Liver Re-transplantation in Adults: Indications and Outcomes Analysis of a 23-year Experience in a Single Center in Argentina.

Background: Liver re-transplantation (re-LT) represents the only treatment for patients with irreversible graft failure. Objective: The aim of the current study was to describe the outcomes of both, patient and graft, after re- LT, at a high-volume referral center. Methods: Our population consisted of patients, with liver disease, who underwent re-LT in our institution between January 1996 and December 2019. Results: 49 patients met the inclusion criteria. The patient's overall survival (OS) for the first year was 85% (Confidence Intervals (CI) 71-92) and 70% at five years (CI 53-82). In our population, three (6.12%) patients presented loss of graft and were included again in the transplant list; of these, one agreed to a new transplant while the remaining two died. This gave us graft survival results similar to those obtained for the re-LT patient; 85% at one year (CI 71-92) and 70% at 5 years (CI 53-82). Conclusion: Our study shows that re-LT is a valid and safe treatment for both early graft dysfunction and for transplanted patients who again present end-stage liver disease, showing a satisfactory long-term evolution, with parameters comparable to primary transplantation.

Failure to improve left ventricular function after coronary revascularization for ischemic cardiomyopathy is not associated with worse outcome.

Background-Preoperative identification of viable myocardium in patients with ischemic cardiomyopathy is considered important because CABG can result in recovery of left ventricular (LV) function. However, the hypothesis that lack of improvement of LV function after CABG is associated with poorer patient outcome is untested. Methods and Results-Outcome was compared in patients with ischemic LV dysfunction (LVEF 0.05 increase in LVEF (group A) and 36 (35%) had no significant change, or

Thallium-201 for assessment of myocardial viability: quantitative comparison of 24-hour redistribution imaging with imaging after reinjection at rest.

Redistribution thallium-201 imaging 2 to 4 h after exercise may be incomplete and therefore may be inadequate to fully assess myocardial variability. Late redistribution imaging 24 h after exercise has been proposed to overcome this limitation of thallium stress imaging. However, because of poor count density the image quality on these studies is often suboptimal. In the present study the diagnostic information on 24-h planar thallium redistribution images was compared with that on images obtained after a reinjection of thallium at rest. Eighty-four patients with a stress thallium-201 defect had delayed redistribution imaging after 2 to 4 h and 24 h later, and again after an injection of thallium at rest. Defect reversibility on 24-h redistribution images was compared quantitatively with that on images after injection of thallium at rest. The quality of thallium images at rest was consistently better than that of 24-h redistribution images. Poor quality studies occurred in 13% of 24-h redistribution images compared with 0.4% of the studies at rest. Significantly more defect reversibility was detected on images after the reinjection at rest. Of 41 patients who appeared to have a fixed defect at 2- to 4-h redistribution imaging, 11 (27%) had a reversible defect by 24-h redistribution imaging compared with 29 (71%) after thallium-201 reinjection. No clinical variables at the time of stress testing were predictive of late defect reversibility. It is concluded that in patients with fixed a thallium defect at 2 to 4 h after exercise, reimaging after a reinjection at rest provides better diagnostic information than does 24-h late redistribution imaging.

Peak filling rate normalized to mitral stroke volume: a new Doppler echocardiographic filling index validated by radionuclide angiographic techniques.

