Bacterial DNA in the diagnosis of spontaneous bacterial peritonitis.

BACKGROUND: Despite inoculation into blood culture bottles, ascitic fluid culture is negative in 50% of cases of spontaneous bacterial peritonitis (SBP). AIM: To determine whether 16S rDNA gene detection by real-time polymerase chain reaction (PCR) and sequencing increases the efficacy of culture in microbiological diagnosis of spontaneous bacterial peritonitis. METHODS: We prospectively included 55 consecutive spontaneous bacterial peritonitis episodes in cirrhotic patients, 20 cirrhotic patients with sterile ascites and 27 patients with neoplasic ascites. Ascitic fluid was inoculated into blood culture bottles at the bedside and tested for bacterial DNA by real-time PCR and sequencing of 16S rDNA gene. RESULTS: Bacterial DNA was detected in 23/25 (92%) culture-positive SBP, 16/30 (53%) culture-negative SBP (P = 0.002 with respect to culture-positive SBP), 12/20 (60%) sterile ascites (P = 0.01 with respect to culture-positive SBP) and 0/27 neoplasic ascites (P < 0.001 with respect to other groups). Sequencing identified to genus or species level 12 culture-positive SBP, six culture-negative SBP and six sterile ascites. In the remaining cases with positive PCR, sequencing did not yield a definitive bacterial identification. CONCLUSIONS: Bacterial DNA was not detected in almost half the culture-negative spontaneous bacterial peritonitis episodes. Methodology used in the present study did not always allow identification of amplified bacterial DNA.

Relevance of genetically determined host factors to the prognosis of meningococcal disease.

To assess the relevance of genetically determined host factors for the prognosis of meningococcal disease, Fc gamma receptor IIA (FcgammaRIIA), the tumor necrosis factor alpha (TNF-alpha) gene promoter region, and plasminogen-activator-inhibitor-1 (PAI-1) gene polymorphisms were studied in 145 patients with meningococcal disease and in 290 healthy controls matched by sex. Distribution of FcgammaRIIA, TNF-alpha, and PAI-1 alleles was not significantly different between patients and controls. Patients with the FcgammaRIIA-R/R 131 allotype scored > or =1 point in the Barcelona prognostic system more frequently than patients with other allotypes (odds ratio, 18.6; 95% confidence interval, 7.1-49.0, P<0.0001), and they had a higher risk of sequelae (odds ratio, 3.5; 95% confidence interval, 1.1-11.7; P=0.03). Fc gamma receptor IIA polymorphism was associated with markers of disease severity, but TNF-alpha and PAI-1 polymorphisms were not.

Fungal infections in patients with solid tumors treated with high-dose chemotherapy and autologous peripheral blood stem cell transplantation.

The incidence and risk factors for fungal infection were assessed in 291 patients who had solid tumors and were undergoing autologous peripheral blood stem cell transplantation. The first 162 patients received prophylactic itraconazole, and 129 patients received nystatin. Empiric amphotericin B was given at day 7 of febrile neutropenia. Fungal infections developed in 52 patients: 47 (16%) were superficial and 6 (2%) were systemic. Itraconazole prophylaxis and only a few days of febrile neutropenia were independently associated with a decrease in the incidence of superficial infections. Only two patients required empiric amphotericin B. Systemic antifungal prophylaxis does not seem to be justified for patients with solid tumors and autologous peripheral blood stem cell transplantation. Empiric amphotericin B may be safely started at day 7 of febrile neutropenia.

Bacteraemia caused by non-glucose-fermenting gram-negative bacilli and Aeromonas species in patients with haematological malignancies and solid tumours.

The clinical characteristics and outcome of bacteraemia caused by non-glucose-fermenting gram-negative bacilli and Aeromonas spp. were examined in 115 adults with haematological malignancies or solid tumours. The most aggressive pathogens were Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Aeromonas spp., Acinetobacter spp. and Burkholderia cepacia, all of which caused either septic syndrome or pneumonia in more than 40% of cases. Pseudomonas aeruginosa was involved less often in catheter-related bacteraemia than other species. Polymicrobial bacteraemia (n=28) was more often catheter-related than monomicrobial bacteraemia and more often required catheter removal for definitive cure. The most important predictors of catheter-related bacteraemia and its outcome were polymicrobial infection, the presence of pneumonia or septic syndrome and the species involved.

