Increased resistance to quinolones in Campylobacter jejuni: a genetic analysis of gyrA gene mutations in quinolone-resistant clinical isolates

Campylobacter jejuni is a frequent cause of enteritis and sometimes it requires antimicrobial therapy. We have studied the evolution of resistance to nine antibiotics from 1990 to 1994 and investigated how frequently gyrA mutations are involved in the acquisition of quinolone resistance. The percentage of chloramphenicol-, clindamycin-, tetracycline- and amoxicillin plus clavulanic acid-resistant strains has remained practically unchanged and erythromycin and gentamicin resistance has decreased, whereas the percentage of ampicillin-, nalidixic acid- or ciprofloxacin-resistant strains has almost doubled in the follow-up period, from 56 to 76% for ampicillin- and from 47.5 to 88% for quinolone-resistant strains. This study clearly shows that a mutation in Thr-86 to Ile or Lys is a frequent mechanism associated with the acquisition of a high level of resistance to quinolones in clinical isolates of C. jejuni.

Treatment of pathologic fractures of the humerus with Seidel nailing

A retrospective study is presented of 14 patients with pathologic fractures of the humerus (12 established, two impending) treated with Seidel nailing from 1988 through 1995 in the authors' institution. There were nine women and five men whose average age was 59.5 years. Breast, prostate, and kidney hypernephroma accounted for the majority of the primary lesions. All but one lesion were located in the middle shaft of the humerus. Ten lesions were considered large (> 5 cm long). In five cases an open curettage and allografting were done. Early pain relief was successful in 85% of the patients. The worst complication found was definite nerve palsy in two (14.28%) patients. Ten fractures healed and two failed to heal. Two thirds of the patients had good functional results. The average survival was 12 months. Intramedullary fixation of pathologic fractures improves the quality of life by controlling pain for most patients.

Unreamed intramedullary locking nailing for open tibial fractures

We reviewed the results of the treatment of 24 cases of open tibial fractures using unreamed intramedullary locking nailing. The fractures were classified, following the Gustilo system as grade I-7, grade II-7 and grade III-10. The average time to achieve bony union was 22 weeks with a 26% incidence of pseudoarthrosis. There were no cases of deep infection. Five cases healed with shortening of over 1 cm, but we did not observe angular deformity in any of the patients. In 2 fractures with associated articular lesions, joint motion was limited at final follow up. The nail broke in 2 cases and the screws in 5. The surgical procedure is well tolerated by patients, allows good management of soft tissue lesions and rehabilitation with low rate of infection and malunion. The main disadvantages have been the relative high incidence of nonunion and breakage of metal.

In vitro activity of two echinocandin derivatives, LY303366 and MK-0991 (L-743,792), against clinical isolates of Aspergillus, Fusarium, Rhizopus, and other filamentous fungi

LY303366 and MK-0991 (previously L-743,792) are new echinocandin derivatives with excellent broad-spectrum antifungal activity. We investigated the in vitro activity of LY303366, MK-0991, itraconazole, amnphotericin B, and 5-flucytosine against 51 clinical isolates of filamentous fungi, including Aspergillus flavus (10), A. fumigatus (12), Fusarium spp. (13), Rhizopus spp. (6), Pseudallescheria boydii (5), and one isolate each of Acremonium spp., A. niger, A terreus, Paecilomyces spp., and Trichoderma spp. In vitro susceptibility testing was performed using a microdilution broth method performed according to National Committee for Clinical Laboratory Standards guidelines. Ly303366 was two- to fourfold more active than MK-0991 against A. flavus, A. fumigatus, and Trichoderma spp. Both LY303366 and MK-0991 were considerably more active (MIC90 of 0.03-0.12 micrograms/mL) than itraconazole, amphotericin B, and 5-flucytosine against Aspergillus spp., but were less active than intraconazole and amphotericin B against Rhizopus spp. MK-0991 was more active than either LY303366 or intraconazole against Acremonium spp., Paecilomyces spp., and P. boydii. These data demonstrate promising activity of both LY303366 and MK-0991 against Aspergillus spp. and other species of filamentous fungi that are likely to be encountered clinically. Further in vitro and in vivo investigation is indicated.

Low-dose vitamin K1 versus short-term with holding of acenocoumarol in the treatment of excessive anticoagulation episodes induced by acenocoumarol. A retrospective comparative study

BACKGROUND

No consensus exists about the management of iatrogenically induced excessive hypocoagulability episodes.

OBJECTIVE

To compare the two most common therapeutic approaches in such situations (discontinuation of the oral anticoagulant vs. low-dose subcutaneous vitamin K1) when acenocoumarol is the normally used anticoagulant.

PATIENTS AND METHODS

The study was retrospective and comparative. Patients received antithrombotic therapy using acenocoumarol. Anticoagulant plasmatic activity was assessed through the international normalized ratio (INR) recorded from December 1994 to December 1997 at two medical centers.

RESULTS

INR is brought faster to a safe range in patients treated with low-dose vitamin K1 (p = 0.01). Their long-term behavior is also more stable and predictable and no resistance to the oral anticoagulant was found.

CONCLUSION

Low-dose vitamin K1 is a safer therapeutic option compared to simply withholding the oral anticoagulant. Its best scheme of administration, however, has yet to be defined.

