Effect of long-term prophylaxis in the development of cytomegalovirus-specific T-cell immunity in D+/R- solid organ transplant recipients

BACKGROUND

This study aimed to characterize the dynamics of acquisition of cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) in CMV donor positive/recipient negative solid organ transplant (SOT) patients receiving long-term antiviral prophylaxis, and to determine whether development of CMI confers protection against CMV disease.

METHODS

A prospective multicenter study was conducted in Spain from September 2009 to September 2012. Whole blood specimens were prospectively collected at 30, 90, 120, 200, and 365 days after SOT, and CMI was determined by enumeration of CMV pp65 and IE-1-specific CD69(+) /interferon-γ-producing CD8(+) and CD4(+) T cells by flow cytometry for intracellular cytokine staining. As part of a simultaneous clinical trial, patients received either early prophylaxis (in the first 3 days after transplantation) in the first period of the study or delayed prophylaxis (initiated at day 14) during the second period of the study. The impact of the dynamics of acquisition of CMV-specific CMI on the incidence of CMV disease was evaluated by Kaplan-Meier survival analysis.

RESULTS

A total of 95 SOT recipients were recruited. CMV infection and disease occurred in 38 (40%) and 26 (27.4%) patients, respectively. The proportion of patients achieving any detectable CMV-specific CMI response at each of the different monitoring points was higher in liver transplant recipients, as compared to kidney or heart transplant recipients. The presence of any detectable response at day 120 or 200 was protective against the development of CMV disease (positive predictive values 92% and 93%, respectively).

CONCLUSIONS

The rate of acquisition of CMV-specific CMI in SOT recipients undergoing antiviral prophylaxis differed significantly between different SOT populations. Patients developing any detectable CMI response were protected against the occurrence of CMV disease.

Effect of delaying prophylaxis against CMV in D+/R- solid organ transplant recipients in the development of CMV-specific cellular immunity and occurrence of late CMV disease

OBJECTIVES

Evaluate the protective effect against late CMV disease of delaying antiviral prophylaxis initiation in D+/R- patients receiving solid organ transplant (SOT).

METHODS

Prospective multicenter study in D+/R- SOT recipients in Spain (Sept/09-Sept/12). Whole blood specimens were prospectively collected after Tx for CMV-specific cell-mediated immunity (CMI) determination. Two prophylaxis strategies were compared: early prophylaxis (EP; starting within the first 3 days after Tx) and delayed prophylaxis (DP; starting 14 days after Tx). Risk factors for the occurrence of CMV disease were determined by survival analysis and proportional risk Cox regression models.

RESULTS

We included 95 patients (50 EP V 45 DP). Twenty six patients (27.4%) developed CMV disease: 32.7% EP vs. 20% DP; (p = 0.2). No cases of CMV disease were reported previously to beginning delayed prophylaxis. The percentage of individuals with detectable CMI response was higher in patients with DP although differences did not reach statistic significance (42% vs 29.6% at day 200 after Tx; p = 0.4). There was a clear trend towards less end-organ CMV disease in patients receiving DP (18.2% EP vs 5% DP; p = 0.09) and DP was the only protective factor in the multivariate analysis (HR: 0.26; CI: 0.05-1.2; p = 0.09).

CONCLUSIONS

A 14-day delay in CMV prophylaxis in D+/R- SOT recipients is safe and may reduce the incidence of late CMV end-organ disease although correlation of this effect with CMI responses was not complete.

Efficacy and safety of fosfomycin plus imipenem as rescue therapy for complicated bacteremia and endocarditis due to methicillin-resistant Staphylococcus aureus: a multicenter clinical trial

BACKGROUND

There is an urgent need for alternative rescue therapies in invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the clinical efficacy and safety of the combination of fosfomycin and imipenem as rescue therapy for MRSA infective endocarditis and complicated bacteremia.

METHODS

The trial was conducted between 2001 and 2010 in 3 Spanish hospitals. Adult patients with complicated MRSA bacteremia or endocarditis requiring rescue therapy were eligible for the study. Treatment with fosfomycin (2 g/6 hours IV) plus imipenem (1 g/6 hours IV) was started and monitored. The primary efficacy endpoints were percentage of sterile blood cultures at 72 hours and clinical success rate assessed at the test-of-cure visit (45 days after the end of therapy).

RESULTS

The combination was administered in 12 patients with endocarditis, 2 with vascular graft infection, and 2 with complicated bacteremia. Therapy had previously failed with vancomycin in 9 patients, daptomycin in 2, and sequential antibiotics in 5. Blood cultures were negative 72 hours after the first dose of the combination in all cases. The success rate was 69%, and only 1 of 5 deaths was related to the MRSA infection. Although the combination was safe in most patients (94%), a patient with liver cirrhosis died of multiorgan failure secondary to sodium overload. There were no episodes of breakthrough bacteremia or relapse.

