Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
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Species of Candida and Aspergillus remain the most common causes of invasive fungal infections, but other yeasts and filamentous fungi are emerging as significant pathogens. Opportunistic yeast-like fungi and moulds such as Zygomycetes, Fusarium spp. and Scedosporium spp. are increasingly being recognised in patient groups such as those with leukaemia and in bone marrow transplant recipients. Recognition of these epidemiological changes is critical to patient care. The key elements in selecting an appropriate antifungal agent are the type of patient (solid-organ or stem-cell transplant), severity of immunosuppression, history of prolonged exposure to antifungal drugs, and knowledge of the genera and species of the infecting pathogen and its typical susceptibility pattern.
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Clin. Microbiol. Infect. · Feb 2008
ReviewMycoplasma pneumoniae-an emerging extra-pulmonary pathogen.
Mycoplasma is a well-recognised pathogen that colonises mucosal surfaces of humans and animals. Mycoplasma pneumoniae infects the upper and lower respiratory tracts of children and adults, leading to a wide range of respiratory and non-respiratory clinical conditions. ⋯ This contrasts with patients who present with non-respiratory symptoms in the context of a recent or current unrecognised M. pneumoniae infection, for whom this pathogen is rarely considered in the initial differential diagnosis. This review considers the microbiological, epidemiological, pathogenic and clinical features of this frequent pathogen that need to be considered in the differential diagnosis of respiratory and non-respiratory infections.
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Genes encoding extended-spectrum beta-lactamases (ESBLs) have been reported in a variety of Gram-negative species, mostly in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. They are mostly either TEM or SHV derivatives, CTX-M-like enzymes--now emerging worldwide--or, less frequently, VEB, GES, and PER ESBLs. The mechanisms responsible for their acquisition are very diverse, and mostly are related to insertion sequences (ISs), transposons, class 1 integrons, and also sul1-type integrons containing the ISCR1 element. This diversity of genetic vehicles at the origin of these mobilisation/acquisition processes enhances the spread of ESBLs.
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Among the many different structurally distinct classes of beta-lactams, the carbapenem class is regarded as that which is most potent and which has the widest spectrum of antimicrobial activity. Rapidly bactericidal, and demonstrating time-dependent killing, carbapenemes have a spectrum of antimicrobial activity that includes Gram-positive and Gram-negative aerobic and anaerobic pathogens. ⋯ Imipenem, meropenem and ertapenem are licensed in the European Community and panipenem and biapenem are also available in Japan and South Korea. Other carbapenemes are under development.
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Clin. Microbiol. Infect. · Sep 2006
ReviewCarbapenem resistance in Acinetobacter baumannii: mechanisms and epidemiology.
The increasing trend of carbapenem resistance in Acinetobacter baumannii worldwide is a concern since it limits drastically the range of therapeutic alternatives. Metallo-beta-lactamases (VIM, IMP, SIM) have been reported worldwide, especially in Asia and western Europe, and confer resistance to all beta-lactams except aztreonam. The most widespread beta-lactamases with carbapenemase activity in A. baumannii are carbapenem-hydrolysing class D beta-lactamases (CHDLs) that are mostly specific for this species. ⋯ A. baumannii also possesses an intrinsic carbapenem-hydrolysing oxacillinase, the expression of which may vary, that may play a role in carbapenem resistance. In addition to beta-lactamases, carbapenem resistance in A. baumannii may also result from porin or penicillin-binding protein modifications. Several porins, including the 33-kDa CarO protein, that constitute a pore channel for influx of carbapenems, might be involved in carbapenem resistance.