 years, receipt of antimicrobial therapy within past 30 days, and presence of a central venous catheter or a urinary device. Among 250 patients without severe immunodeficiency, if no predictor variables existed, the likelihood of having P. aeruginosa bacteremia was 1:42. If ≥ 2 predictors existed, the risk increased to nearly 1:3. CONCLUSIONS: P. aeruginosa bacteremia upon hospital admission in patients without severe immunodeficiency is rare. Among immunocompetent patients with suspected GNR bacteremia who have ≥ 2 predictors, empirical anti-pseudomonal treatment is warranted.

Group A beta-hemolytic streptococcus (GAS) meningitis is a rare disease in adults. We conducted a retrospective study to describe clinical and microbiological features of nine cases of GAS meningitis in Switzerland. Of nine patients, six had neurosurgical conditions, and five had upper respiratory tract infections. Eight cases were community-acquired. The outcome of GAS meningitis was favorable; only one patient died of neurosurgical complications. No patient presented with toxic shock syndrome. Serotyping failed to reveal a dominant strain, and genotyping revealed that two strains carried the gene encoding the streptococcal pyrogenic exotoxin C and that one strain carried the gene encoding the streptococcal pyrogenic exotoxin A. Our observations suggest that GAS meningitis in adults is associated with neurosurgical conditions and/or an upper respiratory tract infection.

Streptococcus sinensis has been described as a causative organism for infective endocarditis in 3 Chinese patients from Hong Kong. We describe a closely related strain in an Italian patient with chronic rheumatic heart disease. The case illustrates that S. sinensis is a worldwide emerging pathogen.

We report the case of an elderly immunocompetent patient with Aeromonas hydrophila bacteremia without evidence of portal of entry. Despite several risk factors for a poor outcome, such as impaired renal function, two positive blood cultures, and community-acquired infections, the patient survived. Antimicrobial susceptibility was normal. Unknown polycystic liver disease was discovered and misdiagnosed as a hepatic abscess at the time of the bacteremia which was confirmed by repeated CT scans. Because of the absence of other risk factors for Aeromonas bacteremia, hepatic polycystic disease may take part in the onset of Aeromonas sp bacteremia as well as immunosenescence.

Following surgery for musculoskeletal infection, a positive suction drainage culture (SDC) is consistent with persistent sepsis. Our objective was to determine the effect of a negative SDC obtained in subsequent operations on the outcome of a musculoskeletal infection. 99 patients were prospectively enrolled, all treated surgically for musculoskeletal infection utilizing suction drainage and appropriate antimicrobial therapy. Surgery consisted of irrigation, debridement, and prosthetic exchange or implant removal. SDC was considered negative if all bottles resulted in negative cultures. Following SDC results, patients were placed into 1 of 2 treatment groups: 1) Negative SDC, and no new operation; or 2) Positive SDC, and new operation(s) until SDC was negative. Antibiotic therapy ranged from 6-12 weeks (osteomyelitis) to 10-21 d (soft tissue). Both groups were similar with regard to baseline characteristics. Cure was obtained in 91.8% of patients (56/61) in group 1 and 91.6% of patients (22/24) in group 2. Similar results were obtained in patients with an infection in the presence of an implant. In conclusion, a negative SDC following surgery for a musculoskeletal infection is a strong indication of eventual outcome.

Treating Candida arthritis is challenging. We report a case of Candida parapsilosis arthritis successfully treated with caspofungin. We illustrate the likelihood of severe infections due fluconazole resistant C. parapsilosis after extensive fluconazole use and discuss the role of newer antifungal agents in the treatment of arthritis due to Candida spp.

Objectives:To describe the epidemiology of nosocomial coagulase-negative staphylococci (CoNS) bacteremia and to evaluate the clinical significance of a single blood culture positive for CoNS.Design:A 3-year retrospective cohort study based on data prospectively collected through hospital-wide surveillance. Bacteremia was defined according to CDC criteria, except that a single blood culture growing CoNS was not systematically considered as a contaminant. All clinically significant blood cultures positive for CoNS nosocomial bacteremia were considered for analysis.Setting:A large university teaching hospital in Geneva, Switzerland.Results:A total of 2,660 positive blood cultures were identified. Of these, 1,108 (41.7%) were nosocomial; CoNS were recovered from 411 nosocomial episodes (37.1%). Two hundred thirty-four episodes of CoNS bacteremia in the presence of signs of sepsis were considered clinically relevant and analyzed. Crude mortality and associated mortality were 24.4% and 12.8%, respectively. Associated mortality was similar among patients with one positive blood culture and those with two or more (16.2% vs 10.8%, respectively;P= .3). Mortality rates after bacteremia for patients with a single positive blood culture and for those with two or more were 15.3% and 7.0%, respectively, at day 14 (RR, 2.2; CI%, 0.87-5.46) and 20.8% and 11.3%, respectively, at day 28 (RR, 1.9; CI95, 0.9-3.8). On multivariate analysis, only age and a rapidly fatal disease were independently associated with death.Conclusion:CoNS bacteremia harbor a significant mortality and a single positive blood culture in the presence of signs of sepsis should be considered as clinically relevant.

