Khaled Alshabani

Epidemiology and Risk Factors for Isolation of Escherichia coli Producing CTX-M-Type Extended-Spectrum β-Lactamase in a Large U.S. Medical Center

ABSTRACT A case-case-control study was conducted to identify independent risk factors for recovery of Escherichia coli strains producing CTX-M-type extended-spectrum β-lactamases (CTX-M E. coli) within a large Southeastern Michigan medical center. Unique cases with isolation of ESBL-producing E. coli from February 2010 through July 2011 were analyzed by PCR for blaCTX-M, blaTEM, and blaSHV genes. Patients with CTX-M E. coli were compared to patients with E. coli strains not producing CTX-M-type ESBLs (non-CTX-M E. coli) and uninfected controls. Of 575 patients with ESBL-producing E. coli, 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-M E. coli (282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-M E. coli patients and to uninfected controls. Independent risk factors for CTX-M E. coli isolation compared to non-CTX-M E. coli included male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillins and/or trimethoprim-sulfamethoxazole. Compared to uninfected controls, independent risk factors for isolation of CTX-M E. coli included presence of a urinary catheter, previous urinary tract infection, exposure to oxyimino-cephalosporins, dependent functional status, non-home residence, and multiple comorbid conditions. Within 48 h of admission, community-acquired CTX-M E. coli (n = 51 [16%]) and non-CTX-M E coli (n = 11 [19%]) strains were isolated from patients with no recent health care contacts. CTX-M E. coli strains were more resistant to multiple antibiotics than non-CTX-M E. coli strains. CTX-M-encoding genes, especially blaCTX-M-15 type, represented the most common ESBL determinants from ESBL-producing E. coli, the majority of which were present upon admission. Septic patients with risk factors for isolation of CTX-M E. coli should be empirically treated with appropriate agents. Regional infection control efforts and judicious antibiotic use are needed to control the spread of these organisms.

Epidemiology of vancomycin-resistant Enterococcus faecalis: a case-case-control study

ABSTRACT Although much is known about vancomycin-resistant (VR) Enterococcus faecium, little is known about the epidemiology of VR Enterococcus faecalis. The predilection of VR E. faecalis to transfer the vancomycin resistance determinant to Staphylococcus aureus is much greater than that of VR E. faecium. The epidemiology of VR E. faecalis has important implications regarding the emergence of vancomycin-resistant S. aureus (VRSA); 8 of 13 reported VRSA cases have been from Michigan. A retrospective case-case-control study was conducted at the Detroit Medical Center, located in southeastern Michigan. Unique patients with VR E. faecalis infection were matched to patients with strains of vancomycin-susceptible (VS) E. faecalis and to uninfected controls at a 1:1:1 ratio. Five hundred thirty-two VR E. faecalis cases were identified and were matched to 532 VS E. faecalis cases and 532 uninfected controls. The overall mean age of the study cohort (n = 1,596) was 63.0 ± 17.4 years, and 747 (46.8%) individuals were male. Independent predictors for the isolation of VR E. faecalis (but not VS E. faecalis) compared to uninfected controls were an age of ≥65 years, nonhome residence, diabetes mellitus, peripheral vascular disease, exposure to cephalosporins and fluoroquinolones in the prior 3 months, and immunosuppressive status. Invasive procedures and/or surgery, chronic skin ulcers, and indwelling devices were risk factors for both VR E. faecalis and VS E. faecalis isolation. Cephalosporin and fluoroquinolone exposures were unique, independent predictors for isolation of VR E. faecalis. A majority of case patients had VR E. faecalis present at the time of admission. Control of VR E. faecalis, and ultimately VRSA, will likely require regional efforts focusing on infection prevention and antimicrobial stewardship.

Lung transplantation following hematopoietic stem cell transplantation: report of two cases and systematic review of literature

Non‐infectious pulmonary complications following hematopoietic stem cell transplantation (HSCT) are major cause of morbidity and mortality with limited treatment options. Lung transplantation (LT) has been rarely reported as a treatment option for selected HSCT recipients with these problems.