Pneumococcal pericarditis with cardiac tamponade in a patient with chronic graft-versus-host disease

We report a case of pneumococcal pericarditis in a 13-year-old boy following allogeneic BMT from an HLA-identical unrelated donor. The post-transplant course was complicated by chronic GVHD which led to reinstitution of immunosuppressive therapy. Eight months after BMT the patient developed pericarditis with cardiac tamponade, and Streptococcus pneumoniae was isolated in the pericardiocentesis fluid. This is the first reported case of pneumococcal pericarditis after BMT. Although pericardial effusions after allogeneic BMT are often sterile and related to conditioning therapy or associated with chronic GVHD, rapid microbiological investigation and empirical treatment with antibiotics are necessary. Prophylaxis for pneumococcal infection in patients with chronic GVHD is recommended.

In vitro activities of voriconazole (UK-109,496) and four other antifungal agents against 394 clinical isolates of Candida spp

Voriconazole (formerly UK-109,496) is a new monotriazole antifungal agent which has potent activity against Candida, Cryptococcus, and Aspergillus species. We investigated the in vitro activity of voriconazole compared to those of fluconazole, itraconazole, amphotericin B, and flucytosine (5FC) against 394 bloodstream isolates of Candida (five species) obtained from more than 30 different medical centers. MICs of all antifungal drugs were determined by the method recommended by the National Committee for Clinical Laboratory Standards using RPMI 1640 test medium. Overall, voriconazole was quite active against all the yeast isolates (MIC at which 90% of the isolates are inhibited [MIC90], < or =0.5 microg/ml). Candida albicans was the most susceptible species (MIC90, 0.06 microg/ml) and Candida glabrata and Candida krusei were the least (MIC90, 1 microg/ml). Voriconazole was more active than amphotericin B and 5FC against all species except C. glabrata and was also more active than itraconazole and fluconazole. For isolates of Candida spp. with decreased susceptibility to fluconazole and itraconazole MICs of voriconazole were also higher. Based on these results, voriconazole has promising antifungal activity and further in vitro and in vivo investigations are warranted.

Anti-Legionella activity of trovafloxacin compared with seven other antimicrobial agents including an intermethod evaluation

The activity of trovafloxacin, a new fluorinated naphtheridone, was tested against 61 Legionella spp. isolates and compared with that of 4 fluoroquinolones, 2 macrolides, and rifampin. Trovafloxacin MICs were determined by a reference agar dilution method and E-test (Solna, Sweden) strips on buffered charcoal yeast extract agar. Among the fluoroquinolone compounds, the rank order of activity (on the basis of MIC90 results) determined with E-test strips was as follows: levofloxacin (MIC90, 0.094 microgram/ml) > trovafloxacin = sparfloxacin = ofloxacin (MIC90, 0.19 microgram/ml). Rifampin (MIC90, 0.008 microgram/ ml) and clarithromycin (MIC90, 0.032 microgram/ml) were the most potent of all drugs tested, and erythromycin and ciprofloxacin were the least active. In this study, the E-test strips with trovafloxacin were validated (100% of results +/- one log2 dilution compared to the reference value) for susceptibility testing with Legionella isolates.

Platelet activation In mice and human Helicobacter pylori infection

Extracts of Helicobacter pylori (HP) have been shown to induce leukocyte adhesion in mesenteric venules, but the effects of HP infection on gastric microvessels are unknown. Inflammatory cell interactions in the gastric microcirculation were studied by intravital videomicroscopy in mice inoculated with either saline or fresh isolates of HP. Platelet aggregates were detected and quantified in murine portal blood, while endothelial P-selectin expression was determined using the dual radiolabeled mAb technique. Platelet activation and aggregation were studied in HP-infected patients and controls by measuring the platelet-aggregate ratio and platelet P-selectin expression. HP infection induced a marked increase in the flux of rolling leukocytes and the appearance of platelet and leukocyte- platelet aggregates in murine gastric venules. The HP-induced rolling and platelet aggregate formation was abrogated by mAbs against L- or P-, but not E- selectin. Endothelial cell expression of P-selectin was not altered, but platelet P-selectin expression was enhanced in HP-infected mice. Circulating platelet aggregates and activated platelets were also detected in HP-infected patients. These findings indicate that platelet activation and aggregation contribute to the microvascular dysfunction and inflammatory cell recruitment associated with HP infections.

Prognostic factors in meningococcal disease. Development of a bedside predictive model and scoring system. Barcelona Meningococcal Disease Surveillance Group

CONTEXT

Meningococcal disease is associated with significant morbidity and mortality. Development of a prognostic model based on clinical findings may be useful for identification and management of patients with meningococcal infection.

OBJECTIVES

To construct and validate a bedside model and scoring system for prognosis in meningococcal disease.

DESIGN

Prospective, population-based study.

SETTING

Twenty-four hospitals in the metropolitan area of Barcelona, Spain.

PATIENTS

A total of 907 patients with microbiologically proven meningococcal disease. Patients diagnosed with meningococcal disease from 1987 through 1990 were used to develop the prognostic model, and those diagnosed in 1991 and 1992 were used to validate it.

OUTCOME MEASURES

Clinical independent prognostic factors for mortality in meningococcal disease. The association between outcome and independent prognostic factors was determined by logistic regression analysis. A scoring system was constructed and tested using receiver operating characteristic curves.

