79 research outputs found
Determination of time dependent antibacterial activities of curcumin, carvacrol and styrax liquidus on Salmonella Enteritidis
No full textSalmonella Enteritidis is amongst the most common causes of foodborne salmonellosis. Multi-drug resistant Salmonella strains has been associated with treatment failures. Plant-derived phytochemicals may be an alternative to antibiotics in combating these bacteria. The purpose of this study is to investigate the antibacterial activity of curcumin, carvacrol and styrax liquidus on S. Enteritidis and S. Enteritidis PT4. Minimum inhibitory concentration (MIC) values of these substances were detected at 1.5, 3, 7.5 and 24 h by broth microdilution method to evaluate their time-dependent antibacterial activities. The findings of the present study showed that MIC values of carvacrol, curcumin and styrax liquids for both S. Enteritidis and S. Enteritidis PT4 were 125.0 μg/mL, 132.5 μg/mL, 31.3 mg/mL for 24 h, respectively. Also, a time-dependent change was observed in the MIC values of curcumin. Carvacrol, curcumin and styrax liquidus can be used to provide antimicrobial effect on S. Enteritidis and S. Enteritidis PT4 in food applications, taking into account the MIC values and contact times.Trdizi
Sığır karkaslarında staphylococcus aureusun varlığı, enterotoksijenik özellikleri ve antimikrobiyal dirençliliği
No full textTrdizinScopu
Sığır karkaslarında Staphylococcus aureus'un varlığı, karakterizasyonu ve antimikrobiyal dirençliliğinin belirlenmesi
No full textBu çalışma, sığır karkaslarında Staphylococcus aureus'un varlığı ile izolatların enterotoksijenik özellikleri ve antimikrobiyal dirençliliğini saptamak amacıyla yapılmıştır. Bu amaçla Haziran 2011 ve Mayıs 2012 tarihleri arasında Ankara'da bulunan 2 farklı mezbahada kesilen, 120 adet sığır karkasından alınan örnekler materyal olarak kullanılmıştır. Örnekler steril bir şablon ile işaretlenen but, kavram ve döş bölgerinden (10x10 cm2, toplam 300 cm2) sünger swap tekniği ile alınmıştır. Alınan örnekler öncelikle fenotipik olarak koagulaz-pozitif stafilokok ve S. aureus yönünden analiz edilmiştir. Fenotipik yönden S. aureus olarak saptanan suşlar PCR tekniği ile doğrulanmış, PCR yöntemiyle enterotoksijenik özellikleri ve mecA geninin varlığı araştırılmıştır. Yapılan analizler sonucu, 120 sığır karkas örneğinin 32'si (% 26,6) koagulaz pozitif stafilokok ve 15'i (% 12,5) S. aureus yönünden pozitif bulunmuştur. Çalışmada izole edilen toplam 70 adet koagulaz-pozitif stafilokok izolatından 22'si fenotipik testler sonucu S. aureus olarak belirlenmiştir. Bu izolatların tümü, PCR tekniğinde S. aureus olarak doğrulanmıştır. S. aureus izolatlarının hiçbirinde mecA geni saptanamazken, 19'unun (% 86,3) enterotoksijenik özellikte olduğu belirlenmiştir. Enterotoksijenik izolatlardan 8'inin (% 36,3) seh, 5'inin ( % 22,7) sea, 2'sinin (% 9) seg+sei, 1'inin (% 4,5) sei, 1'inin (% 4,5) sed+sej, 1'inin (% 4,5) sea+tst ve 1'ininde (% 4,5) tst tipi enterotoksin genine sahip olduğu saptanmıştır. Çalışma kapsamında yapılan antibiyotik dirençlilik testleri sonucunda S. aureus izolatlarından % 72,7'sinın ampisiline, % 54,5'inin tetrasikline, % 40,9'unun eritromisine ve % 22,7'sinin sülfametaksazol-trimetoprim'e yüksek oranda dirençli olduğu belirlenmiştir. Bu antibiyotikleri oksasilin % 18,1, sefoksitin % 13,6, kloramfenikol % 9 ve gentamisin % 4,5 takip etmiştir. İzolatların tamamı ise vankomisine duyarlı bulunmuştur. Sonuç olarak, sığır karkasları kesim sonrası % 12,5 düzeyinde S. aureus ile kontamine bulunmuştur. Başlangıç kontaminasyon düzeyi düşük olsa da izolatların % 86.3'ünün enterotoksijenik özellikte olması halk sağlığı açısından önemlidir. Ayrıca izolatlardan bazılarının klasik enterotoksinlerin yanı sıra, yeni tanımlanan enterotoksin genlerine sahip olmaları da önemlidir. Yine izolatların çoğu bir ve/veya birden fazla antibiyotiğe karşı dirençli bulunmuştur. İzolatların hiçbirinde mecA geni bulunmamasına rağmen, metisilin duyarlılığının belirlenmesinde kullanılan oksasilin ve sefoksitin gibi antibiyotiklere karşı dirençli suşların tespit edilmiş olması önemlidir. Bu nedenle hijyenik sığır eti üretimi ve halk