Adaptations in the physiological heterogeneity and viability of Shigella dysenteriae, Shigella flexneri and Salmonella typhimurium, after exposure to simulated gastric acid fluid

2017 ◽  
Vol 113 ◽  
pp. 378-384 ◽  
Author(s):  
Atheesha Singh ◽  
Tobias George Barnard
Keyword(s):  
Salmonella Typhimurium ◽  
Gastric Acid ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Acid Fluid ◽  
Physiological Heterogeneity

Influence of Different Physico-Chemical Stresses on Growth and Survivality of Shigella dysenteriae and Shigella flexneri

2001 ◽  
Vol 2 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Ishrat Sultana . ◽  
Rahman Md. Mizanur . ◽  
Shakhawat Hossain Bh . ◽  
Md. Majibur Rahman .
Keyword(s):  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Physico Chemical

Molecular Strategies for the Detection, Identification, and Differentiation between Enteroinvasive Escherichia coli and Shigella spp.

2005 ◽  
Vol 68 (2) ◽  
pp. 239-245 ◽  
Author(s):  
CESAR I. BIN KINGOMBE ◽  
MARIA-LUCIA CERQUEIRA-CAMPOS ◽  
JEFFREY M. FARBER
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Shigella Boydii ◽  
Epidemiological Tool ◽  
Pcr Rflp ◽  
Shigella Spp

A strategy for the detection, identification, and differentiation of enteroinvasive Escherichia coli (EIEC) and Shigella spp. has been developed. The strategy includes (i) a multiplex PCR for the amplification of two virulence genes, i.e., iuc (222 bp) and ipaH (629 bp); (ii) amplification of the ial gene (a 1,038-bp amplicon) located within a large plasmid; and (iii) restriction fragment length polymorphism (RFLP) of the ial gene amplicon. The multiplex PCR provided three patterns. Pattern 1 (iuc−/ipaH+) was found in 10 (67%) of 15 EIEC strains tested, pattern 2 (iuc+/ipaH−) in only 2 (4.4%) of 46 non-EIEC isolates, whereas pattern 3 (iuc+/ipaH+) was observed in all Shigella spp. and also in 5 (33%) of 15 EIEC strains tested. The pattern 3 EIEC strains were all positive for the ial gene. The PCR-RFLP of the ial gene amplicon using the endonuclease AclI was used to differentiate Shigella spp. from the EIEC strains that belonged to pattern 3. The ial gene was present in 21 (38%) of 56 and 6 (40%) of 15 Shigella spp. and EIEC strains tested, respectively. The PCR-RFLP of the ial gene amplicon divided the strains in two types. Type 1 did not contain the restriction enzyme site and was found in 6 (100%) of 6 EIEC strains, 4 (80%) of 5 Shigella boydii, and 4 (100%) of 4 Shigella dysenteriae strains tested. Type 2, which gave two fragments of 286 and 752 bp, was observed in 5 (83%) of 6 Shigella flexneri strains and 6 (100%) of 6 Shigella sonnei strains. Detection, identification, and differentiation of Shigella spp. and EIEC were achieved by analyses of the PCR patterns and RFLP types. To our knowledge, this is the first study to demonstrate a simple and rapid method for detecting, identifying, and differentiating, at the molecular level, Shigella spp. and EIEC strains. This method will have tremendous utility as an epidemiological tool and in helping to develop policies, risk assessments, and national and international methods for Shigella spp.

scholarly journals Customizable PCR-Microplate Array for Differential Identification of Multiple Pathogens

2013 ◽  
Vol 76 (11) ◽  
pp. 1948-1957 ◽  
Author(s):  
ABDELA WOUBIT ◽  
TESHOME YEHUALAESHET ◽  
SHERRELLE ROBERTS ◽  
MARTHA GRAHAM ◽  
MOONIL KIM ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Francisella Tularensis ◽  
Yersinia Pseudotuberculosis ◽  
Salmonella Typhi ◽  
Rapid Identification ◽  
Shigella Dysenteriae ◽  
Tularensis Subsp ◽  
Differential Identification ◽  
Hot Dog ◽  
Simultaneous Identification

Customizable PCR-microplate arrays were developed for the rapid identification of Salmonella Typhimurium, Salmonella Saintpaul, Salmonella Typhi, Shigella dysenteriae, Escherichia coli O157:H7, Francisella tularensis subsp. tularensis, Francisella tularensis subsp. novicida, Vibrio cholerae, Vibrio parahaemolyticus, Yersinia pestis, and Yersinia pseudotuberculosis. Previously, we identified highly specific primers targeting each of these pathogens. Here, we report the development of customizable PCR-microplate arrays for simultaneous identification of the pathogens using the primers identified. A mixed aliquot of genomic DNA from 38 strains was used to validate three PCR-microplate array formats. Identical PCR conditions were used to run all the samples on the three formats. Specific amplifications were obtained on all three custom plates. In preliminary tests performed to evaluate the sensitivity of these assays in samples inoculated in the laboratory with Salmonella Typhimurium, amplifications were obtained from 1 g of beef hot dog inoculated at as low as 9 CFU/ml or from milk inoculated at as low as 78 CFU/ml. Such microplate arrays could be valuable tools for initial identification or secondary confirmation of contamination by these pathogens.

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