Real-Time PCR for Detection and Differentiation of Gram-Positive and Gram-Negative Bacteria

ABSTRACT A method for the detection of the SOS response as measured by the liberation of resident prophages from the genomes of their hosts is described. It is based on the use of two converging oligonucleotides that flank the attP attachment site of the phage as primers for real-time PCR. Amplification was observed only after the phage DNA became excised. The system responds to both chemicals and physical conditions. Quantitative data on the concentration and/or potency of the genotoxic condition were obtained. Results can be achieved within 1 day and are less susceptible to possible toxic effects than phage generation or other methods that require DNA synthesis. The use of both gram-positive and gram-negative bacteria widens the range of compounds that can be tested because it eliminates impermeability problems derived from the particular composition of each cell wall type.

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Clots retrieved by mechanical thrombectomy from acute ischemic stroke patients show no evidence of bacteria

Interventional Neuroradiology ◽

10.1177/1591019918819707 ◽

2019 ◽

Vol 25 (5) ◽

pp. 502-507 ◽

Cited By ~ 1

Author(s):

Zenith Khashim ◽

Seán Fitzgerald ◽

Ramanathan Kadirvel ◽

Daying Dai ◽

Karen M Doyle ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Real Time ◽

16S Rdna ◽

Mechanical Thrombectomy ◽

Blood Clot ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Staining

Background Bacteria and bacterial components have been associated with the activation of coagulation factors and initiating the blood clot formation. The aim of this study was to investigate whether bacterial populations are present in clots retrieved from patients that have suffered a large vessel occlusion acute ischemic stroke (AIS). Materials and methods Clot samples were collected from 20 AIS patients who underwent clot retrieval with mechanical thrombectomy. Patient clinical demographic details were noted. Expression of bacterial 16S rDNA was analyzed by standard and real-time polymerase chain reaction (PCR). Gram staining was performed to identify Gram-positive and Gram-negative bacteria. Results Both the real-time and standard PCR demonstrated no expression of 16S rDNA in any of the 20 clots samples from AIS patients. Gram staining results showed no expression of Gram-positive or Gram-negative bacteria present in the clot samples. Conclusion Our current study found no bacteria populations in the clots of AIS patients.

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Real time PCR based detection of broadhost range plasmids and their potential use as biomarker in detection of multidrug resistant gram negative bacteria

Journal of Infection and Public Health ◽

10.1016/j.jiph.2020.01.039 ◽

2020 ◽

Vol 13 (2) ◽

pp. 319

Author(s):

N. Choudhury ◽

D. Paul ◽

B. Das ◽

D. Dhar (Chanda) ◽

A. Bhattacharjee

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Multidrug Resistant ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Potential Use

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Detection of Colistin Resistance in Mannheimia haemolytica & Pasteurella multocida Isolates from Ruminants in Morocco

Pakistan Veterinary Journal ◽

10.29261/pakvetj/2020.077 ◽

2021 ◽

Vol 41 (01) ◽

pp. 127-131

Author(s):

G Sebbar

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Pasteurella Multocida ◽

Mannheimia Haemolytica ◽

Gram Negative Bacteria ◽

Colistin Resistance ◽

Gram Negative ◽

Pcr Screening ◽

Antimicrobial Sensitivity ◽

Resistance Rates

Colistin is an important drug of last resort against lethal infections with multidrugresistant gram-negative bacteria, this antibiotic interacts on phosphate groups of lipopolysaccharides present on the outer membrane of gram-negative bacteria. This first mechanism of transferable colistin resistance involves a gene called mcr-1. Here, we described different tools such as Colistin susceptibility test, Minimal Inhibitory Concentration to find the colistin profiles of Mannheimia haemolytica and Pasteurella multocida serogroup A Moroccan strain isolated from nasal swabs and lung taken from sheep, goat and cattle with respiratory diseases during January 2015 to December 2017 in six different regions, in addition, we investigated either real time PCR to detect mcr-1 gene. Antimicrobial sensitivity test, was achieved for Fortyone isolates, the resistance rates of isolates from Pasteurellaceae species were between 59 and 71%, which respectively correspond to Mannheimia haemolytica and Pasteurella multocida segroup A. The sensitive ratios were between 29 and 41% which respectively correspond to Pasteurella multocida segroup A and Mannheimia haemolytica. Also, the MIC test was done against colistin, the results showed a resistant profile with a MIC >=64 μg/ml except for 3 strains from ruminants which have a value <2 μg/ml. The real time PCR screening test was detected with ct values ranging from 23 to 31 and confirmed the results obtained by MIC test. To our knowledge the present study is the first study which reports the resistance to colistin in Pasteurellaceae species strains isolated from ruminants in Morocco, our results suggest the necessity and the urgency for establishing a national program for monitoring antibacterial resistance against colistin