The noninvasive measurement of left ventricular filling has relied predominantly on radionuclide-derived peak filling rate normalized to end-diastolic volume. Doppler echocardiography also has the ability to measure peak filling rate, but wide application of this technique has been limited by technical errors involved in quantitative echocardiographic determination of mitral anulus cross-sectional area and ventricular volumes. For Doppler echocardiography, normalization of peak filling rate to mitral stroke volume rather than end-diastolic volume permits the derivation of a diastolic filling index that is relatively free of errors caused by geometric assumptions, diameter measurements and sample volume positioning. This normalization process can be achieved by simply dividing early peak filling velocity by the time velocity integral of mitral inflow. To validate this new Doppler echocardiographic filling index, Doppler echocardiographic and radionuclide-derived peak filling rate, both normalized to mitral stroke volume, were compared in 30 patients; there was an excellent correlation (r = 0.91, SEE = 0.88). This variable was not influenced by the position of the sample volume in relation to the mitral apparatus in contrast to early filling velocity, which increased 37%, and early/late filling (E/A) ratio, which increased 43% as the sample volume was moved from the anulus to the tips of the mitral leaflets. In a cohort of 22 normal patients, the mean peak filling rate normalized to mitral stroke volume (SV) was 5.25 +/- 1.47 SV/s. The mean peak filling rate for a subgroup of eight normal patients aged 57 to 89 years (mean 71 +/- 9) was 3.9 +/- 1 SV/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic value of noninvasive testing one year after orthotopic cardiac transplantation.

OBJECTIVES: We sought to evaluate the prognostic value of routine noninvasive testing--stress thallium-201 imaging, rest two-dimensional echocardiography and rest equilibrium radionuclide angiography--1 year after cardiac transplantation. BACKGROUND: Coronary artery vasculopathy is the most important cause of late death after orthotopic cardiac transplantation. Several clinical variables have been identified as risk factors for development of coronary vasculopathy. Traditional noninvasive diagnostic testing has been shown to be relatively insensitive for identifying patients with angiographic vasculopathy. METHODS: Results of prospectively acquired noninvasive testing in 47 consecutive transplant recipients alive 1 year after transplantation were related to subsequent survival. Other clinical variables previously shown to be associated with the development of coronary artery vasculopathy were also included in the analysis. RESULTS: The 5-year survival rate after cardiac transplantation was 81%. By univariate analysis, echocardiography (chi-square 9.21) and stress thallium-201 myocardial perfusion imaging (chi-square 16.76) were predictive for survival, whereas rest equilibrium radionuclide angiography was not. Clinical contributors to survival were donor age (chi-square 4.56), number of human leukocyte antigen mismatches (chi-square 3.06) and cold ischemic time (chi-square 3.23). By multivariate analysis, stress myocardial imaging remained the only significant predictor of survival (risk ratio 0.27; 95% confidence interval 0.06 to 0.89). CONCLUSIONS: Normal thallium-201 stress myocardial perfusion imaging 1 year after cardiac transplantation is an important predictor of 5-year survival.

Knowledge of blood pressure levels and targets in patients with coronary artery disease in the USA.

Little is known about patient awareness of nationally recommended blood pressure targets, especially among patients with cardiac disease. To examine this issue, we interviewed 738 patients hospitalized with coronary artery disease to assess their knowledge of their systolic and diastolic blood pressure levels as well as corresponding national targets. We used bivariate and multivariate analyses to determine if any patient demographic or clinical characteristics were associated with blood pressure knowledge. Only 66.1% of patients could recall their own systolic and diastolic blood pressure levels. Only 48.9% of all patients could correctly name targets for these values. Knowledge of target blood pressure levels was particularly poor among patients who were female (odds ratio (OR) 0.69; 95% confidence interval (CI) 0.49-0.98), aged > or =60 years (OR 0.70, CI 0.51-0.97), without any college education (OR 0.48, CI 0.35-0.65), without a documented history of hypertension (OR 0.57, CI 0.39-0.84), and with known diabetes (OR 0.46, CI 0.33-0.66). Patients in the highest risk group, according to Joint National Committee guidelines stratification, were no more knowledgeable about their blood pressure levels and targets than lower risk patients. A significant proportion of patients hospitalized with coronary artery disease do not know their own blood pressure levels or targets. Current blood pressure education efforts appear inadequate, particularly for certain patient subgroups in which hypertension is an important modifiable risk factor.

['In vitro' activity of different antimicrobial agents on Gram-negative nonfermentative bacilli, excluding Pseudomonas aeruginosa and Acinetobacter spp]. / Actividad "in vitro" de diferentes antibacterianos sobre bacilos gram-negativos no fermentadores, excluidos Pseudomonas aeruginosa y Acinetobacter spp.