Infection caused by Nocardia farcinica: case report and review.

Nocardia farcinica is a rare Nocardia species causing localised and disseminated infections. A case of Nocardia farcinica infection is presented, and 52 cases previously reported in the literature are reviewed. The hosts usually had predisposing conditions (85%), and acquired the infection through the respiratory tract or skin; the infection then often spread to the brain, kidney, joints, bones and eyes. Pulmonary or pleural infections (43%), brain abscesses (30%) and wound infections (15%) which failed to respond to conventional antimicrobial therapy were the more frequent forms of infection. Nocardia farcinica was frequently isolated from pus (100% of samples), bronchial secretions (41%) and biopsy specimens (63%), but isolation from blood and urine, as in the case presented here, is rare. Antibiotic therapy was adequate in 61% of the patients in whom it was specified, the agents most frequently given being trimethoprim-sulfamethoxazole (54%), amikacin combined with imipenem (7%) and amoxicillin-clavulanate (7%). The high mortality (31%) can be attributed to the severe underlying diseases present, difficulties encountered in identifying the pathogen, inappropriate therapy and late initiation of therapy. Although an infrequent pathogen, Nocardia farcinica should be kept in mind as a cause of infection especially in immunosuppressed patients with indolent infections not responding to third-generation cephalosporins.

Group A streptococcal meningitis in the antibiotic era.

A case of group A streptococcal meningitis is reported and the 51 cases reported in the literature since 1966 reviewed. A total of 24 men and 24 women were included in the study; the mean age (+/-SD) was 20.9+/-25.5 years. Fifty-eight percent of the patients had comorbid conditions, 80% had a distant focus of infection, and 65.8% had blood cultures positive for group A streptococci. Seventy-five per cent of the patients were treated with penicillin. The overall case-fatality rate was 12% (6 patients). Sequelae were more prevalent among children (44%) than among adults (7.7%) (OR=9.43; 95% CI, 1.02-438.95; P=0.03). Group A streptococcus is a rare cause of pyogenic meningitis, affecting mainly children or adults with comorbidity. Although the case-fatality rate is relatively low, neurological sequelae are frequent among survivors, especially children.

Bacteremia by gram-negative bacilli in patients with hematologic malignancies. Comparison of the clinical presentation and outcome of infections by enterobacteria and non-glucose-fermenting gram-negative bacilli.

To compare the characteristics of bacteremic infections by different aerobic gram-negative bacilli (GNB) in patients with hematologic malignancies, we studied 54 consecutive monomicrobial bacteremias by Enterobacteriaceae (EB), 15 by Pseudomonas aeruginosa, 43 by other non-glucose-fermenting GNB (NGFGNB) and 11 by other GNB. Patients with EB and P. aeruginosa bacteremia usually developed the infection after intensive chemotherapy for leukemia or during a hematopoietic stem cell transplantation, while most infections in outpatients off therapy were due to NGFGNB. A significant proportion of bacteremias by EB (37%) and P. aeruginosa (40%) were accompanied by severe morbidity (septic shock, pneumonia or deep-seated organ infections) vs. only 7% of other NGFGNB (p < 0.01). Most infections by these latter bacteria were catheter-related bacteremias (80 vs. 2% of EB, p < 0.005), while most EB infections (61%) were uncomplicated bacteremias of unknown source (vs. 14% of other NGFGNB, p < 0.005). Appropriate antibiotics alone cured 98% of EB and 73% of P. aeruginosa bacteremias but only 26% of other NGFGNB (p < 0.005 for both differences), which were cured by catheter removal in 70%, usually after failure of antibiotic treatment. In conclusion, our results suggest that there are significant differences in the patient populations and clinical characteristics of bacteremic infections by the classic GNB (EB and P. aeruginosa) and the new NGFGNB in adults with hematologic malignancies.

[Haemophilus influenzae meningitis in adults: analysis of 12 cases]. / Meningitis por Haemophilus influenzae en adultos: análisis de 12 casos.

