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Fungemia is associated with a high mortality rate. We compared the performance of the Mycosis IC/F selective fungal medium and the Plus Aerobic/F standard bacteriological medium for the diagnosis of fungemia on the Bactec 9240 automatic system. We retrospectively analyzed 550 blood culture pairs composed of one Mycosis IC/F vial and one Plus Aerobic/F vial, drawn in 187 patients with fungemia. The positivity rate by vial was significantly higher on Mycosis IC/F medium than on Plus Aerobic/F medium (88.0% versus 74.9%, P < 0.0001). The positivity rate for fungus detection on Plus Aerobic/F medium fell to 26.9% when bacteria were present in the same vial. The positivity rate by patient was also significantly higher on Mycosis IC/F medium than on Plus Aerobic/F medium (92.5% versus 75.9%, P < 0.0001). A marked superiority of Mycosis IC/F medium was demonstrated for diagnosis of Candida glabrata fungemia (31 of 31, 100%, versus 18 of 31, 58.1%, P < 0.0001). The mean detection time was significantly shorter on Mycosis IC/F medium than on Plus Aerobic/F medium (28.9 +/- 22.2 h versus 36.5 +/- 24.6 h, P < 0.0001). The mean time saving was 8.8 h for Candida albicans and 43.7 h for C. glabrata. Mycosis IC/F medium enabled more sensitive and earlier diagnosis, particularly for the two strains most frequently responsible for fungemia, C. albicans and C. glabrata, and also in the event of the concomitant presence of both yeasts and bacteria. In patients with risk factors, it would thus appear to be sensible to draw a Mycosis IC/F vial in addition to the standard bacteriological vials.

Described herein is our experience with the MicroSeq D2 large-subunit rDNA sequencing kit for the identification of filamentous fungi encountered in the mycology laboratory at the Mayo Clinic. A total of 234 filamentous fungi recovered from clinical specimens were used in the evaluation. All were identified by using phenotypic characteristics as observed macroscopically and microscopically on any medium or a combination of media, which included Sabouraud's dextrose, inhibitory mold, cornmeal, Czapek-Dox, potato dextrose, and V8 juice agars; all isolates were sequenced using the MicroSeq D2 large-subunit rDNA sequencing kit. Of the of 234 isolates, 158 were correctly identified to the appropriate genus or genus and species by using nucleic acid sequencing. Sequences for 70 (29.9%) of the isolates (27 genera) were not included in the MicroSeq library. Of the 80 dematiaceous and 154 hyaline fungi sequenced, 65 and 51.2%, respectively, gave results concordant with those determined by phenotypic identification. Nucleic acid sequencing using the MicroSeq D2 large-subunit rDNA sequencing kit offers promise of being an accurate identification system; however, the associated library needs to include more of the clinically important genera and species.

We performed a prospective study of bloodstream infection to determine factors independently associated with mortality. Between February 1999 and July 2000, 929 consecutive episodes of bloodstream infection at two tertiary care centers were studied. An ICD-9-based Charlson Index was used to adjust for underlying illness. Crude mortality was 24% (14% for community-onset versus 34% for nosocomial bloodstream infections). Mortality attributed to the bloodstream infection was 17% overall (10% for community-onset versus 23% for nosocomial bloodstream infections). Multivariate logistic regression revealed the independent associations with in-hospital mortality to be as follows: nosocomial acquisition (odds ratio [OR] 2.6, P < 0.0001), hypotension (OR 2.6, P < 0.0001), absence of a febrile response (P = 0.003), tachypnea (OR 1.9, P = 0.001), leukopenia or leukocytosis (total white blood cell count of <4500 or >20000, P = 0.003), presence of a central venous catheter (OR 2.0, P = 0.0002), and presence of anaerobic organism (OR 2.5, P = 0.04). Even after adjustments were made for underlying illness and length of stay, nosocomial status of bloodstream infection was strongly associated with increased total hospital charges (P < 0.0001). Although accounting for about half of all bloodstream infections, nosocomial bloodstream infections account for most of the mortality and costs associated with bloodstream infection.

Yeasts are an increasingly common cause of nosocomial bloodstream infections. Methods for their detection are many; controlled comparisons are few. The vented FAN aerobic blood culture medium has been shown to be superior to the standard BacT/ALERT aerobic medium for the detection of fungemia as well as bacteremia. The BACTEC selective fungal medium (FM) (BD Biosciences, Sparks, Md.) allowed detection of more episodes of fungemia than did a resin-containing medium with equal volumes of blood cultured. Therefore, we compared vented FAN to FM for the ability to recover fungi from the blood of patients who were at increased risk of having fungemia. From 5,109 cultures processed for which both FAN and FM bottles were adequately filled, fungi were recovered from 87 cultures. Of these, 47 were detected with both bottles, 12 were detected with FAN only, and 28 were detected with FM only (P < 0.05). FAN was the first bottle positive for 36 of the 47 cultures for which both bottles yielded the same fungus, whereas the FM bottle was the first bottle positive for 11 cultures (P < 0.001). A total of 54 episodes of fungemia were identified, with 40 detected by both media, 4 detected only by FAN, and 10 detected only by FM (P value, not significant). We conclude that the vented FAN aerobic bottle is comparable to the FM bottle for detection of episodes of yeast infection but has the added benefit of detecting bacteria.