Gram-negative nonfermentative bacilli (NFB) are widely spread in the environment. Besides of difficulties for identification, they often have a marked multiresistance to antimicrobial agents, including those active against Pseudomonas aeruginosa. The objective of this study was to evaluate the 'in vitro' activity of different antimicrobial agents on 177 gram-negative nonfermentative bacilli isolates (excluding Pseudomonas aeruginosa and Acinetobacter spp.) isolated from clinical specimens. Minimum inhibitory concentrations (MIC) were determined according to the Mueller Hinton agar dilution method against the following antibacterial agents: ampicillin, piperacillin, piperacillin-tazobactam, sulbactam, cefoperazone, cefoperazone-sulbactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, colistin, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, rifampin, norfloxacin, ciprofloxacin and minocycline. Seven isolates: Sphingobacterium multivorum (2), Sphingobacteriumspiritivorum (1), Empedobacterbrevis (1), Weeksella virosa (1), Bergeyella zoohelcum (1) and Oligella urethralis (1), were tested for amoxicillin-clavulanic acid and ampicillin-sulbactam susceptibility, and susceptibility to cefoperazone or sulbactam was not determined. Multiresistance was generally found in Stenotrophomonas maltophilia, Burkholderia cepacia, Chryseobacterium spp., Myroides spp., Achromobacter xylosoxidans, and Ochrobactrum anthropi isolates. On the other hand, Pseudomonas stutzeri, Shewanella putrefaciens-algae, Sphingomonas paucimobilis, and Pseudomonas oryzihabitans, Bergeyella zoohelcum, Weeksella virosa and Oligella urethralis were widely susceptible to the antibacterial agents tested. As a result of the wide variation in antimicrobial susceptibility shown by different species, a test on susceptibility to different antibacterial agents is essential in order to select an adequate therapy. The marked multiresistance evidenced by some species, prompts the need to develop new antimicrobial agents active against this group of bacteria and to search for synergistic combinations.

Quantitative analysis of planar technetium-99m-sestamibi myocardial perfusion images using modified background subtraction.

Standard interpolative background subtraction, as used for thallium-201 (201Tl), may create artifacts when applied to planar technetium-99m-Sestamibi (99mTc-Sestamibi) images, apparently because of the oversubtraction of relatively high extra-cardiac activity. A modified background subtraction algorithm was developed and compared to standard background subtraction in 16 patients who had both exercise-delayed 201Tl and exercise-rest 99mTc-Sestamibi imaging. Furthermore, a new normal data base was generated. Normal 99mTc-Sestamibi distribution was slightly different compared to 201Tl. Using standard background subtraction, mean defect reversibility was significantly underestimated by 99mTc-Sestamibi compared to 201Tl (2.8 +/- 4.9 versus -1.8 +/- 8.4, p less than 0.05). Using the modified background subtraction, mean defect reversibility on 201Tl and 99mTc-Sestamibi images was comparable (2.8 +/- 4.9 versus 1.7 +/- 5.2, p = NS). We conclude, that for quantification of 99mTc-Sestamibi images a new normal data base, as well as a modification of the interpolative background subtraction method should be employed to obtain quantitative results comparable to those with 201Tl.

Demonstration of reperfusion after thrombolysis with technetium-99m isonitrile myocardial imaging.

Technetium-99m isonitrile myocardial perfusion imaging was employed in a patient undergoing thrombolytic therapy with recombinant tissue plasminogen activator for acute anteroseptal myocardial infarction. Technetium-99m isonitrile does not demonstrate significant myocardial redistribution after intravenous injection. The imaging agent was administered in the emergency room, prior to the initiation of thrombolytic therapy. The initial area at risk for infarction was visualized on images obtained after the patient had been effectively treated. Imaging performed 5 days later, after repeat injection of [99mTc]isonitrile, showed a smaller myocardial perfusion defect indicating salvage of myocardium. Thus, this technique offers promise as a noninvasive means of assessing the area at risk, the success of reperfusion, and the presence of salvaged myocardium, early in the course of acute myocardial infarction.

