[Study of the betalactam resistance of Haemophilus influenzae conferred by the bla(ROB-1) gene]

Given the lack of information on the resistance to betalactams conferred by the bla(ROB-1) gene in our area, we decided to undertake a study to determine if and how often it appears in our isolates. We analyzed the presence of the gene in 177 strains of Haemophilus influenzae and compared the results with those from the biochemical tests (nitrocefin). Sixty-three strains tested positive in the nitrocefin test (35.6%). The presence of the bla(ROB-1) gene was detected in seven of the 177 strains (3.9%). All the strains expressing the gene also tested positive in the nitrocefin test. Of the 63 strains that showed biochemical resistance (positive to nitrocefin), seven were found to be caused by the presence of the bla(ROB-1) gene. An epidemiological follow-up for the presence of this gene in our area is therefore advisable.

Two cases of fungemia due to Candida lusitaniae and a literature review

Reported here are two cases of candidemia caused by Candida lusitaniae that occurred in two immunocompromised patients at Hospital Universitario "La Fe" in Valencia, Spain. Case 1 involved a low-birth-weight premature infant with congenital nephrotic syndrome who was successfully treated with amphotericin B, and case 2 involved a 50-year old woman with a high-grade malignancy lymphoma who succumbed to the infection. Antifungal susceptibility testing of the Candida lusitaniae isolates recovered from both patients revealed sensitivity to amphotericin, 5-flucytosine and fluconazole. Results are presented and discussed together with a comprehensive review of the literature, covering all previously reported cases of fungemia caused by this emerging pathogen.

[Correlation between in vitro susceptibility to antifungal drugs and the clinical evolution of patients with candidiasis and cryptococcosis]

The increase in the incidence of fungal infections and the emergence of resistance call for the development of techniques for measuring in vitro antifungal susceptibility that are useful for predicting clinical outcome in patients suffering from these infections. In the past, the lack of standardized testing techniques led to poor intra- and interlaboratory reproducibility. Recently, the National Committee for Clinical Laboratory Standards (NCCLS) has developed a reference method for antifungal susceptibility testing, document M27A. This document is a necessary and important step towards the standardization of antifungal susceptibility testing, which has important implications in the analysis of clinical and microbiological data. This article provides a comprehensive review of studies correlating in vitro antifungal susceptibility testing and clinical outcome. In general, it is possible to predict the therapeutic outcome, especially in HIV infected patients with oropharyngeal candidiasis treated with fluconazole. However, in other more heterogeneous groups of patients it is more difficult to correlate the in vitro and in vivo data.

[The activity of systemic antimycotic drug combinations]

The treatment of deep mycoses is complex, especially in immunosuppressive patients, owing to several factors: the scarcity of antimycotic drugs, the difficulty of carrying out antimycotic susceptibility tests, the scarcity of in vitro/in vivo correlation studies, the lesser response to therapy in comparison to antibacterial treatment, etc. Aside from this, the adverse effects, therapeutic failure and the appearance of resistance are serious problems that may emerge with the use of antimycotic drugs. These problems can be partly avoided by using combinations of antimycotics. In this article, the results obtained by different authors when using systemic antimycotics in combined therapy are reviewed. The effect of the combination of amphotericin B and azoles varies according to the moment of administration: when the azole is administered before amphotericin B, antagonism between the two has been observed; however, when they are administered simultaneously the effect is synergistic with the hydrophylic azoles (fluconazole), antagonistic with lipophilic azoles (itraconazole) or indifferent. The combination of flucytosine with azoles has been demonstrated to be synergistic on Candida albicans (itraconazole, fluconazole) and on Cryptococcus neoformans (fluconazole). With the combinations of an equinocandine and amphotericin B or fluconazole, synergism has been observed on C. neoformans.

Famciclovir treatment in transplant recipients with HBV-related liver disease: disappointing results

OBJECTIVE

Long-term administration of hepatitis B immune globulin is effective as prophylaxis for hepatitis B virus (HBV) reinfection but is limited by cost, side effects, availability and a failure rate of 20%. Famciclovir has been shown to be effective in the treatment of hepatitis B in the immunocompetent patient. Fewer data exist in the liver transplant setting, particularly regarding its efficacy in de novo HBV infection. The aims of this pilot study were to determine the effectiveness and safety of long-term administration of famciclovir in recurrent (n = 3) and de novo (n = 3) HBV infection after liver transplantation.

METHODS

Six patients with postransplant HBV infection (positivity of serum HBsAg and HBV DNA), four of whom were HBeAg positive, were treated with famciclovir (500 mg, 3 times a day) with a minimum follow-up period of 12 months. Biochemical, serological, virological (HBV DNA by hybridization assays and polymerase chain reaction), and histological (including HBV immunostaining) endpoints were evaluated.

