Recombinant human G6PD for quality control and quality assurance of novel point-of-care diagnostics for G6PD deficiency.

Background: A large gap for the support of point-of-care testing is the availability of reagents to support quality control (QC) of diagnostic assays along the supply chain from the manufacturer to the end user. While reagents and systems exist to support QC of laboratory screening tests for glucose-6-phosphate dehydrogenase (G6PD) deficiency, they are not configured appropriately to support point-of-care testing. The feasibility of using lyophilized recombinant human G6PD as a QC reagent in novel point-of-care tests for G6PD deficiency is demonstrated.

Adaptive resistance to benzalkonium chloride, amikacin and tobramycin: the effect on susceptibility to other antimicrobials.

Aims: To produce strains of antimicrobial-resistant Pseudomonas aeruginosa via adaptation to benzalkonium chloride, amikacin and tobramycin and to then examine the incidence, or otherwise, of cross-resistance between antibiotics and between antibiotics and benzalkonium chloride.

Methods And Results: Adaptation was obtained by progressive subculturing in subinhibitory concentrations of the antimicrobials. Pseudomonas aeruginosa NCIMB 10421 adapted to grow in high concentrations of benzalkonium chloride (BC) had lower MIC to antibiotics than the wild type, whereas Ps.

The relationships and susceptibilities of some industrial, laboratory and clinical isolates of Pseudomonas aeruginosa to some antibiotics and biocides.

Aims: To provide evidence to support or refute the hypothesis that cross-resistance between antibiotics and biocides can occur.

Methods And Results: Fifty-five strains of Pseudomonas aeruginosa were tested for their resistance to anti-pseudomonal antibacterials. Twenty clinical, 19 industrial and 16 culture collection isolates were used.

Direct inoculation into media containing bile salts and antibiotics is unsuitable for the detection of acid/salt stressed Escherichia coli O157:H7.

The efficiency of selective enrichment broths for the recovery of low numbers of acid/salt stressed Escherichia coli O157:H7 was determined. Stressed cultures were diluted to low levels and recovered in tryptone soya broth with added bile salts, to make modified tryptone soya broth, and buffered peptone water with various combinations of antibiotic supplementation including novobiocin, acriflavine and a mixture of vancomycin, cefsulodin and cefixime (VCC) at 37 degrees C and 42 degrees C. Significantly fewer stressed cells, in some cases as little as 0.

The use of an automated growth analyser to measure recovery times of single heat-injured Salmonella cells.

A new approach to the study of recovery times of single heat-injured Salmonella cells is described. It comprises the generation of a standard heat-injured culture, serial dilution of this culture to near extinction, inoculation of the serial dilutions across many microtitre plates and measurement of the subsequent recovery and growth using an automated turbidometric analyser. Lag times for individual cells were estimated from turbidity data using a model that accurately extrapolated the growth curve back to the starting inoculum level.