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•Fabrication of new optical sensor membranes for anthracene detection in Suez Bay.•Validation of new sensor was achieved through comparison with gas chromatography.•Developed MTP ...displayed high efficient and direct determination with low DL.•Applicability of MTP has been demonstrated by the recovery and reusability study.
A luminescent microtiter plate (MTP) sensor was fabricated using Eu (III) complex with 4,4,4 trifluoro 1-(2-naphthyl) 1,3 butanedione for screening anthracene in seawater samples. The quenching constant (KSV), binding constant (KD), detection (DL) and quantification limits (QL) were 2.34 ×106 mol−1 L, 8.89 ×105 mol−1 L, 0.049 μmol L−1, and 0.145 μmol L−1, respectively. Eu(TAN)3 is embedded in a membrane made of polyvinyl chloride to fabricate microtiter plate sensor. Gas chromatography was used to validate Eu(TAN)3 MTP for accurate and precise anthracene sensing. Effect of matrix, incubation time, temperature, selectivity and sensitivity of the Eu(TAN)3 MTP toward anthracene was examined. According to obtained results, Eu(TAN)3 MTP is capable of detecting anthracene quickly and accurately.
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•Fabrication of new optical sensor membranes for anthracene detection in Suez Bay.•Validation of new sensor was achieved through comparison with gas chromatography.•Developed MTP ...displayed high efficient and direct determination with low DL.•Applicability of MTP has been demonstrated by the recovery and reusability study.
A new fluorescent sensing microtiter plate (MTP) was developed for high sensitivity monitoring of anthracene in seawater samples. For this purpose, two ternary complexes of Tb(III) ions with dibenzoylmethane and neocuproine Tb(DBM)2(MePhen) or with dibenzoylmethane and bathocuproine Tb(DBM)2(PhMePhen) were synthesized. Elemental analysis, energy dispersive X-ray analysis, X-ray diffraction, infrared and ultraviolet–visible emission, and thermal analysis were conducted on the Tb(III) complexes. The limits of detection (DL) were 0.14 and 1.05 μmol L−1 for Tb(DBM)2(MePhen) and Tb(DBM)2(PhMePhen), respectively. Tb(DBM)2(PhMePhen) MTP is embedded in a membrane made of cellulose acetate. The first high-throughput anthracene sensor MTP, based on Tb(DBM)2(PhMePhen) sensor showed a linear range, from 0.2 to 20 μmol L−1. Tb(DBM)2(PhMePhen) MTP was validated for accurate and precise monitoring of anthracene using gas chromatography. The selectivity of the Tb(DBM)2(PhMePhen) MTP toward anthracene was examined. The data indicated that Tb(DBM)2(PhMePhen) MTP is suitable for rapid and direct detection of anthracene.
The present study was undertaken on 164 bovine milk samples (cow = 113 and Buffalo = 51) collected from various dairy farms in and around Rewa (Madhya Pradesh, India) and only 24 samples (6.83%) were ...found to be positive for mastitis when screened through California Mastitis Test (CMT). The prevalence of subclinical mastitis in cattle was 21%. All 17 isolates were phenotypically characterized by mannitol fermentation, biochemical tests (acetoin production by Voges-Proskauer test), beta-galactosidase test susceptibility to novobiocin (5 µ µµg disk), resistance to polymyxin B (300 µg disk). We also observed the biofilm formation ability of all the Staphylococcus aureus strains (n=17) by Congo Red Agar (CRA), Microtiter plate (using crystal violet), and light microscopy method, 90% sensitivity was seen through microtiter plate method. Antibiofilm activity of garlic oil was undertaken on positive isolates (3%, 2%, and 1% concentration) along with positive and negative control in every microtiter plate assay. Maximum inhibition was observed at 3% concentration with O.D values ranging from 0.021±0.007 to 0.291 ± 0.005 in all the samples with percent inhibition (50 to 60%). Multi-drug resistance profiles of biofilm-producing isolates were also undertaken against polymyxin, novobiocin, tetracyclines, cotrimoxazole, clindamycin, cefoxitin, and cefoperazone. Eighty-two (82) percent of isolates showed resistance against polymyxin, 52% against novobiocin and erythromycin, and all the isolates showed 100% sensitivity against tetracyclines and cefoxitin.
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•The lower limit of quantification was 0.021 mg/L, below the WHO guideline value.•Recovery tests performed using actual drinking water samples were also favorable.•Fixation of ...analytical reagents in plate wells was also investigated.•Analytical performance was comparable when the analytical reagents were fixed.
Efficient and sensitive trace determination of Cr(VI) in small sample volumes is an important issue for environmental protection and the sustainable development of industries. A microtiter plate and a microplate reader have been applied to the colorimetric determination of Cr(VI) using 1,5-diphenylcarbazide (DPC) as indicator, to realize an efficient method with low detection limits. The DPC reagent was fixed on the plate well and the time for color development was significantly reduced (<1 min) compared to conventional methods by using small volume reaction vessel which made it possible to perform determinations of Cr(VI) in a short period of time. The lower limit of quantification of 0.021 mg/L obtained with this method is better than that of the microplate method reported previously, and is comparable to general analytical methods with large sample volumes. In addition, when the chromogenic reagent is fixed to the plate with a water-soluble polymer, the lower limit of quantitation is comparable as that of the unfixed reagent. This results in improved instrument portability and more efficient analytical operations.