Biokinetics of technetium-99m-tetrofosmin: myocardial perfusion imaging agent: implications for a one-day imaging protocol.

Tetrofosmin is a 99mTc-labeled myocardial perfusion imaging agent that has shown encouraging results in Phase I and II clinical trials. The purpose of this study was to determine the biokinetics of this agent following administration during exercise and at rest in order to determine an optimal imaging protocol. Twenty patients with suspected coronary artery disease underwent symptom-limited treadmill exercise. Six to 8 mCi of 99mTc-tetrofosmin was injected at peak exercise and 22-24 mCi was injected 4 hr later at rest. Serial 5-min planar images were obtained in the left anterior oblique view at 5, 10, 15, 30, 60, 120 and 180 min after the radiotracer injection. Regions of interest were drawn on the serial images around the entire heart and portions of liver, lung, spleen, gallbladder and gastrointestinal tract. Average decay-corrected counts per pixel in each organ were plotted against time. In addition, heart-to-adjacent organ ratios were also determined. On stress images, the heart had the highest activity at all times, with the exception of gallbladder in the first 15 min. On rest images, the gallbladder, liver and gastrointestinal tract initially had higher activity than the heart; but the activity in these organs cleared rapidly over the subsequent 30-60 min. Heart-to-adjacent organ ratios were > 1.0 at all times in the stress images. Heart-to-organ ratios were < 1.0 in the first 15 min on the rest images for the liver and gastrointestinal tract. However, 30 min later, all ratios on the rest images were > or = 1.0. Technetium-99m-tetrofosmin images were considered to be of good to excellent quality with good myocardial delineation and adequate contrast between the heart and background. These These observations indicate that a convenient one-day tetrofosmin imaging protocol similar in duration to conventional 201Tl imaging is feasible.

Reproducibility of quantitative planar thallium-201 scintigraphy: quantitative criteria for reversibility of myocardial perfusion defects.

Fifty-two paired stress/delayed planar 201TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of 201TI perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size. Based upon intraobserver variability, objective quantitative criteria for reversibility of perfusion abnormalities were defined. These objective criteria were tested prospectively in a separate group of 35 201TI studies and compared with the subjective interpretation of quantitative circumferential profiles. Overall, exact agreement existed in 78% of images (kappa statistic k = 0.66). We conclude that quantification of planar 201TI scans is highly reproducible, with acceptable inter- and intraobserver variability. Objective criteria for lesion reversibility correlated well with analysis by experienced observers.

Quantitative comparison of planar and SPECT normal data files of thallium-201, technetium-99m-sestamibi, technetium-99m-tetrofosmin and technetium-99m-furifosmin.

UNLABELLED: In recent years, several of 99mTc-labeled myocardial perfusion imaging agents have been developed, such as 99mTc-sestamibi, 99mTc-tetrofosmin and 99mTc-furifosmin. Although images obtained with these new tracers have a general similar appearance, there are differences in the myocardial kinetics, body distribution, general quality of images and imaging protocols. The aim of this study was to quantitatively compare normal exercise planar and SPECT data files obtained with 201TI and 99mTc-labeled agents. METHODS: Lower-limit-of-normal curves were generated for each specific radiopharmaceutical from normal subjects with low (< 3%) pretest likelihood of coronary artery disease using circumferential count distribution profiles from planar and SPECT exercise images. Lower-limit-of-normal curves were statistically compared using the nonparametric Kruskall-Wallis and Wilcoxon tests. RESULTS: Planar and SPECT lower-limit-of-normal curves generated for each radiopharmaceutical showed general similarities. Statistically significant differences among the lower-limit-of-normal curves were found in the planar left anterior oblique view and in the planar left lateral view (p < 0.05 for each). No statistically significant differences existed between lower-limit-of-normal curves of various radiopharmaceuticals on the planar anterior view and on SPECT imaging. CONCLUSION: For quantitative analysis of planar images, radiopharmaceutical-specific normal data files are mandatory. Although SPECT normal data files of various radiopharmaceuticals are not statistically different, they are not identical. It appears, nevertheless, prudent to use radiopharmaceutical-specific normal data files for quantitative analysis of SPECT images.