RESULTS

None of the patients had a complete biochemical response, with a near complete normalization of ALT levels being observed in 3/6 patients. There was a lack of correlation between virological and biochemical responses. None of the patients seroconverted to anti-HBs or anti-HBe. A virological clearance was observed in only two patients, whereas a moderate reduction in HBV DNA levels was present in one. HBV DNA levels were higher than levels during pretreatment in the three remaining patients. Histological improvement was only observed in one patient.

CONCLUSION

Famciclovir alone appears of limited efficacy in the treatment of HBV infection after liver transplantation.

Repeated pulmonary infection by Nocardia asteroides complex in a patient with bronchiectasis

A rare case of pulmonary nocardiosis was presented in a nonimmunocompromised patient who had chronic airway obstruction and bronchiectasis without corticoid treatment. The microbial diagnosis was established after isolating Nocardia in bronchial aspirate and sputum samples. An in vitro study showed sensitivity only to imipenem, netilmicine, amikacin and ofloxacin. The evolution was chronic, with multiple clinical recurrences in spite of prolonged antibiotic treatment. Finally, the eradication of Nocardia was achieved with the combination of imipenem and amikacin.

Epidemiological, microbiological, clinical, and prognostic factors of bacteremia caused by high-level vancomycin-resistant Enterococcus species

A case-control study was performed between 1994 and 1996 in order to study the epidemiological, microbiological, clinical, and prognostic features of high-level vancomycin-resistant enterococcal bacteremia. Seventeen consecutive patients who had clinically significant bacteremia due to vancomycin-resistant enterococci (vanA genotype: 16 Enterococcus faecalis, 1 Enterococcus faecium) were compared with 169 who had vancomycin-susceptible enterococcal bacteremia. The following were selected by multivariate analysis as independent risk factors that influenced the development of high-level vancomycin-resistant enterococcal bacteremia: prior glycopeptide therapy (P=0.049); inclusion in a hemodialysis program (P=0.046); prior therapy with corticosteroids or antineoplastic agents (P=0.029); and prior surgical treatment (P=0.022). The following other factors were selected by univariate analysis: tracheostomy (P=0.002); prolonged hospitalization (P=0.01); and any kind of puncture (P=0.02). The crude associated-mortality rate was 13.4%. Gene amplification of vanA was positive for 17 strains of enterococci. Pulsed-field gel electrophoresis of genomic DNA after SmaI digestion of vanA isolates revealed that one strain predominated (10 isolates), though at least four similar banding patterns were identified (6 isolates). The 16 strains closely related to the outbreak were investigated further. The surgical intensive care unit was the first and most involved service. The hospital outbreak of vanA vancomycin-resistant enterococcal bacteremia occurred between 1994 and 1995 and was caused by Enterococcus faecalis. This is believed to be the first and only such outbreak described in a Spanish hospital thus far.

[ROC curve analysis of factors predictive of non-response to interferon treatment in patients with chronic hepatitis C, genotype 1]

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6. 5% at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96% and the sensitivity was 63.5%, with the test being unequivocal in 6.5%, whereas when four or five variables were present, the positive predictive value was 97% and 100% and the sensitivity was 40.5% and 18%, respectively. In group B, the positive predictive value when two variables were present was 100% and the sensitivity was 87%, whereas when three, four, five and six variables were present the sensitivity was between 73% and 28%. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

[Comparative analysis of viral load by bDNA HCV RNA-2.0 and amplicor HCV monitor in patients with hepatitis C infection]

BACKGROUND

Two standardized techniques, Quantiplex (bDNA-2.0) and Amplicor Monitor have been evaluated for the quantification of virus load of HCV with these objectives: a) determinate the relationship between virus load and genotype, and b) evaluate the virus load in serial serum samples and in patients with normal or slightly increased liver enzymes in an area with a high prevalence of genotype 1.

RESULTS

A significant correlation of 0.7 (p < 0.0001) in virus load has been observed by both methods, but the virus load is smaller by Monitor than by Quantiplex and does not depend on genotype. The relationship Monitor/Quantiplex is smaller in patients with non-1 genotype than in patients with genotype 1a (p = 0.01) and 1b (p = 0.005). Virus characteristics are similar in patients with normal or slightly increased enzymes than in patients with high enzymes. Virus load by both methods is not related to the age, sex, know duration of the infection, transmission manner of the infection neither to the histologic activity index.