Background: Focal outbreaks of sexually transmitted infections (STIs) such as syphilis and gonorrhoea have been reported in the large cities of Western Europe over the past few years. The aim of our study was to determine whether a similar trend is observed in Geneva and the situation with regard to HIV infection. Methods: We review the incidence of syphilis, gonorrhoea, Chlamydia trachomatis and HIV in Geneva from 1999 to 2004. Results: Figures indicate a steady and sustained increase in the incidence of syphilis, gonorrhoea and Chlamydia trachomatis in Geneva since 1999 that is maintained into 2004. As for HIV, the number of positive testings in Switzerland has stabilised and primary infection figures do not indicate an increase in newly acquired infections in Geneva. Conclusion: The situation in Geneva is similar to that observed elsewhere in Western Europe and indicates the need of public health interventions.

Fusarium infections in solid organ transplant recipients are often localized, occur later in the post-transplantation period, and have a better outcome than fusarial infections in patients with hematologic malignancies or Bone Marrow Transplantations. We report the first case of proven peritonitis caused by Fusarium species in a renal transplant recipient which is also the first successfully managed with voriconazole. We also review previously reported cases of fusarial infection in solid organ transplant recipients.

A commercial system for the rapid detection of methicillin-resistant Staphylococcus aureus, the BBL Crystal MRSA test (C-MRSA ID; Becton Dickinson, USA), was evaluated prospectively and compared with a polymerase chain reaction test for the presence of the mecA gene. Ten European centres tested a total of 676 isolates of Staphylococcus aureus from blood cultures. The system correctly identified 661 (97.8%) isolates within 4 h. All but three mecA gene-negative isolates (99.4% specificity) yielded a negative C-MRSA ID reaction, and 158 of 170 mecA gene-positive isolates were accurately detected (92.9% sensitivity). After repeated testing of discrepant results, sensitivity and specificity increased to 99% and 100%, respectively.

Systemic infections due to Mycoplasma hominis are rare and occur mainly in immunocompromised patients. Reported here are the cases of two renal transplant patients with peritonitis who did not respond to empirical antimicrobial treatment. Effective treatment with doxycycline was administered only after definitive identification of Mycoplasma hominis was achieved. For this identification, the new genetic amplification-sequencing method was invaluable.

Aims: To assess the incidence of nocardia infection over 15 years in a tertiary care hospital. Methods: Over a 15 year period, Nocardia spp were isolated from 20 patients hospitalised at the Geneva University Hospitals, Switzerland. Results: Sixteen patients had one or more underlying conditions. The median time between symptom onset and diagnosis was 30 days. The most common initial unconfirmed diagnosis was pulmonary tuberculosis (four). The lung was involved in 16 cases, followed by the central nervous system (two) and skin (two); one patient had disseminated infection. The most common species identified was N asteroides. In vitro susceptibility testing was performed on 14 of 20 strains. All strains were susceptible to imipenem and amikacin. Initial treatment with trimethoprim/sulfamethoxazole (TMP/SMX) was started in 14 patients, although five patients had to be switched to another treatment because of side effects or lack of efficacy. A cure was observed in 15 patients, death in three, and relapse or complications in two. Conclusions: Nocardiosis can become a severe infection and mainly affects profoundly immunocompromised patients. Differential diagnosis often delays the time to diagnosis, which worsens the outcome. New diagnostic tools, such as the polymerase chain reaction, could provide more rapid and reliable results. TMT/SMX was the most commonly prescribed treatment, but needed to be changed for another treatment because of side effects or lack of efficacy in a considerable proportion of patients. Imipenem should be used as an alternative treatment for severely ill patients, and the sulfa combination for less severe infections.

