Catalase test for bacterial identification v1

Author(s):  
lydiariver not provided

Catalase is an enzyme that catalyzes the rapid decomposition of hydrogen peroxide into water and oxygen (2H2O2 + Catalase → 2H2O + O2). Organisms that do not present the catalase enzyme such as group B Streptoccoccus can not degrade hydrogen peroxide and therefore no bubble formation is observed.

2021 ◽  
Vol 09 (07) ◽  
pp. E1108-E1115
Author(s):  
Sudhir Maharshi ◽  
Shyam Sunder Sharma ◽  
Sandeep Ratra ◽  
Bharat Sapra ◽  
Dhruv Sharma

Abstract Background and study aims Walled-off necrosis (WON) is a known complication of acute necrotizing pancreatitis (ANP). There is no study comparing nasocystic irrigation with hydrogen peroxide (H2O2) versus biflanged metal stent (BMS) in the management of WON. The aim of this study was to compare the clinical efficacy of both the treatment strategies. Patients and methods This study was conducted on patients with symptomatic WON who were randomized to nasocystic irrigation with H2O2 (Group A) and BMS placement (Group B). Primary outcomes were clinical and technical success while secondary outcomes were procedure time, adverse events, need for additional procedures, duration of hospitalization, and mortality. Results Fifty patients were randomized into two groups. Group A (n = 25, age 37.8 ± 17.6 years, 16 men) and Group B (n = 25, age 41.8 ± 15.2 years, 17 men). There were no significant differences in baseline characteristics between the two groups. The most common etiology of pancreatitis was alcohol, observed in 27 (54 %) patients. Technical success (100 % vs 96 %, P = 0.98), clinical success (84 % vs 76 %, P = 0.76), requirement of additional procedures (16 % vs 24 %, P = 0.70) and adverse events (4 vs 7, P = 0.06) were comparable in both the groups. The duration to clinical success (34.4 ± 12 vs 14.8 ± 10.8 days, P = 0.001) and procedure time (36 ± 15 vs 18 ± 12 minutes, P = 0.01) were longer in Group A compared to Group B. Conclusions Nasocystic irrigation with H2O2 and BMS are equally effective in the management of WON but time to clinical success and procedure time is longer with nasocystic irrigation.


1997 ◽  
Vol 477 ◽  
Author(s):  
Steven Verhaverbeke ◽  
Jennifer W. Parker ◽  
Chris F. McConnell

The RCA Standard Clean, developed by W. Kern and D. Puotinen in 1965 and disclosed in 1970 [1] is extremely effective at removing contamination from silicon surfaces and is the defacto industry standard.[2]. The RCA clean consists of two sequential steps: the Standard Clean 1 (SC-1) followed by the Standard Clean 2 (SC-2). The SC-1 solution, consisting of a mixture of ammonium-hydroxide, hydrogen-peroxide, and water, is the most efficient particle removing agent found to date. This mixture is also referred to as the Ammonium- Hydroxide/Hydrogen-Peroxide Mixture (APM). In the past, SC-1 solutions had the tendency to deposit metals on the surface of the wafers, and consequently treatment with the SC-2 mixture was necessary to remove metals. Ultra-clean chemicals minimize the need for SC-2 processing. SC-I solutions facilitate particle removal by etching the wafer underneath the particles; thereby loosening the particles, so that mechanical forces can readily remove the particles from the wafer surface. The ammonium hydroxide in the solution steadily etches silicon dioxide at the boundary between the oxide and the aqueous solution (i.e., the wafer surface). The hydrogen peroxide in SC-I serves to protect the surface from attack by OH" by re-growing a protective oxide directly on the silicon surface (i.e., at the silicon/oxide interface). If sufficient hydrogen peroxide is not present in the solution, the silicon will be aniostropically etched and surface roughening will quickly occur. On the other hand, hydrogen peroxide readily dissociates and forms water and oxygen. If the concentration of the resulting oxygen is too high, bubbles will appear in the solution. The gas liquid interfaces that result from the bubble formation act as a “getter” for particles that can re-deposit on the wafer surface if a bubble comes in contact with the wafer.