Dental caries is a biofilm-dependent disease, and Streptococcus mutans is the primary etiological agent involved in the initiation of the disease. The extensive use of a limited range of ...antimicrobial drugs in dentistry has led to the development of drug-resistant bacteria. There is an increasing need to find new alternatives against drug-resistant bacteria. Globally, there is a continuous effort towards identifying natural anti-caries agents for the prevention and better management of caries. The objective of the present study was to evaluate the antibiofilm potential of Azadirachta indica leaf methanolic (ALM) extract against S. mutans biofilm. The study employed a standard reference strain of S. mutans MTCC 497, for in vitro standardisation of biofilm by microtiter plate assay. The antibiofilm activity of the ALM extract was evaluated against the S. mutans strain, and the same was confirmed by light and scanning electron microscopy (SEM). The in vitro biofilm standardisation results demonstrated that 50 µl/ml of S. mutans inoculum concentration exhibited a much superior biofilm formation than the other concentrations employed. Light microscopy and SEM images revealed that ALM extract at 100 mg/ml concentration significantly inhibited the S. mutans biofilm. To conclude, the study reports that the A. indica leaf extract is a potential source to inhibit the S. mutans biofilm. Further studies are warranted to identify the phytochemicals responsible for the antibiofilm activity of ALM extract against S. mutans biofilm that aid in the design of natural anti-caries products.
Background: Pseudomonas aeruginosa is one of the most prevalent nosocomial pathogens that cause a life-threatening infection. One of the important characteristics of P. aeruginosa is biofilm ...formation which leads to antibiotic resistance.
Aims and Objectives: The aim of the study was to study the antibiotic resistance pattern of P. aeruginosa isolates and correlation with their biofilm-production.
Materials and Methods: A total of 87 P. aeruginosa isolates from different clinical specimens were processed and confirmed by conventional microbiological methods as per standard methodology. Antibiotic sensitivity testing was done for all isolates. Biofilm producing isolates were identified by the microtiter plate method (MTPM).
Results: Of 87 P. aeruginosa isolates, majority were from pus 33 (38%), followed by urine 26 (30%), sputum 19 (22%), body fluids 7 (8%), and blood 2 (2%). Biofilm producing isolates showed more resistance in comparison to non-biofilm producers. The observed difference between biofilm formation for multidrug resistant and susceptible isolates was found to be statistically significant.
Conclusion: MTPM method was an effective test for detection of biofilm formation and was also able to verify biofilm production by P. aeruginosa. This indicated a higher propensity among the clinical isolates of P. aeruginosa to form biofilm and revealed a positive correlation between biofilm formation and antibiotic resistance. This indicates the need for testing of even susceptible isolates for virulence factors such as biofilm production.
Nano-technology applied for the local delivery of different agents and/or drugs has made its path to endodontics. In the current study, the antibacterial efficacy of biopolymer-coated ceramic ...microparticles loaded with a modified combination of triple antibiotics, i.e. Penicillin G, Metronidazole and Ciprofloxacin (PMC), was evaluated against two strains of
(
.
); a standard clinical strain obtained from previously root-filled teeth with persistent periapical lesions, and compared to the most common antimicrobials used in endodontics.
After synthesis of the polymer-coated microparticles loaded with antibiotics, the 21-day release of antibiotics were evaluated and a stock solution was produced using the maximum released amount of drugs and distilled water. The antibacterial activity of PMC, triple antibiotic paste (TAP), calcium hydroxide (CH), chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against two bacterial strains was determined using "Minimum Inhibitory Concentration" and "Agar Diffusion Test". Additionally, "Microtiter Plate Assay" was performed to assess anti-biofilm properties.
Minimum inhibitory concentration values reported for TAP and PMC were 1/256. PMC showed the maximum diameter of growth inhibition in both strains (33 mm and 35 mm), while CH had the minimum diameters (13 mm and13 mm). Based on microtiter plate assay, TAP showed higher biofilm formation than PMC. Biofilm formation was higher in the standard strain for PMC; however, NaOCl, CHX and CH completely inhibited biofilm formation.
Based on the findings of the present study, it could be concluded that PMC and TAP were the most effective medicaments against
.
in its planktonic form; however, none could inhibit its biofilm formation. Further studies using larger sample size and "Confocal Scanning Laser Microscopy" are recommended.
Infections caused by biofilm-embedded pathogens decrease the efficacy of traditional treatments and increase antibiotic tolerance. Most of the human bacterial
infections are biofilm-associated. ...Therefore, this study aimed to detect the biofilm
formation among the clinical isolates of Klebsiella pneumonia collected from
different hospitals in Wasit province-Iraq by phenotypic and genotypic methods.
525 clinical samples were used to isolate 77 K. pneumoniae strains from clinical
specimens for five months. They were identified by microbiological method as K.
pneumoniae. The microtiter plate method is used to detect the biofilm formation.
Results showed that out of 77 K. pneumonia isolates, 76 (98.7%) isolates were
biofilm producers with three different categories; 12 (15.6%) were weak-biofilm
producers, while other isolates 63 (81.8%) and 1 (1.3%) were moderate and vigorous producers, respectively. However, 1 (1.3%) isolates were identified as nonbiofilm producers. Amplification of genes by multiplex PCR technique was done
for 77 isolates of K. pneumonia to detect biofilm production genes, mrkD and
FimH. Results showed that out of 77 isolates, there were 74 isolates (94.8%) positive to mrkD and 33 isolates (42.8%) to fimH.
Keywords: K. pneumonia; Microtiter plate method; mrkD; fimH; Iraq.
The details of all steps involved in the quantification of biofilm formation in microtiter plates are described. The presented protocol incorporates information on assessment of biofilm production by ...staphylococci, gained both by direct experience as well as by analysis of methods for assaying biofilm production. The obtained results should simplify quantification of biofilm formation in microtiter plates, and make it more reliable and comparable among different laboratories.
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