Microbiologic findings and correlations with serum tumor necrosis factor-alpha in patients with severe sepsis and septic shock.
To understand the microbiology of sepsis and its relationship with tumor necrosis factor (TNF)-alpha, 444 septic patients were studied in a phase II clinical trial. In total, 270 (61%) 444 of episodes were microbiologically documented. The most common isolates were Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. In some patients, obligate anaerobes were isolated in pure culture. Data on baseline TNF-alpha (n=409) showed that the geometric mean TNF-alpha concentrations in patients with severe sepsis and in those with late shock were 41 pg/mL (range, 5-3310) and 58 pg/mL (range, 5-1870), respectively. Patients with a positive culture had significantly higher TNF-alpha levels (65.9 vs. 29.2 pg/mL, P=.0001). Patients with a pure gram-negative infection had significantly higher TNF-alpha levels than those with a pure gram-positive or mixed infection, especially in the late shock group (142.6, 64.0, and 52.8 pg/mL, respectively, P=.004). These results provide further support for the concept that patients with sepsis are a heterogeneous group that require more precise definition. (+info)
Developments in fungal taxonomy.
Fungal infections, especially those caused by opportunistic species, have become substantially more common in recent decades. Numerous species cause human infections, and several new human pathogens are discovered yearly. This situation has created an increasing interest in fungal taxonomy and has led to the development of new methods and approaches to fungal biosystematics which have promoted important practical advances in identification procedures. However, the significance of some data provided by the new approaches is still unclear, and results drawn from such studies may even increase nomenclatural confusion. Analyses of rRNA and rDNA sequences constitute an important complement of the morphological criteria needed to allow clinical fungi to be more easily identified and placed on a single phylogenetic tree. Most of the pathogenic fungi so far described belong to the kingdom Fungi; two belong to the kingdom Chromista. Within the Fungi, they are distributed in three phyla and in 15 orders (Pneumocystidales, Saccharomycetales, Dothideales, Sordariales, Onygenales, Eurotiales, Hypocreales, Ophiostomatales, Microascales, Tremellales, Poriales, Stereales, Agaricales, Schizophyllales, and Ustilaginales). (+info)
Comparative performance of the RapID Yeast Plus System and the API 20C AUX Clinical Yeast System.
The performance of the RapID Yeast Plus System (Innovative Diagnostic Systems, Norcross, Ga.), a 4-h micropanel using single-substrate enzymatic test reactions, was compared with that of the API 20C AUX Clinical Yeast System (bioMerieux Vitek, Hazelwood, Mo.), a 48- to 72-h carbohydrate assimilation panel. Two hundred twenty-five yeasts, yeast-like fungi, and algae, comprising 28 species and including 30 isolates of Cryptococcus neoformans, an important pathogen not tested in appreciable numbers in other comparisons, were tested by both methods. On initial testing, 196 (87.1%) and 215 (95.6%) isolates were correctly identified by the RapID and API systems, respectively. Upon repeat testing, the number of correctly identified isolates increased to 220 (97.8%) for the RapID system and 223 (99.1%) for the API system. Reducing the turbidity of the test inoculum to that of a no. 3 McFarland turbidity standard, which is below that recommended by the manufacturer, resulted in the correct identification of most of the isolates initially misidentified by the RapID system, including 10 of 30 C. neoformans isolates. Concordance between the RapID and API results after repeat testing was 97.3%. (+info)
Mastigobasidium, a new teleomorphic genus for the perfect state of ballistosporous yeast Bensingtonia intermedia.
A new genus, Mastigobasidium, is proposed for teliospore-forming, xylose-lacking, ballistosporogenous, glucuronate-positive yeasts. The distinguishing features of the genus are: germination of the teliospore by several long aseptate hyphae; curved phragmometabasidia development on the apices of these hyphae; and production of basidiospores on a peg in clusters. The type strain of heterothallic, nitrate-negative species Mastigobasidium intermedium is VKM Y-2720T (Bullera intermedia type strain) and the allotype strain is VKM Y-2727AL (Sporobolomyces weijmanii type strain). (+info)
Comparison of four methods for DNA typing of clinical isolates of Candida glabrata.