RESULTS

Among 624 patients in the derivation set, 287 (46%) were male, the mean age was 12.4 years, and 34 patients (5.4%) died. Among 283 patients in the validation set, 124 (43.8%) were male, the mean age was 12.7 years, and 17 patients (6.0%) died. In multivariate analysis, independent predictors of death were hemorrhagic diathesis (odds ratio [OR], 101; 95% confidence interval [CI], 30-333), focal neurologic signs (OR, 25; 95% CI, 7-83), and age 60 years or older (OR, 10; 95% CI, 3-34), whereas receipt of adequate antibiotic therapy prior to admission was associated with reduced likelihood of death (OR, 0.09; 95% CI, 0.02-0.4). Hemorrhagic diathesis was scored with 2 points, presence of focal neurologic signs with 1 point, age of 60 years or older with 1 point, and preadmission antibiotic therapy was scored as -1. The clinical scores of -1, 0, 1, 2, and 3 or more points were associated with a probability of death of 0%, 2.3%, 27.3%, 73.3%, and 100%, respectively.

CONCLUSIONS

Hemorrhagic diathesis, focal neurologic signs, and age of 60 years or older were independent predictors of death in meningococcal disease, whereas receipt of adequate antibiotic therapy was associated with a more favorable prognosis. The scoring system presented is simple, is based on findings readily available at the bedside, and may be useful to help guide aggressive therapy.

[Yield of blood cultures in relation to the cultured blood volume in Bactec 6A bottles]

BACKGROUND

Concentration of microorganisms in blood is low in bacteremia from extravascular sources. The best yield from blood cultures is achieved by culturing a minimum of 10-20 ml, although in some processing blood culture systems such as Bactec NR-860, smaller volume is used. The objectives of the present study were to establish the frequency in which inadequate small blood volumes are employed for culturing and to analyze the relation between the cultured blood volume in Bactec 6A bottles and the yield achieved.

MATERIAL AND METHODS

We weighed 2000 Bactec 6A bottles pertaining to consecutive blood cultures obtained from untreated patients with clinical suspicion of Infection. The cultured blood volume was estimated subtracting the mean empty bottle weight.

RESULTS

Microorganisms were recovered from 251 bottles (12.5%). One hundred and thirty one (6.8%) isolates were considered as clinically significant and 115 (5.7%) as contaminant. The inoculated blood volume in both significant (5.532 +/- 1.587 ml) and non-significant (5.471 +/- 1.563 ml) recoveries was superior than that of bottles without microbiologic growth (5.209 +/- 1.575 ml, p = 0.016 and p = 0.06, respectively). A linear positive trend was found between the cultivated blood volume and the rate of recoveries (p = 0.008). Within the range of 1 up to 10 ml, the rate of recoveries increased 2.28% for each additional ml of cultivated blood (r = 0.953, p < 0.0001). Out of the 2,000 weighed bottles 127 (6.3%) contained less than 3 ml of blood and 576 (29%) between 3 and 5 ml.

CONCLUSIONS

We have proved that the rate of recoveries from Bactec 6A bottles increased with the volume of cultured blood. In untreated patients, this increase is maintained up to volumes of 7 to 10 ml.

Risk factors for oxacillin/methicillin resistance in coagulase-negative staphylococci

The clinical variables associated with isolation of oxacillin- and methicillin-resistant, coagulase-negative staphylococci (CNS) from blood cultures of hospitalized patients were studied. One hundred CNS strains (49 oxacillin-susceptible; 51 oxacillin-resistant) isolated consecutively from one of two or more sets of blood cultures were collected. Only two variables were independently associated with recovery of oxacillin/methicillin-resistant strains by a multivariate analysis: length of hospital stay > 10 days (OR 5.2, 95% CI = 1.7-15.7), and administration of antimicrobial agents in the previous 14 days (OR 4.5, 95% CI = 1.7-11.7). Analysis of the antibiotics administered indicated that only beta-lactams were associated with a statistically significant risk of resistance to oxacillin/methicillin (OR of beta-lactams vs no antibiotics = 6.94, 95% CI = 1.9-25.3; OR of non-beta-lactams vs no antibiotics = 2.64, 95% CI = 0.8-8.3). Length of hospital stay (especially > 10 days) and prior administration of antimicrobial agents (mainly beta-lactams) independently predicted the presence of oxacillin/methicillin-resistant CNS in blood cultures.

[Transesophageal cardiac echography and paracardiac tumor masses. Apropos of a case]

Computed tomography is currently the reference examination in the investigation of mediastinal tumours. We report a case of pericardial tumour revealed by transoesophageal echocardiography. This investigation immediately defined the limits of this mass and its relations with cardiac cavities and large vessels and suggested the main features of its tissue structure. However, the aetiological diagnosis is still based on CT-guided needle biopsy or investigation by mediastinoscopy or thoracotomy. Our case consisted of a non-Hodgkin lymphoma. Transoesophageal echocardiography is a non-irradiating technique, which can be performed at the patient's bed and which allows a precise assessment of the pericardial regions, especially the right pericardial regions.

Epidemiology and outcome of Pseudomonas aeruginosa bacteremia, with special emphasis on the influence of antibiotic treatment. Analysis of 189 episodes

OBJECTIVE

To evaluate the trend in incidence of Pseudomonas aeruginosa bacteremia, underlying conditions of patients, mortality rate, and factors associated with poor outcome.

