Gisele Madeira Duboc de Almeida

Central venous catheter-associated fungemia due to Rhodotorula spp. – A systematic review

Rhodotorula spp. are emergent opportunistic pathogens, particularly in immunocompromised individuals. They have been associated with endocarditis, peritonitis, meningitis endophthalmitis and catheter-associated fungemia. The aim of this study was to review all cases of central venous catheter-related fungemia due to Rhodotorula spp. reported in the literature in order to determine the best management of this uncommon infection. All patients but one in the 88 cases examined had some form of underlying disease including sixty-nine (78.4%) who had cancer. Rhodotorula mucilaginosa was the species most frequently recovered (75%), followed by Rhodotorula glutinis (6%). Amphotericin B deoxycholate was the most common antifungal agent used as treatment and the overall mortality was 9.1% in this review. This fungemia is a rare disease which can be found in immunocompromised and in the intensive care patients. The use of specific antifungal therapy may be associated with an increase in the survival. It should be noted that Rhodotorula spp. is resistant to fluconazole.

Rhodotorula spp. isolated from blood cultures: clinical and microbiological aspects

The emergence of less common fungal pathogens has been increasingly reported in the last decade. We describe 25 cases of Rhodotorula spp. isolated from blood cultures at a large Brazilian tertiary teaching hospital from 1996-2004. We also investigated the in vitro activity of four antifungal drugs, using a standardized method. The median age of patients was 43 years. The majority of patients (88%) had a central venous catheter (CVC) and 10 (40%) were recipients of a bone marrow transplant. The episode was classified as a bloodstream infection (BSI) in 80% of the patients. Amphotericin B deoxycholate was the most common antifungal used and CVC was removed in 89.5% of the patients. Death occurred in four patients (17.4%), all classified as BSI. All strains were identified as R. mucilaginosa by conventional methods. Misidentification of the species was observed in 20% and 5% of the strains with the Vitek Yeast Biochemical Card and API 20C AUX systems, respectively. Amphotericin B demonstrated good in vitro activity (MIC50/90, 0.5 microg/ml) and the MICs for fluconazole were high for all strains (MIC50/90, >64 microg/ml).

SEROTYPE, MATING TYPE AND PLOIDY OF Cryptococcus neoformans STRAINS ISOLATED FROM PATIENTS IN BRAZIL

Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A). Only one strain was var. gattii (serotype B). No var. neoformans (serotype D) was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A) and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha) and the remaining 2 were untypable (asexual). Most of the MATalpha strains (69/73) were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha) strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.

The usefulness of adenosine deaminase in the diagnosis of tuberculous pericarditis

The objective of this study was to evaluate the adenosine deaminase (ADA) activity usefulness in the diagnosis of tuberculous pericarditis (TP), comparing its value with pericardial effusions (PE) caused by other pericardial diseases. A retrospective case-control study was conducted with nine cases of TP and 39 other than TP diseases (12 neoplastic, 11 septic and 16 unknown origin). Every patient included in this study had PE samples submitted to ADA activity measures and microbiological analysis, and then had pericardial tissue samples submitted to microbiological and histopathological examination. Considering the value of 40 U/L as the cut-off for the diagnosis of TP, the specificity and sensitivity were respectively of 72% and 89%. The specificity of ADA activity for the TP was best applied in the differential diagnosis from PE of unknown origin. The present study demonstrates the clinical value of the measurement of ADA activity in PE in the diagnosis of TP.

Listeria monocytogenes peritonitis in cirrhotic patients: first description in Brazil

Two cases of spontaneous bacterial peritonitis (SBP) caused by Listeria monocytogenes in cirrhotic patients are reported. In one of the cases, the microorganism was isolated from pleural effusion and ascites. SBP is a serious and common complication of patients with ascites caused by hepatic cirrhosis and the culture of the ascitic fluid is an important tool for the diagnosis and for the more appropriate treatment. Although a third generation cephalosporin has usually been employed for empiric treatment of SBP, it does not provide adequate coverage against Listeria spp. In such cases the use of ampicillin (with or without sulbactam) or sulfamethoxazole-trimethoprim is recommended. The last one is used for secondary prophylaxis, instead of norfloxacin. To summarize, Listeria monocytogenes infection is a rare cause of SBP, whose treatment should be specific for the bacteria.

Use of hepatitis C-positive donors in transplantation.

