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 ◽  
...  

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.

2012 ◽  
Vol 75 (4) ◽  
pp. 660-670 ◽  
Author(s):  
ABDELA WOUBIT ◽  
TESHOME YEHUALAESHET ◽  
TSEGAYE HABTEMARIAM ◽  
TEMESGEN SAMUEL

The bacterial genera Escherichia, Salmonella, Shigella, Vibrio, Yersinia, and Francisella include important food safety and biothreat agents. By extensive mining of the whole genome and protein databases of diverse, closely and distantly related bacterial species and strains, we have identified novel genome regions, which we utilized to develop a rapid detection platform for these pathogens. The specific genomic targets we have identified to design the primers in Francisella tularensis subsp. tularensis, F. tularensis subsp. novicida, Shigella dysenteriae, Salmonella enterica serovar Typhimurium, Vibrio cholerae, Yersinia pestis, and Yersinia pseudotuberculosis contained either known genes or putative proteins. Primer sets were designed from the target regions for use in real-time PCR assays to detect specific biothreat pathogens at species or strain levels. The primer sets were first tested by in silico PCR against whole-genome sequences of different species, subspecies, or strains and then by in vitro PCR against genomic DNA preparations from 23 strains representing six biothreat agents (Escherichia coli O157:H7 strain EDL 933, Shigella dysenteriae, S. enterica serovar Typhi, F. tularensis subsp. tularensis, V. cholerae, and Y. pestis) and six foodborne pathogens (Salmonella Typhimurium, Salmonella Saintpaul, Shigella sonnei, F. tularensis subsp. novicida, Vibrio parahaemolyticus, and Y. pseudotuberculosis). Each pathogen was specifically identifiable at the genus and species levels. Sensitivity assays performed with purified DNA showed the lowest detection limit of 128 fg of DNA/μl for F. tularensis subsp. tularensis. A preliminary test to detect Shigella organisms in a milk matrix also enabled the detection of 6 to 60 CFU/ml. These new tools could ultimately be used to develop platforms to simultaneously detect these pathogens.


2020 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Jirapat Kanklai ◽  
Tasneem Chemama Somwong ◽  
Patthanasak Rungsirivanich ◽  
Narumol Thongwai

Gamma-aminobutyric acid (GABA), the inhibitory neurotransmitter, can be naturally synthesized by a group of lactic acid bacteria (LAB) which is commonly found in rich carbohydrate materials such as fruits and fermented foods. Thirty-six isolates of GABA-producing LAB were obtained from Thai fermented foods. Among these, Levilactobacillus brevis F064A isolated from Thai fermented sausage displayed high GABA content, 2.85 ± 0.10 mg/mL and could tolerate acidic pH and bile salts indicating a promising probiotic. Mulberry (Morus sp.) is widely grown in Thailand. Many mulberry fruits are left to deteriorate during the high season. To increase its value, mulberry juice was prepared and added to monosodium glutamate (MSG), 2% (w/v) prior to inoculation with 5% (v/v) of L. brevis F064A and incubated at 37 °C for 48 h to obtain the GABA-fermented mulberry juice (GABA-FMJ). The GABA-FMJ obtained had 3.31 ± 0.06 mg/mL of GABA content, 5.58 ± 0.52 mg gallic acid equivalent/mL of antioxidant activity, 234.68 ± 15.53 mg cyanidin-3-glucoside/mL of anthocyanin, an ability to inhibit growth of Bacillus cereus TISTR 687, Salmonella Typhi DMST 22842 and Shigella dysenteriae DMST 1511, and 10.54 ± 0.5 log10 colony-forming units (CFU)/mL of viable L. brevis F064A cell count. This GABA-FMJ was considered as a potential naturally functional food for human of all ages.


2016 ◽  
Vol 14 (1) ◽  
Author(s):  
Crystal N. Propst ◽  
Albert O. Nwabueze ◽  
Igor L. Kanev ◽  
Rachel E. Pepin ◽  
Bradford W. Gutting ◽  
...  

2021 ◽  
Vol 19 (6) ◽  
pp. 129-138
Author(s):  
Yasser Fakri Mustafa ◽  
Moath Kahtan Bashir ◽  
Mahmood Khudhayer Oglah ◽  
Raghad Riyadh Khalil ◽  
Eman Tareq Mohammed

