Novel primer designing and PCR-AFLP approach for an expeditious detection of coliforms in potable waters

Molecular techniques involving 16S rRNA gene have long been proved to be a mainstay of sequence-based bacterial analysis and enhance the competence of bacterial removal in drinking water and food. The main goal of this analysis was to reduce the time of detection of total coliforms by developing 16S rRNA based DNA markers by targeting variable region in the 16S rRNA gene position of V2 and V9. Coliform specific primers (189F and 1447R) were designed to amplify total coliform with an amplicon size of 1300 bp. The PCR product was later digested with Hind III and BseRI (restriction enzymes) to differentiate the type of contamination caused by fecal and non-fecal coliforms respectively. The digested amplicons were run on agarose gel electrophoresis and contamination levels were estimated based on the respective band pattern. This method can be applicable to know the coliform contamination levels of potable waters, in food and beverage industries within a short period of time. To our knowledge, this is the first report on newly designed primers which not only amplify coliform bacteria, followed by various restriction digestions of these amplicons but also provides unique band patterns to identify coliforms at genus level.

Estimation of high density lipoprotein cholesterol in the diagnosis of lepromatous leprosy.

A high incidence of increased plasma level of high density lipoprotein cholesterol (HDL-C) has been reported in cases of lepromatous leprosy. HDL-C levels were estimated in 96 (50 under treatment and 46 untreated) lepromatous leprosy patients and 84 randomly selected matched control patients suffering from other skin diseases attending skin out-patients department. HDL-C estimations were performed for the diagnosis of lepromatous leprosy in patients aged below 60 years, taking plasma HDL-C levels as 28-71 mg./dl. in men and 34-91 mg./dl. in women, as range of normal values. The study revealed that HDL-C levels in lepromatous leprosy group were raised and significantly different when compared with control group (t = 35.1668 and P less than 0.001). The sensitivity of the test was very high, 97.9 per cent (94/96), but specificity was low 80.95 per cent (68/84). False positive and false negative results were 19.04 per cent (16/84) and 2.08 per cent (2/96) respectively. It is opined that a negative test will be mainly useful in excluding diagnosis of lepromatous leprosy.