Candida Biofilm Formation Assay on Essential Oil Coated Silicone Rubber

Development of biofilm associated candidemia for patients with implanted biomaterials causes an urgency to develop antimicrobial and biofilm inhibitive coatings in the management of recalcitrant Candida infections. Recently, there is an increase in the number of patients with biofilm formation and resistance to antifungal therapy. Therefore, there is a growing interest to use essential oils as coating agents in order to prevent biomaterial-associated Candida infections. Often high costs, complicated and laborious technologies are used for both applying the coating and determination of the antibiofilm effects hampering a rapid screening of essential oils. In order to determine biofilm formation of Candida on essential oil coated surfaces easier, cheaper and faster, we developed an essential oil (lemongrass oil) coated surface (silicone-rubber) by using a hypromellose ointment/essential oil mixture. Furthermore, we modified the “crystal violet binding assay” to quantify the biofilm mass of Candida biofilm formed on the lemongrass oil coated silicone rubber surface. The essential oil coating and the biomass determination of biofilms on silicone rubber can be easily applied with simple and accessible equipment, and will therefore provide rapid information about whether or not a particular essential oil is antiseptic, also when it is used as a coating agent

Antifungal and biofilm inhibitory effect of Cymbopogon citratus (lemongrass) essential oil on biofilm forming by Candida tropicalis isolates; an in vitro study

Ethnopharmacological relevance: Cymbopogon citratus (lemongrass) essential oil has been widely used as a traditional medicine and is well known for antimicrobial properties. Therefore, it might be a potent anti-infective and biofilm inhibitive against Candida tropicalis infections. Until now, no ideal coating or cleaning method based on an essential oil has been described to prevent biofilm formation of Candida strains on silicone rubber maxillofacial prostheses, voice prostheses and medical devices susceptible to C. tropicalis infections.Aim of the study: To investigate the antifungal and biofilm inhibitory effects of Cymbopogon citratus oil. Clinical isolates of C. tropicalis biofilms on different biomaterials were used to study the inhibitory effect.Materials and methods: The efficacy of Cymbopogon citratus, Cuminum cyminum, Citrus Limon and Cinnamomum verum essential oils were compared on biofilm formation of three C. tropicalis isolates on 24 well polystyrene plates. C. citratus oil coated silicone rubber surfaces were prepared using hypromellose ointment as a vehicle. The antifungal tests to determine minimum inhibitory and minimum fungicidal concentrations were assessed by a microbroth dilution method and biofilm formation was determined by a crystal violet binding assay.Results: C. tropicalis strains formed more biofilm on hydrophobic materials than on hydrophilic glass. C. citratus oil showed a high antifungal effect against all C. tropicalis strains. For comparison, C. limon oil and C. cyminum oil showed minor to no killing effect against the C. tropicalis strains. C. citratus oil had the lowest minimal inhibitory concentration of all essential oils tested and inhibited biofilm formation of all C. tropicalis strains. C. citratus oil coating on silicone rubber resulted in a 45-76% reduction in biofilm formation of all C. tropicalis strains.Conclusion: Cymbopogon citratus oil has good potential to be used as an antifungal and antibiofilm agent on silicone rubber prostheses and medical devices on which C. tropicalis biofilms pose a serious risk for skin infections and may cause a shorter lifespan of the prosthesis.</p

Determination of biosorption conditions of Methyl Orange by <i>Humicola fuscoatra</i>

1075-1077 This study presents effects of biomass concentration, dye concentration, agitation time, initial pH and temperature on dye (Methyl Orange) removal by dead fungal biomass of Humicola fuscoatra. Biosorption capacity was found dependent mainly on dye and adsorbent dosage. Highest adsorption efficiency was achieved with fungal biomass at 0.5g/l. Dye concentration (100 mg/ l) was found optimum for maximum dye removal. At acidic pH (3-5) and 30 C, Methyl Orange biosorption increased significantly in first 6 h. </smarttagtype

Multi Drug Resistance In Strong Biofilm Forming Clinical Isolates Of Staphylococcus Epidermidis

Staphylococcus epidermidis which exists in healthy human skin as a commensal inhabitant is also an important pathogen forming biofilms on many surfaces and recently, increased resistance traits were suggested to be acquired in biofilm environments. In this study; clinical Prevalences, antibiotic resistances and biofilm formations of S. epidermidis strains were determined and comparison of all these findings with each other was carried out in order to take precautions against them and figure out if high biofilm forming S. epidermidis strains display multi drug resistance. According to our results; samples of wound and blood were the most S. epidermidis isolated clinical materials (40%; 35%) and cardiothoracic surgery was the most S. epidermidis observed service unit. All of these strains were sensitive to vancomycin, however 65% of them showed resistance to all β-lactam antibiotics (Penicillin, Oxacillin, Amoxicilin/Clavulonic acid), used in this study and 60% of all S. epidermidis strains were found as multi drug resistant. When the results of strong biofilm forming S. epidermidis strains are examined; they were isolated from sample of blood and service unit of cardiovascular surgery in highest frequency and 80% of them were β-lactam resistant whereas 100% of them were multi drug resistant. One of these multi drug resistant strains which was resistant to maximum amount of different antimicrobial classes, was also observed as maximum biofilm forming strain among all the other S. epidermidis isolates. Multi drug resistance in strong biofilm forming strains shows that; biofilms play a role in antimicrobial resistance traits of S. epidermidis.PubMedWoSScopu

