CMV reactivation is associated with a lower incidence of relapse after allo-SCT for CML.

Preemptive therapy at CMV reactivation has diminished post-transplant CMV mortality. Furthermore, recent studies suggest a favorable 'virus-versus-leukemia' effect from reactivating CMV, reducing relapse of AML after SCT. We studied the relationship of CMV reactivation with leukemic relapse in 110 patients with CML receiving HLA-identical sibling SCT between 1993 and 2008. Of these, 79 (72%) were in chronic phase, 5 in second chronic phase, 17 in accelerated phase and 9 in blast phase. A total of 97 patients (88%) received a myeloablative conditioning regimen, 97 received 4-log ex vivo T cell-depleted grafts and 13 received T-replete grafts. CMV reactivation before day 100 was observed in 72 patients (65.5%). At a median follow-up of 6.2 years, CMV reactivation < day 100 as a time-dependent covariate was an independent factor associated with decreased relapse. We conclude that CMV reactivation may contribute to a beneficial GVL effect in CML transplant recipients.

Death by edible mushroom: first report of Volvariella volvacea as an etiologic agent of invasive disease in a patient following double umbilical cord blood transplantation.

We describe a case of invasive fungal infection caused by Volvariella volvacea following double umbilical cord blood transplantation (UCBT). Although infections caused by several mushroom species have been documented, we believe this to be the first published report of invasive infection with Volvariella volvacea, an edible mushroom belonging to Agaricales.

Comparison of six commercial DNA extraction kits for recovery of cytomegalovirus DNA from spiked human specimens.

We evaluated six commercially available DNA extraction kits for their ability to recover DNA from various dilutions of cytomegalovirus (CMV) added to four different specimens: bronchoalveolar lavage, cerebral spinal fluid, plasma, and whole blood. The kits evaluated included the Puregene DNA isolation kit (PG), Generation Capture Column kit, MasterPure DNA purification kit, IsoQuick nucleic acid extraction kit, QIAamp blood kit, and NucliSens isolation kit (NS). All six kits evaluated effectively removed PCR inhibitors from each of the four specimen types and produced consistently positive results down to a spiked concentration of 200 PFU of whole CMV per ml. However, the NS and PG resulted in the most consistently positive results at the lowest concentrations of spiked CMV (4 and 0.4 PFU/ml) and, in this evaluation, offered the most sensitive methods for extracting CMV DNA from the four different spiked specimens. Processing time and cost were also evaluated.

Multisite reproducibility of Etest for susceptibility testing of Mycobacterium abscessus, Mycobacterium chelonae, and Mycobacterium fortuitum.

A multicenter study was conducted to assess the inter- and intralaboratory reproducibility of the Etest for susceptibility testing of the rapidly growing mycobacteria. The accuracy also was evaluated by comparing Etest results to those obtained by broth microdilution. Ten isolates (four of the Mycobacterium fortuitum group, three of Mycobacterium abscessus, and three of Mycobacterium chelonae) were tested against amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, and trimethoprim-sulfamethoxazole in each of four laboratories. At each site, isolates were tested three times on each of three separate days (nine testing events per isolate) using common lots of media and Etest strips. Interlaboratory agreement among MICs (i.e., mode +/- 1 twofold dilution) varied for the different drug-isolate combinations and overall was best for trimethoprim-sulfamethoxazole (75% for one isolate and 100% for all others), followed by doxycycline and ciprofloxacin. Interlaboratory agreement based on interpretive category also varied and overall was best for doxycycline (100% for all isolates), followed by trimethoprim-sulfamethoxazole and ciprofloxacin. Interlaboratory reproducibility among MICs was most variable for imipenem, and agreement by interpretive category was lowest for imipenem and amikacin. Modal Etest MICs agreed with those by broth microdilution only for doxycycline and the sulfonamides. For all other drugs, the modal MICs by the two methods differed by more than +/- 1 twofold dilution for one or more isolates. In all cases, the Etest MIC was higher and would have caused reports of false resistance. In summary, the Etest in this evaluation did not perform as well as broth microdilution for susceptibility testing of the rapidly growing mycobacteria. It was problematic for most species and drugs, primarily because of a trailing endpoint and/or high MICs compared to broth. Its use will necessitate further investigation, including determination of the optimal medium and incubation conditions and clarification of endpoint interpretation.

Multisite reproducibility of results obtained by the broth microdilution method for susceptibility testing of Mycobacterium abscessus, Mycobacterium chelonae, and Mycobacterium fortuitum.

