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Showing posts with label Staphylococci. Show all posts
Showing posts with label Staphylococci. Show all posts

Sunday, July 5, 2009

Ceftobiprole: first cephalosporin with activity against MRSA

Ceftobiprole is the first member of a new series of advanced cephalosporins with activity against methicillin-resistant Staphylococcus aureus (MRSA). The drug received a letter of approval from the United States Food and Drug Administration (FDA) in March 2008 for the treatment of complicated skin and skin structure infections including diabetic foot infections. Ceftobiprole exerts its antibacterial activity by inhibiting the penicillin-binding proteins (PBPs) involved in cell wall synthesis. It is stable against hydrolysis by many gram-positive beta-lactamases and a has higher affinity for various PBPs (such as PBP2a of MRSA or PBP2x of Streptococcus pneumoniae), which leads to a wider spectrum of activity compared with older beta-lactams. Ceftobiprole activity does not cover extended-spectrum beta-lactamase-producing Enterobacteriaceae and some other pathogens, including Enterococcus faecium or Acinetobacter baumanii.
Generally well tolerated, with nausea and taste disturbance being the most common adverse events, ceftobiprole appeared noninferior to empiric therapy in several clinical trials. Several precautions regarding hypersensitivity and drug incompatibility are reported.
Ceftobiprole is available only for i.v. administration. Dosage recommendations are 500 mg as a 1-hour intravenous infusion every 12 hours for the treatment of complicated skin and skin structure infections caused by certain gram-positive pathogens, and 500 mg as a 2-hour infusion every 8 hours when susceptible gram-negative or both gram-positive and susceptible gram-negative pathogens are involved. Dosage adjustments are indicated for patients with moderate or severe renal impairment, and dosage recommendations are expected to be 500 or 250 mg, respectively, as a 2-hour infusion every 12 hours.
Ceftobiprole represents a promising option for the treatment of mono- and polymicrobial infections caused by multidrug-resistant gram-positive and susceptible gram-negative pathogens, but further toxicity and safety studies are warranted.

Thursday, September 18, 2008

New Antimicrobial against Methicillin-resistant Staphylococcus aureus (MRSA)

ZEFTERA the only approved antibiotic in its class (cephalosporin) by Health Canada to demonstrate efficacy against Methicillin-resistant Staphylococcus aureus (
MRSA), a growing public health concern in both hospital and community settings.ZEFTERA is specially designed to tightly bind to and inhibit targets in both gram-positive (including MRSA) and gram-negative bacteria. The approval of ZEFTERA for the treatment of complicated skin and skin structure infections, including non-limb threatening diabetic foot infections without concomitant osteomyelitis, was based on results of two Phase III, double-blind, randomized, multi-centre, global trials involving 817 patients with cSSSI 2,3. The second Phase III trial included patients with non-limb threatening diabetic foot infections (mild, moderate or severe)3. Pathogens identified at baseline in this subpopulation included MSSA (38 per cent), MRSA (13 per cent), E. cloacae (9 per cent), and P. mirabilis (7 per cent). The results demonstrated the non-inferiority of ceftobiprole versus vancomycin plus ceftazidime in the treatment of diabetic foot infections. In both studies, ZEFTERA was well tolerated. The most common treatment-emergent adverse reactions were nausea (9 per cent) taste disturbance (6 per cent), diarrhea (5 per cent) and vomiting (5 per cent).

Monday, June 16, 2008

Antimicrobial activity of Nigella sativa Linn. seed oil against multi-drug resistant bacteria from clinical isolates

Salman, Mohd Tariq; Khan, Rahat Ali and Shukla, Indu (2008) Antimicrobial activity of Nigella sativa Linn. seed oil against multi-drug resistant bacteria from clinical isolates. Natural Product Radiance, 7 (1). pp. 10-14. ISSN 0972-592X, IPC code; Int. cl.8— A61K 36/00, A61P 31/04.
Abstract
An alarming increase in bacterial strains resistant to existing antimicrobial agents demands a renewed effort to seek agents effective against pathogenic bacteria resistant to current antimicrobials. Nigella sativa Linn. essential oil was studied for antibacterial activity against various clinical isolates of bacteria resistant to a number of antibiotics, in varying concentrations by Disc Agar diffusion technique using impregnated filter paper discs on inoculated Muellar Hinton agar plates. The oil showed pronounced dose dependent antibacterial activity which was more against Gram positive than Gram negative bacteria. Among Gram positive bacteria tested, Staphylococcus aureus, S. epidermidis, other coagulase –ve Staphylococci and Streptococcus pyogenes were sensitive to the oil and Enterococcus faecalis, Streptococcus agalactiae were resistant. Among Gram –ve bacteria tested, only Pseudomonas aeruginosa was sensitive to oil and rest (Acinetobacter baumannii, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, P. vulgaris and Vibrio cholerae) were insensitive. Out of 144 strains tested, most of which were resistant to a number of antibiotics, 97 were inhibited by the oil of black cumin. To the best of our knowledge, the activity of essential oil against coagulase negative Staphylococci (except S. epidermidis) and S. pyogenes is being reported for the first time.

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