CONCLUSION

The virus load not depends on genotype. The determination of virus load in a single serum sample adequately reflects the virus load are in several serum samples in patients with chronic HCV infection. The genotype and the virus load are similar in patients with normal enzymes than in patients with high enzymes.

[Neonatal colonization by Ureaplasma urealyticum and the development of bronchopulmonary dysplasia]

OBJECTIVE

The study purpose was to investigate the association between neonatal Ureaplasma urealyticum isolation, and bronchopulmonary dysplasia (BDP), in infants who had birth weights < 1,500 g, admitted in the Pediatric Intensive Care Unit, La Fe Hospital, Valencia, Spain.

METHODS

A cohort study was designed, since March 1996 until April 1998, with a cohort of exposed and no exposed, determined by isolation of U. urealyticum in tracheal aspirate or pharyngeal cultures. 137 infants were admitted to the intensive care unit in this period, and 101 of them were enrolled in this study.

RESULTS

U. urealyticum was isolated in 27 (26.7%) patients. The infants with U. urealyticum positive culture had a significantly lower gestational age (mean 28.1, SD 2.4 vs 29.2, SD 2.4; p = 0.048) than negative culture infants. BDP occurred in 30 infants (29.7%), and was significantly associated with decreasing gestational age (mean 26.9, SD 1.7 vs 29.7, SD 2.2; p < 0.001) and lower birth weight (mean 965.8, SD 166.7 vs 1121.4, SD 232.1; p < 0.001). However, after correction for gestational age by logistic regression analysis, DBP was significantly related to decreasing gestational age, but not to the presence of a positive U. urealyticum culture. In the cohort of U. urealyticum positive infants, BPD occurred in 9 (33%) vs 21 (28%) in the not colonized cohort. The odds ratio associated with colonization was 1.3 (CI 95% 0.5-3.2; p = 0.63).

CONCLUSIONS

BPD was significantly associated with decreasing gestational age, independently of birth weight and U. urealyticum colonization.

[Early prediction of lack of response to treatment with interferon and interferon plus ribavirin using biochemical and virological criteria in patients with chronic hepatitis C]

The objectives of this study were the following: 1) to evaluate the predictive value of the detection of RNA-HVC compared to GPT in the third month of treatment in patients with chronic hepatitis C treated with IFN, and at the first and third month in patients treated with IFN and ribavirin for 6 and 12 months. The study included: A) 80/132 patients treated with IFN (3 MU/3 times a week for 6-12 months), and B) 70/110 patients who had previously not responded to IFN, and who were treated with combination therapy (IFN: standard dose, ribavirin: 1200 mg/day) for 6 months (n = 40) and 12 months (n = 30). In group A, the positive predictive value (the probability of predicting the lack of response if the RNA-HVC was positive or if the GPT was elevated at the third month) was greater for RNA-HVC than for GPT (97.9% vs. 94.4%), although the response was not unequivocal (2.3% vs. 10.5%). The negative predictive value was 48.6% vs. 36.2%, respectively. The prediction level (odds ratio) of RNA-HVC and of GPT was 39.7 vs. 8.78 (p <0.000001 vs. p <0.002). The positive predictive value was 97.6% in patients with genotype 1, 4 and 5, and 100% in those with genotype 2 and 3. In group B, the positive predictive value was also greater for RNA-HVC than for GPT at the first month (100% vs. 94.4%) following six months of therapy, the odds ratio being infinite vs. 7.6. The positive predictive value was greater for RNA-HVC at the third month than at the first (100% vs. 91%), whereas it was similar for GPT (100%) with 12 months of therapy, the odds ratio being greater for GPT than for RNA-HVC at the first month (infinite and 7.27). The following was concluded: 1) detection of RNA-HVC at the third month of treatment with IFN predicts in advance a lack of response in patients, with a minimum risk of error; 2) in patients with six months of combined therapy, the detection of RNA-HVC at the first month is extremely reliable in the prediction of a lack of response, whereas after 12 months of combined therapy, elevated GPT values at the first month and the detection of RNA-HVC at the third are highly predictive of a lack of response.

[Molecular typing and sensitivity of Candida albicans isolates proceeding from critically ill patients]

BACKGROUND

Nosocomial infection due Candida albicans in immunocompromised patients are recognized as a significant cause of morbidity and mortality. The endogenous forms of infections may require effective strategies for prevention which are different from those for exogenous infections due to transmission of any organism from patient to patient. Typing by PCR of isolates of C. albicans maybe useful for that.

METHODS

Twenty-four isolates in blood cultures of 24 critically ill patients were studied. Typing by interrepeat PCR and in vitro antifungal susceptibility tests was performed by a microdilution.