A multicenter study was conducted to assess the interlaboratory reproducibility of broth microdilution testing of the more common rapidly growing pathogenic mycobacteria. Ten isolates (four Mycobacterium fortuitum group, three Mycobacterium abscessus, and three Mycobacterium chelonae isolates) were tested against amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, sulfamethoxazole, and tobramycin (M. chelonae only) in four laboratories. At each site, isolates were tested three times on each of three separate days (nine testing events per isolate) with a common lot of microdilution trays. Agreement among MICs (i.e., mode +/- 1 twofold dilution) varied considerably for the different drug-isolate combinations and overall was best for cefoxitin (91.7 and 97.2% for one isolate each and 100% for all others), followed by doxycycline, amikacin, and ciprofloxacin. Agreement based on the interpretive category, using currently suggested breakpoints, also varied and overall was best for doxycycline (97.2% for one isolate and 100% for the rest), followed by ciprofloxacin and clarithromycin. Reproducibility among MICs and agreement by interpretive category was most variable for imipenem. Based on results reported from the individual sites, it appears that inexperience contributed significantly to the wide range of MICs of several drugs, especially clarithromycin, ciprofloxacin, and sulfamethoxazole. New interpretive guidelines are presented for the testing of M. fortuitum against clarithromycin; M. abscessus and M. chelonae against the aminoglycosides; and all three species against cefoxitin, doxycycline, and imipenem.

Optimal activation of isopsoralen to prevent amplicon carryover.

We compared the efficiencies of activation of the photochemical isopsoralen compound 10 and its resulting amplicon neutralizations under conditions with a UV transilluminator box at room temperature (RT) and a HRI-300 UV photothermal reaction chamber at RT and at 5 degrees C. Our data suggest that use of the HRI-300 reaction chamber at 5 degrees C results in a statistically significantly higher degree of amplicon neutralization.

Correlation of in vitro susceptibility results for amoxicillin-clavulanate and ampicillin-sulbactam tested against Escherichia coli.

The results of amoxicillin-clavulanate (AUG) and ampicillin-sulbactam (A/S) susceptibility testing by three different susceptibility testing methods, the MicroScan, Etest, and Kirby-Bauer methods, for 61 consecutive isolates of ampicillin-resistant Escherichia coli from different patients were compared. There was poor correlation of results for the two agents, the most and least marked discrepancies being observed by the MicroScan method (86.9% susceptible to AUG and 4.9% susceptible to A/S) and the Kirby-Bauer method (39.4% susceptible to AUG and 32.8% susceptible to A/S), respectively. More organisms were susceptible to AUG than A/S, regardless of the susceptibility testing methodology. The results from a College of American Pathologists survey with one E. coli isolate tested at different institutions also indicated greater susceptibility to AUG than to A/S. These agents are thought to be equally efficacious clinically. The discrepancies observed among methods for each antimicrobial inhibitor combination and the discrepancies observed between the two agents by each testing method suggest that the breakpoints for these agents need to be reevaluated.

Clinical evaluation of the BacT/Alert and isolator aerobic blood culture systems.

The BacT/Alert (BTA) (Organon Teknika, Durham, NC) and Isolator 10 (ISO) (Wampole Laboratories, Cranbury, NJ) blood culture systems were evaluated for their ability to detect aerobic and facultatively anaerobic microorganisms in blood of adult patients. For each culture 8 mL of blood was inoculated into both the aerobic standard BTA bottle and the ISO tube. Of 7,259 paired culture sets, 1,168 organisms were recovered, and 667 (57.1%) of these were considered clinically significant. This represented 540 clinically significant positive cultures from 266 patients. Of the significant isolates, 410 were recovered by both systems, 108 by BTA only and 149 by ISO only (P <.025). Overall, the BTA detected 77.7% of the significant isolates, whereas ISO detected 83.8%. The ISO recovered significantly more isolates of Staphylococcus aureus (P = .0001), coagulase-negative Staphylococcus spp (P <.01), and non-Enterobacteriaceae gram-negative rod species (P <.0025), whereas the BTA detected significantly more isolates of Streptococcus spp (P <.0025). Growth of S aureus (P <.0025), Enterococcus spp (P <.0025), and Streptococcus spp (P <.0075) was detected earlier by the BTA when laboratory coverage was available during the first shift only (7:30 AM to 4:00 PM), and additionally of Enterobacteriaceae (P <.0005) and other gram-negative rod species (P <.0001) if coverage was extended to 12:00 AM. Yeasts were detected more rapidly by the ISO (P <.0025). The ISO contamination rate (5.9%) was six times that of the BTA. Taking into account its ability to rapidly detect most organisms, its automated and thus labor-saving features, and the minimal contamination rate associated with its use, the BTA appears to be a reliable alternative to the ISO as a blood culturing system, although improvement in detection of staphylococci and non-Enterobacteriaceae gram-negative rods would be desirable.

Comparison of pigment production and motility tests with PCR for reliable identification of intrinsically vancomycin-resistant enterococci.

Forty-eight clinical isolates identified as either Enterococcus faecium or Enterococcus faecalis with the MicroScan system (Dade International, MicroScan Inc., West Sacramento, Calif.) were further characterized by two supplementary biochemical tests (pigment production and motility). Twenty isolates (42%), all initially identified as E. faecium, were motile. Of these 20, 8 isolates (17%) produced yellow pigment and were identified as Enterococcus casseliflavus and the remaining 12 (25%) were nonpigmented and were identified as Enterococcus gallinarum. Identical identification results were obtained when PCR amplification of regions of the vanC gene was used as a technique for differentiating these organisms. The results of this study indicate that motility and pigment production tests together with commercial test systems are sufficient for reliable identifications of E. faecium, E. casseliflavus, and E. gallinarum.