Coralia N. Mihu

BACKGROUND: Quinolones are used extensively for prophylaxis in high-risk cancer patients; however, increasing quinolone resistance is being reported. Extended-spectrum β-lactamase (ESBL)-producing E. coli may be associated with increased morbidity and mortality particularly in neutropenic cancer patients. METHODS: We conducted a retrospective study of consecutive E. coli isolates from January 2009 to August 2009 at our institution. Data on antimicrobial susceptibility of E. coli isolates to commonly used antimicrobial agents and the frequency of ESBL production and fluoroquinolone resistance were gathered based on CLSI guidelines. RESULTS: There were 443 isolates of E. coli recovered. The majority were from urine cultures (308 isolates, 69.5%). Forty-one (9.2%) isolates were ESBL producing. Nine (18.3%) of the 49 isolates recovered from blood stream infections were ESBL producing. Quinolone resistance was present in 204 isolates (46%). Carbapenems and aminoglycosides retained excellent activity. E. coli resistance to quinolones increased from 13 to 46% in a period of 13 years (p = 0.001). CONCLUSION: The incidence of resistance to quinolones at our center may be increasing as a consequence of widespread use of quinolones as prophylaxis for neutropenic patients. ESBL-producing E. coli are frequent at our center and are associated with blood stream infections.

Abstract BACKGROUND: In vitro and in vivo studies suggested that combination of lipid formulation of amphotericin B (L‐AMB) and echinocandins may have a synergistic or additive effect against Aspergillus . Furthermore, clinical studies suggested that this combination may improve response of invasive aspergillosis (IA). METHODS: Between August 1993 and June 2008, the authors identified a total of 159 patients with hematological malignancies who received salvage therapy for IA, with L‐AMB alone, echinocandins alone, or a combination of L‐AMB and echinocandins. Clinical characteristics, response to salvage therapy, and death up to 12 weeks after initiation of salvage therapy were retrospectively determined for all patients. RESULTS: Seventy patients received salvage therapy with L‐AMB, 18 patients received echinocandins alone (89% of whom received caspofungin), and 71 patients received the combination therapy of amphotericin B and echinocandins (90% of who received caspofungin). The 3 salvage treatment groups were comparable in regard to clinical characteristics; graft versus host disease was more frequently encountered in the echinocandin group, whereas more patients in the L‐AMB and combination groups had neutropenia and received immunotherapy. The response to salvage therapy was better in the echinocandin group (9% L‐AMB, 28% echinocandins, and 21% for combination therapy). The 3 groups had a comparable rate of Aspergillus ‐related death (58%‐64%) and overall mortality (61%‐67%). CONCLUSIONS: The combination of L‐AMB and echinocandins offered no advantage in terms of improving response or reducing mortality over either drug alone. Hence, this combination will only add to the cost of therapy without any improvement in outcome in patients with hematological malignancies. Cancer 2010. © 2010 American Cancer Society.

BACKGROUND: Diarrhea is a common complication of allogeneic bone marrow transplantation. Microbiologic stool studies are frequently ordered to rule out infectious etiology. The utility of examining multiple stool specimens per diarrheal episode has not been examined. METHODS: . We performed a retrospective review of 169 adult and pediatric patients who underwent hematopoietic stem cell transplantation at Memorial Sloan-Kettering Cancer Center from January 1, 2000 though December 31, 2001, who had at least 1 microbiologic stool study. We report on the incidence of enteric pathogens in our population and diagnostic yield of stool studies. A diarrheal episode was defined as a 14-day period from the date of the first stool study. Cost savings analysis was based on projected savings from implementation of proposed guidelines to the study population. RESULTS: A total of 1649 stool tests were performed (mean 10.6 tests per patient). An infectious cause of diarrhea was found in 45 (28.8%) patients. Diagnostic yield was 6.2% for Clostridum difficile toxin assay, 12.9% for viral cultures, and 1.3% for rotavirus enzyme immunoassay. Bacterial cultures for enteric pathogens, examination for parasites, and rotavirus antigen assay combined had 0.5% positive yield. CONCLUSIONS: Testing of multiple specimens per diarrheal episode did not increase diagnostic yield. The estimated cost savings by implementing single testing for each type of stool study per diarrheal episode was $49,764 annually (in 2001 US dollars). Judicious use of stool tests to evaluate diarrhea results in significant cost savings without compromising diagnostic yield.