Sains Medika ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Ayyasi Izaz Almaz ◽  
Ratna Dama Purnawati ◽  
Hermawan Istiadi ◽  
Neni Susilaningsih

Introduction: Burn therapy is generally done using a burn ointment. However, honey can also be used as an alternative treatment for burns. Honey contains active flavonoid as an antioxidant and hydrogen peroxide which can stimulate fibroblasts proliferation also angiogenesis on burn healing phase.Objective: to determine the effect of honey in second degree burn healing from angiogenesis and the number of fibroblasts on Wistar rats. Methods: This research used a posttest only controlled group design on 15 rats with random selection and divided into 3 groups: H-G was given honey, B-G was given Bioplacenton�, N-G without any treatment after burn was induced. Rats were given a second degree burn in a size of 2 cm x 2cm on the back area and were treated twice a day for 14 days. Burn healing was measured by calculating the observation results of microscopic VEGF expression, the number of neovascularization, and the number of fibroblasts. Hypothesis analysis used Annova post hoc LSD and Mann-Whitney.Results: The highest mean in VEGF expression and the number of neovascularization was obtained from group B-G followed by group H-G and group N-G. Significant differences in the number of neovascularization between group B-G with group N-G, p<0.05.Conclusion: Honey can provide a healing effect on the second degree of burns in Wistar rats in terms of the number of neovascularization as well as Bioplacenton�


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jonathan Faro ◽  
Malika Mitchell ◽  
Yuh-Jue Chen ◽  
Sarah Kamal ◽  
Gerald Riddle ◽  
...  

Background. Elucidation of a pathogen’s antimicrobial susceptibility requires subculture after the organism is first isolated. This takes several days, requiring patients to be treated with broad-spectrum antibiotics. This approach contributes to the development of bacterial resistance.Methods. Microtiter wells were coated with a polyclonal antibody targeting the pathogen of interest. Bacterial suspensions were added in the presence/absence of selected antibiotics. After washing, captured bacteria were detected.Findings. Group B streptococcus (GBS),Enterococcus faecalis, andNeisseria gonorrhoeaewere each detected at 105 bacteria/mL following a 20-minute incubation period. Susceptibility to select antibiotics was discernable following a 6-hour incubation period (GBS andEnterococcus). Sensitivity was increased to 10−2 bacteria/mL for GBS, 10−1 bacteria/mL forE. faecalis, and 101 bacteria/mL forN. gonorrhoeaefollowing 18–24-hour culture.Conclusion. This novel assay allows for the highly sensitive and specific identification of a pathogen and simultaneous determination of its antimicrobial susceptibility in a reduced time.


2009 ◽  
Vol 55 (7) ◽  
pp. 887-894 ◽  
Author(s):  
Miguel J. Beltrán-García ◽  
Gilberto Manzo-Sanchez ◽  
Salvador Guzmán-González ◽  
Carlos Arias-Castro ◽  
Martha Rodríguez-Mendiola ◽  
...  

Mycosphaerella fijiensis causes black leaf streak disease in banana and plantain. This fungus is usually attacked by reactive oxygen species secreted by the plant or during exposure to fungicide, however, little is known about the antioxidant response of the fungus. In this study, mycelia were observed to totally decompose 30 mmol/L of hydrogen peroxide (H2O2) within 120 min, liberating oxygen bubbles, and also to survive in concentrations as high as 100 mmol/L H2O2. The oxidative stress responses to H2O2, paraquat, and hydroquinone were characterized in terms of the activities of catalase and superoxide dismutase (SOD). Two active catalase bands were seen in native PAGE induced by H2O2. Band I had monofunctional activity and band II had bifunctional catalase–peroxidase activity. Two isozymes of SOD, distinguishable by their cyanide sensitivity, were found; CuZnSOD was the main one. The combination of H2O2 and 3-aminotriazole reduced the accumulation of biomass up to 40% compared with exposure to H2O2 alone, suggesting that catalase is important for the rapid decomposition of H2O2 and has a direct bearing on cell viability. The results also suggest that the superoxide anion formed through the redox of paraquat and hydroquinone has a greater effect than H2O2 on the cellular viability of M. fijiensis.