A couple of natural coumarins was identified in the seeds of two apples’ cultivars commonly known as Granny Smith and Red Delicious. The effect of the phenolic hydroxyl moieties found in these products was evaluated on the bioactivity. This evaluation included the structural alteration of these moieties into less hydrophilic ones to explore the significance of the parent moieties on the biological activity. The investigated biopotentials were antioxidant, antiproliferative, antibacterial, and antifungal effects. The antioxidant potential was investigated by detecting the ability of the natural and semisynthetic coumarins to trap the free hydroxyl and DPPH radicals. The antiproliferative potential was assessed via an MTT-depended assay versus eight cancerous-cell lines, included HeLa, SK-OV-3, AR42J, MCF-7, AB12, KYSE-30, LC540, and AMN3. The antibacterial potential was tested versus six common pathogenic bacterial strains via a well-defined disc diffusion assay. These pathogens were Escherichia coli, Salmonella typhi, Klebsiella pneumonia, Haemophilus influenzae, Shigella dysenteriae, and Pseudomonas aeruginosa. The antifungal potential was also screened by utilizing a similar microbiological technique versus three pathogenic fungi, involved Candida albicans, Aspergillus flavus, and Aspergillus niger. It is concluded that the investigated chemical moiety has a positive influence on the antioxidant and antiproliferative potentials of the natural derivatives, and a negative one on their antibacterial and antifungal potentials.


2013 ◽  
Vol 7 (20) ◽  
pp. 2365-2371
Author(s):  
A Palma Quiroz Israel ◽  
A Goacute mez Aldapa Carlos ◽  
del Refugio Torres Vitela M ◽  
Rangel Vargas Esmeralda ◽  
M Santos Loacute pez Eva ◽  
...  

2011 ◽  
Vol 39 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Chai Fung Pui ◽  
Woan Chwen Wong ◽  
Lay Ching Chai ◽  
Hai Yen Lee ◽  
Ahmad Noorlis ◽  
...  

2018 ◽  
Vol 86 (4) ◽  
pp. 52
Author(s):  
Andressa Batista ◽  
Hilania Dodou ◽  
Matheus Rodrigues ◽  
Pedro Pereira ◽  
Gleilton Sales ◽  
...  

The essential oil obtained from the leaves of Lippia alba (Mill.) N.E. Brown (Verbenaceae) has shown great pharmacological potential as an analgesic, antispasmodic, and antimicrobial agent. The aim of this study was to evaluate the modulatory effect of Lippia alba essential oil (LaEO I) on the activity of clinically used antimicrobial agents on Salmonella enterica serovar Typhi (Salmonella typhi) and Shigella dysenteriae biofilms. The Minimum Inhibitory Concentration of LaEO I (MICLaEO I) was determined by the microdilution method, and the effect of LaEO I on the activity of clinically used antimicrobials was assessed by the Checkboard method. The values obtained from MICLaEO I and ciprofloxacin were used to evaluate the effect of time of exposure on cell viability. LaEO I main components were geranial (34.2%), neral (25.9%), and myrcene (12.5%). The MICLaEO I was 1 mg/mL for both strains. LaEO I positively modulated the action of ciprofloxacin, cefepime, and ceftriaxone. After the first hour of treatment with MICLaEO I, the cell viability of the strains showed a 5 log10 CFU/mL reduction, and the LaEO I-CIP association was able to inhibit growth during the first 6 h of the test. Regarding the anti-biofilm activity, MICLaEO I was able to reduce the biofilm mass of Salmonella typhi by 61.2% and of Shigella dysenteriae by 38.9%. MICLaEO I was not able to eradicate the preformed biofilm; however, there was a reduction in the biofilm microbial viability. LaEO I has the potential to be used as an antimicrobial agent and interferes with biofilm formation; also, it is able to reduce cell viability in preformed biofilm and synergistically modulate the activity of ciprofloxacin.


2008 ◽  
Vol 62 (1) ◽  
pp. 208-210 ◽  
Author(s):  
Eric Valade ◽  
Josée Vaissaire ◽  
Audrey Mérens ◽  
Eric Hernandez ◽  
Chantal Gros ◽  
...  

2012 ◽  
Vol 17 (40) ◽  
Author(s):  
M E Raguenaud ◽  
S Le Hello ◽  
S Salah ◽  
F X Weill ◽  
A Brisabois ◽  
...  

An outbreak due to the emerging monophasic Salmonella Typhimurium 4,5,12:i:- occurred in four schools in Poitiers in October 2010. Food trace-back investigation led to the identification of beef burgers as the cause of the outbreak and their subsequent withdrawal. The Institute for Public Health Surveillance conducted a retrospective epidemiological investigation to assess the extent of the outbreak and describe cases. Self-administered questionnaires were completed by students and personnel attending each of the four schools affected. Clinical cases were defined as anyone having eaten at the school when the beef burgers were served and reporting diarrhoea or fever with at least one digestive symptom (nausea, vomiting or abdominal pain), within five days after the incriminated school meal or with unknown date of onset within a 15-day period after the incriminated school meal. Of 1,559 persons exposed, 554 clinical cases were identified corresponding to an overall attack rate of 35.5%. Of 554 clinical cases, a total of 286 (53%) sought medical care and 31 (6%) were hospitalised for more than 24 hours. This multi-school outbreak is one of the biggest food-borne outbreaks of monophasic Salmonella Typhimurium 4,5,12:i:- described in France. Prompt notification of cases and rapid identification and withdrawal of the incriminated batch of beef burgers was crucial to limit the extension of this outbreak.


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