Transplantation (Tx) is a therapeutic alternative intervention for terminal organ dysfunction, fatal disease or, in some cases, to improve the quality of life and reduce the risk of complications from chronic diseases. One of the major limitations in performing transplants is obtaining donor organs because of the difficulties in the process of organ donation of deceased donors and the unavailability of compatible living donors. In Brazil, there are many more patients on waiting lists, especially for liver and kidney transplants, than the number of procedures performed. Therefore, non-ideal donors are sometimes considered for transplantation, including those with a higher risk of primary graft dysfunction and infection transmission, such as hepatitis C virus (HCV)-seropositive donors. HCV-seropositive donors have routinely been used by a few groups or in cases of extreme urgency. However, the safety of transplantation from HCV-positive donors has not been clearly determined and may vary according to the type of transplant. To establish a set of recommendations, we performed an analysis based on the data available in the literature. The following items were considered according to the type of transplantation: 1) the position on the list, 2) the urgency of transplantation, 3) the HCV infection status of the donor (serology, viral replication and histological activity), 4) the HCV infection status of the recipient (serology, viral replication and histological activity) and 5) the safety data available regarding the use of HCV-seropositive donors. We analyzed liver, kidney, heart, lung and hematopoietic stem cell transplants (HSCTs). The IDSA (Infectious Diseases Society of America) rating system was used to establish levels of evidence. 1. Liver Transplantation Chronic liver disease due to HCV accounts for almost one-half of liver Tx indications. The risk of the histological recurrence of hepatitis after transplantation is approximately 70%. The graft and recipient survival is lower compared with other etiologies. Descriptive and comparative studies and case-control analyses have shown that the use of seropositive donors for seropositive recipients does not interfere with graft or patient survival. 2. Kidney Transplantation Some descriptive studies have shown that the use of seropositive donors for seropositive recipients does not interfere with graft or patient survival. However, one publication described five cases of discordant donor and recipient genotypes: in three of these cases, elevated enzyme levels and genotype substitution or association were observed in the recipient after transplant. 3. Heart Transplantation Little data are available regarding heart Tx. One multicenter study reported a lower survival rate in patients who received organs from seropositive donors, regardless of the HCV serostatus of the recipient. 4. Lung Transplantation Little data are also available regarding lung Tx. However, in a multicenter survey, 72% of the participating groups considered the use of HCV-seropositive donors for HCV-seropositive recipients. Nevertheless, there have been no descriptions of liver disease progression or graft and patient survival in positive viremia recipients. It is important to consider that treatment with interferon-gamma is usually not recommended after lung Tx due to the high risk of acute cellular rejection. 5. Hematopoietic Stem Cell Transplantation (HSCT) In HSCT, there have been reports of a significantly increased risk of hepatitis in HCV-seronegative recipients of seropositive donors, especially when there is evidence of viral replication. Because HSCT often involves situations in which there is an imminent risk of death and the need for an HLA-matched living donor, the decision should be based on the urgency of the Tx and level of viremia in the donor.

Prophylaxis of fungal infections in transplant patients

Fungi are an important cause of infection in patients undergoing solid organ transplantation and bone marrow or hematopoietic stem cell transplantation (BMT/HSCT). The incidence and mortality of fungal infections differ according to the organ and the time since transplantation. In the first 30 days after transplantation, yeast (primarily Candida spp.) predominate. After the first month, filamentous fungi, such as Aspergillus spp., are the most frequent agents of infection (1-6). In BMT/HSCT patients, however, invasive aspergillosis has two peaks of incidence: one at one month post-transplantation and another approximately 90 days after the transplant if the patient develops chronic graft versus host disease (7,8). Among solid organ transplantation, liver and lung transplant have the highest risk for fungal infection due to underlying diseases, surgical techniques and the graft itself (4,9). Antifungal prophylaxis use is well established following some transplant types, such as BMT/HSCT and liver (10,11). However, few studies have evaluated heart and pancreas transplants. One of the major challenges is the prevention of filamentous fungal infections, especially by Aspergillus spp., in high-risk patients, such as those who have undergone an allogeneic BMT and developed chronic graft versus host disease or undergone a lung transplantation (12,13). To standardize the use of primary prophylaxis in transplant patients, we analyzed the literature related to the following transplants: liver, kidney, heart, lung, and HSCT. The IDSA (Infectious Diseases Society of America) system was used to determine the levels of evidence.

Diferença de tempo de positividade: método útil no diagnóstico de infecção de corrente sanguínea relacionada com cateter?

INTRODUCTION: Not only do catheter related bloodstream infections (CRBSIs) have considerable impact on morbidity and mortality in hospitalized patients, but they also raise hospital costs. The use of automated equipment in blood culture processing has allowed an alternative diagnosis of CRBSI by analyzing the differential time to positivity (DTP) of paired blood cultures (collected simultaneously) of peripheral blood and catheter blood. A rapid and accurate diagnosis of these infections may optimize clinical and therapeutic management, which prevents early catheter removal. OBJECTIVES: To assess DTP as an auxiliary tool for the diagnosis of CRBSI as well as to determine the main isolated microorganisms. METHODS: We evaluated blood cultures that had previously been collected in the complex Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HC/FMUSP) from May to August 2008. According to the laboratory criteria, only DTP higher than 120 minutes was regarded as possible CRBSI. RESULTS: During the investigation period 11,017 aerobic blood cultures were processed, from which only 5% were paired samples. One hundred forty-eight (28%) samples were positive, from which 9% showed growth in peripheral blood, 41% only in catheter blood and 50% in both blood samples with 88% homology of identified microorganisms. DTP higher than 120 minutes occurred in 50% of the cases. The most common isolated microorganisms were: Staphylococcus aureus (22%), Candida spp. (18%), Klebsiella spp (7%). and Enterobacter spp (7%). CONCLUSION: The determination of the DTP as an auxiliary tool for the diagnosis of CRBSI is feasible and easily performed in clinical laboratories with automation, although the process of paired sample collection must be rigidly standardized.