Changing aetiology, clinical features, antimicrobial resistance, and outcomes of bloodstream infection in neutropenic cancer patients.

Recent changes in the management of patients with haematological malignancies might have influenced the aetiology, characteristics, antimicrobial resistance and outcomes of bloodstream infection (BSI) during neutropenia. We compared 272 episodes of BSI in adult neutropenic patients with cancer prospectively collected from January 1991 to December 1996 (first period), when quinolone prophylaxis was used, with 283 episodes recorded from January 2006 to March 2010 (second period), when antibacterial prophylaxis was stopped. Patients in the second period were significantly older and were more likely to have graft-versus-host disease and a urinary catheter in place, whereas the presence of a central venous catheter, parenteral nutrition, corticosteroids and antifungal and quinolone prophylaxis, were more frequent in the first period. More patients in the first period had mucositis and soft-tissue infection as the origin of BSI, but an endogenous source was more common during the second. Gram-positive BSI was more frequent in the first period (64% versus 41%; p <0.001), mainly due to coagulase-negative staphylococci and viridans group streptococci. In the second period gram-negative BSI increased (28% versus 49%; p <0.001), quinolone susceptibilities were recovered, but multidrug-resistant gram-negative BSI also increased (1% versus 6%; p <0.001). Although patients in the second period were more likely to need admission to the intensive-care unit, overall case-fatality rate was similar in the two periods (19% versus 15%). The aetiology of BSI in neutropenic patients with cancer has shifted from gram-positive to gram-negative organisms. Multidrug resistance among gram-negative bacilli is emerging as a therapeutic challenge. Overall case-fatality rate remains high.

Bacteraemia due to multidrug-resistant Gram-negative bacilli in cancer patients: risk factors, antibiotic therapy and outcomes.

OBJECTIVES: To assess the risk factors, antibiotic therapy and outcomes of multidrug-resistant Gram-negative bacilli (MDRGNB) bacteraemia in hospitalized patients with cancer. METHODS: Episodes of MDRGNB bacteraemia were compared with a susceptible control group in a 4 year prospective study. RESULTS: Of 747 bacteraemias, 372 (49.7%) were caused by a Gram-negative bacilli (GNB). Fifty-one of these (13.7%) were caused by a multidrug-resistant (MDR) strain. Previous antibiotics [odds ratio (OR) 3.57; 95% confidence interval (CI) 1.63-7.80] and urinary catheter (OR 2.41; 95% CI 1.01-5.74) were identified as independent risk factors for MDRGNB acquisition. The most frequent mechanism of resistance was extended-spectrum ß-lactamase (ESBL) production (45%), mainly by Escherichia coli, followed by Amp-C cephalosporinase hyperproduction (24%). Patients with MDRGNB bacteraemia more frequently received inadequate initial antibiotic therapy (69% versus 9%; P < 0.001) and time to adequate therapy was longer in this group (41% versus 4%; P < 0.001). Patients in the resistant group more frequently required intensive care unit (ICU) admission (14% versus 5%; P = 0.023), had greater need for mechanical ventilation (14% versus 3%; P = 0.005) and had a higher overall case-fatality rate (41% versus 21%; P = 0.003). Risk factors for mortality were solid tumour (OR 5.04; 95% CI 2.49-10.19), current corticosteroid use (OR 4.38; 95% CI 2.39-8.05), ICU admission (OR 11.40; 95% CI 3.19-40.74) and MDRGNB bacteraemia (OR 3.52; 95% CI 1.36-9.09). CONCLUSIONS: MDRGNB bacteraemia was common among cancer patients, especially in those exposed to antibiotics and urinary catheter. The most frequent mechanism of resistance was ESBL production. Patients with MDRGNB more frequently received inadequate empirical antibiotic therapy and presented poorer outcomes with a higher overall case-fatality rate (within 30 days).

Effect of statins on outcomes in immunosuppressed patients with bloodstream infection.

Although it has been suggested that statins have a beneficial effect on the outcome of bloodstream infection (BSI) in immunosuppressed patients, prospective studies testing this hypothesis are lacking. We performed an observational analysis of consecutive cancer patients and transplant recipients hospitalized at two tertiary hospitals in Spain (2006-2009). The first episode of BSI occurring in statin users was compared with those occurring in non-statin users. During the study period, 668 consecutive episodes of BSI in 476 immunosuppressed patients were recorded. Underlying diseases were solid tumor (46.2%), hematologic malignancy (35.1%), and transplantation (18.7%). Fifty-nine (12.4%) patients were receiving statins at the onset of BSI. Comparing with statin non-users, patients on statin treatment were older (67.3 vs. 58.7 years; p < 0.001) and had higher frequency of comorbidities (74.6% vs. 40.6%; p < 0.001). There were no significant differences in intensive care unit admission (6.8% vs. 7.7%; p = 1) and overall mortality (15.3% vs. 24%; p = 0.13) between groups. In a multivariate analysis, prior statin use was not associated with increased survival (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.22-1.23; p = 0.14). In conclusion, prior statin use is not associated with increased survival in immunosuppressed patients with BSI. Caution is warranted in attributing beneficial effects to statin use in infections among immunocompromised patients.