Several subtypes of Mycobacterium kansasii have been described, but their respective pathogenic roles are not clear. This study investigated the distribution of subtypes and the pathogenicity of M. kansasii strains ( n = 191) isolated in Switzerland between 1991 and 1997. Demographic, clinical, and microbiological information was recorded from clinical files. Patients were classified as having an infection according to the criteria of the American Thoracic Society. Subtypes were defined by PCR-restriction enzyme analysis of the hsp65 gene. Subtype 1 comprised 67% of the isolates ( n = 128), while subtypes 2 and 3 comprised 21% ( n = 40) and 8% ( n = 15), respectively. Other subtypes (subtypes 4 and 6 and a new subtype, 7) were recovered from only 4% of patients ( n = 8). M. kansasii subtype 1 was considered pathogenic in 81% of patients, while M. kansasii subtype 2 was considered pathogenic in 67% of patients and other subtypes were considered pathogenic in 6% of patients. The majority of patients with M. kansasii subtype 2 were immunocompromised due to the use of corticosteroids (21% of patients) or coinfection with HIV (62.5% of patients). Subtyping M. kansasii may improve clinical management by distinguishing pathogenic from nonpathogenic subtypes.

Background:In treating orthopedic infections, the long-term impact of vancomycin therapy on colonization by methicillin-resistantStaphylococcus aureus(MRSA) and the emergence of vancomycin-intermediate S.aureusis unknown.Design:Prospective surveillance of the effect of long-term vancomycin therapy on colonization by MRSA and the emergence of vancomycin-intermediateS. aureus.Methods:Thirty-four patients with MRSA osteomyelitis that was microbiologically documented were longitudinally observed for the emergence of vancomycin-intermediate S.aureusat 3 body sites (wound, anterior nares, and groin) during the initial period of vancomycin therapy and at the 2-month follow-up. Twenty patients received the standard dose (20 mg/kg/d) for 34 ± 6 days and 14 patients received a high dose (40 mg/kg/d) of vancomycin for 37 ± 9 days.Results:During vancomycin treatment, global MRSA carriage (all body sites) fell from 100% to 25% in the group of patients receiving the standard dose of vancomycin, and from 100% to 40% in the group receiving the high dose. During the 2-month follow-up period after vancomycin therapy, global MRSA carriage increased from 25% to 55% in the group receiving the standard dose and decreased from 43% to 36% in the group receiving the high dose.Conclusion:Therapy with a high dose of vancomycin contributes to the sustained eradication of MRSA carriage without promoting the emergence of glycopeptide resistance.

Candida species rarely cause spondylodiscitis. During 3 y, 3 cases of vertebral osteomyelitis due to Candida spp. (Candida albicans and Candida tropicalis) were diagnosed, 2 of which were associated with a spinal epidural abscess.

The incidence of fungal infections has been increasing for the last 3 decades, especially among neutropenic, cancer, and critically ill patients. These infections are associated with high mortality rates. We retrospectively reviewed medical charts of adult patients with fungemia from 1989 to 2000 at our institution. The characteristics of the population groups served by the hospital were described. Of 328 patients with fungemia, we reviewed 315 (96%) medical records, and focused on those with candidemia (n = 294). The species distribution in patients with candidemia showed that the most commonly identified species were Candida albicans (66%), followed by C. glabrata (17%), and C. parapsilosis (6%). The incidence of candidemia ranged from 0.2 to 0.46 per 10,000 patient-days with the highest incidence in 1993 and the lowest in 1997. Although most studies show an increased incidence of candidemia, we observed a reduction over the study period. Furthermore, we observed no shift from C. albicans to non-albicans Candida species despite a significant increase in the use of fluconazole. The overall mortality among patients with candidemia was 44%, with the highest rate in patients over 65 years (52%). Factors independently associated with higher mortality were patient age greater than 65 years, intensive care unit admission, and underlying cancer.