PATIENTS AND METHODS

Medical charts of 189 consecutive episodes of P aeruginosa bacteremia, detected between January 1, 1991, and December 31, 1994, were prospectively evaluated. Associated risk factors, treatment, and outcome were recorded.

RESULTS

Pseudomonas aeruginosa bacteremia represented 5.7% of the total number of bacteremias, 6.9% of nosocomial bacteremias, and 23.6% of nosocomial gram-negative bacteremias. There were 1.5 episodes per 1000 discharges. These numbers were slightly lower than those recorded at our hospital 10 years earlier. Human immunodeficiency virus infection was the most frequent underlying disease (28/189 [15%]). Overall mortality was 18% (34/189). The presence of fatal underlying disease (P < .001), surgery (P = .001), pneumonia (P = .02), and severe sepsis (P < .001) were associated with poor prognosis, the mortality of the patients with these variables being 28%, 28%, 47%, and 62%, respectively. The presence of inappropriate definitive antimicrobial treatment became an independent factor predictive of death (P = .04) only when the subset of patients with intravenous catheter-associated bacteremia was excluded from the analysis. The survival rate was no greater in patients who received 2 or more antibiotics active in vitro against P aeruginosa than in those who received only 1. Neutropenia was not associated with increased mortality. The use of colony-stimulating factors did not affect the outcome of the neutropenic patients.

CONCLUSIONS

The rate of P aeruginosa bacteremia is falling slightly at our hospital. The emergence of the human immunodeficiency virus epidemic has had a considerable impact on both epidemiology and mortality. The presence of severe underlying disease, surgery, pneumonia, and, especially, severe sepsis are associated with a poor outcome. With the exclusion of patients with intravenous catheter-associated P aeruginosa bacteremia, the administration of an appropriate antimicrobial therapy is essential to a good outcome. Treatment with 1 active antibiotic seems to be sufficient.

Randomized, comparative study of oral ofloxacin versus intravenous cefotaxime in spontaneous bacterial peritonitis

BACKGROUND & AIMS

Treatment of spontaneous bacterial peritonitis currently involves intravenous antibiotic administration. To test the possibility of treating spontaneous bacterial peritonitis with oral antibiotics, oral ofloxacin was compared with intravenous cefotaxime in this infection.

METHODS

One hundred twenty-three cirrhotics with uncomplicated spontaneous bacterial peritonitis (no septic shock, grade II-IV hepatic encephalopathy, serum creatinine level of > 3 mg/dL, and gastrointestinal hemorrhage or ileus) were randomly given oral ofloxacin (64 patients) or intravenous cefotaxime (59 patients).

RESULTS

Infection resolution rate was 84% in the ofloxacin group and 85% in the cefotaxime group. Peak serum levels and trough serum and ascitic fluid levels of ofloxacin and cefotaxime measured on days 3 (23 patients) and 6 (11 patients) of therapy were greater than the minimal inhibitory concentration of isolated organisms. Hospital survival rate was 81% in each group of patients. Blood urea nitrogen and hepatic encephalopathy at diagnosis were associated with prognosis. None of the 36 nonazotemic patients with community-acquired spontaneous bacterial peritonitis and without hepatic encephalopathy developed complications during hospitalization, and all were alive at time of discharge.

CONCLUSIONS

Oral ofloxacin is as effective as intravenous cefotaxime in uncomplicated spontaneous bacterial peritonitis. Nonazotemic cirrhotic patients with uncomplicated community-acquired spontaneous bacterial peritonitis and without hepatic encephalopathy have an excellent prognosis and may be treated with oral ofloxacin without requiring hospitalization.

European multicentre evaluation of a commercial system for identification of methicillin-resistant Staphylococcus aureus

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.

Prevention and control of nosocomial infections in Spain: current problems and future trends

Spain is a state member of the European Union, with more than 180,000 hospital beds and 800 public and private institutions. Only 6.9% of our gross national product is devoted to health expenditures. All citizens receive free health care through the National Health System. This system has given increasing attention to the prevention and control of nosocomial infections since 1986. In this article, results of serial prevalence surveys of antibiotic use and resistance patterns of microorganisms isolated from nosocomial infections are discussed. The needs for future development of infection control and quality assurance training programs in Spain also are discussed. Overall, a clinically and epidemiologically oriented approach to infection control is preferred, with greater emphasis in the role of infection control practitioners and infection control committees.

Bilateral Smith fracture of the radius caused by airbag deployment

A passenger-side occupant of a car involved in a collision suffered bilateral Smith's fracture after extending both arms for protection and being hit by the deploying airbag.

Comparison of rufloxacin and norfloxacin effects on faecal flora

The suppression of faecal Escherichia coli by quinolones was studied in a randomized cross-over phase I trial with single oral doses of 400 mg rufloxacin or norfloxacin. Both drugs caused > 70% decontamination in a similar number of subjects in the 72 h post-dose period (83% vs 100% respectively), but suppression of E. coli at 168 h was significantly (P < 0.05) higher after rufloxacin (83.3 vs 40%).