Clinical epidemiology and outcomes of peripheral venous catheter-related bloodstream infections at a university-affiliated hospital.

Despite enormous clinical experience of using peripheral vascular catheters, there is still controversy over the incidence and clinical relevance of bloodstream infections caused by these devices and the measures for preventing them. We performed a prospective study to determine the clinical epidemiology and outcomes of nosocomial bloodstream infections caused by short- and mid-line peripheral venous catheters among a group of non-intensive care unit patients. Cases of peripheral venous catheter-related bloodstream infections (PVC-BSIs) were compared to cases of central venous catheter-related bloodstream infections (CVC-BSIs). From October 2001 to March 2003, 150 cases of vascular catheter-related bloodstream infections were identified among 147 patients. Seventy-seven episodes (0.19 cases/1000 patient-days) were PVC-BSIs and 73 episodes (0.18 cases/1000 patient-days) were CVC-BSIs. Compared with CVC-BSIs, patients with PVC-BSIs more often had the catheter inserted in the emergency department (0 vs 42%), had a shorter duration from catheter insertion to bacteraemia (mean: 15.4 vs 4.9 days) and had Staphylococcus aureus (33 vs 53%) more frequently as the causative pathogen. Among patients with PVC-BSIs, catheters inserted in the emergency department had a significantly shorter duration in situ compared with those inserted on hospital wards (mean: 3.7 vs 5.7 days). Patients with PVC-BSIs caused by S. aureus had a higher rate of complicated bacteraemia (7%) and higher overall mortality (27%) than patients with PVC-BSIs caused by other pathogens (0 and 11%, respectively). Bloodstream infections remain underestimated and potentially serious complications of peripheral vascular catheterisation. Targeted interventions should be introduced to minimise this complication.

Predictive factors of meticillin resistance among patients with Staphylococcus aureus bloodstream infections at hospital admission.

Meticillin-resistant Staphylococcus aureus (MRSA) is prevalent throughout the healthcare system in Spain, particularly in long-term care facilities (LTCF) and the incidence of MRSA bloodstream infection (MRSA-BSI) at hospital admission is increasing. This study aimed to determine factors that predict meticillin resistance among patients who require hospitalization for S. aureus BSI. We performed a case-control study comparing patients with S. aureus at hospital admission from January 1991 to December 2003. Case patients with MRSA-BSI at hospital admission (N=50) were compared with control patients with meticillin-susceptible S. aureus bloodstream infection (MSSA-BSI) at hospital admission (N=98). The incidence of MRSA-BSI at hospital admission increased significantly from 0.08 cases/1000 hospital admissions in 1991 to 0.37 cases in 2003 (P<0.001). Univariate analysis comparing patients with MRSA- and MSSA-BSI found a significant association between meticillin resistance and age >60 years, female sex, prior MRSA isolation and healthcare-related BSI. No differences were found in underlying conditions such as diabetes, haemodialysis, immunosuppression, source of infection or mortality between the two groups. Multivariate analyses identified prior MRSA isolation [odds ratio (OR): 41; 95% confidence interval (CI): 4-350] and admission from long-term care facilities (OR: 37; 95% CI: 4.5-316) as independent risk factors for MRSA-BSI.

Bacteremic pneumococcal cellulitis compared with bacteremic cellulitis caused by Staphylococcus aureus and Streptococcus pyogenes.

