scholarly journals Differences in photodynamic therapy exposure time and Staphylococcus aureus counts

2018 ◽  
Vol 51 (2) ◽  
pp. 95
Author(s):  
Adeline Jovita Tambayong ◽  
Ira Widjiastuti ◽  
Cecilia G. J. Lunardhi

Background: The success of endodontic treatment can be achieved when pathogenic bacteria are eliminated from the root canal and periapical tissue resulting in healing of such tissue. One of the bacteria located in root canals is Staphylococcus aureus (S. aureus) reportedly found to be in severe periapical abscesses. Photodynamic therapy is one current technology that can help eliminate microorganisms without causing damage to human body cells. Average of research has been conducted using different tools and bacteria to evaluate the effects of exposure time used in photodynamic therapy on the number of bacteria. Purpose: The research reported here aimed to determine the correlation between the exposure time of photodynamic therapy and the number of S. aureus bacteria. Methods: The S. aureus bacteria used in this research were divided into seven treatment groups: a control group and six treatment groups with respective exposure times of 10, 20, 30, 40, 50 and 60 seconds. All of the bacteria were administered a photosensitiser and radiated according to the treatment intended for each group. They were then planted in nutrient agar and incubated for 48 hours. The colonies of bacteria formed were calculated using the Quebec colony counter and subsequently analyzed by means of both Kruskal Wallis and Mann Whitney U tests. Results: After calculating the number of bacterial colonies, the average number of Staphylococcus aureus bacteria in the non-irradiated group was 119 CFU/ml, 29 CFU/ml in the group with a 10-second exposure time, 20 CFU/ml in the group with a 20-second exposure time, 13 CFU/ml in the group with a 30-second exposure time, 7 CFU/ml in the group with a 40-second exposure time, but none in the groups with exposure times of 50 or 60 seconds. Conclusion: The longer the photodynamic therapy exposure time, the greater the number of S. aureus bacteria eliminated. An exposure time of 50 seconds was found to be sufficient to exterminate all S. aureus bacteria present.

2016 ◽  
Vol 52 (5) ◽  
pp. 277-280 ◽  
Author(s):  
Benjamin Ley ◽  
Edward Silverman ◽  
Kara Peery ◽  
Delfina Dominguez

ABSTRACT Nosocomial infections are a concern of growing interest in veterinary medicine. Clipper blades have been confirmed as fomites for numerous potential pathogens and, as such, may be associated with wound and surgical site infections. The goal of this study was to evaluate the disinfectant capabilities of several commonly used clipper blade cleaning products. Seventy sterile clipper blades were inoculated with strains of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. Blades were then subjected to one of seven treatment groups for disinfecting. Quantitative cultures of remaining bacteria were performed. All blades in the control group showed large amounts of bacterial recovery. Culture results showed no recovery in blades soaked in alcohol or chlorhexidine or those sprayed with an ethanol/o-phenylphenol product, while moderate recovery was seen with all other treatments. These results show that persistent contamination of clipper blades can occur with the use of several commonly used disinfectant products. Further research is necessary to evaluate fungicidal capabilities as well as the effect of disinfection on clipper blade maintenance.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.


