The Rising Influx of Multidrug-Resistant Gram-Negative Bacilli into a Tertiary Care Hospital

Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
Clinical Infectious Diseases (Impact Factor: 8.89). 06/2005; 40(12):1792-8. DOI: 10.1086/430314
Source: PubMed


The prevalence of multidrug resistance (MDR) among gram-negative bacilli is rapidly increasing. Quantification of the prevalence and the common antimicrobial coresistance patterns of MDR gram-negative bacilli (MDR-GNB) isolates recovered from patients at hospital admission, as well as identification of patients with a high risk of harboring MDR-GNB, would have important implications for patient care.
Over a 6-year period, patients who harbored MDR-GNB (i.e., patients who had MDR-GNB isolates recovered from clinical cultures within the first 48 h after hospital admission) were identified. "MDR-GNB isolates" were defined as Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, and Klebsiella species isolates with resistance to at least 3 antimicrobial groups. A case-control study was performed to determine the independent risk factors for harboring MDR-GNB at hospital admission.
Between 1998 and 2003, the prevalence of MDR-GNB isolates recovered from patients at hospital admission increased significantly for all isolate species (P < .001), with the exception of P. aeruginosa (P = .09). Of 464 MDR-GNB isolates, 12%, 35%, and 53% of isolates were coresistant to 5, 4, and 3 antimicrobial groups, respectively. Multivariable analysis identified age > or = 65 years (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.1-7.4; P < .04), prior exposure to antibiotics for > or = 14 days (OR, 8.7; 95% CI, 2.5 -30; P < .001), and prior residence in a long-term care facility (OR, 3.5; 95% CI, 1.3-9.4; P < .01) as independent risk factors for harboring MDR-GNB at hospital admission.
A substantial number of patients harbor MDR-GNB at hospital admission. Identification of common coresistance patterns among MDR-GNB isolates may assist in the selection of empirical antimicrobial therapy for patients with a high risk of harboring MDR-GNB.

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    • "– HAI - localized or systemic condition: 1) that results from adverse reaction to the presence of an infectious agent(s) or its toxin(s) and 2) that was present 48 hours or more after hospital admission and not incubating at hospital admission time [15]. "
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    ABSTRACT: Ten years after the first proposal, a consensus definition of healthcare-associated infection (HCAI) has not been reached, preventing the development of specific treatment recommendations. A systematic review of all definitions of HCAI used in clinical studies is made. The search strategy focused on an HCAI definition. MEDLINE, SCOPUS and ISI Web of Knowledge were searched for articles published from earliest achievable data until November 2012. Abstracts from scientific meetings were searched for relevant abstracts along with a manual search of references from reports, earlier reviews and retrieved studies. The search retrieved 49,405 references: 15,311 were duplicates and 33,828 were excluded based on title and abstract. Of the remaining 266, 43 met the inclusion criteria. The definition more frequently used was the initial proposed in 2002 - an infection present at hospital admission or within 48 hours of admission in patients that fulfilled any of the following criteria: received intravenous therapy at home, wound care or specialized nursing care in the previous 30 days; attended a hospital or hemodialysis clinic or received intravenous chemotherapy in the previous 30 days; were hospitalized in an acute care hospital for >=2 days in the previous 90 days, resided in a nursing home or long-term care facility. Additional criteria founded in other studies were: immunosuppression, active or metastatic cancer, previous radiation therapy, transfer from another care facility, elderly or physically disabled persons who need healthcare, previous submission to invasive procedures, surgery performed in the last 180 days, family member with a multi-drug resistant microorganism and recent treatment with antibiotics. Based on the evidence gathered we conclude that the definition initially proposed is widely accepted. In a future revision, recent invasive procedures, hospitalization in the last year or previous antibiotic treatment should be considered for inclusion in the definition. The role of immunosuppression in the definition of HCAI still requires ongoing discussion.
    BMC Medicine 03/2014; 12(1):40. DOI:10.1186/1741-7015-12-40 · 7.25 Impact Factor
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    • "In contrast to previous studies [16,19], older age was not shown to be a predictor for acquiring MDR organisms; on the contrary, older patients were less likely to have a COBSI with MDR GNB. Our data suggest a potential shift in the epidemiology of MDR GNB to a younger patient population, and this was not limited to patients with underlying medical conditions or predisposing healthcare-associated risk factors. "
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    ABSTRACT: Multidrug-resistant (MDR) organisms have been increasingly reported at hospital admission. Recognising the magnitude, trend and predictors for MDR organisms in community-onset bloodstream infections (COBSI) is crucial for guiding empiric antibiotic prescribing. Positive blood culture isolates recovered from patients presenting to the emergency department during a ten-year period (1st Jan 2002-31st Dec 2011) were assessed. Trend analyses of MDR organisms were performed. Risk factors for COBSI caused by an MDR organism and predictors for 30-day mortality were also determined. A total of 1721 positive blood culture isolates were identified during the study period with a yearly incidence of 30-43 isolates / 10 000 ED presentations. The proportion of MDR Escherichia coli causing COBSI increased from 9%-26% (P < 0.001), whilst methicillin-resistant Staphylococcus aureus remained at high levels (20%-30%). A total of 360 patients were included in a matched case-control (1:1) study, and residents in long-term care facilities (adjusted odds ratio [AOR], 4.9 [95% CI, 2.1-11.6]), home wound care (AOR, 5.5 [95% CI, 1.6-18.7]), underlying immunosuppression (AOR, 3.5 [95% CI, 1.6-7.7]), recent surgery (AOR, 3.5 [95% CI, 1.1-11.6]), and exposure to antibiotics within 3 months (AOR, 5.5 [95% CI, 2.8-10.6]) were independently associated with MDR COBSI. High risk source of COBSI, age and Pitt bacteraemia score were independent predictors for 30-day mortality. A concerning trend in MDR organisms causing bloodstream infection from the community is occurring. Risk factors for MDR organisms have been identified to assist in empiric antibiotic prescribing for those presenting to hospital with sepsis.
    BMC Infectious Diseases 03/2014; 14(1):126. DOI:10.1186/1471-2334-14-126 · 2.61 Impact Factor
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    • "Carbapenem antibiotics have been used as the last resort salvage treatment for infections caused by multidrug resistancegram negative bacteria (MDR-GNB) [1], that is, gram negative bacteria resistant to at least three of the following antimicrobials: ampicillin, augmentin, ceftazidime, ciprofloxacin, gentamicin, and/or trimethoprim-sulfamethoxazole (SXT) [2]. Thus, resistance to carbapenems becomes a real threat to the survival of patients with infections caused by MDR-GNB, and the overall mortality in such infections has been reported to be up to 50% [3] [4]. "
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    02/2014; 2014:303104. DOI:10.1155/2014/303104
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