Quantitative planar thallium-201 stress scintigraphy: a critical evaluation of the method.

The results of quantitative analysis of planar thallium-201 stress scintigraphy are superior to those of visual analysis. The increased sensitivity for detection of coronary artery disease is associated with maintenance of specificity. Consequently, we believe that quantitative analysis is the state-of-the-art for planar 201Tl stress scintigraphy. We emphasize that for reliable and reproducible results, rigorous quality control and strict adherence to a standardized imaging protocol are necessary. An important feature is clarity of display of computer data. In our experience, the most important feature for making quantitative analysis reliable and accessible for a broader user market is simultaneous display of the lower limits of normal with processed patient data. This provides a simple visual impression of the degree and extent of abnormal 201Tl distribution and kinetics relative to the lower limit of normal.

Blood cultures have limited value in predicting severity of illness and as a diagnostic tool in ventilator-associated pneumonia.

STUDY OBJECTIVES: To define the usefulness of blood cultures for confirming the pathogenic microorganism and severity of illness in patients with ventilator-associated pneumonia (VAP). DESIGN: Prospective observational study using BAL and blood cultures collected within 24 h of establishing a clinical diagnosis of VAP. SETTING: A 15-bed medical and surgical ICU. PATIENTS: One hundred and sixty-two patients receiving mechanical ventilation hospitalized for > 72 h who had new or progressive lung infiltrate plus at least two of three clinical criteria for VAP. INTERVENTIONS: BAL and blood culture performed within 24 h of establishing a clinical diagnosis of VAP. MEASUREMENTS AND RESULTS: Ninety patients were BAL positive (BAL+), satisfying a microbiological definition of VAP (>/= 10(4) cfu/mL), 72 patients were BAL negative (BAL-). Bacteremia was diagnosed when at least two sets of blood cultures yielded a microorganism or when only one set was positive, but the same bacteria was present at a concentration >/= 10(4) cfu/mL in the BAL fluid. Bacteremia was significantly more frequent in the BAL+ than in the BAL- group (22/90 patients vs 5/72 patients; p = 0.006). In 6 of 22 BAL+ patients with bacteremia, an extrapulmonary site of infection was the source of bacteremia. Sensitivity of blood culture for disclosing the pathogenic microorganism in BAL+ patients was 26%, and the positive predictive value to detect the pathogen was 73%. Factors associated with mortality were age > 50 years, simplified acute physiology score > 14, prior inadequate antibiotic therapy, PaO(2)/fraction of inspired oxygen < 205, and use of H(2) blockers. By multivariate analysis, only the use of prior inadequate antimicrobial therapy (odds ratio [OR], 6.47) and age > 50 years (OR, 5.12) were independently associated with higher mortality. The rate of complications was not different in patients with bacteremia. CONCLUSIONS: Blood cultures have a low sensitivity for detecting the same pathogenic microorganism as BAL culture in patients with VAP. The presence of bacteremia does not predict complications, it is not related to the length of stay, and it does not identify patients with more severe illness. Inadequacy of prior antimicrobial therapy and age > 50 years were the only factors associated with mortality in a multivariate analysis. Blood cultures in patients with VAP are clearly useful if there is suspicion of another probable infectious condition, but the isolation of a microorganism in the blood does not confirm that microorganism as the pathogen causing VAP.

Data feedback efforts in quality improvement: lessons learned from US hospitals.

