scholarly journals Microtitre Plate Assay for the Quantification of Biofilm Formation by Pathogenic Leptospira

2017 ◽  
Vol 12 (2) ◽  
pp. 146-153 ◽  
Author(s):  
Kasing Apun ◽  
Chai Fung Pui ◽  
Jennifer Jalan ◽  
Lesley Maurice Bi ◽  
Lela Su`ut ◽  
...  
2019 ◽  
Vol 6 ◽  
pp. 63-69
Author(s):  
Roshani Nhuchhen Pradhan ◽  
Surendra Kumar Madhup ◽  
Shyam Prasad Pant

Objectives: This cross-sectional study was designed to detect the carbapenemase producing K. pneumoniae along with biofilm producers from different clinical specimens and to compare antibiotic susceptibility pattern of biofilm producing carbapenem resistant Klebsiella pneumoniae and biofilm non-producing carbapenem resistant Klebsiella pneumoniae. Methods: A total of 1475 non-repetitive clinical samples were included on this study. Antibiotic Sensitivity Testing (AST), Modified Hodge Test (MHT) and Modified Carbapenem inactivation method (mCIM) were performed for detection of carbapenemase production and Congo red agar method (CRA) along with Microtitre plate method were performed for detecting biofilm production. Results: Among the clinical specimens cultured, growth positivity was 62.71%. E. coli was most predominant organism followed by K. pneumoniae (17.89%). Among the 110 K. pneumoniae, 57 were found to be carbapenemase producer. Majority of the carbapenemase producing K. pneumoniae were isolated from sputum (45.61%), in the specimen collected from age group 61-70 (28.07%) and in out-patient department (50.88%). Similarly, 65.45% K. pneumoniae out of 110 were found to be biofilm producer by Congo red agar method while among those 72, 73.59% isolates were found to be quantitatively biofilm producer in Microtitre plate assay. Out of 57 carbapenemase producer, 35.08% were strongly biofilm producer while among 53 carbapenemase non-producer 30.18% were strongly biofilm producer from Congo red agar method. Moreover, Microtitre plate assay evidenced that, out of 57 carbapenemase producer, 40.35% were highly biofilm producing and among the 15 carbapenemase nonproducer 66.66% were highly biofilm producer.  Conclusion: Biofilm formation is highly prevalent with varying degree of resistance among different antibiotics including carbapenems that further augments antibiotic resistance. The study showed carbapenemase producers are stronger biofilm producer than the non-carbapenemase producer. Therefore, it is recommended to identify biofilm formation among carbapenemase producers for effective choice of antibiotics.


Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 517-522 ◽  
Author(s):  
Michael P. Anderson ◽  
Curtis N. Bensch ◽  
Jimmy F. Stritzke

This paper reports on a microtitre plate version of the 2,6-dichlorophenol-indophenol (DCPIP) reduction assay. DCPIP reduction rates of alfalfa thylakoid membranes were determined by measuring absorbance at 600 nm before and after a 1 min illumination period. The membranes were near light-saturated at intensities above 600 μE m–2s–1. Saturation of thylakoid membranes with DCPIP occurred above 120 μM. DCPIP reduction rates increased linearly with chlorophyll concentrations from 0.25 to 2 μg. The rate of DCPIP reduction was linear throughout a 2 min illumination period (R2= 0.99). The assay was sensitive enough to terbacil to differentiate between a 20% change in the I50concentration. DCPIP reduction rates were sensitive to concentrations of terbacil as low as 100 nM. It only takes 13 minutes to load and read 96 samples using the microtitre plate assay compared to 5.5 h using the conventional procedure.


2008 ◽  
Vol 23 (1) ◽  
pp. 131-135 ◽  
Author(s):  
Andrea L. Ball ◽  
Kirsty A. Chambers ◽  
Meera Hewinson ◽  
Sambavi Navaratnarajah ◽  
Lamia Samrin ◽  
...  

The Analyst ◽  
2000 ◽  
Vol 125 (3) ◽  
pp. 395-396 ◽  
Author(s):  
Robert K. Buick ◽  
Nuala M. Greer ◽  
Christopher T. Elliott

2008 ◽  
Vol 63 (7-8) ◽  
pp. 599-604 ◽  
Author(s):  
Zahra Etemadifar ◽  
Giti Emtiazi

Gasoline-contaminated soil from Isfahan, Iran was selected to isolate a bacterium capable of desulfurizing dibenzothiophene (DBT). The isolated strain was named R1 and identified as Rhodococcus erythropolis through biochemical tests as well as sequencing of 16S rRNA gene. This strain could efficiently produce 2-hydroxybiphenyl (HBP) from DBT via the 4S metabolic pathway. The highest HBP amount was produced at 2 mm DBT with addition of glucose (10 g l-1), ethanol (3 g l-1), glycerol (2 g l-1) or succinate (10 g l-1) as carbon sources at pH 7. Highest respiration and growth rates were observed by microplate titration on 0.1 mm HBP, and addition of 0.2 mm HBP to glucose (1 g l-1) and DBT (0.3 mm) could inhibite the respiration of the isolate. The isolated strain could grow up to 0.4 mm of HBP when it is used with mineral sulfur as sole sulfur source. To the best of our knowledge this is the first report on a microtiter assay for the production and utilization of HBP by Rhodococcus.


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