Haemophilus influenzae is an infrequent etiologic agent of bacterial meningitis in adult patients. In the last 12 years, it was the cause in 12 out of 238 cases (5.0%) of acute bacterial meningitis in adults. There were 5 men and 7 women with a mean age (SD) of 45.4 (16) years (range: 18-68 years). Seven patients (60%) had a communication between subarachnoid space and skin surface or mucosal cavities, and five (41.7%) had otitis or sinusitis. Most of the strains (9/12) were serotype b. Only one patient (8.3%) developed severe neurologic and extra-neurologic complications, and was the one who died. One of the survivors (9.1%) had partial deafness. H. influenzae is not a negligible cause of bacterial meningitis in adults. Moreover, its detection has been increasing in the last years. Patients with a cerebrospinal fluid leak, otitis or sinusitis are at high risk. The outcome is usually favorable if an early adequate therapy is given.

Effect of discontinuing prophylaxis with norfloxacin in patients with hematologic malignancies and severe neutropenia. A matched case-control study of the effect on infectious morbidity.

The use of fluorinated quinolones for prophylaxis of infections in neutropenic cancer patients has led to a reduction of infections with gram-negative enteric bacilli, but there is concern about the emergence of antibiotic-resistant entero-bacterial infections and a rise of gram-positive bacteremias. Due to these concerns, in mid-1995 the use of prophylactic norfloxacin was discontinued in our unit. In order to evaluate the impact of this measure on the infectious morbidity in our unit, 91 severe neutropenic episodes in 58 patients with hematologic malignancies who did not receive norfloxacin prophylaxis (NO group) were closely matched to 91 episodes in 60 patients who received norfloxacin prophylaxis (NORFLO group). There were no differences in the incidence of febrile neutropenia, fever of unknown origin or bacteremia during the first febrile episode. There was a trend for a higher rate of coagulase-negative staphylococcal bacteremia in the NORFLO group (5 vs. 11 cases in the NO and NORFLO groups, respectively, p = NS). Enterobacterial bloodstream infections were more frequent in the NO group (13 vs. 2 cases, respectively, p = 0.01), especially Escherichia coli (9 vs. 1 case, respectively, p = 0.01). Twelve of 13 enterobacterial isolates in the NO group were sensitive to the fluoroquinolones vs. 0/2 in the NORFLO group (p = 0.07). We conclude that the abrupt discontinuation of norfloxacin prophylaxis in our ward led to a rapid increase in the rate of fluoroquinolone-susceptible enterobacterial infections, with a scarce impact on infectious morbidity. This suggests that the selection of resistant flora in an inpatient ward by prophylactic antimicrobials may be reversible following the discontinuation of the prophylactic agent(s).

Achromobacter xylosoxidans bacteremia in patients with hematologic malignancies.

We report nine cases of Achromobacter xylosoxidans bacteremia diagnosed in patients with hematologic malignancies. There was not an obvious epidemiologic link between cases and the organism was not isolated from any source. Outcome was cure in all nine cases. In our experience, catheter removal is generally required for eradication of A. xylosoxidans.

[Etiology of enteritis in a university general hospital in Barcelona (1992-1995)]. / Etiología de la enteritis en un hospital general universitario en Barcelona (1992-1995).

BACKGROUND: The aim of the study was to describe the etiology of enteropathogenic agents over a four-year period (1992-1995) in a University Hospital in Barcelona. METHODS: We studied 12,793 stool samples, 4519 were obtained from patients under 15 years and 8274 were obtained from patients over 14 years. The specimens were examined for bacteriological, parasitological and virological enteropathogens. RESULTS: In 3380 specimens of 12,793 stool samples studied were identified an enteropathogen (26.4%). Polymicrobial associations were observed in the 6.8% of the cases. Pathogens were identified in 45% of children samples and 16.3% of adults samples. The etiological enteritis agents more frequently detected in the paediatric patients were Campylobacter (13.5%), rotavirus (11.3%) and Salmonella (10.2%); and Salmonella (4.9%), Campylobacter (3.1%) and Giardia intestinalis (2.1%) in adults. Cryptosporidium (13.5%) was the most frequent cause of gastrointestinal tract infections in HIV-infected subjects. In the children with stools positives, the presence of red and white blood cells were more frequent than the adults with stools positives (73% versus 26.6%). CONCLUSIONS: The enteropathogenic agents such as Campylobacter, Salmonella, and Giardia were the most frequent cause of gastroenteritis in our environment. In the children, rotavirus infections predominated during the cold months. The most frequent cause of gastroenteritis in HIV-infected patients was Cryptosporidium followed by Campylobacter.