BACKGROUND: Data feedback is a fundamental component of quality improvement efforts, but previous studies provide mixed results on its effectiveness. This study illustrates the diversity of hospital based efforts at data feedback and highlights successful strategies and common pitfalls in designing and implementing data feedback to support performance improvement. METHODS: Open ended interviews with 45 clinical and administrative staff in eight US hospitals in 2000 concerning their perceptions about the effectiveness of data feedback in supporting performance improvement efforts were analysed. The hospitals were chosen to represent a range of sizes, geographical regions, and beta blocker improvement rates over a 3 year period. Data were organized and analyzed in NUD-IST 4 using the constant comparative method of qualitative data analysis. RESULTS: Although the data feedback efforts at the hospitals were diverse, the interviews suggested that seven key themes may be important: (1) data must be perceived by physicians as valid to motivate change; (2) it takes time to develop the credibility of data within a hospital; (3) the source and timeliness of data are critical to perceived validity; (4) benchmarking improves the meaningfulness of data feedback; (5) physician leaders can enhance the effectiveness of data feedback; (6) data feedback that profiles an individual physician's practices can be effective but may be perceived as punitive; (7) data feedback must persist to sustain improved performance. Embedded in several themes was the view that the effectiveness of data feedback depends not only on the quality and timeliness of the data, but also on the organizational context in which such efforts are implemented. CONCLUSIONS: Data feedback is a complex and textured concept. Data feedback strategies that might be most effective are suggested, as well as potential pitfalls in using data to promote performance improvement.

Trends in costs of percutaneous transluminal coronary angioplasty.

OBJECTIVE: To evaluate recent trends in the cost of percutaneous transluminal coronary angioplasty (PTCA), particularly the impact of newer technology and changing patient profile. STUDY DESIGN: Retrospective study with a 6-month follow up. PATIENTS AND METHODS: We compared the data on two groups of 100 consecutive patients admitted for elective PTCA at Yale-New Haven Hospital in 1995 and 1996. Hospital records, cineangiograms, and hospital cost accounting system were reviewed, and 6-month clinical outcomes were obtained from telephone interviews and medical chart review. RESULTS: Demographic and clinical characteristics did not differ between the 1995 and 1996 groups of patients, nor was a difference detected in in-hospital and 6-month clinical outcomes between 1995 and 1996. Angiographic features of treated lesions were different between the two groups, with a significantly higher frequency of type C and totally occluded lesions in 1996 (p = 0.002 and p = 0.04, respectively). The total hospital costs were higher in 1996 compared with 1995 ($11,799 +/- $6189 vs $10,087 +/- $5608; p = 0.04). This difference persisted after adjustment for changes in patient population. The major factor responsible for escalating costs was a 45% increase in catheterization laboratory costs ($8575 +/- $4524 in 1996 vs $5916 +/- $3030 in 1995; P < 0.0001). In contrast, the noncatheterization costs decreased substantially during this period, largely as a result of an approximately 33% decrease in length of stay (3.75 +/- 2.66 days in 1995 vs 2.57 +/- 1.99 days in 1996; P = 0.0005). In a multiple linear regression model, the most important determinants of cost were lesion characteristics, stent use, and radiographic contrast volume. CONCLUSIONS: Despite cost reduction efforts, the costs of PTCA are rising because of increased consumption of resources in the catheterization laboratory.

Oral terbutaline augments cardiac performance in chronic obstructive pulmonary disease.

In previous research, we have demonstrated that parenterally administered terbutaline can augment resting cardiac function in patients with chronic obstructive pulmonary disease (COPD). Because the oral form of terbutaline is more widely utilized, a double-blind, randomized, crossover, placebo-controlled trial of the cardiopulmonary effects of oral terbutaline was conducted in ten patients with COPD. Right and left ventricular ejection fractions (RVEF and LVEF) were determined by first pass radionuclide angiography. There were no differences in spirometry and hemodynamic measurements between treatment and placebo days. Following 5 mg of oral terbutaline, there was a small but statistically significant increase in forced expiratory volume in 1 second and in heart rate, but no significant change in forced vital capacity or blood pressure. LVEF improved significantly with terbutaline both at rest (62% +/- 6% vs. 67% +/- 9%, mean +/- SD) and during submaximal steady state exercise (61% +/- 5% vs. 67% +/- 10%). RVEF improved significantly at rest (64% +/- 6% vs. 69% +/- 5%), but not during submaximal steady state exercise (65% +/- 6% vs. 68% +/- 7%). Thus, oral terbutaline produces significant improvement in biventricular systolic pump performance at rest, and increases left ventricular ejection fraction during submaximal exercise in patients with moderate to severe COPD.

