Salmonella aortitis treated with endovascular aortic repair.

Salmonella aortitis is a known complication of Salmonella infection that usually requires surgical therapy. It is unknown whether endovascular aortic repair (EVAR) is an acceptable alternative to conventional aortic surgery for patients with Salmonella aortitis who are at high risk for perioperative complications. We therefore report 2 cases of Salmonella aortitis treated with EVAR and review the literature to further characterize previously published cases.

Complete nucleotide sequences of blaKPC-4- and blaKPC-5-harboring IncN and IncX plasmids from Klebsiella pneumoniae strains isolated in New Jersey.

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae have emerged as major nosocomial pathogens. bla(KPC), commonly located on Tn4401, is found in Gram-negative bacterial strains, with the two most common variants, bla(KPC-2) and bla(KPC-3), identified in plasmids with diverse genetic backgrounds. In this study, we examined bla(KPC-4)- and bla(KPC-5)-bearing plasmids recovered from two K. pneumoniae strains, which were isolated from a single New Jersey hospital in 2005 and 2006, respectively. IncN plasmid pBK31551 is 84 kb in length and harbors bla(KPC-4), bla(TEM-1), qnrB2, aac(3)-Ib, aph(3')-I, qacF, qacEΔ1, sul1, and dfrA14, which confer resistance to ß-lactams, quinolones, aminoglycosides, quaternary ammonium compounds, and co-trimoxazole. The conserved regions within pBK31551 are similar to those of other IncN plasmids. Surprisingly, analysis of the Tn4401 sequence revealed a large IS110- and Tn6901-carrying element (8.3 kb) inserted into the istA gene, encoding glyoxalase/bleomycin resistance, alcohol dehydrogenase, and S-formylglutathione hydrolase. Plasmid pBK31567 is 47 kb in length and harbors bla(KPC-5), dfrA5, qacEΔ1, and sul1. pBK31567 belongs to a novel IncX subgroup (IncX5) and possesses a highly syntenic plasmid backbone like other IncX plasmids; however, sequence similarity at the nucleotide level is divergent. The bla(KPC-5) gene is carried on a Tn4401 element and differs from the genetic environment of bla(KPC-5) described in Pseudomonas aeruginosa strain P28 from Puerto Rico. This study underscores the genetic diversity of multidrug-resistant plasmids involved in the spread of bla(KPC) genes and highlights the mobility and plasticity of Tn4401. Comparative genomic analysis provides new insights into the evolution and dissemination of KPC plasmids belonging to different incompatibility groups.

Multiplex real-time PCR for detection of an epidemic KPC-producing Klebsiella pneumoniae ST258 clone.

We describe a multiplex real-time PCR assay capable of identifying both the epidemic Klebsiella pneumoniae ST258 clone and bla(KPC) carbapenemase genes in a single reaction. The assay displayed excellent sensitivity (100%) and specificity (100%) for identification of ST258 clone and bla(KPC) in a collection of 75 K. pneumoniae isolates comprising 41 sequence types. Our results suggest that this assay is an effective tool for surveillance of this clone among carbapenem-resistant K. pneumoniae clinical isolates.

Malignant Fungating Wounds of the Head and Neck: Management and Antibiotic Stewardship.

OBJECTIVE: Malignant fungating wounds (MFWs) are unfortunate and underreported manifestations of some advanced head and neck cancers. The management of MFWs is complex and challenging. MFWs are often mistaken for infectious processes/abscesses and treated indiscriminately with oral or intravenous antibiotics. Our aim is to promote awareness of MFWs and provide education on their management. We summarize their cost-effective and evidence-based therapies and highlight antibiotic stewardship with respect to their management. DATA SOURCES: A literature review was performed of PubMed, Cochrane Review, SCOPUS, Embase, and Google Scholar databases regarding topical and systemic treatments for MFWs. REVIEW METHODS: Full-text articles were identified with the following terms: fungating, ulcerative, wound, tumor, malignancy, antibiotics, topical, dressings, radiotherapy, head, neck, scalp, face, lip, and ear. Treatment recommendations were extrapolated, categorically summarized, and retrospectively assigned with an evidence level based on the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation). CONCLUSIONS: In the absence of systemic signs and symptoms of infections, MFWs should not be treated as conventional infections or abscesses, with prophylactic oral or intravenous antibiotics. Topical treatments such as ointments and wound dressings are the mainstay in terms of managing the unsightly appearance and fetid odor from these entities. IMPLICATIONS FOR PRACTICE: MFWs are most often not amenable to definitive/curative surgical or nonsurgical therapy, but consultation with a head and neck oncologic specialist will help to determine if the underlying malignancy requires surgery, radiation therapy, or palliative treatment.