1970 ◽  
Vol 18 ◽  
pp. 16-20
Author(s):  
BA Omogbai ◽  
FA Eze

Context: Plant based antimicrobial represent a vast untapped source for medicines and further exploration of plant antimicrobial neeto occur. Evolvulus alsinoides (L) (Convolvulaceae) is a perennial herb is used in traditional medicine in East Asia, India, Africa and Philippines to cure fever, cough, cold, venereal diseases, azoospermia, adenitis and dementia.   Objective: The objective of this research was to evaluate the antimicrobial activity of the extracts of E. alsinoides on some clinical microbial isolates.   Materials and Methods: The ed thanolic and aqueous extracts of the whole plant (leaves and twigs) were analysed for alkanoids, tannins, glycosides, steroids, flavonoids, saponins, volatile oil and resins. The determination of antibacterial activity was done using the agar well diffusion technique. Pure cultures of pathogenic bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus leutus, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi were used for antibacterial activity assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).   Results: The ethanolic extract of the plant had MIC values ranging from 16 mg/ml to 512.5 mg/ml. The least MIC was 16mg-ml against Salmonella typhi while Bacillus cereus and Staphylococcus aureus showed the highest MIC of 512.5 mg-ml. In the aqueous extract the MIC ranged between 512.5 to >1025 mg/ml. Salmonella typhi, Micrococcus luteus and Staphylococcus aureus were not inhibited by the water extract. Phytochemical result showed ethanol to be a better solvent for the extraction of the bioactive agents in this plant which include: glycosides, alkaloids, saponins, tannins, flavonoids and volatile oil.   Conclusion: In this study the gram-negative organisms had the lowest MICs and MBCs. This suggests their higher susceptibility to the extract of this plant. On the basis of the result obtained in this investigation it can be concluded that ethanol extract of Evolvulus alsinoides had significant in vitro broad spectrum antimicrobial activity.   Keywords: Evolvulus alsinoides; Phytochemical screening; Antibacterial activity. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8769 JBS 2010; 18(0): 16-20


2018 ◽  
Vol 16 (1) ◽  
pp. 105-113 ◽  
Author(s):  
A Dey ◽  
K Ghosh ◽  
N Hazra

Growth and survival of Clarias batrachus juveniles (10-day old) fed probiotic Bacillus cereus (KR809412) encapsulated live feed (chironomid larvae) have been evaluated after differential exposure to the pathogenic Aeromonas hydrophila (MTCC 1739). Catfish juveniles were stocked at a density of 30 fish per tank in five experimental groups (T1-T5) along with a control group in triplicate and fed twice @ 5% of body weight day-1 for four weeks. Groups T1 and T2 were fed probiotic-encapsulated (PR) or pathogen-inoculated (PGN) live feed respectively, for initial three weeks. During this period groups T3 (PGN-PR-PR), T4 (PR-PGN-PR), and T5 (PR-PR-PGN) were differentially exposed to the pathogen. Live feed without probiotic and pathogen was offered to the control group throughout the experimental period and all other treatment groups (T1-T5) during the 4th week. Continuous exposure to probiotics in group T1 resulted in significantly higher (P<0.05) specific growth rate (SGR, % d-1) and survivability than other groups, whereas, pathogen exposed and probiotic deprived group (T2) noticed with the lowest SGR and the highest mortality. Among other treatment groups (T3, T4 and T5), group T4 resulted in improved SGR and survivability. The coefficient (r value) of 0.867 along with regression slope suggested a positive correlation (0.01 levels) between RNA: DNA and SGR. The study might suggest protective effects of probiotic B. cereus in pathogen exposed C. batrachus juveniles.SAARC J. Agri., 16(1): 105-113 (2018)


2009 ◽  
Vol 34 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Senem Selvi Kuvvetli ◽  
Nuket Sandalli ◽  
Nursen Topcuoglu ◽  
Guven Kulekci

Objective: In vitro comparison of the antibacterial efficacy of Diode and Er:YAG laser irradiation with that of NaOCl irrigation in contaminated primary molar root canals. Study Design: 96 root canals prepared from 32 extracted primary molar teeth were mechanically enlarged and the teeth were randomly divided into 4 subgroups. The roots were inoculated with an overnight culture of Enterococcus faecalis in tryptic soy broth for 24 hours. The root canals irradiated with diode and Er:YAG laser and irrigated with NaOCl(5.25%) were experimental groups and untreated canals served as positive control group. Bacterial growth was analysed by counting viable E.faecalis on tryptic soy agar plates. Results: The number of bacteria was significantly reduced in experimental groups in comparison with the control group. Diode laser was determined to be more effective in reducing the number of bacteria when compared to Er:YAG laser. NaOCl irrigation was found significantly most effective. Conclusions: Diode laser irradiation and 5.25 % NaOCl application provided a significant antibacterial effect in vitro, in contaminated primary molar root canals.


