Colistin exposure as a risk factor for infections caused by inherently colistin resistant Enterobacteriaceae-a case-control study.

OBJECTIVES: Epidemiological studies have suggested an association between increased colistin use and selection for inherently colistin-resistant Enterobacteriaceae (ICRE). We aimed to evaluate whether colistin exposure is a risk factor for ICRE infection. METHODS: A matched 1:1 case-control study including patients recently hospitalized for ≥14 days with ICRE infection as cases matched with similar patients with a clinical isolate of a colistin-susceptible Enterobacteriaceae as controls was performed. Univariate analysis using McNemar test and multivariate analysis were conducted to explore risk factors for ICRE isolation, including colistin exposure 90 days before the positive culture. RESULTS: We included 446 patients, 223 cases and 223 controls matched for gender, age, department, year, source of culture and duration of hospitalization before positive culture. Colistin exposure was significantly associated with ICRE isolation in both univariate (14/223, 6.3% of cases versus 4/223, 1.8% of controls, p 0.031) and multivariate analyses (odds ratio 4.415, 95% CI 1.078-18.082). Curtailed functional capacity was a significant risk factor for ICRE as well. Exposure to other broad-spectrum antibiotics was associated with isolation of a colistin-susceptible pathogen. CONCLUSIONS: Exposure to colistin is associated with an increased risk of isolating an inherently colistin-resistant Enterobacteriaceae in patients with prolonged hospitalization. This should be taken into account while considering empirical therapy for such patients. Use of colistin should be judicious. The correlation between duration and magnitude of exposure and ICRE infection should be investigated in further studies.

The effect of statins on the outcome of Clostridium difficile infection in hospitalized patients.

UNLABELLED: Several studies have shown an association between exposure to statins and favorable clinical outcomes for various types of infections. We aimed to assess the impact of statin use on mortality, disease severity and complications among hospitalized patients with Clostridium difficile infection (CDI). Data were analyzed from a retrospectively collected database of 499 patients diagnosed with CDI during 2009-2014. We compared infection outcomes between 178 statin (36 %) users and 321 (64 %) non-users. On multivariate analysis, we found that statin use did not have a significant impact on 30-day mortality (OR = 1.54; 95 % CI, 0.85-2.79; p = 0.15) or any significant effect on CDI severity and complication. Concomitant statin use has no significant impact on short-term mortality or effect on CDI severity and complications among hospitalized patients with CDI. However, patients in the statin group were older and had higher Charlson score compared with the non-statin group. Whether these factors affected a possible impact of statins on the disease course remains to be investigated. KEY MESSAGES: • Clostridium difficile is the most common cause of infectious nosocomial diarrhea among hospitalized adult patients in the developed countries. • There is an increasing morbidity and mortality of CDI patients due to the emergence of new strains of high virulence. • Recent studies demonstrated that prior statin use has protective and ameliorating effects on morbidity and mortality among CDI patients. • Our study showed that concomitant statin use has no significant impact on short-term mortality, CDI severity and its complications.

Multidrug-resistant Acinetobacter baumannii infections in lung transplant patients in the cardiothoracic intensive care unit.

BACKGROUND: Multidrug-resistant (MDR) gram-negative bacteria are a growing threat to solid organ transplantation (SOT) patients in the intensive care unit (ICU). We aimed to examine the mortality rates of gram-negative MDR bacterial infection in SOT patients compared with patient population undergoing other cardiothoracic surgeries and hospitalized under similar ICU conditions. METHODS: A retrospective study from a single medical center, including patients with MDR Acinetobacter baumannii and carbapenem-resistant Klebsiella pneumoniae infection, hospitalized in the cardiothoracic ICU. Data were collected from computerized databases, and data were verified using the hospitalization files. Microbiological data were provided by the microbiology laboratory. RESULTS: During the study period, 205 SOT patients and 5031 other patients were hospitalized in the cardiothoracic ICU. Active infection with gram-negative MDR bacteria was identified in 147 patients, of which 37 underwent SOT (18% of total transplant recipients) and 110 underwent another cardiothoracic surgery (2% of total patients who are not transplant recipients). Mortality rates were high among both groups of patients, with no significant difference between them. CONCLUSIONS: Infection with resistant bacteria is more prevalent among patients following SOT compared with patients following other cardiothoracic surgeries. Mortality is high in all patients regardless of the immunocompromised condition.

Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen.

BACKGROUND: Necrotizing fasciitis (NF) is a life-threatening soft tissue infection. It is usually caused by Streptococcus pyogenes and other Gram-positive bacteria. Several reports, however, emphasize the importance of Gram-negative rods in this infection. METHODS: We retrospectively studied all cases of monomicrobial necrotizing fasciitis hospitalized in our center during the years 2002-2012. We compared clinical characteristics and outcomes of patients with Gram-negative versus Gram-positive infection. RESULTS: Forty-five cases were reviewed, 19 caused by Gram-negative organisms, 10 of them Escherichia coli, and 26 caused by Gram-positive organisms, 10 of them S. pyogenes. Compared to Gram-positive infections, patients with Gram-negative infections were more likely to have a baseline malignancy (9/19, 47.4%) or to have undergone recent surgery (4/19, 42.3%). The 30-day mortality was higher among Gram-negative infected patients (8/19, 42.1% vs. 8/26, 30.8%). Creatine phosphokinase (CPK) was elevated in a minority of patients with Gram-negative necrotizing fasciitis, and its absolute value was lower than in Gram-positive necrotizing fasciitis. CONCLUSIONS: In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.