Opportunistic infections caused by fungi are common in human immunodeficiency virus (HIV)-infected patients. We focused on severe infections as indicated by detectable fungemia. Medical charts available for patients having positive blood cultures with fungi at the University of Geneva Hospital were retrospectively (1989 to 2000) reviewed. Of 328 patients with fungemia during the study period, 315 (96%) medical charts were accessible. Of these 315 patients, 37 (12.2%) were HIV-positive, and 13 (35.1%) died within 6 months from their episode of fungemia. This was a lower mortality rate than for the HIV seronegative patients (45.8%). The median and average age of the 34 HIV-positive patients was 37.2 years, and 24 (64.9%) were males. Cryptococcus neoformans (n = 14) and Candida albicans (n = 12) were the most frequently identified species, followed by Candida glabrata (n = 3), of which 3 were mixed C. albicans + C. glabrata, Histoplasma capsulatum (n = 2), and Penicillium marneffei (n = 2). The frequency decreased significantly (p < 0.007) from the time period 1993 to 1996 (n = 21) to the period 1997 to 2000 (n = 6). Fungemias in HIV-infected patients have declined significantly since 1996. This coincides with the introduction of highly active antiretroviral therapy (HAART).

Background: The aetiology of sarcoidosis remains controversial. An infectious origin is often discussed, but only anti-inflammatory or immunosuppressive treatment is recommended. Objectives: To investigate the hypothesis of bacterial origin by treating cutaneous sarcoidosis with antibiotics. Methods: Patients with chronic cutaneous sarcoidosis, unresponsive to the usual treatment and not requiring systemic corticotherapy, were given combined antibiotherapy for 6 months. Search for bacterial DNA by amplification and sequencing of the 16S ribosomal RNA gene in skin biopsies of lesions before and after antibiotherapy was done. Results: Three patients received a combined treatment with clarithromycin 1 g/day and ciprofloxacin 1 g/day. No clinical changes occurred in 2 cases and transient worsening in 1. Amplification for bacterial DNA was positive in all skin biopsies. The sequencing of this DNA could not identify a unique bacterial species. Conclusion: No evident bacterial origin could be demonstrated; however, this approach should be extended to more patients.

The use of the COBAS AMPLICOR System (Roche Molecular Diagnostics, Basel, Switzerland), the only automated system for PCR testing, was evaluated for a rapid identification of mycobacteria with positive BACTEC 12B cultures. Two hundred ninety-six specimens with a growth index of ≥30 were analyzed for the presence of Mycobacterium tuberculosis complex, Mycobacterium avium , and Mycobacterium intracellulare . Compared to traditional methods and provided that samples with PCR inhibition are retested at a 1:10 dilution, the sensitivity and specificity of the COBAS AMPLICOR System with BACTEC 12B cultures were 100 and 98%, respectively. The COBAS AMPLICOR method is rapid and reliable for identifying the most common mycobacteria in cultures.

ObjectiveTo characterize antimicrobial resistance patterns to amikacin (AN) and gentamicin (GM) among Gramnegative bloodstream isolates and to determine the possible relationship between use of AN and GM and the occurrence of antibiotic resistance during a 6-year period.MethodsStandard media and techniques of isolation and identification were used. Antimicrobial susceptibility testing was performed with the disk diffusion method and API rapid ATE E strips. Data on consumption of aminoglycosides were collected by the central hospital pharmacy and were expressed as daily defined doses.ResultsOne thousand nine hundred and four bloodstream isolates were tested for AN and GM susceptibility between 1989 and 1994. Activities of AN and GM remained high during the study period against most isolates of Gram-negative bacteria. No relationship could be observed between the use of AN/GM and the rate of AN/GM resistance. Nosocomial Gram-negative No relationship could be bloodstream isolates showed a higher degree of resistance towards both AN (3.9% of all nosocomial iveisolates) and GM (7.9%) than community-acquired isolates (1.8% toward AN and 3.1% towards GM, respectively). There was a significant increase (7.9%)than(P= 0.004) in the risk of GM resistance in patients with nosocomial Gram-negative bacteremia detected more than 14 days after admission. The proportion of GM-susceptible Pseudornonas aeruginosa isolates detected decreased linearly from 97% for infections acquired between day 3 and day 10 following admission to 80% for bacteremia developing 30 days or more after admission (P= 0.008).ConclusionsAN and GM remain highly active antimicrobial drugs for treatment of GNB in times of growing resistance to cephalosporins and fluoroquinolones.

