scholarly journals Semi-nested polymerase chain reaction for detection of toxigenic Vibrio cholerae from environmental water samples

2007 ◽  
Vol 47 (3) ◽  
pp. 207-211 ◽  
Author(s):  
Ajay Kumar Goel ◽  
Shweta Bhadauria ◽  
Pramod Kumar ◽  
Dev V. Kamboj ◽  
Lokendra Singh
Keyword(s):  
Polymerase Chain Reaction ◽  
Vibrio Cholerae ◽  
Water Samples ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain

Evaluation of Legionella presence in the water system of a public building by semi-nested polymerase chain reaction as a rapid screening method complementary to plate count

2013 ◽  
Vol 13 (6) ◽  
pp. 1560-1568 ◽  
Author(s):  
Alejandra Serrano-Suárez ◽  
Rosa Araujo
Keyword(s):  
Polymerase Chain Reaction ◽  
Water Samples ◽  
Water System ◽  
Culture Method ◽  
Water Systems ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Public Building ◽  
Plate Counts ◽  
Polymerase Chain

The aim of this study was to apply a fast and efficient protocol for monitoring levels of Legionella contamination in high-risk water systems using molecular techniques and culture methods. Forty-nine water samples from a public building were analyzed by a culture method (BCYE agar) and a specific semi-nested polymerase chain reaction (PCR). The first 30 analyses using plate counts were positive in 28% of hot water and 8% of cold water samples. The analysis by PCR, obtained within 24 h of collection, revealed the presence of DNA in 100 and 54% respectively. Only four PCR results coincided with the cultures. A second survey (19 samples) was performed 1 year later. Semi-nested PCR revealed that 53% of the samples were positive; however, plate counts yielded no positive results. The 16S rRNA sequence comparison between the first and second samplings showed 100% homology. In conclusion, the study of the design of the building's water system, the use of a fast screening semi-nested PCR and a culture method for the detection of Legionella allowed accurate assessment of the contamination, thus contributing to the early implementation of measures to eliminate the presence of the bacteria in water systems and consequently reduce a latent public health risk.

scholarly journals Conventional and molecular detection of vibrio cholerae isolated from environmental water with the prevalence of antibiotic resistance mechanisms.

2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Suad A Al-Hilu ◽  
Ali M Al-Mohana ◽  
Zainab Jaber
Keyword(s):  
Polymerase Chain Reaction ◽  
Vibrio Cholerae ◽  
Molecular Detection ◽  
Public Health Problem ◽  
Environmental Water ◽  
Selective Medium ◽  
Chain Reaction ◽  
Biochemical Tests ◽  
Vibrio Cholera ◽  
Polymerase Chain

Environmental water is an important source for Vibrio cholerae, which is autochthonous to the aquatic environment, monitoring this bacterium in water is important for control of cholera. Vibrio cholerae represents an enormous public health problem around the world, especially in developing countries. One hundred samples were collected and selected. The samples were filtered and transferred to slants containing 2ml of alkaline peptone water, then subcultured on selective medium Thiosulphate Citrate Bile Salt Sucrose agar. All presumptive isolates were confirmed by using a series of biochemical tests including Oxidase test, Simmon Citrate test, DNase test, Indole test, Klingler Iron Agar (KIA) test, MacConkey agar test and motility. Confirmed Vibrio cholera strains were then screening for slide agglutination test by using commercially antisera polyvalent and monovalent O1 and O139 for determining strain serotype. The DNA extracted from pure culture and Polymerase Chain Reaction assay was used for molecular detection of Vibrio cholerae, a specific primer which designed according to ctxA gene sequences. This primer was detection and amplifying 241 base pairs of the ctxA gene. The resistance to antibiotics by Vibrio cholerae was determining by using thirteen standardized disc diffusion including Amikacin, Ceftriaxone, Ceftazidime, Gentamycin, Tetracycline, Streptomycin, Tobramycin, Cephotaxime, Nalidixic Acid, Norfloxacin, Cephalothin, Rifampicin, Cefixime. From one hundred water samples were detected, fifty-six samples were motile and positive for biochemical tests. Fifteen isolates confirmed as Vibrio cholera by Polymerase Chain Reaction (PCR) assay with primers de­signed for ctxA and 241bp band was observed. These fifteen isolates showed agglutination with polyvalent and monovalent O1 antisera, and two strains represented Ogawa from other strains that showed Inaba. The fifteen isolates exhibited an identical response to each antibiotic examined. They showed sensitive to all antibiotics except Amikacin, Streptomycin, Cefixime, Norfloxacin, Cephalothin. the aim of this study was determined the accurate method for detection of Vibrio cholerae in environmental water. In the current study, we found that the molecular method using Polymerase Chain Reaction performance using the ctxA gene-specific primers for detection of Vibrio cholerae was faster and accurate and specific.

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