[Myocardial infarction in non-menopausal women. Coronary lesions and prognosis]

Between 1977 and 1990, 64 premenopausal women, under 50 years of age (42 +/- 5.6 years), were admitted for typical acute myocardial infarction with pathological Q waves. Twenty one patients had attempted myocardial revascularisation either by intravenous thrombolysis or primary angioplasty (n = 3). All patients underwent coronary angiography with selective left ventriculography during their hospital admission. This group of 64 women was characterised by the association of coronary risk factors (2.8 per patient): smoking (89%), hyperlipidaemia (67%), diabetes (45%) and oral contraception (35%). Coronary angiography showed single vessel occlusion in 86% of patients receiving oral contraception, multiple vessel disease in 36.5% and single or double vessel disease in 31.7% of the other patients. There were 3 deaths during the hospital period (4.6%), 12 cases of left ventricular failure, 2 ventricular aneurysms, 2 operated ischaemic mitral regurgitations and 9 recurrences of pain treated by angioplasty. During follow-up (36.5 +/- 4 months), 22 patients were readmitted to hospital and there were 3 further deaths, 12 cases of persistent cardiac failure, 10 cases of latent ventricular dysfunction and 9 ischaemic reoccurrences treated by angioplasty or surgery. The results in this group of patients suffering from myocardial infarction at an unusually early age for women showed that although the mortality was similar to that observed in men of the same age (9%) there was a very high morbidity and a high risk of cardiac failure. The prognosis of myocardial infarction in women, though better than 10 years ago, should improve with immediate revascularisation, the correction of cardiovascular risk factors and the rapid application of all techniques of modern cardiology.

A cluster of fever and hypotension on a surgical intensive care unit related to the contamination of plasma expanders by cell wall products of Bacillus stearothermophilus

OBJECTIVE

To evaluate an outbreak of fever and hypotension after cardiac surgical procedures and the role of polygeline, a plasma expander.

DESIGN

Unmatched case-control study.

SETTING

A six-bed cardiac surgery intensive care unit (SICU) of the Hospital Clinic of Barcelona (Spain), a 940-bed public teaching hospital.

PATIENTS

Eight cases and 25 control patients admitted to the SICU over a 4-week epidemic period.

MAIN OUTCOME MEASURES

Development of hypotension (systolic blood pressure < or = 90 mm Hg or a drop of 40 mm Hg from baseline systolic blood pressure) and fever (axillary temperature > 38.5 degrees C) within 24 hours of a cardiac surgical procedure.

RESULTS

The single risk factor significantly different between cases and controls was the total volume of polygeline used throughout the surgical procedure for extracorporeal circulation: a median of 1,250 mL (mean, 1,312.5 +/- 842.5 mL) in cases versus 500 mL (mean, 566.0 +/- 159.9 mL) in controls (P = .0029). By multiple logistic regression analysis, polygeline use was the single risk factor significantly related to the outcome (odds ratio, 8.75; CI95, 1.36 to 56.2; P = .01). Neither blood cultures from patients nor cultures of the polygeline used yielded growth of any microorganism. Stopping use of the implicated polygeline lot controlled the outbreak.

CONCLUSIONS

Use of polygeline was associated with an outbreak of fever and hypotension in a SICU. Information from the manufacturer indicated the likelihood of contamination of the product with Bacillus stearothermophilus components. The manufacturer has since changed the production and control processes, and no further adverse events have been seen.

Cardiac beta-receptors in experimental Chagas' disease

Experimental Chagas' disease (45 to 90 days post-infection) showed serious cardiac alterations in the contractility and in the pharmacological response to beta adrenergic receptors in normal and T. cruzi infected mice (post-acute phase). Chagasic infection did not change the beta receptors density (78.591 +/- 3.125 fmol/mg protein and 73.647 +/- 2.194 fmol/mg protein for controls) but their affinity was significantly diminished (Kd = 7.299 +/- 0.426 significantly diminished (Kd = 7.299 +/- 0.426 nM and Kd = 3.759 +/- 0.212 nM for the control) p < 0.001. This results demonstrate that the alterations in pharmacological response previously reported in chagasic myocardium are related to a significantly less beta cardiac receptor affinity. During this experimental period serious cardiac cell alterations take place and functional consequences will be detected in the chronic phase.

Monitoring biological effects of contamination in marine fish along French coasts by measurement of ethoxyresorufin-O-deethylase activity

The use of bioindicators to evaluate exposure to the biological effects of chemical pollutants in marine organisms constitutes a new tool in the monitoring field. The establishment of a North Sea monitoring network in 1991, involving such international organizations as the North Sea Task Force, the International Council for the Exploration of the Sea, and the Intergovernmental Oceanography Commission, led French researchers to develop an enzymatic biomarker to monitor biological effects within the National Observation Network. The biomarker, ethoxyresorufin-O-deethylase (EROD), dependent on the CP450 system, has been monitored biannually since 1992 in several species of fish (Callionymus lyra, Limanda limanda, Serranus sp., Mullus barbatus) in two coastal sites particularly exposed to industrial and domestic pollution. A rapid method is used to assay EROD enzymatic activity determined along a pollution gradient, and results are interpreted on a microplate reader. The strategy of this approach is to assess the effects on the marine ecosystem during prolonged exposure to specific pollutants such as polyaromatic hydrocarbons, polychlorinated biphenyls, and dioxins.