Application of Rapd-Pcr For Determining The Clonality of Methicillin Resistant Staphylococcus Aureus Isolated From Different Hospitals

Randomly amplified polymorphic DNA (RAPD)-PCR was applied with ten random 10-mer primers to examine the molecular diversity among methicillin resistant Staphylococcus aureus (MRSA) strains in the hospitals and to investigate the epidemiological spread of these strains between different hospitals. The main objective of the study was to identify appropriate primers, which successfully established the clonality of MRSA. Three of the primers yielded particularly discriminatory patterns and they were used to perform the RAPD analysis which revealed different bands ranging from 200 to 1500 bp. Dendogram was created by the un-weighted pair group method using arithmetic (UPGMA) average clustering and it was constructed based on the combination results of the new primers (S224, S232 and S395) which represented a novel approach for rapid screening of the strains and also provided the opportunity for monitoring the emergence and determining clonal dissemination of MRSA strains between the hospitals. Dendogram generated two main groups (Group I and II) with three clusters (A, B and C) and indicated that the strains isolated from the same hospital were closely related and they placed together in the same group. This technique could be of attractive use in controlling the sources and routes of transmission, tracking the spread of strains within hospital and between the hospitals, and especially preventing the nosocomial infections caused by the MRSA

Biological Treatment of Cyanide by Using Klebsiella Pneumoniae Species

In this study, optimization conditions for cyanide biodegradation by Klebsiella pneumoniae strain were determined to be 25 degrees C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium cyanide in the medium. Additionally, it was found that K. pneumoniae strain is not only able to degrade potassium cyanide, but also to degrade potassium hexacyanoferrate(II) trihydrate and sodium ferrocyanide decahydrate with the efficiencies of 85 and 87.5 %, respectively. Furthermore, this strain degraded potassium cyanide in the presence of different ions such as magnesium, nickel, cobalt, iron, chromium, arsenic and zinc, in variable concentrations (0.1, 0.25 and 0.5 mM) and as a result the amount of the bacteria in the biodegradation media decreased with the increase of ion concentration. Lastly, it was also observed that sterile crude extract of K. pneumoniae strain degraded potassium cyanide on the fifth day of incubation. Based on these results, it is concluded that both culture and sterile crude extract of K. pnemoniae will be used in cyanide removal from different wastes.Wo

Antibiofilm Effects of Citrus Limonum and Zingiber Officinale Oils on Biofilm Formation of Klebsiella Ornithinolytica, Klebsiella Oxytoca and Klebsiella Terrigena Species

Background: Microbial cells growing in biofilms, play a huge role in the spread of antimicrobial resistance. In this study, biofilm formation of Klebsiella strains belonging to 3 different Klebsiella species (K. ornithinolytica, K. oxytoca and K. terrigena), cooccurences’ effect on biofilm formation amount and anti-biofilm effects of Citrus limon and Zingiber officinale essential oils on biofilm formations of highest biofilm forming K. ornithinolytica, K. oxytoca and K. terrigena strains were determined. Materials and Methods: Anti-biofilm effects of Citrus limon and Zingiber officinale essential oils on biofilm formations of highest biofilm forming K. ornithinolytica, K. oxytoca and K. terrigena strains were investigated. Results: 57% of K. ornithinolytica strains and 50% of K. oxytoca strains were found as Strong Biofilm Forming (SBF), there wasn’t any SBF strain in K. terrigena species. In addition to this, clinical materials of urine and sperm were found as the most frequent clinical materials for strong biofilm forming K. ornithinolytica and K. oxytoca isolations respectively (63%; 100%) Secondly, all K. ornithinolytica strains isolated from surgical intensive care unit and all K. oxytoca strains isolated from service units of urology were found as SBF. Apart from these, although the amount of biofilm, formed by co-occurence of K. ornithinolytica - K. oxytoca and K. oxytoca - K. terrigena were more than the amount ofbiofilm formed by themselves separately, biofilm formation amount of co-occurrence of K. ornitholytica - K. terrigena strains was lower than biofilm formation amount of K. ornithinolytica but higher than biofilm formation amount of K. terrigena. Conclusion: The antibiofilm effects of Citrus limonum and Zingiber officinale essential oils could be used against biofilm Klebsiella aquired infections.PubMedWo

Investigation of Biofilm Formation in Clinical Strains of Klebsiella pneumoniae and Klebsiella rhinoscleromatis

Klebsiella species which are natural colonizers of human upper respiratory and human gastrointestinal tracts are also responsible for every reoccurring nosocomial infections by means of having ability to form slimy layers known as biofilm on many surfaces. Therefore, in this study, investigation of biofilm formation in K. pneumoniae and K. rhinoscleromatis and examination of each Klebsiella strains' clinical information in the light of their biofilm formation results were aimed. In this respect, biofilm formation of Klebsiella strains was analyzed via crystal violet binding assay. According to our results, biofilm formation levels of K. pneumoniae and K. rhinoscleromatis strains were different from each other. Additionally, in comparison to K. rhinoscleromatis strains, K. pneumoniae was observed to include higher amounts of strong biofilm forming strains. Besides, it was also seen that clinical information of patients from which strong biofilm forming Klebsiella strains were isolated were similar to each other. Our results indicate that there should be more precautions against K. pneumoniae which includes higher amount of strong biofilm forming strains