iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova.

We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observations to resolve four images of the lensed supernova, approximately 0.3 arc seconds from the center of the foreground galaxy. The observations probe a physical scale of ~1 kiloparsec, smaller than is typical in other studies of extragalactic gravitational lensing. The large magnification and symmetric image configuration imply close alignment between the lines of sight to the supernova and to the lens. The relative magnifications of the four images provide evidence for substructures in the lensing galaxy.

In vitro activity of cefepime, a new parenteral cephalosporin, against recent European blood isolates and in comparison with piperacillin/tazobactam.

Cefepime, a new parenteral cephalosporin with broad antibacterial spectrum and stability to the hydrolysis to many bacterial beta-lactamases, was tested against recent blood culture isolates (369 strains of gram-negative bacilli and 131 strains of staphylococci) collected in 29 European laboratories by the microdilution method in Mueller-Hinton broth. Cefepime was very active against the gram-negative bacilli (MIC50 less than or equal to 0.016-0.064 mg/l; MIC90 0.064-4 mg/l) and less active against Pseudomonas (MIC50 4 mg/l; MIC90 greater than 16 mg/l) or Acinetobacter (MIC50 and MIC90 greater than 16 mg/l). The staphylococci were also inhibited (MIC50 8 mg/l; MIC90 16 mg/l). Cefepime was very active against bacteria producing different plasmid-encoded beta-lactamases (MIC 0.016-0.5 mg/l). Piperacillin was not active against the latter strains (MIC from 2 to greater than 64 mg/l), but the presence of the beta-lactamase inhibitor tazobactam restored the activity of piperacillin. The bactericidal activity of cefepime and piperacillin/tazobactam against beta-lactamase-producing strains was confirmed by the killing curve technique.

In-vitro activity of FCE 22101 against respiratory tract pathogens with reference to production of beta-lactamases.

FCE 22101 is a new penem with broad antibacterial spectrum, excluding the pseudomonads, and has stability to many beta-lactamases. FCE 22101 and imipenem were very potent against the bacteria studied, including beta-lactamase producing strains, which can be isolated from patients with respiratory tract infections (MIC less than or equal to 8 mg/l). No strains were found to be resistant to FCE 22101. FCE 22101 was rapidly bactericidal and more stable to inactivation by beta-lactamases from Branhamella catarrhalis, Haemophilus influenzae, Enterobacter cloacae and Klebsiella pneumoniae than imipenem and ceftibuten. The other antibiotics tested varied in their activities against the respiratory tract pathogens.

Comparative in-vitro activity of the penem FCE 22101 against recent European blood culture isolates.

Recent blood culture isolates (462 strains of Gram-negative bacilli and 288 strains of staphylococci) collected in 30 European laboratories were tested for susceptibility to five beta-lactam antibiotics by a microdilution method in Mueller-Hinton broth. The penem FCE 22101 and imipenem were very active against the Gram-negative bacilli, except the pseudomonads, FCE 22101 being four- to 16-fold less active (MIC50 2 mg/l; MIC90 8 mg/l) than imipenem MIC50 0.5 mg/l; MIC90 2 mg/l). Ceftibuten and ceftazidime were also active (MIC50 0.25 mg/l; MIC90 greater than 16 mg/l). The MIC of piperacillin (MIC50 8 mg/l; MIC90 greater than 64 mg/l) were two- to 16-fold reduced in the presence of the beta-lactamase inhibitor YTR-830 against these bacteria. Only imipenem and piperacillin inhibited the pseudomonads (MIC50 4 and 8 mg/l respectively; MIC90 16 mg/l and greater than 64 mg/l), with two-fold reduction in MIC50 of piperacillin in the presence of YTR-830. The staphylococci were very susceptible to FCE 22101 and imipenem (MIC50 less than or equal to 0.25 mg/l) except some cefazolin-resistant strains. In Staphylococcus aureus penem resistance was better expressed after bacterial growth at 30 degrees C. Some strains of Staph. epidermidis were susceptible to FCE 22101 but resistant to imipenem. The cephalosporins were not active against the staphylococci, and the presence of YTR-830 caused a four- to 16-fold reduction in MIC of piperacillin.