Antimicrobial resistance of Shigella isolates causing traveler's diarrhea

Shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in Spain. Ampicillin and chloramphenicol resistance was more frequent in Shigella flexneri (60 and 46%, respectively) than in Shigella sonnei (32 and 18%, respectively) and in travel-related isolates (P < 0.05 and 0.04, respectively). Of S. sonnei isolates from patients with traveler's diarrhea, 73 and 54% showed tetracycline and trimethoprim-sulfamethoxazole resistance, respectively, compared with only 8% of isolates from patients without a history of travel to developing countries (P < 0.007 and P < 0.0002). Low-level resistance to cephalosporins was found, whereas quinolone-resistant strains were not detected among travel-related Shigella isolates. Thus, quinolones may be an effective alternative therapy for travel-related shigellosis.

Association between double mutation in gyrA gene of ciprofloxacin-resistant clinical isolates of Escherichia coli and MICs

The mutations in the quinolone resistance-determining region of the gyrA and gyrB genes from 27 clinical isolates of Escherichia coli with a range of MICs of ciprofloxacin from 0.007 to 128 micrograms/ml and of nalidixic acid from 2 to > 2,000 micrograms/ml were determined by DNA sequencing. All 15 isolates with ciprofloxacin MICs of > or = 1 micrograms/ml showed a change in Ser-83 to Leu of GyrA protein, whereas in clinical isolates with a MIC of > or = 8 micrograms/ml (11 strains), a double change in Ser-83 and Asp-87 was found. All isolates with a MIC of nalidixic acid of > or = 128 micrograms/ml showed a mutation at amino acid codon Ser-83. Only 1 of the 27 clinical isolates of E. coli analyzed showed a change in Lys-447 of the B subunit of DNA gyrase. A change in Ser-83 is sufficient to generate a high level of resistance to nalidixic acid, whereas a second mutation at Asp-87 in the A subunit of DNA gyrase may play a complementary role in developing the strain's high levels of ciprofloxacin resistance.

Levofloxacin in vitro activity: results from an international comparative study with ofloxacin and ciprofloxacin

Levofloxacin, the S-(-)-isomer of ofloxacin, was compared to ofloxacin and ciprofloxacin against > 6000 recent clinical isolates of Gram-positive and Gram-negative bacteria from six different countries. This international multicenter study demonstrated a high level of antibacterial activity of levofloxacin against all the members of Enterobacteriaceae [minimum inhibitory concentration (MIC)50s, < or = 0.03 to 0.12 mg/L] except Providencia rettgeri (MIC50, 2 mg/L), and Providencia stuartii (MIC50, 1 mg/L). Oxacillin-susceptible staphylococci (MIC50s, 0.12 to 0.25 mg/L), enterococci (MIC50s, 0.5 to 2 mg/L), and streptococci (MIC50s, 0.5 mg/L) were also susceptible to levofloxacin, but most isolates of oxacillin-resistant staphylococci had MICs of > or = 4 mg/L. Levofloxacin was also active against non-enteric Gram-negative bacilli, including Acinetobacter species (MIC50s, < or = 0.03 to 1 mg/L), Pseudomonas species (MIC50s, 0.5 to 1 mg/L) and Xanthomonas maltophilia (MIC50, 0.5 mg/L). Overall, levofloxacin inhibited 50% and 90% of all the tested strains at the concentrations of 0.12 and 4 mg/L, respectively. The activity of levofloxacin was generally two-fold greater than ofloxacin and equal to or slightly less potent than ciprofloxacin.

Antimicrobial activity of FK-037, a new broad-spectrum cephalosporin. International in vitro comparison with cefepime and ceftazidime

The in vitro activity of FK-037, a new parenteral 7-aminothiazolyl-methoxyimino cephalosporin, was compared with cefepime and ceftazidime against 6094 aerobic isolates collected in six medical centers worldwide. FK-037 demonstrated potent activity against the Enterobacteriaceae family except for some Enterobacter spp., Providencia spp., and Serratia liquefaciens (MIC90s, > or = 16 micrograms/ml). Against nonenteric Gram-negative bacilli, all compounds tested showed similar, but more limited activity. The FK-037 MIC50s for Pseudomonas spp. and P. aeruginosa were 2 and 4 micrograms/ml, respectively. The least susceptible organisms were Xanthomonas maltophilia, enterococci, and Bacillus spp. (MIC50s, > 16 micrograms/ml), followed by Flavobacterium spp., other nonenterics, and oxacillin-resistant Staphylococcus aureus (MIC50s, 16 micrograms/ml). Good FK-037 activity was observed against oxacillin-susceptible staphylococci as well as against beta-hemolytic and viridans-group streptococci (MIC90 range, < or = 0.12 to 2 micrograms/ml). While FK-037 was slightly more active than cefepime against Gram-positive organisms, enteric bacilli were most susceptible to cefepime. Overall, the antibacterial spectrum of both FK-037 and cefepime was superior to ceftazidime.

[Mitral endocarditis caused by Staphylococcus aureus resistant to methicillin, aminoglucosides and rifampicin: description of 2 cases with fatal course]

Two patients with infectious endocarditis (IE) by Staphylococcus aureus resistant to methicillin, aminoglucosides and rifampicin (SARMAR) acquired in hospital during the course of an epidemic outbreak of this microorganism in the Hospital Clínic i Provincial of Barcelona. Both patients had undergone surgery of the lower limbs. The entrance of the microorganism was the infection of the surgical wound, with bacteriemia, followed by mitral IE after a short time interval (20 days). Despite adequate treatment with vancomycin both patients died. The culture of mitral vegetation was positive for SARMAR in one. Analysis of the chromosomic DNA of all the isolations from the patients was identical and coincided with that of the SARMAR strains isolated in the epidemic outbreak of the hospital. The current situation of IE by SARMAR is reviewed and the therapeutic implications commented upon suggesting that treatment of this entity should simultaneously include the administration of vancomycin and phosphomycin or cotrimoxazole, with surgery being considered if infection persists.

