Bacterial recovery in hemodialysis fluids

To examine the culture method that could provide the highest bacterial recovery, 150 reverse osmosis water samples used in hemodialysis were collected for comparison of the media [Tryptic Soy Agar, TSA vs Reasoner's 2A Agar, R2A], the temperature [20oC vs 37oC], the duration of incubation [48-hour vs 7-day], and the culture technique [membrane filtration vs spread plate methods]. The European Best Practice Guideline method, R2A at 20oC for 7-day incubation provided higher bacterial recovery than the Association for the Advancement of Medical Instrumentation [AAMI] method, TSA at 37oC for 48-hour incubation. The membrane filtration method gave better yield than the spread plate method. As such, the European Best Practice Guideline method in combination with the membrane filtration technique would be the culture method of choice for hemodialysis fluids

Angiotensin I converting enzyme gene polymorphism in glomerulonephritis

Since an insertion / deletion [I/D] polymorphism of the angiotensin converting enzyme [ACE] gene significantly influences circulating ACE levels, we examined the role of this polymorphism in glomerulonephritis. ACE genotypes were retrospectively analyzed in 39 patients with clinical and biopsy proven glomerulonephritis [27 with idiopathic and 12 with lupus nephritis] and compared with ACE genotypes of 36 age and sex matched healthy control subjects. The ACE variants were determined by PCR and the genotypes were classified as DD, ID and II. Patients with glomerulonephritis had significantly higher frequency of DD genotype when compared to the control [DD: ID+II 61.5%: 38.5% vs 25%: 75%, p = 0.001]. Still, patients with lupus nephritis had a higher frequency of DD genotype than those with idiopathic glomerulonephritis [although non-significantly [75% vs 55.6%, p > 0.05]]. The risk of presence of DD genotype was 5 times greater in patients with glomerulonephritis than the control [Odds ratio 4.8, 95% CI - 1.6 - 14.75]. Patients with glomerulonephritis had significantly lower frequency of I allele compared to the control [38.5% vs 75%, p = 0.001]. Patients with DD genotype were significantly younger and belong to the male gender compared to patients having ID+II genotypes [p < 0.05, p < 0.01 respectively]. Taken together, these findings suggest a strong association between the DD genotype and histopathologic proven glomerulonephritis and that it may be a genetic marker identifying patients at risk of developing such disease. Moreover, it may identify patients with systemic lupus erythematosus at risk of developing lupus nephritis. The presence of I allele may be protective against development of glomerulonephritis