Early microbiologic diagnosis of spontaneous bacterial peritonitis with BacT/ALERT.

BACKGROUND/AIMS: Inoculation of ascitic fluid into conventional blood culture bottles is more sensitive than conventional culture in the diagnosis of spontaneous bacterial peritonitis. BacT/ALERT is an automated colorimetric microbial detection system that has been shown to be faster than conventional blood culture bottles in the diagnosis of bacteremia. The aim of the study was to compare the BacT/ALERT system with the conventional culture and the conventional blood culture bottles method in the diagnosis of spontaneous bacterial peritonitis. METHODS: All the ascitic fluid samples from patients with cirrhosis hospitalized in our Department between September 1992 and May 1994 (n=1032) were prospectively evaluated. In all cases, an aliquot of ascitic fluid was sent for Gram's stain and conventional culture, and 20 ml were inoculated at the bedside into blood culture bottles: 10 ml into conventional blood culture bottles and 10 ml into BacT/ALERT. RESULTS: Thirty ascitic fluid infections (23 spontaneous bacterial peritonitis and 7 neutrocytic ascites) and 20 bacterascites were diagnosed. Conventional culture was positive in 10/30 ascitic fluid infections (33.3%), conventional blood culture bottles in 22/30 (73.3%) (p<0.01 compared to conventional culture) and BacT/ALERT in 20/30 (66.6%) (p<0.05 compared to conventional culture, pNS compared to conventional blood culture bottles). The time elapsed for culture positivity was 43.4+/-34.2 h for conventional blood culture bottles and 13.3+/-9.2 h for BacT/ALERT (p<0.001). Thirteen of the 23 cases of spontaneous bacterial peritonitis (56.5%) were detected within the first 12 h with BacT/ALERT, as compared to only three (13%) with conventional blood culture bottles (p<0.03). CONCLUSION: The automated system BacT/ALERT provides an earlier microbiologic diagnosis of spontaneous bacterial peritonitis than conventional blood culture bottles with similar sensitivity.

Acute rhabdomyolysis and myonecrosis complicating aeromonas bacteremia in neutropenic patients with hematologic malignancies: report of two cases.

Infections by Aeromonas spp. are a rare cause of systemic infection in normal and immunocompromised hosts. We report the cases of two patients with acute non-lymphoblastic leukemia who developed septic shock by Aeromonas species with unusual soft-tissue complications. One patient who was undergoing consolidation chemotherapy developed septic shock by Aeromonas hydrophila with rhabdomyolysis and subsequent soft-tissue destruction consistent with myonecrosis. She recovered with combination antibiotic therapy and supportive care. The second patient developed neutropenia due to ganciclovir treatment for post-allogeneic transplant cytomegalovirus antigenemia. He developed a rapidly progressive septic shock due to Aeromonas sobria with rhabdomyolysis, multi-organ failure and bilateral lower limb myonecrosis, and died within 48 hours. The portal of entry was not identified in either case. These cases confirm the potentially aggressive nature of these bacteria in neutropenic cancer patients with an unusual tendency to produce muscular and soft-tissue destruction.

Bacteremia due to glucose non-fermenting gram-negative bacilli in patients with hematological neoplasias and solid tumors.

Twenty-six patients with hematological or solid tumors who developed bacteremia caused by Stenotrophomonas maltophilia (n = 10), Pseudomonas putida (n = 6), Sphingomonas paucimobilis complex (n = 4) or Alcaligenes xylosoxidans (n = 6) in the period between 1993 and 1995 were studied. Seventeen patients were neutropenic during the infection, and 13 were undergoing bone marrow or peripheral blood stem cell transplantation. Twenty-three patients had catheter-related infections; only 3 of the 26 patients developed septic complications (all due to Stenotrophomonas maltophilia). Twenty patients were cured following catheter removal, either as primary measure (n = 8) or salvage measure (n = 12). Four responded to antibiotic therapy only, and two died of septic complications. Such infections in hematological and oncological patients have increased in this hospital from no cases in 1975 to 11 cases in 1995.