Risk of Clostridium difficile infection in intensive care unit patients with sepsis exposed to metronidazole.

BACKGROUND: Antimicrobial agents used to treat Clostridium difficile infection (CDI), such as metronidazole and vancomycin, have been used during antibiotic treatment of other infections to try to prevent the development of CDI. We evaluated the hypothesis that intensive care unit (ICU) patients who receive metronidazole as part of an antibiotic treatment regimen for sepsis have a lower risk of subsequently developing CDI. METHODS: This was a nested case-control study in a cohort of ICU patients who received antibiotic therapy for sepsis. RESULTS: A total of 10 012 patients aged ≥ 18 years were admitted to the Cooper University Hospital medical/surgical ICU from 1/1/2003 to 12/31/2008. After applying inclusion criteria including having received antibiotic therapy for sepsis and subsequently having developed CDI, 67 cases were identified. The cases were matched for age, gender, date of ICU admission, and hospital length of stay to 67 controls that also received antibiotic therapy for sepsis but did not subsequently develop CDI. In the multivariate analysis, there was no association between metronidazole exposure and the risk of CDI (odds ratio (OR) = 0.57; p = 0.23). The only significant associations on multivariate analysis were antifungal therapy (OR = 0.30; p = 0.02) and aminoglycoside and/or colistin therapy (OR = 0.17; p = 0.02). CONCLUSIONS: No association was found between metronidazole use and subsequent CDI in ICU patients who received antibiotic therapy for sepsis.

Pathogens resistant to antimicrobial agents: epidemiology, molecular mechanisms, and clinical management.

Resistance to antimicrobial drugs is increasing at an alarming rate among both gram-positive and gram-negative bacteria. Traditionally, bacteria resistant to multiple antimicrobial agents have been restricted to the nosocomial environment. A disturbing trend has been the recent emergence and spread of resistant pathogens and resistance traits in nursing homes, the community, as well as in hospitals. This article reviews the epidemiology, molecular mechanisms of resistance, and treatment options for pathogens resistant to antimicrobial drugs.

Antimicrobial resistance in the intensive care unit: mechanisms, epidemiology, and management of specific resistant pathogens.

Infections caused by drug-resistant and multidrug-resistant microbial pathogens pose tremendous challenges to health care systems, including challenges related to the diagnosis, treatment, and containment of these infections. These challenges are amplified in the intensive care unit (ICU), where pressures for selection and emergence of resistance and risks of transmission of resistant pathogens are highest, and where the threat of resistance drives selection of empiric antimicrobial regimens. This article reviews basic concepts of resistance to antibacterial agents including mechanisms and modes of transmission, and discusses management issues for the important drug-resistant pathogens found in the ICU.

Systemic antimicrobial therapy in osteomyelitis.

Appropriately designed antibiotic regimens are critical to the management of all stages of osteomyelitis, although goals of therapy may vary in different stages of infection. The most important consideration for antibiotic selection is spectrum of action. Route of administration by intravenous or oral route is less important than drug levels that are achievable at the site of infection. Outpatient parenteral therapy and use of oral agents has simplified delivery of long-term treatment regimens. There are few high-quality studies that compare specific treatment regimens or durations of therapy, and recommendations for drugs and duration of antibiotic therapy are based on expert opinion, case series, and extrapolations from animal models. Intravenous beta-lactams are the treatment of choice for methicillin-susceptible Staphylococcus aureus, but there are also oral options available. Vancomycin has been the treatment of choice for methicillin-resistant Staphylococcus aureus osteomyelitis, but there are several newer parenteral and oral agents for treatment of methicillin-resistant Staphylococcus aureus including linezolid and daptomycin. Rifampin combined with other staphylococcal agents may increase cure rates, especially for device-associated infections. Oral fluoroquinolones and parenteral beta-lactam agents can be used for treatment of gram-negative osteomyelitis, but increasing resistance has complicated management of these infections.