sağlığının korunması amacıyla HACCP sistemi etkin bir şekilde uygulanmalıdır.AbstractThe objectives of this study were, to determine the incidence, enterotoxigenic properties and antimicrobial resistance of S. aureus. For this purpose, 120 beef carcass samples, obtained from 2 different slaughterhouses in Ankara between June 2011 and May 2012. Samples obtained from three carcass sides (brisket, flank and round) marked with sterile template and sponge swap used to sample on carcass (10x10 cm2, totaly 300 cm2). Obtained samples firstly analyzed for phenotypically as coagulase positive staphylococci and S. aureus. Then phenotypically determined S. aureus isolates confirmed with PCR assay and detected by multiplex PCR for enterotoxin genes and mecA genes. Results of microbiological examinations, coagulase positive staphylococci isolated from 32 ( 26,6 %) of the 120 beef carcasses samples, 15 ( 12,5 %) of the 120 beef carcasses samples were confirmed as S. auerus. In this study, 22 out of 70 coagulase positive isolates identified as phenotypically S. aureus. All of this isolates confirmed with PCR assay. 19 (86,3 %) out of 22 S. aureus isolates determined as enteotoxigenic. It was determined that these enterotoxins contained 8 (36,3 %) seh, 5 (22,7 %) sea, 2 (9 %) seg+sei, 1 (4,5 %) sei, 1 (4,5 %) sed+sej, 1 (4,5 %) sea+tst, 1 (4,5 %) tst gene distribution, respectively. None of the S. aureus isolates contain mecA gene. In this study, according to the disc diffusion test results, 72,7 %; 54,5 %; 40,9 %; 22,7 % of S. aureus isolates were high level resistant to ampicillin, tetracycline, erythromycin, sulphamethoxazole- trimethoprim, respectively. In addition, 18,1 %; 13;6 %; 9 %; 4,5 % of S. aureus isolates were resistant to oxacillin, cefoxitin chloramphenicol and gentamicin, respectively. All of the isolates were sensitive to vancomycin. Finally, it was found that beef carcasses contaminated with S. aureus. Even if first level of contamination is low, enterotoxigenic S. aureus level is relatively high. This situation is important for public healthy. Also, isolates contained newly described enterotoxin genes. This results indicated that new types enterotoxin genes could be effective in food intoxication. In this study, isolates were found resistance to one or more antibiotics. None of the S. aureus isolates contain mecA gene but some of them were identified as resistant to a group of antibiotics like oxacillin and cefoxitin which are used in determining methicilin sensitivity. For public healthy and hygienic meat production HACCP systems would be implemented effectively
Detection of antibiotic resistance properties of Staphylococcus aureus isolated from raw milk samples
No full textFielding Peter Carey: economy, archive, celebrity
No full text© 2018 Dr. Keyvan AllahyariThis thesis accounts for a method of reading Carey’s fiction as works of national literature in the minor register (colonial, peripheral, small) which refract a sense of the possibility of circulation in transnational literary markets. The publication of Carey’s debut work, The Fat Man in History, by the University of Queensland Press in 1974 coincided with the termination of The Traditional Markets Agreement, which resulted in assisting American publishers to roam more freely in the Australian literary market. Drawing on Pierre Bourdieu’s concepts of the literary field, capital, and habitus, my thesis starts by examining the publication of The Fat Man as a microevent to better understand the macroevent of Carey’s position-taking in the transnational marketplace. The mid-1970s shifted Carey’s position in the field and established a trajectory through which he accumulated significant cultural and economic capital in the following decades. This method interrogates Carey’s rising visibility in relation to the construction of a new status for the postcolonial authors and the possibilities of the global publishing industry since the 1960s throughout to the present moment, including the politics of literary prizes and literary festivals, the rise of literary agents, the commodification of literary archives, and the merging of conglomerate publishing houses.