Invasive pulmonary aspergillosis in patients with influenza infection: Report of two cases and systematic review of the literature

Superinfection or coinfections are major causes of morbidity and mortality in patients with influenza. There are limited data on invasive pulmonary aspergillosis (IPA) in this setting. We conducted a systematic review of the literature for patients with IPA following influenza infection. A total of 68 patients (two reported from our institution and 66 identified by literature review) were analyzed. The majority of patients had underlying comorbid illnesses. Overall, the mortality rate in this cohort was 47%. On multivariate analysis, H1N1 infection was associated with better outcome (odds ratio [OR]: 0.19; 95% CI: 0.05–0.67; p = 0.010), whereas corticosteroid therapy during hospitalization was associated with worse outcome (OR: 13.5; 95% CI: 3.65–49.67; p < 0.0001). In conclusion, IPA is an emerging serious infection in patients with influenza. A high index of suspicion is necessary for the timely identification and treatment of these patients.

Impact of Different Antimicrobial Therapies on Clinical and Fiscal Outcomes of Patients with Bacteremia Due to Vancomycin-Resistant Enterococci

ABSTRACT Vancomycin-resistant enterococci (VRE) are a growing health problem, and uncertainties exist regarding the optimal therapy for bloodstream infection due to VRE. We conducted systematic comparative evaluations of the impact of different antimicrobial therapies on the outcomes of patients with bloodstream infections due to VRE. A retrospective study from January 2008 to October 2010 was conducted at Detroit Medical Center. Unique patients with blood cultures due to VRE were included and reviewed. Three major therapeutic classes were analyzed: daptomycin, linezolid, and β-lactams. Three multivariate models were conducted for each outcome, matching for a propensity score predicting the likelihood of receipt of one of the therapeutic classes. A total of 225 cases of bacteremia due to VRE were included, including 86 (38.2%) cases of VR Enterococcus faecalis and 139 (61.8%) of VR Enterococcus faecium. Bacteremia due to VR E. faecalis was more frequent among subjects treated with β-lactams than among those treated with daptomycin or linezolid. The median dose of daptomycin was 6 mg/kg of body weight (range, 6 to 12 mg/kg). After controlling for propensity score and bacteremia due to VR E. faecalis, differences in mortality were nonsignificant among the treatment groups. Therapy with daptomycin was associated with higher median variable direct cost per day than that for linezolid. This large study revealed the three therapeutic classes (daptomycin, linezolid, and β-lactams) are similarly efficacious in the treatment of bacteremia due to susceptible strains of VRE.

Predictors of outcome in patients with hematologic malignancies admitted to the intensive care unit

PURPOSE Several studies showed conflicting results about prognosis and predictors of outcome of critically ill patients with hematological malignancies (HM). The aim of this study is to determine the hospital outcome of critically ill patients with HM and the factors predicting the outcome. METHODS AND MATERIALS All patients with HM admitted to MICU at a tertiary academic medical center were enrolled. Clinical data upon admission and during ICU stay were collected. Hospital, ICU, and 6 months outcomes were documented. RESULTS There were 130 HM patients during the study period. Acute Leukemia was the most common malignancy (31.5%) followed by Non-Hodgkins Lymphoma (28.5%). About 12.5% patients had autologous HSCT and 51.5% had allogeneic HSCT. Sepsis was the most common ICU diagnosis (25.9%). ICU mortality and hospital mortality were 24.8% and 45.3%, respectively. Six months mortality (available on 80% of patients) was 56.7%. Hospital mortality was higher among mechanically ventilated patients (75%). Using multivariate analysis, only mechanical ventilation (OR of 19.0, CI: 3.1-117.4, P: 0.001) and allogeneic HSCT (OR of 10.9, CI: 1.8-66.9, P: 0.01) predicted hospital mortality. CONCLUSION Overall hospital outcome of critically ill patients with HM is improving. However those who require mechanical ventilation or underwent allogeneic HSCT continue to have poor outcome.