[Sepsis due to Vibrio cholerae no 01]. / Sepsis por Vibrio cholerae no 01.

Two fatal sepsis cases in two male patients (58 and 14 years old) due to Vibrio cholerae non 01 are described. Their original diseases were hepatic cirrhosis and acute lymphoblastic leukemia in its third complete remission. In this last case, gastroenteritis due to V. cholerae non 01 was also diagnosed. These sepsis presented a rapid evolution and positive hemoculture after 24 and 48 hours of incubation. Both strains isolated presented similar biochemical characteristics and did not agglutinate in the presence of the specific serum against V. cholerae. Both strains were susceptible to most of the antibiotics available. Sepsis due to V. cholerae non 01 is usually associated to other original diseases and to immunodepression. Management of these sepsis is difficult and mortality rates are very high.

[Evaluation of API 20 NE (version 6.0) in rare Gram-negative non-glucose-fermenting bacilli]. / Evaluación de API 20 NE (versión 6.0) en bacilos gram-negativos no fermentadores de glucosa infrecuentes.

The ability of the API 20 NE method (6.0 version, bio-Mérieux, Marcy L'Etoile, France) to identify 188 strains of gram negative nonfermentative bacilli (NFB) was evaluated (Fenazinic pigment producing Pseudomonas aeruginosa and Acinetobacter spp. were excluded). These were isolated from patients treated at the Hospital de Clínicas José de San Martín of the University of Buenos Aires during the period 1996-2001. Strains were identified according to the Schreckenberger P testing method. Out of 188 NFB strains, 175 (93.09%) were correctly identified by the API 20 NE method at the genus and species level (IC95 = 88.47-96.27) while 61 (32.45%) required additional testing for correct identification. Thirteen strains (6.91%; IC95 3.73-11.53) could not be correctly identified and none of them were classified as "non identified". The API 20 NE method is a practical, easy to handle, fast and useful system for the identification of NFB since conventional manual methods take longer and require many biochemical, enzymatic and physiological tests which are sometimes not available depending on the size and capability of the laboratory. Although it is easy to handle, the API 20 NE identification system must be interpreted by an expert microbiologist who must compare the results obtained by this system with the information provided by the distinctive cultures and mobility patterns of these organisms.

[Activity of 14 antimicrobials against Eikenella corrodens]. / Actividad de catorce antimicrobianos sobre Eikenella corrodens.

Eikenella corrodens is a gram-negative bacillus that colonizes as normal flora of the mouth, the upper respiratory tract and the gastrointestinal tract. The aim of this study was to determine the susceptibility patterns against fourteen antibiotics of 25 E. corrodens strains isolated at our hospital. MICs were determined by the agar dilution technique using Müeller-Hinton agar with sheep blood (5% v/v) to penicillin, ampicillin, ampicillin-sulbactam, cephalotin, cefoxitin, ceftiaxone, colistin, gentamicin, amikacin, erythromycin, rifampin, ciprofloxacin and clindamycin. The most active antibiotics were ciprofloxacin and ceftriaxone (MIC90 = 0.008 and 0.125 microgram/ml, respectively), whereas eritromycin, gentamicin and amikacin showed less activity. Only one strain was beta lactamase positive, and it was inhibited by sulbactam. Erithromycin, gentamicin and amikacin had poor activity (MIC90 = 16.8 and 64 micrograms/ml, respectively), whereas all the strains were uniformly resistant to clindamycin (MIC > or = 32 micrograms/ml). We suggest about the need of periodical surveys of E. corrodens susceptibility patterns, since strains have been found with decreased susceptibility against antibiotics which are currently being used for the treatment of infectious diseases.