A series of 35 isolates of Candida glabrata from 29 subjects (five AIDS patients and 24 HIV-seronegative individuals) was typed by electrophoretic karyotyping (EK), restriction fragment length polymorphism (RFLP) analysis, random amplification of polymorphic DNA (RAPD) and inter-repeat PCR (IR-PCR). The rank order of discriminatory ability among the four methods was as follows: EK (25 DNA types) > RAPD (19 DNA types) > IR-PCR (14 DNA types) > RFLP (4 DNA types). A composite DNA type was defined for each of the strains as the combination of types obtained by the four molecular methods. A total of 32 DNA types was obtained by this procedure; each individual harboured their own specific isolate (DNA type). Neither source of isolation nor HIV status was associated with a given DNA type. In three of five cases, initial and relapse isolates from individual patients were assigned to the same DNA type. These findings indicate that EK is the most useful method for the investigation of inter-strain variations within this Candida species. (+info)
Distinctive electrophoretic isoenzyme profiles in Saccharomyces sensu stricto.
Genetic variation among 35 strains representing the four currently recognized species of Saccharomyces sensu stricto (Saccharomyces cerevisiae, Saccharomyces bayanus, Saccharomyces pastorianus/carlsbergensis and Saccharomyces paradoxus) was estimated by analysing the electrophoretic mobilities of nonspecific esterases, acid phosphatase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase isoenzymes. Twenty-two electrophoretic types were identified, a result in agreement with the phenotypic and genetic polymorphisms reported for this group of yeasts. However, the four species were clearly distinguishable based on the patterns obtained using three of the enzymes assayed, the resolving power not being improved by the introduction of data correspondent to lactate dehydrogenase. The overall diversity was higher among S. cerevisiae isolates, in contrast with S. paradoxus which showed only two patterns, one of which was common to four of the five strains studied. Concordant results from the application of the method and DNA hybridization experiments demonstrate its value for identification purposes. (+info)
Species and genotypic diversities and similarities of pathogenic yeasts colonizing women.
We examined the patterns of strain relatedness among pathogenic yeasts from within and among groups of women to determine whether there were significant associations between genotype and host condition or body site. A total of 80 yeast strains were isolated, identified, and genotyped from 49 female volunteers, who were placed in three groups: (i) 19 women with AIDS, (ii) 11 pregnant women without human immunodeficiency virus (HIV) infection, and (iii) 19 women who were neither pregnant nor infected with HIV. Seven yeast species were recovered, including 59 isolates of Candida albicans, 9 isolates of Candida parapsilosis, 5 isolates of Candida krusei, 3 isolates of Candida glabrata, 2 isolates of Saccharomyces cerevisiae, and 1 isolate each of Candida tropicalis and Candida lusitaniae. Seventy unique genotypes were identified by PCR fingerprinting with the M13 core sequence and by random amplified polymorphic DNA analysis. Of the nine shared genotypes, isolates from three different hosts were of one genotype and pairs of strains from different body sites of the same host shared each of the other eight genotypes. Genetic similarities among groups of strains were calculated and compared. We found no significant difference in the patterns of relatedness of strains from the three body sites (oral cavity, vagina, and rectum), regardless of host conditions. The yeast microflora of all three host groups had similar species and genotypic diversities. Furthermore, a single host can be colonized with multiple species or multiple genotypes of the same species at the same or different body sites, indicating dynamic processes of yeast colonization on women. (+info)
Epidemiology of oropharyngeal Candida colonization and infection in patients receiving radiation for head and neck cancer.
Oral mucosal colonization and infection with Candida are common in patients receiving radiation therapy for head and neck cancer. Infection is marked by oral pain and/or burning and can lead to significant patient morbidity. The purpose of this study was to identify Candida strain diversity in this population by using a chromogenic medium, subculturing, molecular typing, and antifungal susceptibility testing of clinical isolates. These results were then correlated with clinical outcome in patients treated with fluconazole for infection. Specimens from 30 patients receiving radiation therapy for head and neck cancer were cultured weekly for Candida. Patients exhibiting clinical infection were treated with oral fluconazole. All isolates were plated on CHROMagar Candida and RPMI medium, subcultured, and submitted for antifungal susceptibility testing and molecular typing. Infections occurred in 27% of the patients and were predominantly due to Candida albicans (78%). Candida carriage occurred in 73% of patients and at 51% of patient visits. Yeasts other than C. albicans predominated in carriage, as they were isolated from 59% of patients and at 52% of patient visits. All infections responded clinically, and all isolates were susceptible to fluconazole. Molecular typing showed that most patients had similar strains throughout their radiation treatment. One patient, however, did show the acquisition of a new strain. With this high rate of infection (27%), prophylaxis to prevent infection should be evaluated for these patients. (+info)