Quantification Of Total Coliforms Research Articles

Assessment of Microbial Contamination in the Infulene River Basin, Mozambique

Water microbial contamination is one of the major threats to human health. The study focus is on Infulene River Basin, a urban catchment with mainly informal settlements, with limited water supply and sanitation. In the catchment there are two wastewater treatment plants, one hospital and beer factory located on the banks of the main stream; water from this stream is used for urban agriculture and domestic uses by some dwellers. These factors present a significant health risk from water-borne diseases. At the moment there is limited knowledge about the level of microbial contamination of the different sources of water at the disposal of the communities. Thus, a preliminary study on fecal microbial contamination was conducted targeting the Infulene River and the drainage system from the nearby Maputo city draining into the system, with additional investigation on the drinking water provided by the city water supply company. The quantification of Total Coliforms (TC) and Escherichia coli (EC) was conducted at several sampling locations. Results were compared with official drinking water standards. Eighty two percent (82%) and 61% of Infulene river water and drainage water samples were positive for TC (105 to 109 NPN/100 mL) and EC (105 to 107 NPN/100 mL), respectively. For drinking water samples, 63% and 23% were positive for TC (up to 6000 NPN/100 mL) and EC (up to 1000 NPN/100 mL), respectively. Higher microbial contamination was found in neighborhoods with the poorest sanitation and shallow groundwater, i.e., Chamanculo, Xipamanine, Mafalala, Aeroporto and Maxaquene, a situation that was more expressive during the rainy season. Overall, the study confirmed the high vulnerability to microbial contamination of all sources investigated due to poor sanitation and lack of drainage infrastructure. The risks to human health might be even higher considering that contaminated water is used for gardening of vegetable watering and domestic use.

Avaliação microbiológica de uma estação de piscicultura no Território Central do Estado de Rondônia, Brasil

O presente estudo teve como objetivo avaliar, a qualidade microbiológica de amostras de água da base de piscicultura Carlos Eduardo Matiazze, no município de Presidente Médici, RO, Brasil, através da quantificação de coliformes totais (CT) e termotolerantes (CTT). Os coliformes foram quantificados através do método do Número Mais Provável (NMP)/100mL. Houve grande variabilidade nos resultados, tanto de CT quanto de CTT, ao longo do ano. Os resultados variaram de 300 a 1100000 e 300 a 93000 NMP/100 mL para CT e CTT, respectivamente. As maiores concentrações em NMP/100 mL para CT e CTT ocorreram no ponto 6 e no período chuvoso. Este ponto está localizado a jusante, recebendo toda água dos demais devido ao fluxo de escoamento. Constatou-se que 47,7% das amostras avaliadas para CTT apresentaram valores de NMP/100 mL superiores ao limite máximo estabelecido (1000 NMP/100 mL) pela legislação vigente, Resolução CONAMA, nº. 357/2005. Desta forma, o sistema avaliado é considerado impróprio para o desenvolvimento de atividades destinadas à aquicultura.

The Development and Application of DDPCR Technology on Quantification of Total Coliforms in Water

In this research, the detection method for absolute quantification of total coliforms was established based on Droplet Digital Polymerase Chain Reaction (DDPCR) technology using lacZ as the target gene for coliform group detection. The experimental conditions (e.g. primer and probe concentrations, annealing temperatures, etc) were well optimized. Besides, the linear range, precision and limit of quantification (LOQ) of this method were investigated and evaluated. The results illustrated that the optimal primer concentration was 0.2 μmol/L, whereas the optimal probe concentration was 0.5 μmol/L. The optimal annealing temperature was 56°C. The linear relationship between the total coliform genome DNA concentrations derived from DDPCR and DNA fluorometer was quite good (R2 = 0.999). The linear range was 3.95 ~ 7.80 × 104 copies/20 μL DDPCR reaction system. The LOQ for total coliforms was single copy per reaction system. Practical applications using real water samples collected from water supply system in Macao illustrated that this innovative method possessed high efficiencies and capabilities. This is probably the first research using DDPCR technology to absolutely qualify and quantify total coliforms and successfully applied it in Macao water supply system. The achievements from this research could provide with significant values for setting-up the emergency mechanism of water pollution in early stage.

Occurrence of total coliforms, Escherichia coli and Cronobacter species in commercially available 20 l bottled drinking water sold in Rio de Janeiro State, Brazil.