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Rapid Screening Technique for Class 1 Integrons inEnterobacteriaceae and Nonfermenting Gram-Negative Bacteria and Its Use in Molecular Epidemiology

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.4.1022-1029.2001 ◽

2001 ◽

Vol 45 (4) ◽

pp. 1022-1029 ◽

Cited By ~ 48

Author(s):

Alison J. Maguire ◽

Derek F. J. Brown ◽

James J. Gray ◽

Ulrich Desselberger

Keyword(s):

Molecular Epidemiology ◽

Real Time ◽

Real Time Pcr ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Gene Cassettes ◽

Screening Technique ◽

Class 1 Integrons ◽

Antimicrobial Resistance Genes ◽

Class 1

ABSTRACT A screening technique for integrons in members of the familyEnterobacteriaceae and nonfermenting gram-negative bacteria by real-time PCR is reported. A total of 226 isolates of gram-negative bacteria obtained from a variety of clinical specimens were screened for class 1 integrons by real-time PCR performed on a LightCycler instrument. This technique used a primer pair specific for a 300-bp conserved region at the 5′ ends of class 1 integrons. The screening assay was evaluated by comparison with results obtained by the conventional, thermal-block PCR (long PCR) by using established conditions and primers for the detection of class 1 integrons, and the real-time PCR technique was thus shown to be both sensitive and specific. DNA from 50 of 226 (22%) isolates screened was identified as containing an integron by the screening PCR, and sequence data were obtained across the integron for 34 of 50 (68%) of these isolates. In an attempt to study the molecular epidemiology of antimicrobial resistance genes carried within integrons, a comparison of the types of gene cassettes carried by isolates from different patients was made. Adenyltransferase genes conferring resistance to streptomycin and spectinomycin were the predominant gene cassettes amplified in the study. Resistance to trimethoprim was also frequently found to be encoded within integrons. Furthermore, multiple bacterial isolates obtained from one patient over a 5-month period were all shown to carry an integron containing the same single adenyltransferase gene cassette, suggesting that these elements were relatively stable in this case.

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Quantitative Real-time PCR detection of putrescine-producing Gram-negative bacteria

Potravinarstvo Slovak Journal of Food Sciences ◽

10.5219/739 ◽

2017 ◽

Vol 11 (1) ◽

Author(s):

Kristýna Maršálková ◽

Khatantuul Purevdorj ◽

Petra Jančová ◽

Hana Pištěková ◽

Leona Buňková

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Pcr Detection ◽

Gram Negative Bacteria ◽

Quantitative Real Time Pcr ◽

Gram Negative

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Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123830 ◽

1992 ◽

Vol 50 (1) ◽

pp. 686-687

Author(s):

Jacob S. Hanker ◽

Paul R. Gross ◽

Beverly L. Giammara

Keyword(s):

Chronic Arthritis ◽

Blood Cultures ◽

Gram Negative Bacteria ◽

Infectious Arthritis ◽

Bacterial Arthritis ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

International Journal of Pharmaceutical and Phytopharmacological Research ◽

10.24896/eijppr.2016641 ◽

2016 ◽

Vol 6 (4) ◽

pp. 68

Author(s):

Sushma Vashisht ◽

Manish Pal Singh ◽

Viney Chawla

Keyword(s):

Antibacterial Activity ◽

Methanolic Extract ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Disc Diffusion ◽

Gram Positive ◽

Gram Negative ◽

Shorea Robusta ◽

Dose Dependent ◽

Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

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