A 7-day incubation protocol was instituted with the BACTEC 9240 system for a 1-year period to determine the times to detection of clinically relevant organisms. A total of 23,686 blood and 693 sterile body fluid cultures were received; some cultures were held longer by special request. Of 1,609 likely skin contaminants, 42 were recovered on day 5, 34 on day 6, 16 on day 7, and 5 on day 8. Of 2,803 usual pathogens, 34 were recovered on day 5, 24 on day 6, 15 on day 7 and 1 on day 8. Twenty-one of the latter organisms were considered significant laboratory isolates because they were the first isolates from the respective patients. Chart review showed that 10 of 21 were considered clinically significant, but only 3 (all yeasts) affected the treatment of the patient. Our data show that 4 days of incubation were sufficient to recover all clinically relevant bacteria and 6 days were required to recover all clinically relevant yeasts.

A total of 9,446 blood cultures were collected from adult patients at three university-affiliated hospitals. Of these, 8,943 cultures were received with both aerobic bottles filled adequately; 885 yielded 1,016 microorganisms, including 622 isolates (61%) that were the cause of sepsis, 337 isolates (33%) that were contaminants, and 57 isolates (6%) that were indeterminate as the cause of sepsis. With the exception of Staphylococcus aureus, which was recovered more often from VITAL aerobic bottles, more pathogenic microorganisms were recovered from BACTEC NR6 (aerobic) bottles than from VITAL aerobic bottles. Growth of pathogenic microorganisms was detected earlier in VITAL aerobic bottles. A total of 8,647 blood cultures were received with both anaerobic bottles filled adequately; 655 yielded 740 microorganisms, including 486 isolates (66%) that were the cause of sepsis, 215 isolates (29%) that were contaminants, and 39 isolates (6%) that were indeterminate as the cause of sepsis. More pathogenic microorganisms were recovered from VITAL anaerobic bottles than from BACTEC NR7 (anaerobic) bottles. Growth of pathogenic microorganisms was detected earlier in VITAL anaerobic bottles. In 8,500 sets all four bottles were received adequately filled. When paired aerobic and anaerobic bottle sets (systems) were compared, more pathogenic microorganisms (again with the exception of S. aureus) were recovered from the BACTEC system. For the 304 septic episodes (253 unimicrobial and 51 polymicrobial), significantly more were detected by the BACTEC system. We conclude that VITAL requires modification to improve recovery of pathogenic microorganisms to make it competitive with other commercially available blood culture systems.

Scopulariopsis chartarum was reported as the agent of a multisystemic infection in a dog. The clinical syndromes in this dog with a fulminating mycotic disease mimicked those observed in dogs infected with canine distemper virus.

Trichosporon asahii is a major causative agent of deep-seated trichosporonosis, which has a high mortality rate. To detect T. asahii, we have developed specific oligonucleotide primers based on the internal transcribed spacer regions of this organism's genome. Amplification products were selectively obtained from only T. asahii DNA; the DNAs of other Trichosporon species, as well as those of medically relevant yeasts such as Candida albicans, Cryptococcus neoformans, and Malassezia furfur, were not amplified. This detection system will be useful as a microbiological tool for the diagnosis of trichosporonosis.

Fingerprinting by randomly amplified polymorphic DNA (RAPD) analysis was used to differentiate Scedosporium prolificans isolates. A total of 59 arbitrary primers were screened with six unrelated S. prolificans isolates, and a panel of 12 primers was selected. The 12 primers were then used to detect DNA polymorphisms among 17 S. prolificans isolates from 11 patients with systemic S. prolificans infections diagnosed in three hospitals located in geographically different areas of Spain. Eight patients were diagnosed with S. prolificans infection in a single institution over a 6-year period, and two other patients were diagnosed with S. prolificans infection in a different hospital over a 1-year period. No single primer allowed for the discrimination of all the isolates from different patients, but this was possible by combining the RAPD patterns from three primers (UBC 701, AB1.08, and AB1.11 or UBC 701, AB1.08, and UBC 707). However, multiple isolates from the same patient were identical. In this study, we also compared a visual method and a computerized method for the analysis of the RAPD patterns. Both methods were satisfactory and gave few discordances, but given the advantages and disadvantages of each method, both systems should be used together. RAPD analysis provided a fast and economical means of typing S. prolificans isolates, with a high level of discrimination among unrelated isolates. Typing by RAPD analysis confirmed that the S. prolificans infections were epidemiologically unrelated.