Cronobacter infections of infants are commonly regarded as due to the ingestion of contaminated feed. The aim of this study was to determine the occurrence of Cronobacter, total coliforms and Escherichia coli in different brands of natural mineral waters as sold in 20l returnable bottles in Rio de Janeiro, Brazil. The quantification of total coliforms and E. coli was performed by Most Probable Number. The detection of Cronobacter was as according to the ISO 22964:2017 and Bacteriological Analytical Manual/FDA. Molecular characterization of Cronobacter isolates was performed by real-time PCR and by multi-locus sequence typing. The antibiotic susceptibility profile was determined and biofilm production was evaluated in polystyrene microplates. Total coliforms and E. coli were detected in 13 (39·4%) and 2 (6·1%) of the 33 lots analysed respectively, and were considered unsatisfactory for human consumption according to Brazilian law. One (3·0%) lot showed contamination by C. malonaticus ST440 (Cronobacter MLST Databases accession no. ID 2646). The strain was susceptible to all (n=13) antibiotics tested and only formed a weak biofilm. Since there is a high consumption of natural mineral waters by elderly and immunosuppressed persons, epidemiological surveillance agencies should be aware of the risk that these waters may represent for these groups. SIGNIFICANCE AND IMPACT OF THE STUDY: Cronobacter malonaticus ST440 was isolated from 20l bottled drinking natural mineral waters sold in markets in Rio de Janeiro State, Brazil, and can be a potential threat to human health, particularly for neonates. Thirteen lots (39·4%) were unsatisfactory for human consumption due to the presence of total coliforms and/or Escherichia coli.

Descripción del ciclo fenológico de cuatro ecotipos de (chenopodium quinua willd.), en Purace – Cauca, Colombia

The quantification of total coliforms in the estuary of the Rancheria river is an important factor for both agricultural activities and urban life. The area is formed by different water channels that form a dynamic and complex estuary. One of the most commonly used criteria for determining water quality is the measurement of total coliforms. In order to study the spatial and temporal distribution of these elements, water samples were collected in five different zones and the total coliform content was analyzed using the most probable NMP technique. Sampling was carried out every month, the first in September 2014 and the month of August 2015. The results established differences in the spatial and temporal distribution of the microorganisms analyzed. The highest values of total coliforms were found in the lower or higher watercourses, as well as in those closest to urban centers or farms. The dry season coincided with the lowest values of total coliforms, and the lowest values also coincided with the lower water temperatures.

Qualidade microbiológica da água do Lago Igapó de Londrina - PR e caracterização genotípica de fatores de virulência associados a Escherichia coli enteropatogênica (EPEC) e E. coli produtora de toxina Shiga (STEC)

Esse trabalho teve como objetivo a detecção e quantificação de Coliformes Totais e Escherichia coli, no Lago Igapó, com a finalidade de avaliar a qualidade destas águas como próprias ou impróprias para recreação, além da caracterização genotípica de fatores de virulência associados a EPEC e STEC pela técnica da PCR. A área de estudo foi o Lago Igapó I, II, III e IV. As coletas foram realizadas mensalmente entre março de 2011 a fevereiro de 2012. A técnica utilizada para detecção e quantificação de Coliformes Totais e E. coli foi a do substrato cromogênico Colilert. Na PCR os genes eae e bfp foram pesquisados para caracterizar o patotipo de EPEC típica; stx1, stx2, eae e hlyA o de STEC e as que apresentaram somente o gene eae foram caracterizadas como EPEC atípica. De acordo com a Resolução CONAMA 357/2005, foi observado que para a recreação de contato primário, apenas o Lago Igapó III foi classificado impróprio, já para recreação de contato secundário, todos os lagos apresentaram-se próprios. Além disso, pode ser observada uma forte relação entre o índice pluviométrico e os índices de E. coli no Lago Igapó, na qual em meses mais secos a sua quantidade decresce drasticamente, enquanto que em meses chuvosos se observava uma relação contrária. Das 97 cepas de E. coli isoladas, duas apresentaram o gene eae (EPEC atípica). Nenhum isolado apresentou os genes stx1, stx2, bfp e hlyA. Desse modo, esperamos conscientizar a população e os órgãos públicos da importância do monitoramento microbiológico das águas recreacionais para prevenção de surtos de infecções de veiculação hídrica.

Evaluation of Commercial Colilert18-Quantitray® Method by ISO Techniques for Enumeration and Quantification of Total Coliforms and Escherichia coli in Drinking-Water of Buraidah, Saudi Arabia

Evaluation of Commercial Colilert18-Quantitray® Method by ISO Techniques for Enumeration and Quantification of Total Coliforms and Escherichia coli in Drinking-Water of Buraidah, Saudi Arabia