Number Of Positive Tubes Research Articles

ANALISIS UJI MIKROBA PADA MINUMAN COCOGHURT

Cocoghurt is a fermented drink made from coconut milk sediment. This study aims to analyze the microbial test on cocogurt drink. In this study the tests carried out were salmonella, coliform, escherichia coli, and bacillus tests using the Most Likely Number (APM) method in accordance with SNI 01-2897-1992, in addition to this test using a presumptive test approach or estimation and confirmation or confirmation with using liquid media in test tubes and carried out based on the number of positive tubes. Samples that were confirmed positive could be seen by the appearance of gas in the Durham tube and the bacillus test was carried out by observing using a binocular microscope with two temperature treatments, namely 400 C and 40 C. The Coliform and E. coli tests that had been carried out showed that the cocoghurt contained coliform bacteria contamination. of <3 APM/g and Escherichia coli of <3 APM/g. The amount of contaminants from the microbial test results is within the safe limit of the Indonesian National Standard for fermented beverages.

Factors associated with bacterial contamination of shallow well water sources. Case Study of Juja hostels Kiambu County

The use of water from polluted water sources poses numerous public health challenges in developing countries. The ultimate purpose of any solid and liquid waste management plan is to mitigate environmental pollution; these goals become unachievable in the absence of a participatory approach to integrated waste management. This study sought to determine the extent of underground pollution of groundwater sources in Juja Town. Sanitary inspection and water quality analysis are complementary and valuable tools for characterizing and protecting water safety. The quality of the shallow wells is of great importance because it is used for consumption in Juja hostels. A two-stage cluster sampling strategy was adopted to obtain a representative sample size. Data collection involved the administration of questionnaires and field observation checklists, and E. coli levels present in the water were determined by the number of positive tubes in the table of computation of most probable number (MPN). Results showed that the predominant types of waste disposal practices observed in Juja were septic tank systems (77%) for liquid waste and private collection (87.3%) for solid waste methods. Sixty-eight per cent of the water samples were found to be positive (they exceeded the WHO (2004) maximum permissible load of 0.01/100 ml for drinking water. Three sanitary risk factors had a statistically significant effect on the dependent variable: the distance of the septic tank from the well on the level of water contamination (0.016), the liquid waste management plan (0.039), and the fitness of the water well cover on the level of water contamination (0.024). Shallow well water sources are unsuitable for use in food processing and drinking due to the presence of E. coli bacteria. The consequences of consuming contaminated water can be expensive to treat. Water from wells in Juja is contaminated with E. coli levels ranging from <3 - >1000 MPN/g, indicating fecal contamination in the area's underground water sources.

Detection of Coliform and Escherichia coli on Ice Cubes from Beverage Sellers around Campus 4 of Universitas Ahmad Dahlan

Ice cubes are a complement to drinks. Ice cubes must not contain Coliform or Escherichia coli. Coliform and Escherichia coli are indicator microorganisms used in water quality analysis. Its presence indicates fecal contamination. The purpose of this study was to analyze the presence of Coliform and E.coli on ice cubes found in drinks sold around the Kampus 4 Universitas Ahmad Dahlan. Sampling was done by purposive sampling. The sample used in this study was 7 ice cube samples taken from different stalls around the campus. This study used the MPN (Most Probable Number) method which consists of a presumptive test, a confirmative test and the Escherichia coli test. A positive result was indicated by changes in the turbidity of the media and the presence of gas bubbles in the durham tube. Data analysis was performed by comparing the number of positive tubes in the observation results with the MPN table. Based on the data obtained, samples of ice cubes from 7 sellers around Kampus 4 Universitas Ahmad Dahlan were positive for Coliform and Escherichia coli bacteria. The principles of food sanitation hygiene need to be improved to prevent bacterial contamination on ice cubes.

The impact of screening-test negative samples not enumerated by MPN

In microbiological surveys, false negative results in detection tests precluding the enumeration by MPN may occur. The objective of this study was to illustrate the impact of screening test failure on the probability distribution of Salmonella concentrations in pork using a Bayesian method. A total of 276 swab samples in four slaughter steps (69 samples in each slaughter step: after dehairing, after singeing, after evisceration, and before chilling) were screened for Salmonella and enumerated by the MPN method. Salmonella contamination data were fitted to a lognormal distribution by using a Bayesian model that uses the number of positive tubes at each dilution in an MPN analysis to estimate the parameters of the concentration distribution. With Salmonella paired data, three data sets were used for each slaughter step: one that includes the positives in the screening test only, a second one that includes false negative results from the screening, and a third that considers the entire data set. The relative sensitivity of the screening test was also calculated assuming as gold standard samples with confirmed Salmonella. Salmonella was confirmed by a reference laboratory in 29 samples either by screening or MPN method. The relative sensitivity of the screening test was 69% (CI 95%: 52%–85%). The data set that included enumerations from screen-negative samples (false negative results) tended to have higher μ^ and smaller σ^ in comparison with the data set that discards false negative results, suggesting that the lack of sensitivity of the screening test affects the distribution that describes the contamination across the population. Numerous surveys on fitting distribution methods of microbial censored data have been published and discuss source of bias due to fitting method. Results of this survey contribute with that discussion by illustrating another possible source of bias due to failure of the screening methods preceding the MPN.

MEASURING IMPROBABILITY OF OUTCOMES FROM A SERIAL DILUTION TEST

ABSTRACT This article introduces a max, designated, and MPN measure of the rarity of an outcome for serial dilution tests. All three measures divide the likelihood of the specified outcome at its MPN by the likelihood of an outcome with the same design. The max measure divides by the maximum of the likelihood at their MPN of all outcomes with the same number of positive tubes. The designated measure divides by the likelihood of an outcome that maximizes over a single dilution at a time. The MPN measure divides by the largest likelihood of any outcome at the MPN of the specified outcome. These new measures appear to agree well with improb and are much easier to compute.

An assay for the enumeration of total coliforms and Escherichia coli in water and wastewater

A novel pad was developed for identifying the end points of the β‐galactosidase and β‐glucuronidase reactions used in determining total coliforms and Escherichia coli, respectively, in environmental samples. This method (ColiPAD®) was run in parallel with the standard multiple tube fermentation (MTF) technique on a total of 33 samples from the influent and treated effluent of two wastewater treatment plants and from a eutrophic lake. Differences in the number of positive tubes by the two methods were not significant for wastewater influent and lake samples and were marginally significant for treated effluents. Regression analysis of log‐transformed data yielded highly significant linear correlations between total coliforms by ColiPAD and total coliforms by the MTF method and between E. coli by ColiPAD and fecal coliforms by the MTF method.

Evaluation of the Autoanalysis Colilert test for detection and enumeration of total coliforms

The Autoanalysis Colilert (AC) test was compared with the membrane filter (MF), 10-tube multiple-tube fermentation (MTF) technique, and the presence-absence test as described in Standard Methods for the Examination of Water and Wastewater for the detection and enumeration of total coliforms in water. The methods were evaluated with 31 samples from seven different sources. Each sample was analyzed by each of the techniques, using replicate 100-ml sample volumes. A total of 582 confirmed tubes were positive by the MTF test, and 533 tubes were positive by the AC test. Statistical analysis of the most-probable-number comparability data showed a statistically significant difference in the number of positive tubes, with the MTF test resulting in more positive tubes. There were no statistically significant differences in precision between the two methods. All the methods were comparable in detection of total coliforms. Levels of heterotrophic bacteria generally encountered in drinking water did not interfere with detection or enumeration of coliforms by the AC test.