CONCLUSIONS

Fosfomycin plus imipenem was an effective and safe combination when used as rescue therapy for complicated MRSA bloodstream infections and deserves further clinical evaluation as initial therapy in these infections.

Group B Streptococcal Disease in Nonpregnant Adults: Incidence, Clinical Characteristics, and Outcome

A retrospective review of 150 cases of group B streptococcal disease in nonpregnant adults over an 8-year period was performed in a single tertiary-care teaching hospital to determine the incidence, clinical spectrum, and outcome of the disease. Incidence increased from 0.53 cases per 1,000 admissions in the 1993-1994 period to 0.96 cases per 1,000 admissions in 1999-2000 (P=0.013, chi-square test for trend). Bacteremia also increased from 0.15 to 0.42 cases per 1,000 admissions over the same period of time (P=0.005, chi-square test for trend). The mean age of the patients was 61.4 years, and 92% had at least one underlying disease. Bacteremia was detected in 60.9% of patients in whom blood cultures were performed. Fourteen (9.3%) patients died. Factors independently associated with an increased risk of dying were shock at diagnosis (OR, 23.96; 95%CI, 3.44-166.57; P=0.001) and cancer (OR, 4.96; 95%CI, 1.43-17.20; P=0.012). Group B streptococcal disease in nonpregnant adults is on the rise in the hospital investigated, particularly in persons with underlying conditions. The clinical spectrum of the disease ranges from localized to severe bacteremic infections. Shock at diagnosis and cancer are factors independently associated with a higher fatality rate.

[Changes in the epidemiology of infections in patients with febrile neutropenia]

Over the last years, advances in the treatment and supportive care of patients with cancer have led to substantial improvement in long-term survival. Nevertheless, bacterial infection continues to contribute significantly to illness and death in patients developing chemotherapy-induced neutropenia. In this severely ill population, the early administration of appropriate empirical antibiotic therapy for febrile episodes is crucial. This therapeutic approach has been shown to decrease morbidity and mortality due to infections caused by gram negative bacilli. However, in recent years, gram positive pathogens have been recovered at a notably increased rate from neutropenic patients with cancer. Although mortality associated to gram positive bacteremia is commonly lower than that caused by gram negative bacilli, an increasing frequency of serious complications of bacteremia due to viridans group streptococci has been observed in some institutions. Moreover, the emerging problems of bacterial resistance to various antimicrobial agents is of great concern. Herein, we examine major changes in the epidemiology of bacterial infections in neutropenic patients with cancer and some clinical aspects of infections caused by most frequent pathogens.

In vitro activities of eight macrolide antibiotics and RP-59500 (quinupristin-dalfopristin) against viridans group streptococci isolated from blood of neutropenic cancer patients

From January 1988 to December 1994, 66 consecutive blood culture isolates of viridans group streptococci collected from febrile neutropenic cancer patients were tested for antimicrobial susceptibilities by the agar dilution method. The antibiotics studied were erythromycin, clarithromycin, roxithromycin, dirithromycin, azithromycin, josamycin, diacetyl-midecamycin, spiramycin, and quinupristin-dalfopristin. A total of 26 (39.4%) strains were resistant to erythromycin with an MIC range of 0.5 to > 128 micrograms/ml. The strains were classified into three groups according to their penicillin susceptibility: 42 (63.6%) were susceptible, 8 (12.1%) were intermediately resistant, and 16 (24.3%) were highly resistant. The percentages of erythromycin-resistant strains in each group were 23.8, 62.5, and 68.8%, respectively. Streptococcus mitis was the species most frequently isolated (83.3%) and showed the highest rates of penicillin (40%) and erythromycin (43.6%) resistance. MICs of all macrolide antibiotics tested and of quinupristin-dalfopristin were higher for penicillin-resistant strains than for penicillin-susceptible strains. All macrolide antibiotics tested had cross-resistance to erythromycin, which was not observed with quinupristin-dalfopristin. Our study shows a high rate of macrolide resistance among viridans group streptococci isolated from blood samples of neutropenic cancer patients, especially those infected with penicillin-resistant strains. These findings make macrolides unsuitable prophylactic agents against viridans group streptococcal bacteremia in this patient population.

Emergence of fluoroquinolone-resistant Escherichia coli in fecal flora of cancer patients receiving norfloxacin prophylaxis

We studied 122 stool samples collected from 25 patients with hematologic malignancies who received prophylactic norfloxacin. Fecal samples were obtained at admission and twice weekly thereafter during prophylaxis. Fluoroquinolone-resistant Escherichia coli strains were isolated from the feces of 10 (40%) of the patients; two patients had fluoroquinolone-resistant E. coli strains prior to beginning norfloxacin treatment, and in the other eight patients, the strains appeared subsequently. One patient developed fluoroquinolone-resistant E. coli bacteremia after 10 days of norfloxacin administration.