RESULTS

Twenty-one different genotypes were obtained. The isolates with same genotype shown different patterns of susceptibility. With one strain a band pattern very different from that obtained with the remaining isolates.

CONCLUSIONS

No were relation between strain of same unit. The isolates with same genotype was different critically unit or year of isolation.

Killing of gram-negative bacteria by ciprofloxacin within both healthy human neutrophils and neutrophils with inactivated O2-dependent bactericidal mechanisms

The intraphagocytic killing of Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa, and Salmonella typhi by ciprofloxacin (0.1, 1 and 5 microg/ml) within human neutrophils with intact and impaired (by phenylbutazone treatment) O2-dependent killing mechanisms was studied and compared with the extracellular killing in the same medium of the intraphagocytic killing, but omitting neutrophils. The MIC/MBC of ciprofloxacin in vitro (assays performed according to NCCLS specifications) were: 0.015/0.06 for E. coli, 0.12/32 for S. marcescens, 1/16 for P. aeruginosa, and 0.007/0.06 for S. typhi. Ciprofloxacin showed bactericidal activity both extracellular and within phenylbutazone-treated and untreated neutrophils. The minimum concentration of ciprofloxacin to kill 90% of phagocytosed bacteria within neutrophils with normal O2-dependent killing power after 30 min was: 0.1 microg/ml for E. coli, and S. typhi, 1 microg/ml for P. aeruginosa, and 5 microg/ml for S. marcescens. In contrast, exposure for 60 min was required to reach this percentage within phenylbutazone treated neutrophils. The minimum concentration to kill 90% of extracellular bacteria after 30 min was: 0.1 microg/ml for E. coli, P. aeruginosa and S. typhi, and 5 microg/ml, for S. marcescens. A positive interaction between ciprofloxacin and the O2-dependent mechanisms of phagocytes was found. The reactive oxygen metabolites produced in the respiratory burst did not affect the intraphagocytic activity of ciprofloxacin. Phenylbutazone treatment of phagocytes would be a good experimental model to study the intraphagocytic killing of drugs in situations such as AIDS and chronic granulomatous disease where inefficient oxidative mechanisms of neutrophils exist.

Fluconazole susceptibilities of bloodstream Candida sp. isolates as determined by National Committee for Clinical Laboratory Standards method M27-A and two other methods

The in vitro activity of fluconazole against 143 Candida spp. obtained from the bloodstreams of 143 hospitalized patients from 1995 to 1997 was studied. Susceptibility tests were carried out by two macrodilution methods, the M27-A and a modified M27-A method (0. 165 M, pH 7/morpholinepropanesulfonic acid-buffered RPMI 1640 medium supplemented with 20 g of D-dextrose per liter), and by the agar diffusion method (with 15-microg fluconazole [Neo-Sensitab] tablets). With 2 microg of fluconazole per ml, 96.92% of 65 C. albicans isolates, 86.2% of 58 C. parapsilosis isolates 7 of 8 C. tropicalis isolates, and 1 of 6 C. glabrata isolates were inhibited. Only one strain of C. albicans and one strain of C. tropicalis were resistant. The agreement between the two macrodilution methods was greater than 90% within +/-2 log2 dilutions for all strains except C. glabrata (83.3%) and C. tropicalis (87.5%). Generally, MICs were 1 log2 dilution lower in glucose-supplemented RPMI 1640 medium. No correlation between zone sizes and MICs was found. All strains susceptible by the diffusion test were susceptible by the dilution method, but the converse was not necessarily true. Interestingly, inhibition zones were smaller for C. albicans, for which the geometric mean MIC was 0.29 microg/ml and the mean inhibition zone diameter was 25.7 mm, while for C. parapsilosis the geometric mean MIC was 0.96 microg/ml and the mean inhibition zone diameter was 31. 52 mm. In conclusion, the two macrodilution methods give similar results. The modified M27-A method with 2% dextrose has the advantage of shortening the incubation time and simplifying the endpoint determination.

[Update on the pharmacological interactions of systemic antifungal agents]

The incidence of systemic fungal infections has increased considerably in the last few decades, however the number of available antifungal agents continues to be reduced. Furthermore, these infections tend to affect patients with severe underlying diseases who are treated with different types of medication which may interact with antifungal agents, thus reducing their therapeutic efficacy or increasing their toxicity. In this paper, we discuss the interactions of systemic antifungal agents with other medications and comment on their clinical consequences and the therapeutic approach to adopt in each case.

