The poly(A) tail at the 3' end of mRNAs determines their stability, translational efficiency, and fate. The shortening of the poly(A) tail, and its efficient removal, triggers the degradation of mRNAs, thus, regulating gene expression. The process is catalyzed by a family of enzymes, known as deadenylases.
View Article and Find Full Text PDFLimited antimicrobials remain active for treating severe infections due to KPC-producing pathogens, and optimal regimens have not been established. In murine thigh infections caused by nine KPC-producing clinical strains of Enterobacteriaceae (meropenem MICs, 1 to 4 μg/ml), we evaluated the activities of tigecycline, colistin, meropenem, rifampin, and gentamicin in single and combination regimens lasting for 24 h and 48 h. Rifampin, tigecycline, and gentamicin were the most effective monotherapies, reducing significantly the CFU counts yielded from thighs infected by 88.
View Article and Find Full Text PDFBackground/aims: The degradation of mRNA is a key process in the control of gene expression correlated to anomalous cell proliferation. The rate-limiting step of mRNA degradation is the removal of the poly(A) tail by deadenylases. However, studies on deadenylase expression in cancer are limited.
View Article and Find Full Text PDFObjectives: Outbreaks caused by linezolid-resistant (LR) enterococci remain rare. We report the epidemiological and molecular characteristics of the multiclonal dissemination of LR enterococci in the intensive care unit (ICU) of a Greek hospital.
Methods: All LR enterococcal isolates recovered from patients hospitalized in the ICU of the University Hospital of Larissa, Greece, between January 2007 and October 2008 were included.
The present study investigated the possible correlation between carriage of the virulence genes esp and fsrb, production of hemolysin and gelatinase and biofilm formation in human vs. animal enterococcal isolates. A collection of 219 enterococcal isolates recovered from clinical and fecal surveillance samples of hospitalized patients and 132 isolates from animal feces were studied.
View Article and Find Full Text PDFWe compared the activity of dicloxacillin with that of vancomycin against 15 oxacillin-susceptible, methicillin-resistant Staphylococcus aureus (OS-MRSA) clinical isolates. By population analyses, we found that 6 OS-MRSA isolates were able to grow in the presence of up to 8 μg/ml dicloxacillin and 9 isolates were able to grow in 12 to >32 μg/ml dicloxacillin; all isolates grew in up to 2 μg/ml vancomycin. Both drugs exhibited similar bactericidal activities.
View Article and Find Full Text PDFObjectives Methicillin-resistant Staphylococcus aureus (MRSA) strains that express the mecA gene but are oxacillin susceptible (OS-MRSA; oxacillin MIC =2 mg/L) are increasingly reported. To gain molecular and functional insights on this observation, we focused on additional factors possibly contributing to phenotypic susceptibility. Methods The nucleotide content of mecA, femA, femB and femX genes, which are considered essential for methicillin resistance, was determined in four OS-MRSA clinical isolates and a genetically similar low-level MRSA control (oxacillin MIC 6 mg/L).
View Article and Find Full Text PDFCommunity-type Staphylococcus aureus strains that are positive for mecA and PBP2a but appear phenotypically susceptible to oxacillin are increasingly reported worldwide. Four S. aureus clinical isolates carrying the mecA gene with oxacillin MICs of <2 microg/ml were tested for oxacillin efficiency by population analyses and experimental thigh infections.
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