By simultaneously amplifying more than one locus in the same reaction, multiplex PCR is becoming a rapid and convenient screening assay in both the clinical and the research laboratory. While numerous papers and manuals discuss in detail conditions influencing the quality of PCR in general, relatively little has been published about the important experimental factors and the common difficulties frequently encountered with multiplex PCR. We have examined various conditions of the multiplex PCR, using a large number of primer pairs. Especially important for a successful multiplex PCR assay are the relative concentrations of the primers at the various loci, the concentration of the PCR buffer, the cycling temperatures and the balance between the magnesium chloride and deoxynucleotide concentrations. Based on our experience, we propose a protocol for developing a multiplex PCR assay and suggest ways to overcome commonly encountered problems.

Multiplex PCR: Critical Parameters and Step-by-Step Protocol

http://link.springer.com/content/pdf/10.1007/BF02927128.pdf

Aquatic microbiology: F. A. Skinner andJ. M. Shewan Academic Press, London 1978; 370 pp.

The aim of this study was to investigate the effects of domestic waste on aquatic bacterial distribution in the Meric River located in the city centre of Edirne (Turkey). For this purpose, total mesophilic aerobic bacteria, total coliform, faecal coliform, and Eschericia coli bacteria were examined in the river. Also, some physicochemical features (water temperature, dissolved oxygen, pH, conductivity, total hardness, magnesium, calcium, orthophosphate, nitrite nitrogen and nitrate nitrogen) were measured at the same time with bacterial sampling. The Spearman correlation index was used to evaluate the correlation between the bacterial distribution and environmental features. According to the results of the index, it was found that bacterial distribution related with some environmental variables, but overloading of wastewaters from settlements lead to bacterial contamination. Furthermore, bacterial and physicochemical datasets were grouped using some multivariate analysis techniques (cluster analysis, principle components, and correspondence analysis). The results grouped the sampling localities by their bacterial, including physicochemical, features.

/pdf/investigation-of-the-effects-of-domestic-waste-on-aquatic-3wknlll6tc.pdf

Investigation of the effects of domestic waste on aquatic bacterial distribution in the Meric River (Edirne, Turkey)

Rural environments lack basic sanitation services. Facilities for obtaining water and disposing sewage are often under the initiative of each resident, who may not be able to build and maintain them properly. Thus, water for human consumption is subject to fecal contamination and, consequently, the presence of waterborne pathogens, such as enteric viruses. This study evaluated fecal contamination of water samples from individual sources used for domestic water supply on small farms in the state of Goias, Brazil. Samples were collected from 78 houses whose water sources were tubular wells, dug wells, springs, and surface waters. Escherichia coli (EC) bacteria, analyzed by the defined chromogenic substrate method, was used as a traditional indicator of fecal contamination. The enteric viruses Human mastadenovirus (HAdV) and Enterovirus (EV), analyzed by qPCR, were tested as complementary indicators of fecal contamination. At least one of these markers was found in 89.7% of the samples. Detection rates were 79.5% for EC, 52.6% for HAdV, and 5.1% for EV. The average concentration for EC was 8.82 × 101 most probable number (MPN) per 100 mL, while for HAdV and EV the concentrations were 7.51 × 105 and 1.89 × 106 genomic copies (GC) per liter, respectively. EC was the most frequent marker in ground and surface water samples. HAdV was detected significantly more frequently in groundwater than in surface water and was more efficient in indicating contamination in tubular wells. There was no association of frequencies or correlation of concentrations between EC and HAdV. HAdV indicated human fecal contamination and performed well as a complementary indicator. The results reveal that a large part of the analyzed population is vulnerable to waterborne diseases caused by enteric pathogens.

Escherichia coli, Species C Human Adenovirus, and Enterovirus in Water Samples Consumed in Rural Areas of Goiás, Brazil.

Bacterial contamination levels of representative 4 natural springs were detected seasonally through indicator bacterial contents in a rural area of Ordu, Turkiye. Total coliform bacteria, enterococi, Escherichia coli and Clostridium perfringens spores were used as the indicator organisms. According to the bacterial parameters, none of the detected springs comply with the standards implemented by the state health authorities. Contamination level of the springs increases with human and domestic animal activities in spring and summer. Using PCR and duplex PCR, samples collected from the most densely contaminated spring, Soguksu, were analyzed for three pathogenic bacterial groups. After eight-hour enrichment of the samples, positive results were found only for Salmonella spp. In conclusion, this investigation revealed that the natural springs used for drinking water supply in the research area are exposed to bacterial contaminations and the level of contamination increased with settlement density.

/pdf/an-investigation-on-the-bacterial-contents-of-natural-5ciidf3xlz.pdf

Alaa Aqso

Papers

An Investigation on the Bacterial Contents of Natural Springs in a Rural Area of the Middle Blacksea Region in Turkey