Value of the polymerase chain reaction assay in noninvasive respiratory samples for diagnosis of community-acquired pneumonia

We studied the causes of community-acquired pneumonia (CAP) in 184 patients. Microbiologic evaluation included sputum examination, blood culture, assessment of acute and convalescent antibody titers for Legionella pneumophila, Mycoplasma pneumoniae, Chlamydia pneumoniae, Coxiella psitacci, Coxiella burnetii and respiratory viruses, polymerase chain reaction (PCR) assays for M. pneumoniae and C. pneumoniae in throat swab, and PCR assay based on the amplification of pneumolysin gene fragment in sera. The causative pathogen was identified in 78 patients (Streptococcus pneumoniae, 44; M. pneumoniae, 26; C. pneumoniae, 1; others, 7). S. pneumoniae was detected in serum by the PCR assay in 41 patients, five of whom also had a positive blood culture. PCR assay was negative in two patients with positive blood culture for S. pneumoniae. C. pneumoniae was detected by PCR in nine patients, but only one showed seroconversion. M. pneumoniae was detected by PCR in only three patients (two without seroconversion). The diagnosis of pneumonia caused by S. pneumoniae was five times greater using PCR in serum than with blood culture. Detection of C. pneumoniae by PCR without fulfilling criteria for acute infection may be considered a prior infection. The PCR assay for the diagnosis of M. pneumoniae has a lower sensitivity than serologic methods.

[Effect of antiinflammatory agents on the accumulation of ofloxacin in human polymorphonuclear leukocytes]

The uptake of quinolones is a recently defined pharmacokinetic parameter which is increasing in importance in clinical practice, especially for immunocompromised patients whose polymorphonuclear leukocytes (PMNLs) have their bactericidal systems impaired, or in infections due to bacteria able to survive in the phagocytes. In both situations, antibiotics able to penetrate and be active in the phagocytes are required. The simultaneous administration of an antibiotic and an antiinflammatory drug is frequent, and previous studies have described interactions between the intracellular activity of the quinolones and the presence of phenylbutazone. We studied the effect of the presence of and the pretreatment (37 C for 30 and 60 min) of human PMNLs with the antiinflammatory drugs betamethasone (1 mg/l), hydrocortisone (1 mg/l), phenylbutazone (10 mg/ml), and acetylsalicylic acid (200 mg/l) on the uptake of ofloxacin (10 mg/l) by the PMNLs using a fluorometric method to measure the intra-PMNL concentration of ofloxacin. The presence of betamethasone did not modify the uptake of ofloxacin by PMNLs. Pretreatment of PMNLs with hydrocortisone, phenylbutazone and acetylsalicylic acid produced a significant decrease in the maximum intracellular concentration/extracellular concentration ratios compared with the maximum reached without pretreatment. These results suggest that hydrocortisone, phenylbutazone and acetylsalicylic acid interfere with the uptake of ofloxacin by PMNLs and increase the efflux of ofloxacin from PMNLs.

Human intestinal infection due to coccidia in Mozambique: two cases

A case of intestinal infection by Cryptosporidium parvum and another of intestinal Isospora belli infection, both in AIDS patients, are described. The two patients presented pulmonary tuberculosis symptoms and watery diarrhoea. Modified Ziehl-Neelsen stain of stools gave a definitive diagnosis in both cases. They are the first reports of intestinal coccidia infections in AIDS patients described in Mozambique.

Antibiotic susceptibility among aerobic gram-negative bacilli in intensive care units in 5 European countries. French and Portuguese ICU Study Groups

CONTEXT

Surveillance of antibiotic resistance is especially important in intensive care units (ICUs) because the infection rates are much higher there than in other hospital wards and most epidemics with multiresistant bacteria originate in ICUs.

OBJECTIVE

To evaluate the incidence of decreased antibiotic susceptibility among aerobic gram-negative bacilli isolated from patients in ICUs.

DESIGN

Consecutive specimens collected on clinical indications from ICU patients were cultured and tested. Minimum inhibitory concentrations for amikacin, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, and piperacillin-tazobactam were determined using E test.

SETTING

Eighteen hospitals in Belgium, 40 in France, 20 in Portugal, 30 in Spain, and 10 in Sweden.

SUBJECTS

A total of 9166 gram-negative strains were initially isolated from 7308 patients between June 1994 and June 1995.

MAIN OUTCOME MEASURES

The incidence of decreased susceptibility, defined as the sum of resistant and intermediate categories with use of the minimum inhibitory concentration break points recommended by the National Committee for Clinical Laboratory Standards.