2020 ◽  
Vol 352 ◽  
pp. 54-59
Author(s):  
Sang-Chul Jung ◽  
Heon Lee ◽  
Seo Jin Ki ◽  
Sun-Jae Kim ◽  
Young-Kwon Park

2017 ◽  
Vol 42 (3) ◽  
pp. 244-252 ◽  
Author(s):  
P Vildósola ◽  
F Vera ◽  
J Ramírez ◽  
J Rencoret ◽  
H Pretel ◽  
...  

SUMMARY Objective: The aim of this blinded and randomized clinical trial was to compare two application protocols (one 36-minute application vs three 12-minute applications). We then assessed the effectiveness of the bleaching and any increase in sensitivity that was induced by bleaching via a split-mouth design. Methods and Materials: Thirty patients were treated. One group had a half arch of teeth treated with a traditional application protocol (group A: 3 × 12 minutes for two sessions). The other received an abbreviated protocol (group B: 1 × 36 minutes over two sessions). Two sessions were appointed with a two-day interval between them. The tooth color was registered at each session, as well as one week and one month after completing the treatment via a spectrophotometer. This measured L*, a*, and b*. This was also evaluated subjectively using the VITA classical A1-D4 guide and VITA Bleachedguide 3D-MASTER. Tooth sensitivity was registered according to the visual analogue scale (VAS) scale. Tooth color variation and sensitivity were compared between groups. Results: Both treatments changed tooth color vs baseline. The ΔE* = 5.71 ± 2.62 in group A, and ΔE* = 4.93 ± 2.09 in group B one month after completing the bleaching (p=0.20). No statistical differences were seen via subjective evaluations. There were no differences in tooth sensitivity between the groups. The absolute risk of sensitivity reported for both groups was 6.25% (p=0.298). The intensity by VAS was mild (p=1.00). Conclusions: We used hydrogen peroxide (6%) that was light activated with a hybrid LED/laser and two different protocols (one 36-minute application vs three 12-minute applications each for two sessions). These approaches were equally effective. There were no differences in absolute risk of sensitivity; both groups reported mild sensitivity.


2015 ◽  
Vol 12 (1) ◽  
pp. 6-9
Author(s):  
N Kansakar ◽  
H Mahendra ◽  
S Acharya

Background: Dry socket is the most common post-operative complication following extraction of teeth. Various risk factors have been mentioned for this complication including gender, age, amount of trauma during extraction, difficulty of surgery, inappropriate irrigation, infection, smoking, and oral contraceptive use. Traditional treatment of dry socket require frequent visit of patient to the dental hospital and is very inconvenient to the patient.Objective: The aim of the study was to assess outcome of the treatment using two different techniques for the management of dry socket.Methods: Patients with dry socket were randomly distributed among two treatment groups (21 patients in each group). Group A received irrigation of socket with diluted hydrogen peroxide and zinc oxide eugenol dressing was given and patients were followed for following consecutive days by replacing dressing each day until the pain subsides. Group B received irrigation of socket with diluted hydrogen peroxide, sockets and surrounding gingival tissue were debrided to promote the re-establishment of blood clot. The gingival margins were meticulously sutured to protect the clot formation.Result 19 patients out of 21 in Group A, received two or more than two procedures to subside pain whereas in Group B, 19 out of 21 patients received just one procedure for successful treatment.Concusion: There is reduction in duration of treatment in debridement group of patients when compared with those treated traditionally.Journal of Nepalgunj Medical College Vol.12(1) 2014: 6-9


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