Osteochondral allografts for osteochondritis dissecans and osteonecrosis of the femoral condyles

Osteochondral allografts were used in 11 patients with osteochondritis dissecans and 4 with osteonecrosis of the femoral condyles. The lesions were mainly in the medial condyle in 13 cases, and in the weightbearing area in 10. The grafts had a mean size of 6 cm2; 8 were kept in hypothermia at 4 degrees C for less than 24 h and 7 were stored at -80 degrees C with cryoprotection. After an average follow up of 3.2 years, only 2 patients needed a further operation, one for nonunion and the other for a fracture of the graft. The others had improved clinically and showed radiological union of the graft with preservation of the joint space.

[Clinical epidemiology of an outbreak of nosocomial infection caused by Staphylococcus aureus resistant to methicillin and aminoglycosides: efficacy of control measures. Comité de Control de Infecciones]

BACKGROUND

The appearance of outbreaks of nosocomial infections due to methicillin resistant Staphylococcus aureus (MRSA) is a current problem in Spain. The clinical and molecular epidemiology of these outbreaks as well as the efficacy of their control measures are a matter of controversy.

METHODS

An outbreak of MRSA nosocomial infections in the Hospital Clínic i Provincial of Barcelona, a 953-bed University Hospital, with a total of 347 cases from September 1989 to October 1991 is described. The control measures used include prospective and continued surveillance of all MRSA isolations, identification of the reservoir, use of different types of isolation and control of nasal carriers among health care workers. The MRSA strains isolated were studied by standard microbiological procedures, phage-typing and extrachromosomal (plasmid) DNA analysis by means of restriction endonuclease analysis (REAP).

RESULTS

From the Intensive Care Units, the outbreak extended to the medical and surgical wards. Seventy-one percent of the cases corresponded to infected patients and 29% to asymptomatic carrier patients. The MRSA strain responsible of the outbreak had a notable antibiotic multiple-resistance pattern. The studies performed showed that most of the strains belonged to phage group III and were lysed by phage 77. Plasmid DNA analysis showed that 95% of the strains isolated had a unique homogeneous profile. Despite the different control measures used, the MRSA infection has acquired a medium level endemic rate in the Hospital Clínic i Provincial.

CONCLUSIONS

The introduction and spread of methicillin-resistant MRSA in a teaching hospital with more than 500-bed may be rapid and affecting large number of patients. Effective control measures carries multiple problems, which must be addressed with the collaboration of all hospital employees. The molecular typing techniques used (REAP) further identified that the outbreak is due to one single MRSA strain, with an epidemiologic behavior identical to the one showed by the epidemic strains previously described in the United Kingdom and Australia.

In vitro antimicrobial production of beta-lactamases, aminoglycoside-modifying enzymes, and chloramphenicol acetyltransferase by and susceptibility of clinical isolates of Acinetobacter baumannii

Antimicrobial susceptibility testing was performed on 54 epidemiologically unrelated clinical isolates of Acinetobacter baumannii by using a standard agar dilution technique. On the basis of the in vitro activities, imipenem and doxycycline were the most active agents, whereas amikacin, isepamicin, and the new fluorquinolones ciprofloxacin and ofloxacin presented moderate activity. Cephalosporinase activity was found in 98% of the strains, whereas lactamases of TEM type 1 and one with a pI of 7 to 7.5 were present in 16 and 11% of the strains, respectively. Resistance to aminoglycosides was explained by the production of the three classes of aminoglycoside-modifying enzymes, with predominance of aminoglycoside-3'-phosphotransferase VI in 28% of the strains.

Intact articular cartilage cryopreservation. In vivo evaluation

By varying the parameters that determine the cryopreservation process (freezing rate, storage temperature, cryoprotective agents, storage time), various protocols have been designed for preservation of osteochondral allografts of rabbit femoral condyles. The grafts were implanted orthotopically for three months. After harvesting, the results were evaluated by optical microscopy, histochemistry, and electron microscopy (scanning and transmission). A quantitative study and statistical analysis was performed using a gradation scale of chondral degeneration. Synovial reaction was higher in the fresh allograft than in the cryopreservation groups. Glycerol yielded better results than DMSO as a cryoprotective agent. No cryopreservation protocols produced the results equal to the control groups of either fresh auto- or allografts. Optimal preservation was achieved with either the group with hypothermic storage at 4 degrees for no more than 48 hours or the group with slow freezing to -80 degrees and preparative exposure to 15% glycerol at 4 degrees for 60 minutes. No statistically significant differences were found in these two groups.

Prosthetic valve endocarditis caused by Corynebacterium pilosum

A case of prosthetic valve endocarditis caused by Corynebacterium pilosum in a 79-year-old woman developed eighty years after aortic valve replacement with bovine pericardium bioprosthesis is described. In spite of the antibiotic therapy she presented an unfavourable course that led to her death.