In order to better characterize bacteremic cellulitis caused by Streptococcus pneumoniae, a review was conducted of 10 cases of bacteremic pneumococcal cellulitis, which represented 0.9% of all cases of pneumococcal bacteremia (n=1,076) and 3.2% of all cases of community-acquired bacteremic cellulitis (n=312) that occurred in the Hospital de Bellvitge, Barcelona, from 1984 to 2001. In addition to these 10 cases, 28 cases of bacteremic pneumococcal cellulitis from the literature (Medline 1975-2001) were reviewed. Pneumococcal cellulitis of the face, neck, and trunk was observed more frequently in patients with systemic lupus erythematosus and hematologic disorders, while pneumococcal cellulitis of the limbs was more common in patients with diabetes, alcoholism, and parenteral drug use. In the Hospital de Bellvitge group, bacteremic cellulitis due to Streptococcus pneumoniae was more frequently associated with severe underlying diseases than that due to Staphylococcus aureus or Streptococcus pyogenes (100%, 57%, and 72%, respectively;P=0.01). A concomitant extracutaneous focus of infection (e.g., respiratory tract infection) suggesting hematogenous spread with metastatic cellulitis was more frequent in patients with pneumococcal cellulitis, while a local cutaneous entry of microorganisms was feasible in most patients with Staphylococcus aureus or Streptococcus pyogenes cellulitis. The 30-day mortality was 10% in patients with pneumococcal cellulitis, 13% in patients with Staphylococcus aureus cellulitis, and 23% in patients with Streptococcus pyogenes cellulitis (P=0.3). Thus, bacteremic pneumococcal cellulitis is an unusual manifestation of pneumococcal disease and occurs mainly in patients with severe underlying diseases. In most cases, pneumococcal cellulitis has a different pathophysiologic mechanism than cellulitis caused by Staphylococcus aureus or Streptococcus pyogenes.

CDC group IV c-2 infection in a stem cell transplant recipient.

Patients undergoing high-dose chemotherapy for cancer are at a high risk of infections caused by unusual microorganisms. Previous chemotherapy, use of indwelling catheters and prior antibiotic treatment are common predisposing factors. We present a case of septicaemia due to a rare non-fermentative bacillus, CDC group IV c-2, found in the blood and venous catheter from a patient with a testicular germ cell tumour undergoing high-dose consolidation chemotherapy.

[Nosocomial bacteremia caused by Enterobacter spp.: epidemiology and prognostic factors]. / Bacteriemia nosocomial por Enterobacter spp.: epidemiología y factores pronósticos.

BACKGROUND: The aim of this study was to establish the clinical and epidemiologic features of nosocomial bacteremia by Enterobacter spp. and to analyse its prognostic factors. METHODS: A prospective study of the episodes of nosocomial bacteremia by Enterobacter spp. with clinical significance, detected in a third level university hospital from January 1984 to December 1990 was performed. RESULTS: During the study period, 226 episodes of bacteremia by Enterobacter spp., of which 184 (81%) were of nosocomial origin (8.1% of all the nosocomial bacteremias), while 14% were polymicrobial. An increasing trend was observed in the number of episodes (1984 vs 1990) from 0.9 vs 1.8 episodes per 1,000 admissions, respectively. The mean age was 57 years and the male/female relation was 2.4/1. The most frequent focus of origin was infection of the vascular catheter (43%), followed by intraabdominal catheter (21%), urinary tract (14%), and other foci (17%). Fifty-four percent of the patients had received antibiotics prior to the episode of bacteremia. Most of the cases were detected in the Intensive Care Units (ICU) (41%) and in the gastrointestinal surgery area (24%). Global mortality was 23%. Logistic regression analysis selected an entry site other than infection of the vascular catheter (odds ratio 6.1; CI [95%)] 2.0-18.4), shock (odds ratio, 6; CI [95%], 1.6-21.9) and immunosuppressive treatment (odds ratio, 5; CI [95%], 1.5-16.2) as independent variables of bad prognosis. CONCLUSIONS: Enterobacter spp. is an important nosocomial pathogen taking fourth place in the ranking of nosocomial bacteremia by gram negative bacilli. It predominantly affects a population of patients admitted in the ICU and surgery. The intravascular catheter is a frequent entry site for nosocomial bacteremia by Enterobacter spp.

Lactobacillus pneumonia in a patient with oesophageal carcinoma.

We report a case of necrotizing pneumonia caused by Lactobacillus secondary to a tracheo-oesophageal fistula created by an oesophageal carcinoma. We emphasize the presence of resistance of Lactobacillus to clindamycin and cotrimoxazole, previously reported to be effective.

In-vitro activity of ciprofloxacin, ceftriaxone and five other antimicrobial agents against 95 strains of Brucella melitensis.

We studied the in-vitro activity of seven antibiotics against 95 strains of Brucella melitensis isolated in blood cultures of 95 patients with brucellosis. The minimum inhibitory concentration (MIC) was measured by the agar dilution method. All strains of B. melitensis were inhibited by doxycycline at 0.25 mg/l, tetracycline at 0.5 mg/l, ciprofloxacin at 0.5 mg/l, streptomycin at 1 mg/l, ceftriaxone at 1 mg/l, rifampicin at 4 mg/l and by co-trimoxazole at 0.5/9.5 mg/l. We did not find strains resistant to any of the antibiotics studied. All antibiotics, including ciprofloxacin and ceftriaxone, showed a good in-vitro activity against B. melitensis.