2008 ◽  
Vol 71 (2) ◽  
pp. 325-332 ◽  
Author(s):  
YONG-SUK KIM ◽  
ZIAN-BIN ZHENG ◽  
DONG-HWA SHIN

Kimchi is a unique Korean traditional vegetable product that is fermented by lactic acid bacteria (LAB) and is mainly consumed as a side dish with boiled rice. Its main ingredients are brined Chinese cabbage, red pepper powder, and fermented fish sauce, and these are combined with many spices such as garlic, green onion, ginger, and some seaweed. The relationship between the concentration of LAB or the pH and the growth of three gram-positive foodborne pathogens (Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus) was evaluated. Heat treatment (HT; 85°C for 15 min) or neutralization treatment (NT; pH 7.0) was conducted on day 0 (0-D group) and day 3 (3-D group) of incubation. The pH in the control group and the NT group dropped sharply to 4.12 to 4.30 after 2 days of incubation and slightly decreased thereafter, whereas the pH in the control group and HT group stayed at 7.0 during incubation. LAB were not detected in the HT kimchi during incubation. B. cereus in the NT-0-D, NT-3-D, and HT-3-D groups was reduced by 1.5 to 3.1 log CFU/ml but increased slightly in the HT-0-D group. L. monocytogenes in HT-3-D and NT-3-D groups disappeared after 5 days of incubation, and S. aureus in the NT-0-D group disappeared after 4 days. These findings indicate that growth of all the foodborne pathogens was inhibited by NT-0-D, HT-3-D, and NT-3-D, but B. cereus was not inhibited by HT-0-D. Thus, growth of LAB in kimchi is an important factor in the control of foodborne pathogens.


2021 ◽  
Vol 16 (Supp. 1) ◽  
pp. 33-36
Author(s):  
Sri Kunarti ◽  
Nunik Nuraini ◽  
Farida Widhi Astuti ◽  
Cecilia GJ Lunardi ◽  
Lulytha Rahmanike Putri

Lactobacillus acidophilus (L. acidophilus) is one of the etiological agents for dental caries and dominant in the deep carious lesion. L. acidophilus has also been identified in persistent root canal infection and also related to the failure of endodontic treatment. Photodynamic therapy is a therapeutic process involving the combination of a nontoxic photosensitizer and a light source. The excited photosensitizer reacts with reactive oxygen species (ROS), which induce injury and death of the microorganism. This study aimed to prove the effect of irradiation time of photodynamic therapy to the number of L. acidophilus. Fortytwo Eppendorf tubes were treated with 0.5 ml L. acidophilus distributed into seven groups. Group 1 as the control group received no treatment. Groups 2, 3, 4, 5, 6 and 7 were treated with a combination of 0.5 ml toluidine blue O (TBO) as a photosensitizer and 630 nm photoactivated (Fotosan®) exposure time for 10, 20, 30, 40, 50 and 60 sec. Then, all were stored in an incubator of 37ºC for 48 h. Later, the colony-forming unit (CFU) was counted for each group. There were significant differences in the number of L. acidophilus in CFU of the various irradiation times. The longer the photodynamic therapy irradiation was, the lesser the number of live L. acidophilus became. At 50 sec and 60 sec irradiation, none of the L. acidophilus was found alive.


2015 ◽  
Vol 1 (2) ◽  
pp. 126
Author(s):  
Urnemi ◽  
Sumaryati Syukur ◽  
Endang Purwati ◽  
Sanusi Ibrahim ◽  
Jamsari