The MB/BacT automated system is designed for the isolation of mycobacteria from clinical specimens. It utilizes a colorimetric sensor and reflected light to continuously monitor the CO2 concentration in the culture medium. We compared its performance to that of the BACTEC 12B media for the radiometric BACTEC 460 instrument and that of solid culture media. Respiratory specimens and urine samples were decontaminated with 4% NaOH. The vials of the two instruments were inoculated with 500 microl of sample and two solid egg-based media at 200 microl each. All vials were incubated at 37 degrees C for 6 weeks. A total of 1,078 specimens (633 respiratory specimens, 78 cerebrospinal fluid specimens, 177 other body fluid specimens, 87 urine specimens, and 103 other types of specimens) were cultured in parallel. Mycobacteria could be identified from 73 (6.8%) specimens: 67 M. tuberculosis, 3 M. kansasii, 1 M. xenopi, 1 M. terrae, and 1 mixed M. avium with M. scrofulaceum. Of these, 63 (86.3%) specimens were positive with the MB/BacT system, 67 (91.8%) were positive with the BACTEC 460 instrument, and 58 (79.5%) were positive with the two egg-based media. MB/BacT cultures were positive on average after 17.5 (+/-6.4) days, BACTEC cultures with a growth index of >20 (mean, 200) were positive after 14.3 (+/-8.2) days, and egg-based media were positive after 24.2 (+/-7.5) days. Microorganisms other than mycobacteria contaminated 46 (4.3%) MB/BacT cultures and 31 (2.9%) BACTEC cultures, which had to be discarded. The MB/BacT system is a well-automated system for the detection of M. tuberculosis in clinical specimens without using radioactive reagents. Further trials are required to determine whether it is suitable for the culture of nontuberculous mycobacteria.

The BACTEC 9240 (Becton Dickinson, Sparks, Md.) automated blood culture system is based on the continuous monitoring of CO2 production by means of a fluorescent sensor attached to the bottom of a culture vial. We compared two media for this system, resin-containing Plus aerobic/F and Lytic anaerobic/F. Sets of Plus aerobic/F and Lytic anaerobic/F vials inoculated with similar volumes (9 +/- 2.5 ml) were evaluated. In the laboratory, the vials were introduced into the system in accordance with the recommendations of the manufacturer and incubated at 35 degrees C for 5 days. A total of 10,914 sets consisting of two bottles each were obtained from 3,674 patients (2.97 cultures per patient). Of these, 1,233 (11%) were culture positive, including 1,074 (10%) yielding at least one pathogen, and 178 (2%) were contaminated. A total of 1,135 isolates were considered clinically relevant in 624 septic episodes; we isolated 894 from Plus aerobic/F and 852 from Lytic anaerobic/F (P = 0.06 [not significant]). More S. aureus isolates (P = 0.05), Pseudomonas spp. (P < 0.0001), other gram-negative bacteria (P = 0.004), and yeasts (P < 0.0001) were isolated from Plus aerobic/F medium, but more streptococci (P < 0.0001), E. coli (P = 0.02) strains and anaerobes (P < 0.0001) were detected with Lytic anaerobic/F medium. Lytic anaerobic/F vials were significantly (P < 0.0001) more often positive at least 6 h before Plus aerobic/F vials (n = 112 versus 52, respectively). Significantly more (P < 0.0001) Plus aerobic/F vials (n = 210; 1.9%) than Lytic anaerobic/F vials (n = 42; 0.4%) were unconfirmed positives. Plus aerobic/F and Lytic anaerobic/F proved to be a valuable pair of blood culture media. Plus aerobic/F performs better for patients under antibiotic treatment, due to the antimicrobial-neutralizing effect of resins. For patients without antibiotic therapy, more microorganisms could be isolated from Lytic anaerobic/F due to cell lysis.

The BACTEC 9240 (Becton Dickinson, Sparks, Md.) automated blood culture system is based on the continuous monitoring of CO2 production by means of a fluorescent sensor attached to the bottom of culture vials. We compared the performance of the BACTEC aerobic Plus/F medium to that of the Septi-Chek Release medium (Becton Dickinson, Sparks, Md.), a manual biphasic blood culture system. Sets consisting of BACTEC aerobic Plus/F and Septi-Chek Release vials inoculated with similar volumes (7 +/- 2 ml) were evaluated. In the laboratory, systems were equipped and analyzed according to the manufacturer's recommendations. The BACTEC and Septi-Chek vials were incubated at 35 degrees C for 5 days. A total of 6,116 compliant sets were obtained from 1,972 adult patients (3.1 cultures per patient). Of these, 731 (12%) were culture positive, including 612 (10%) that yielded at least one pathogen, and 143 (2%) were considered to be contaminated. Of the 672 pathogenic organisms detected, 524 were isolated from the BACTEC aerobic Plus/F medium and 574 were isolated from the Septi-Chek Release medium, 428 organisms grew in both media, 96 organisms grew only in the BACTEC aerobic Plus/F medium, and 146 organisms grew only in the Septi-Chek Release medium (P = 0.001). Haemophilus spp. were isolated more often (P = 0.03) from the BACTEC aerobic Plus/F medium; however, more Streptococcus anginosus organisms (P = 0.02), members of the Enterobacteriaceae family (P < 0.03), and gram-negative anaerobes (P = 0.03) were isolated from the Septi-Chek Release medium. Pathogenic organisms were detected significantly earlier (P < 0.0001) with the BACTEC aerobic Plus/F medium in conjunction with the BACTEC 9240 instrument than with the Septi-Chek Release medium.