Carey’s fiction exhibits the anxieties of an Australian author ensnared in neoliberal systems of literary production and distribution, a free market economy biased against national territories (such as Australia) on the periphery of a world republic of letters. Drawing on the sociological paradigm of Pierre Bourdieu, this thesis asks how, and to what extent, can we think of Carey’s fiction and his writerly persona as cultural objects circulating within the global literary marketplace? How does his fiction refract the global forces that produce and distribute his books and celebrity? And what is the relationship between Carey’s stories and the literary marketplace, between the making of his books and the reading of them? Thus, my study offers a lateral examination of two interrelated aspects of Carey’s fiction. On the one hand, it captures a continuum of Australian and transnational practices of literary distinction and advancement that governed the critical and financial success of Carey’s fiction; on the other, it produces insights into the structural homologies between the literary spaces that Carey inhabits and those of his Australian characters confined to minor systems of cultural production and consumption
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No full textIn this thesis, we study the Simultenous Localization and Mapping problem with op-
timization based routines. We rely on a object based map representation that utilizes
Gaussian Processes to represent the boundaries of the objects in the environment. On
top of this representation, we provide an optimization based SLAM system based on
a novel smoothing scheme that is able to perform better than the existing filtering
based approaches. We show that our approach has better Localization and mapping
accuracy while performing better at situations where odometry information is less re-
liable. When compared to previous methods, we show that our representation has a
much better memory performance whilst providing stochastic information about the
environment. At last, we show comparisons with previous methods to demonstrate
the capabilities of our new approach.Bu tezde eş zamanlı haritalandırma ve konum bulma problemi, optimizasyon tabanlı
metodlar çerçevesinde ele alınmıştır. Harita gösterimi olarak obje tabanlı bir tem-
sil kullanılıyor olup, Gauss Süreçleri kullanarak objelerin şekilleri kestirilmiştir. Bu
temsilin üzerine, yeni bir düzenleme yöntemi kullanılarak haritalandırma ve konum
bulma performansı arttırılmıştır. Bu yöntem, odometri bilgilerinin güvenilir olmadığı
durumlarda da iyi sonuçlar vermiştir. Önceki metodlar ile karşılaştırıldığında, yeni
metodun hafıza kullanımı açısından da artan performansı ayrıca gösterilmiştir. Son
olarak, metodumuzun önceki metodlarla olan karşılaştırmalarına yer verilmiştir.M.S. - Master of Scienc
Determination of Aflatoxin M1 and Ochratoxin A in Raw, Pasteurized and UHT Milk in Turkey
No full textBackground: Mycotoxins produced by yeast and fungi have toxic effects on human and animal health. Aflatoxin B1 (AFB1) is the most toxic hepatocarcinogen to mammals. Aflatoxin M1 (AFM1), which has been found in milk and dairy products, is the hydroxylated metabolite of AFB1. Aflatoxin M1 is formed by the cytochrome P450 enzyme in the liver. Ochratoxin A (OTA) is synthesized by Aspergillus and Penicillium species. Ochratoxin A is known to cause teratogenic, immunotoxic, nephrotoxic and carcinogenic effects. Due to the potential harmful effects on human and animal health, OTA has also been receiving increased attention globally; however, there is limited information on the presence of OTA in milk and dairy products. The aim of this study was to determine how mycotoxins impact the hygienic quality of raw and heat-processed milk.Materials, Methods & Results: In this study, a total of 105 milk samples were analyzed (35 raw, 35 pasteurized and 35 UHT) to identify AFM1 and OTA in raw, pasteurized and ultra-high temperature processing (UHT) milk. The levels of AFM1 were detected by using the enzyme-linked immunosorbent assay (ELISA). The milk samples were centrifugedin order to remove the fat content from the milk. After centrifugation, the upper cream layer was withdrawn with a pipette. The non-fat liquid portion was placed in wells at 100 μL for analysis. The concentration of AFM1 in the milk samples was analyzed by AFM1 test kit.The milk samples with AFM1 levels greater than 50 ng/L were confirmed by using High-Performance Liquid Chromatography (HPLC). An Ochratoxin A Serum / Milk ELISA test kit was used for the analyses of OTA. The analyses were made according to the manufacturer’s instructions, and samples were analyzed in duplicate. The absorbance value of milk samples was obtained from the ELISA plate reader at 450 nm. The mean value of AFM1 was found to be 19.54 ng/L in the milk samples. According to the European Commission (EC), the maximum limit for AFM1 in milk is 50 ng/L. In our study, eight (7.61%) of the 105 samples exceeded this limit. The mean value of OTA was found to be 119 ng/L in the milk samples. The relationship between milk type and levels of AFM1 was found to be significant at (P < 0.01). The mean value of AFM1 in pasteurized milk was found statistically significant and lower than raw milk (P < 0.05). The difference between levels of OTA and milk type was not statistically significant at (P > 0.05).Discussion: Milk is a great protein source especially for children in the age of growth. Yeasts such as Fusarium, Aspergillus and Penicillium produce mycotoxins that cause food, feed contamination. Owing to carcinogenic, mutagenic and teratogenic effects of AFM1, presence of AFM1 in milk samples may adversely affect human health. The presence of AFM1 in different contamination levels can be observed in milk and milk products. Factors such as ration type, climate conditions, feed storage conditions, feeding regime and health status of dairy animals may be effective in the occurrence of these contamination. It is necessary to establish legal limits by conducting effective research on the existence of OTA in animal-derived products. The existence of mycotoxins in milk and dairy products can be reduced by preventing the contamination of feed materials with yeast and molds used in the feeding of dairy cows. Milk is one of the most important protein source for the human, effective hygienic controls should be applied to prevent microbiological and chemical hazards. Our data suggest that heat-treated milk may also be dangerous to human health, mycotoxins contamination should be controled with monitoring programs routinely in milk and feed materials for food safety. Determination of Aflatoxin M1 and Ochratoxin A in Raw, Pasteurized and UHT Milk in Turke
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