RESULTS

The most frequently isolated organisms were Enterobacteriaceae (59%) followed by Pseudomonas aeruginosa (24%). The main sources were respiratory tract (42%), urine (26%), blood (14%), abdomen (11%), and skin and soft tissue (7%). Decreased antibiotic susceptibility across all species and drugs was highest in Portuguese ICUs followed by French, Spanish, Belgian, and Swedish ICUs. The highest incidence of resistance was seen in all countries among P aeruginosa (up to 37% resistant to ciprofloxacin in Portuguese ICUs and 46% resistant to gentamicin in French ICUs), Enterobacter species, Acinetobacter species, and Stenotrophomonas maltophilia, and in Portugal and France among Klebsiella species.

CONCLUSION

The high incidence of reduced antibiotic susceptibility among gram-negative bacteria in these ICUs suggests that more effective strategies are needed to control the selection and spread of resistant organisms.

High incidence of allograft cirrhosis in hepatitis C virus genotype 1b infection following transplantation: relationship with rejection episodes

The natural history of hepatitis C virus (HCV) infection following liver transplantation and predictors of disease severity remain controversial. The aims of the study were to assess in a homogeneous population of 81 cyclosporine-based HCV-infected liver transplant recipients mostly infected with genotype 1b and undergoing strict protocol annual biopsies: 1) the histological progression of posttransplantation HCV disease and, in particular, the incidence of HCV-related graft cirrhosis within the first 5 years after surgery; and 2) the relationship between progression to cirrhosis and i) rejection episodes and ii) first-year liver biopsy findings. We studied 81 consecutive HCV-RNA-positive patients (96% genotype 1b) undergoing liver transplantation between 1991 and 1996 with a minimum histological follow-up of 1 year. All patients received cyclosporine-based immunosuppression and underwent protocol yearly liver biopsies for the first 5 years. The mean histological follow-up was 32 months (range, 12-60 months). Biopsies were scored according to the histological activity index (HAI), with separate evaluation of grade (activity) and stage (fibrosis). Histological hepatitis, present in 97% of patients in the most recent biopsy, was moderate or severe in 64%. Twelve patients developed HCV-related cirrhosis at a median time of 24 months (range, 12-48 months), with an actuarial rate of HCV-cirrhosis of 3.7%, 8.5%, 16%, 28%, and 28% at 1, 2, 3, 4, and 5 years, respectively. Rejection was significantly more common among patients with cirrhosis versus those without (83% vs. 48%; P =.02), with an association between the incidence of cirrhosis and the number of rejection episodes: 5%, 15%, and 50% in patients without rejection, one and two episodes, respectively (P =.001). The degree of activity and fibrosis score in the first-year biopsy were higher in patients who developed cirrhosis than in those who did not (P =.008 and.18, respectively). In conclusion, HCV genotype 1b-infected liver recipients are at a high risk of developing graft cirrhosis in the first 4 to 5 years following transplantation, especially those with previous rejection episodes. First-year liver biopsies may help to sooner identify patients at the highest risk, improving further patient management.

[Evolution of resistance in the genus Enterococcus in strains isolated from blood]

The objective of this study was to determine the evolution of the species distribution and the prevalence of resistance to the Enterococcus genus. We studied 281 strains of enterococcus isolated from blood samples: 90 throughout 1984 and 791 from the years 1994 to 1996. identification was made using PosCombo 4Y Microscan-Baxter dehydrated panels and the Rapid ID 32 Strep system (bioMerieux). The MICs were calculated using the agar dilution method according to recommendations of the NCCLS for the following antibiotics: ampicillin, vancomycin, teicoplanin, gentamicin, kanamycin and streptomycin. The production of betalactamases were evaluated using a paper disk with nitrocefin for all the strains. The genotypes with resistance to glycopeptides were determined using PCR. The percentage of E. faecalis for 1984-1986/1994-1996 was 82.2/79.4; of E. faecium 4.4/16.4; and other species 12.214.3. The resistance to ampicillin went from 1.1% to 5.8%; high level resistance to glycopeptides went from 0% to 9.9%; for low level from 7.7% to 2.6%; resistance to a high charge of gentamicin went from 27.7% to 40.8%; and that for kanamycin from 45.5% to 62.8%. Resistance to streptomycin remained constant (45.5%). No strains produced betalactamases. For the species E. faecium, a statistically significant increase was detected for global resistance to ampicillin, gentamicin and kanamycin, with resistance to streptomycin remaining at similar percentages. No high level resistance to glycopeptides was detected in the first time period, but the low level resistance was greater.

[In vitro activity of fluconazole against Candida albicans isolated from blood culture]

The in vitro activity of fluconazole against 65 Candida albicans isolated from blood culture in 1995, 1996 and 1997 was studied by macrodilution and disk diffusion methods. The MIC ranged from 0.03 to 64 microg/ml, with 93.6% of strains being inhibited with 1 microg/ml fluconazole; the mode MIC was 0.25 microg/ml. Using this method, only one strain was resistant and another was susceptible depending on the dose. By diffusion, eight strains were susceptible, 53 intermediate, and four resistant. The strains susceptible by dilution were also susceptible by diffusion, but the strains resistant by diffusion were not always resistant by dilution. We find it therefore useful to determine the MIC of fluconazole to the C. albicans resistant by diffusion.