OBJECTIVES: To evaluate the efficacy of low dose fluconazole treatment for the prevention of yeast colonization and infection in severely neutropenic patients. METHODS: An open randomized trial, comparing fluconazole (100 mg per day) with nystatin (800,000 IU per day), in a University Hospital setting. RESULTS: Antifungal prophylaxis was given during the period of neutropenia, defined as less than 500 polymorphonuclear cells (PMN)/mm3). Thirty-six patients were randomly assigned to fluconazole and 33 to nystatin treatment groups. New oropharyngeal colonizations were significantly reduced by fluconazole (P=0.005), and oropharyngeal infections occurred less frequently in the fluconazole group (3% versus 16%, P=0.07). Stool colonization was identical between both groups. Systemic fungal infections were rare; one fluconazole patient had pulmonary aspergillosis and one nystatin patient developped Candida pseudotropicalis fungemia. Empiric amphotericin B was given with the same frequency in both groups. No side effects were associated with fluconazole. However, the administration of nystatin became impossible for three patients because of vomiting and lack of compliance. CONCLUSIONS: Fluconazole (100 mg per day) is more effective than nystatin for the prevention of oropharyngeal yeast colonization. Comparison with results in the literature suggests that a 100-mg dose of fluconazole has similar effects to 200 or 400 mg per day.

The BacT/Alert (Organon Teknika Corp., Durham, N.C.) is an automated blood culture system. It is based on the detection of CO2 by means of a colorimetric sensor internally attached to the bottom of culture bottles. The aerobic and anaerobic media of this system were compared with one bottle of the Signal system (Oxoid Ltd., Hampshire, United Kingdom). At bedside, 20 ml of blood was drawn from each adult patient. The two BacT/Alert bottles were inoculated with 5 ml of blood each; the Signal bottle was inoculated with 10 ml. A total of 5,284 sets (2,483 patients; 2.1 cultures per patient) consisting of three bottles each were evaluated, of which 781 sets (14.8%) revealed microorganisms (n = 892); 642 of these were considered to be pathogenic. Significantly more (P < 0.0001) pathogens were isolated from the two BacT/Alert bottles together (n = 584) than from the single Signal bottle (n = 515). Escherichia coli (P = 0.007), gram-negative bacteria other than members of the family Enterobacteriaceae or Pseudomonas spp. (P = 0.006), and yeasts (P = 0.02) were isolated more often from both or either BacT/Alert bottle. Comparing the systems in terms of 388 different organisms per septic episode, the difference between BacT/Alert and Signal was significant for the total number of septicemia cases (P = 0.003). More contaminants grew in the BacT/Alert system (173 versus 116; P = 0.0001). False-positive indications were more frequent in the BacT/Alert system, 198 (3.7%) aerobic bottles and 57 (1.1%) anaerobic bottles, than in the Signal bottles, 24 (0.5%) bottles. Pathogens could be detected significantly earlier (P < 0.0001) in the BacT/Alert system than in the Signal system. The BacT/Alert instrument with two bottles allowed earlier detection as well as the isolation of more microorganisms than the manual, one-bottle Signal system.

Expert systems methodology investigated within the GAMES-II European Union research project was applied in the Hopital Cantonal Universitaire of Geneva to infection control, and in particular to the control of methicillin-resistant Staphylococcus aureus (MRSA) outbreak.