Norfloxacin prevents spontaneous bacterial peritonitis recurrence in cirrhosis: results of a double-blind, placebo-controlled trial

Eighty cirrhotic patients who had recovered from an episode of spontaneous bacterial peritonitis were included in a multicenter, double-blind trial aimed at comparing long-term norfloxacin administration (400 mg/day; 40 patients) vs. placebo (40 patients) in the prevention of spontaneous bacterial peritonitis recurrence. At entry, both groups were similar with respect to clinical and laboratory data, ascitic fluid protein and polymorphonuclear concentrations, number of previous episodes of spontaneous bacterial peritonitis and causative organisms of the index spontaneous bacterial peritonitis. Norfloxacin administration produced a selective intestinal decontamination (elimination of aerobic gram-negative bacilli from the fecal flora without significant changes in other microorganisms) throughout the study in six patients in whom the effect of norfloxacin on the fecal flora was periodically assessed. Fourteen patients from the placebo group (35%) and five from the norfloxacin group (12%) developed spontaneous bacterial peritonitis recurrence during follow-up (chi 2 = 5.97; p = 0.014) (mean follow-up period = 6.4 +/- 0.6 mo; range = 1 to 19 mo). Ten of the 14 spontaneous bacterial peritonitis recurrences in the placebo group and only one of the five spontaneous bacterial peritonitis recurrences in the norfloxacin group were caused by aerobic gram-negative bacilli (chi 2 = 8.87; p = 0.0029). The overall probability of spontaneous bacterial peritonitis recurrence at 1 yr of follow-up was 20% in the norfloxacin group and 68% in the placebo group (p = 0.0063) and the probability of spontaneous bacterial peritonitis recurrence caused by aerobic gram-negative bacilli at 1 yr of follow-up was 3% and 60%, respectively (p = 0.0013).(ABSTRACT TRUNCATED AT 250 WORDS)

[Infective endocarditis caused by coagulase-negative staphylococci: a review of 19 cases]

The clinical, microbiological and echocardiographical features as well as the response to therapy of 19 cases of infective endocarditis (IE) caused by coagulase-negative staphylococci (CNS) are reported. Six patients had native valve IE, 11 had prosthetic valve endocarditis and 2 were associated with catheters in right cardiac chambers. In the group of native valve IE, 11 patients were heroin abusers and 4 had previous valvular disease. IE was left sided in 3 cases, mixed in 2 and right sided in 1. All CNS were methicillin-sensitive. The echocardiogram detected vegetations in 5 of the 6 cases. One patient required surgery and another died. In the group of prosthetic valve IE, 5 patients had early endocarditis and 6 had late endocarditis. A bioprosthesis was involved in 5 cases, a mechanical prosthesis in another 5, and an annuloplasty annulus in one. The involved prosthesis was aortic in 5 cases and mitral in 6. The echocardiogram detected vegetations in 3 cases (27%) and prosthetic dysfunction in 4. One patient had a relapse, 8 (73%) required valve replacement and 3 died. Although the greatest incidence of IE caused by CNS is found among patients with prosthetic valves, it can also be seen in patients with underlying valvular heart disease, drug abusers and patients with indwelling catheters in right cardiac chambers.

[A community outbreak of Legionnaires' disease in Barcelona: clinical and microbiological study]

In February and March 1989 a community-acquired outbreak of legionnaires' disease developed in Barcelona, involving at least 56 patients (48 males and 8 females) with a mean age of 60 years (range 22-87). 70% were smokers, 20% alcohol abusers, 50% had chronic bronchitis and 20% were immunologically depressed. The most common signs and symptoms were: fever (100%), features of lung condensation (77%), cough (51%), stupor (27%), diarrhea (18%), thoracic pain (18%, hyponatremia (53%), increased serum level of hepatic enzymes (44%) or CK (37%), and renal failure (21%). Radiological involvement was bilateral in 30% of cases. In most patients the diagnosis was made by seroconversion (70%). Late seroconversion (between 4 and 14 weeks) was seen in 20 patients, whose age was significantly higher than that of patients with early seroconversion (p less than 0.02). All cases were caused by Legionella pneumophila serogroup 1. Forty-six patients (81%) were admitted to the hospital and 10 (18%) required tracheal intubation. Although all received erythromycin, seven patients died. Hypoxemia, leukopenia, hyponatremia and renal failure were associated with a higher mortality rate. However, after multivariate analysis renal failure appeared as the only independent prognostic variable. Finally, it was concluded that in the community-acquired outbreaks of pneumonia Legionella pneumophila infection should be ruled out.

Rapid detection of gastric Campylobacter pylori colonization by a simple biochemical test

A simple and rapid urease test to detect Campylobacter pylori infection was evaluated with bacterial culture as the "gold standard." The test was compared with the Gram stain and the conventional Christensen urease test. The culture method detected C. pylori in 29 of 49 gastric biopsy specimens. The rapid urease test showed 27 positive samples within 1 h at 55 degrees C (specificity, 100%; sensitivity, 93%) and 18 at room temperature (specificity, 100%; sensitivity, 62%). The Gram stain exhibited a sensitivity of 86% and a specificity of 91%. The conventional Christensen urease test detected C. pylori in only 4, 10, and 18 samples after 24, 48, and 72 h, respectively (sensitivities, 12, 36, and 60%, respectively; specificities, 95, 95, and 83%, respectively). We conclude that the rapid urease test is simple and highly specific for the detection of C. pylori and that it can be performed with small amounts of sample.