[Bacteremia caused by Stenotrophomonas maltophilia: a clinical-epidemiological study and resistance profile]

Over a 7-year period (1990-1996), the causal disease, predisposing factors, focus infection, clinical manifestations, complications and evolution of patients presenting bacteremia from Stenotrophomonas maltophilia were analyzed retrospectively in a university hospital. A microbiological study was carried out to determine the percentage of positive blood cultures per episode and the characteristics of bacteremia and to evaluate the antibiotic susceptibility of the isolated strains. Twenty-seven episodes of bacteremia from S. maltophilia were identified in 26 patients, half of whom were women, and the median age was 40 years. A total of 48% of the patients had blood malignancy (12 cases), with acute myeloid leukemia (5 cases) being the most frequent. Seven patients (27%) needed to be admitted to an intensive care unit for some type of vital support and/or intensive treatment. The previous administration of large spectrum antimicrobials (21/26) and the presence of a catheter or central catheter (19/26) were the most frequently found predisposing factors (81% and 73%, respectively). One-quarter of the patients had received treatment with carbapenems. Immunodepression caused by chemotherapy or corticosteroids occurred in 65% of the cases. Half of the patients had undergone a major surgical procedure or had been intubated and submitted to mechanical ventilation. One-third presented granulocytopenia on the detection of bacteremia and 6 of the 12 patients with blood malignancy showed severe neutropenia (<500 neutrophils/mm3). The bacteremia was acquired in hospital in 78% of the cases (21/27). In 26% of these cases, S. maltophilia was diagnosed as the probable cause of bacteremia; in 34% this was just a possibility. The origin of the bacteremia was unknown in 11 cases (40%). Infection from the vascular catheter was the most frequent focus infection (7 cases). An average of 3.6 blood cultures were performed per patient, out of a total of 92, and 54% showed positive. The average time of growth for S. maltophilia in the blood culture bottles was 30 hours. One-third of the bacteremia episodes from S. maltophilia were polymicrobial (9/27). Clinical evolution was favorable in 18 patients, while 8 died (31%), 5 cases (20%) from causes directly related to the bacteremia (4 from septic shock). The mortality associated with the polymicrobial bacteremia was not significantly different from that for single microbial bacteremia from S. maltophilia. Ninety percent of the isolated strains showed susceptibility to co-trimoxazole, 77% to ticarcillin-clavulanic acid, 60% to ciprofloxacin, 62% to ceftazidime, 20% to amikacin and just 18% to imipenem.

[Ampicillin-sulbactam activity against respiratory isolates of Haemophilus influenzae]

A study was conducted on the in vitro activity of ampicillin/sulbactam against 100 respiratory strains of Haemophilus influenzae (45 betalactamase positive and 55 betalactamase negative strains) simultaneously isolated during 1997 in 6 Spanish hospitals: Hospital Clínico San Carlos (Madrid), Hospital de Cruces de Basurto (Bilbao), Hospital La Fe (Valencia), Hospital Virgen Macarena (Seville), Hospital de Bellvitge (Barcelona) and Hospital Clínico Universitario (Salamanca). It was studied in comparison to amoxicillin, amoxicillin/clavulanic acid, cefuroxime, clarithromycin and ciprofloxacin. The MIC breakpoints used for the interpretation of data were those published by the National Committee for Clinical Laboratory Standards in 1997. All of the strains tested were susceptible to ampicillin/sulbactam, amoxicillin/clavulanic acid, cefuroxime and ciprofloxacin. The rate of resistance to clarithromycin was 55.5% for betalactamase positive strains and 38. 2% for betalactamase negative strains. A total of 23.6% of the betalactamase negative strains were resistant or showed intermediate susceptibility to amoxicillin but were susceptible to betalactam/betalactamase inhibitor combinations and cefuroxime.