A papular eruption secondary to infection with Corynebacterium jeikeium, with histopathological features mimicking botryomycosis

Corynebacterium jeikeium has been increasingly recognized as a pathogen, particularly in immunocompromised patients and in those with a prosthetic heart valve. Although cutaneous manifestations of C. jeikeium infection have been described, we have only found two case reports that give an histological description of the lesions. We present three patients with haematological malignancies who developed infection with C. jeikeium and a papular eruption. Skin biopsy disclosed similar histological features in all three patients, namely numerous Gram-positive bacteria enclosed in an eosinophilic matrix, with a minimal inflammatory response. C. jeikeium was cultured from cutaneous lesions in two cases.

In vitro activities of 22 beta-lactam antibiotics against penicillin-resistant and penicillin-susceptible viridans group streptococci isolated from blood

A total of 410 strains of viridans group streptococci isolated consecutively from blood were tested by the microdilution method for in vitro susceptibility to 22 beta-lactam antibiotics. One hundred thirty-eight strains (33.6%) were resistant to penicillin with a MIC range of 0.25 to 8 micrograms/ml. MICs of all beta-lactam agents tested were higher for penicillin-resistant strains than for susceptible strains. These antibiotics were classified into three groups according to their in vitro activities (MICs at which 50 and 90% of the isolates are inhibited). Beta-Lactams of the first group (these included imipenem, cefpirome, FK-037, cefditoren, cefotaxime, ceftriaxone, and cefepime) showed activities higher than or similar to that of penicillin against penicillin-resistant viridans group streptococci. However, 80% of highly penicillin-resistant Streptococcus mitis organisms required cefotaxime and ceftriaxone MICs of > or = 2 micrograms/ml (range, 2 to 16 micrograms/ml). Beta-Lactams of the second group (cefpodoxime, ampicillin, amoxicillin-clavulanate, piperacillin, and cefuroxime) showed lower activities than penicillin. Finally, antibiotics of the third group (cephalothin, oxacillin, ceftazidime, cefixime, cefaclor, cefetamet, cefadroxil, cephalexin, and ceftibuten) showed poor in vitro activities. Therefore, some of the beta-lactam agents included in the first group could be an acceptable alternative in the treatment of serious infections due to strains highly resistant to penicillin, although clinical experience is needed.

Risk factors for nosocomial Legionella pneumophila pneumonia

Over a 5-yr period, from January 1985 to January 1990, we prospectively studied 300 episodes of nosocomial pneumonia in a 1,000-bed teaching hospital. All cases had an accurate bacteriologic diagnosis obtained by means of highly reliable techniques. Legionella pneumophila caused a total of 36 episodes; 22 were endemic and 14 occurred during an epidemic outbreak. No patient with Legionella pneumonia had been intubated before infection. To identify risk factors for nosocomial L. pneumophila pneumonia, we compared the 22 endemic cases of nosocomial pneumonia due to L. pneumophila with the 264 cases due to other bacteria. After adjusting for other variables by means of logistic regression analysis, cytotoxic chemotherapy (OR = 5.2; 95% CI, 1.5 to 17.9) and use of corticosteroids (OR = 4.6; 95% CI, 1.5 to 14.1) were positively associated with L. pneumophila pneumonia, whereas previous antibiotic therapy (OR = 0.2; 95% CI, 0.1 to 0.8) and lowered consciousness (OR = 0.2; 95% CI, 0.07 to 0.8) were negatively associated. The major risk factors for Legionella pneumonia delineated in this study should be considered in the clinical approach to and empiric therapy of patients with suspected nosocomial pneumonia.

AIDS presenting as septic shock caused by Mycobacterium tuberculosis

Concurrent with the AIDS epidemic, an increasing incidence of tuberculosis has been noted. In HIV-infected patients with immunodeficiency, atypical forms of tuberculosis are seen. A case of disseminated tuberculosis with septic shock in an elderly patient with previously unknown HIV infection is reported.

Fluconazole treatment in Torulopsis glabrata upper urinary tract infection causing ureteral obstruction

We report a case of Torulopsis glabrata upper urinary tract infection causing ureteral obstruction. The infection was successfully treated with fluconazole, a new triazole derivative, combined with ureteral catheterization.

Randomized double-blind evaluation of ciprofloxacin and doxycycline for Mediterranean spotted fever

A study of 43 patients with Mediterranean spotted fever showed that a 2-day course of ciprofloxacin or a 2-day course of doxycycline may be an effective mode of therapy. All patients in both arms of the study were cured; however, doxycycline produced a more rapid defervescence.