A novel model of experimental foreign body infection was developed in rats: four perforated Teflon tissue cages per animal were implanted subcutaneously and 3 to 4 weeks later were infected with 0.5 x 10(5) to 2 x 10(5) CFU of methicillin-resistant Staphylococcus aureus. After 2 weeks, the number of CFU in the cage fluid was determined [day 1 mean, (7.25 +/- 0.79) log10 CFU/ml], and treatment with vancomycin (50 mg/kg twice a day [BID]), fleroxacin (50 mg/kg BID), or fifampin (25 mg/kg BID), alone and in combination, was initiated for a duration of 6 days. Concentrations of antibiotics in cage fluids were in the range of those encountered in clinical conditions. Eighteen hours after the last injection (day 7), the number of CFU in the cage fluid was determined and the difference between day 1 and day 7 values was calculated. Rifampin, alone and in combination with fleroxacin or vancomycin, was the most effective regimen in reducing the bacterial counts in the tissue cage fluids [(1.87 +/- 1.44, 2.18 +/- 1.02, and 2.55 +/- 1.09 log10) CFU/ml, P less than 0.001, respectively]. After treatment, cage fluids and cages were analyzed for resistant bacteria. Resistance to rifampin occurred in 15 of 19 cages in animals treated with rifampin alone and in 4 of 25 in animals treated with rifampin plus vancomycin. We detected no development of resistance to rifampin in animals treated with rifampin plus fleroxacin or to fleroxacin in animals treated with this antimicrobial agent. In conclusion, regimens including rifampin alone or in combination with vancomycin or fleroxacin were an effective treatment of foreign body infection due to methicillin-resistant S. aureus in reducing bacteria counts, but rifampin monotherapy was compromised by significant emergence of resistance. The combined therapy of fleroxacin with rifampin prevent development of resistance to rifampin.

The LCx MTB amplification assay is a nucleic acid amplification test intended for the direct detection of Mycobacterium tuberculosis complex in respiratory specimens. We evaluated its performance on 2,001 consecutive respiratory specimens; 78 were culture positive for M. tuberculosis . Sensitivity, specificity, and positive and negative predictive values of this assay for all specimens compared to culture results were 88.5, 97.7, 60.5, and 99.5%, respectively. When referred to resolved clinical diagnosis of active tuberculosis, these values improved to 90.2, 98.4, 72.8, and 99.5%, respectively.

STREPTOCOCCUS AND INVASIVE E. COLI COLONIZATION AT DELIVERY BEGONA MARTINEZ DE TEJADA, MICHEL BOULVAIN, CATALIN STAN, GESUELE RENZI, PATRICE FRANCOIS, PETER ROHNER, JOACHIM FREY, JACQUES SCHRENZEL, OLIVIER IRION, University of Geneva, Gynecology and Obstetrics, Geneva, Switzerland, University of Geneva, Central Bacteriology Laboratory, Geneva, Switzerland, University of Bern, Institute of Veterinary Bacteriology, Bern, Switzerland OBJECTIVE: Group B Streptococcus (GBS) and Escherichia coli (E. coli) are the leading causes of early-onset neonatal sepsis. Intrapartum antibiotic prophylaxis decreases vertical transmission of GBS, but testing women during labor is limited by the late availability of results. Antenatal culture screening for GBS has been shown to have relatively low sensitivity in some settings. To allow testing women during labor, we developed a real-time PCR assay for the simultaneous screening of GBS and neonatal invasive strains of E. coli. STUDY DESIGN: Specific DNA targets for GBS are publicly available (cfb). For invasive E. coli, we identified candidate DNA targets by DNA hybridization on microarrays using invasive strains isolated from neonatal E. coli sepsis or meningitis (K1 and not K1 serotypes). Specificity of DNA probes was tested against a panel of bacteria and simulating clinical conditions (spiking vaginal samples from pregnant women). Then, the characteristics of the selected probes were evaluated in a pilot study including 200 women in labor. RESULTS: Prevalence of rectovaginal GBS and vaginal E. coli K1 colonization by culture were 16.0% and 3.5%, respectively. Prevalence of rectovaginal GBS, and vaginal invasive E. coli and E. coli K1 colonization by PCR were 27%, 20% and 10%, respectively. The turn-around time needed for PCR analysis was 2 hours. Compared to the culture, considered as the gold standard, the sensitivities of the PCRs for the GBS and E. coli were 97% and 71%, respectively. Specificities were 86% and 92%, respectively. Specificity is difficult to interpret, as a ‘‘false’’ positive PCR result may actually be a false negative result of the culture. CONCLUSION: The rapid PCR assay for GBS screening is reliable. There is a need for further development of the PCR test for E coli. Whether bacteria only detected by PCR are virulent needs further investigation.