[A national multicenter study of the in-vitro activity of piperacillin-tazobactam. The Spanish Piperacillin-Tazobactam Group]

The action of piperacillin-tazobactam on 4,137 of the 4,364 strains collected in a Spanish multicenter study involving 46 participating hospitals was studied. The samples were from the following: 41% urine, 18% exuded from wound abscesses, 13% respiratory, 9% blood, 3% peritoneal liquid, and the remainder from other various sources. The gram-negative bacteria included 2,778 strains from 13 genera: Escherichia (1,289), Pseudomonas (451), Proteus (230), Klebsiella (203), Haemophilus (172), Enterobacter (145), Acinetobacter (88), Salmonella (60), Bacteroides (57), Morganella (53), Serratia (46), Citrobacter (46), Stenotrophonomas (23) and Moraxella (21). The gram-positive bacteria were S. aureus (316), E. faecalis (239), S. epidermis (130), S. pneumoniae (115) and Clostridium spp. (12). The global susceptibility of the gram-negatives to piperacillin-tazobactam was 94%: E. coli 98%, P. aeruginosa 92%, and P. mirabilis, Morganella, K. pneumoniae, Serratia and Salmonella spp. all greater than 94%. The susceptibility of other bacteria was as follows: 91% Citrobacter, 77% E. cloacae, 42% A. baumannii, 61% S. maltophilia, 97% E. faecalis, 93% S. epidermidis, 100% M. catarrhalis, 99% H. influenzae and 100% anaerobic bacteria. The action on S. pneumoniae and S. aureus varied according to the susceptibility or lack there of to penicillin or methicillin. In comparison to other antibiotics (piperacillin, cefoxitin, cefotaxime, ceftazidime, cefepime, imipenem and ciprofloxacin), piperacillin-tazobactam was far better than piperacillin alone and better or similar to the others.

[Human immunodeficiency virus and resistance]

It has been demonstrated that following prolonged treatment with reverse transcriptase inhibitors, especially with nucleoside analogs, resistant viral strains appear that show mutations in the nucleotides of the gene that codifies reverse transcriptase. These mutations cause changes in amino acids, which gradually increases resistance. In this study we evaluated the applicability af the LiPA HIV-1 RT test in determining the presence of mutations in this gene that can lead to resistance to antiretroviral treatments.Twenty-one samples were studied without previous knowledge of the antiviral treatments that the patients had received. No mutations in the HIV-1 stains from untreated patients were found. In the other patients who had undergone various treatment regimens, the results obtained With the LiPA HIV-1 RT made in possible to retrospectively identify the different nucleoside analogs they had been treated with. The most frequently found mutations were those that lead to a certain degree of resistance to AZT, followed by those related to resistance to ddl, which in effect in this order were the drugs used in the treatment of the patients. However, the LiPA HIV-1 RT test has certain limitations. It can only detect mutations that can be recognized by its sequences. As such, including sequences that would make it possible to study the possible genotypic variations in the gene that codifies the protease of HIV-1 would be helpful, given the importance of the protease inhibitors in clinical practice. In any case, direct sequencing continues to be standard method as it allows us to obtain full information on the genes that need to be studied.

Early development of chronic active hepatitis in recurrent hepatitis C virus infection after liver transplantation: association with treatment of rejection

BACKGROUND/AIMS

We retrospectively studied 63 consecutive patients (mean age 54+/-8) with hepatitis C virus genotype 1b recurrence after liver transplantation and with a minimum histological follow-up of 1 year, in order to determine whether an early severe recurrence, defined as the development of chronic active hepatitis within the first 2 years post-liver transplantation, was associated with increased immunosuppression.

METHODS

The 1st year immunosuppression data (rejection episodes, boluses of methyl-prednisolone, cumulative doses of prednisone and azathioprine, OKT3 use) were recorded, and evaluated as predictive of severe recurrence at 1 and 2 years post-liver transplantation. Chronic active hepatitis and rejection were defined by histological criteria. Immunosuppression consisted of cyclosporine, azathioprine and prednisone. The treatment of rejection was based on a "bolus" of 1 g methyl-prednisolone/3 days.

RESULTS

At 1 year, 64% (40/63) of the patients had chronic active hepatitis, whereas of the 40 patients who had a 2nd year biopsy available, 75% had chronic active hepatitis at 2 years. At 1 year post-liver transplantation, no significant association was observed between immunosuppression and the development of chronic active hepatitis. In contrast, at 2 years, rejection (p=0.006), treatment of rejection (p=0.05), methyl-prednisolone boluses (p=0.013) and the number of rejection episodes (p=0.0034) occurring during the 1st year post-liver transplantation were significantly more common in patients with chronic active hepatitis. There was also a trend towards higher cumulative steroids (9447+/-3176.5 vs 7891.5+/-2111 mg) and higher cumulative azathioprine doses (13472+/-11154 vs 6233.5+/-5937 mg) in patients with chronic active hepatitis as compared to those who did not develop chronic active hepatitis.

CONCLUSIONS

Rejection and/or its treatment may accelerate the natural history of hepatitis C virus genotype 1b infection post-liver transplantation.