ABSTRACT Lactic acid bacteria (LAB) were isolated from of cocoa beans fermentation Forestero variety from West Sumatera, that were eleven isolates. The isolates were tested to antimicrobial activity against pathogenic bacteria E.coli NBRC 14237, Staphylococcus aureus NBRC 13276, Bacillus subtilis BTCCB 612, listeria m. dan S. Typhii. Results the research showed that, isolates had inhibition zone to pathogenic bacteria, that were 7 mm till 12 mm at 48 hours observation. R2.4 isolate was most potential to inhibition zones growth pathogenic bacteria, that was 11mm till 12 mm to five pathogens. R2.4 isolates was the highest to against pathogenic bacteria (Bacillus subtilis BTCCB, Listeria monocytogenesis and Staphylococcus aureus NBRC) had inhibition zones, that was 12.00 mm till 48 hours. Listeria monocytogenesis had been known as pest bacterium of food born, so that R2.4 isolate can be used as food biopreservative. Crude of R2.4 isolate molecular weight was 10 kDa by SDS-PAGE.  Key words: Lactic acid bacteria, Antimicrobial activity, SDS-PAGE, Cocoa fermentation and food biopreservative                                                      


2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Steviany Towoliu

Abstract: E. coli is part of the normal flora of the human and animal intestine and is commonly non pathogenic. However, one of the serotypes of this bacteria, which is enteropathogenic E. coli (EPEC), can cause primary infection on the intestine such diarrhea.  The growth of pathogenic bacteria in diarrheal patients can be inhibited by Lactobacillus.  Lactobacillus can function as probiotic which can affect the immune system of the digestive canals.  In addition, Lactobacillus also produce mucus  which can act as barrier to the pathogens.  The objective of this study was to reveal the effects of the administration of Lactobacillus on the microscopic features of the mucosa of the intestine of wistar rats infected by Escherichia coli.  This study was a laboratory experimental research employing 16 wistar rats divided into the control group (4 rats) and three treatment groups (12 rats) consisting of 4 rats each.  Results showed that; in group I the histological features were normal, in group II part of the epithelium of the mucosa showed erosion, dilatation of the capillary vessels, and many lymphosites were observed, in group III the epithelium of the mucosa was intact and the number of lymphosites was liitle, and in group IV the surface of the epithelium was intact, the presence of cell regeneration indicated by the increase number of goblet cells and a small number of  lymphocyes. Conclusions: The administration of after infection by E. coli has benefial effects indicated by the improvement of epithelial cells and the absence of denudation of the epithelium of the intestine. Keywords: E.coli, Lactobacillus, intestinal mucosa.   Abstrak: E.coli merupakan flora normal usus halus manusia dan hewan umumnya tidak menyebabkan penyakit.  Namun salah satu serotipe E.coli yaitu E.coli Enteropatogenik (EPEK) bersifat patogen dan dapat menyebabkan infeksi primer pada usus misalnya diare.  Pertumbuhan bakteri patogen pada pasien diare dapat dihambat oleh Lactobacillus. Lactobacillus merupakan probiotik yang akan mempengaruhi sistem imun saluran cerna serta memproduksi mukus yang berfungsi sebagai penghalang saluran cerna terhadap bakteri patogen.  Penelitian ini bertujuan untuk melihat efek pemberian Lactobacillus terhadap gambaran mikroskopis mukosa usus halus tikus wistar yang diinfeksi dengan Escherichia coli.  Penelitian ini merupakan penelitian eksperimental laboratorik.  Subjek penelitian terdiri dari 16 ekor tikur wistar yang dibagi dalam kelompok kontrol (4 ekor) dan kelompok  perlakuan (12 ekor) dibagi dalam 3 kelompok masing-masing 4 ekor.  Hasil penelitian kelompok I dengan gambaran histologik jaringan usus normal, kelompok II sebagian epitel mukosa usus halus terlihat erosi,  ada pelebaran pembuluh darah kapiler, dan banyak limfosit, kelompok III dengan permukaan epitel mukosa yang utuh dan jumlah limfosit sedikit, dan kelompok IV dengan permukaan epitel yang utuh, adanya regenerasi sel ditandai dengan bertambahnya sel goblet, dan sedikit limfosit.  Simpulan: Pemberian Lactobacillus setelah diberikan E.coli memberi efek yang baik berupa perbaikan sel epitel permukaan dan tidak terlihat denudasi epitel permukaan usus halus. Kata Kunci: E.coli, Lactobacillus, mukosa usus halus.


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