Metacognitive Strategies of English Department Students in Virtual Speaking Assessment

Metacognitive strategies are learners’ strategies to think or organize their learning. There have been a lot of studies conducted on this subject area in which most of them quantitatively found that there were differences in the frequency of using metacognitive strategies between different achievers. This study is specially presented to depict how students deploy their metacognitive strategies especially in facing and executing a language assessment, performing a persuasive speech virtually. The l assessment should be conducted virtually in an English Education study program in Indonesia due to the Covid-19 outbreak. There were 11 participants from a speaking class of the department from different level of achievements took part in the study. The high, middle, and low achiever joined a stimulated recall interview to pour everything in their mind when they were preparing for the persuasive speech assessment, executing it, and evaluating it.  Based on the investigation done through stimulated recall interview, the study reveals that there are differences between high, middle, and low achievers in preparing for the final test and in executing it, in which the high performer achievers prepared more comprehensively in the preparation which affect to their performance. The study also confirms that higher achievers have more responsibilities and confidence compared to the low achievers in preparing for their task performances

Human health risks associated with harvested rainwater: implementation of biocontrol strategies

Thesis (PhD)--Stellenbosch University, 2020.ENGLISH ABSTRACT: Rainwater harvesting has been earmarked as an additional fresh water source, which could be utilised to supplement municipal water supplies, especially in water scarce regions. However, various studies have indicated that the microbial quality of this water source is substandard. These microbial contaminants may pose a significant health risk to end-users and it is recommended that treatment systems are implemented to reduce the level of contamination in rainwater. Solar disinfection (SODIS) has been identified as an easy-to-use and cost-effective strategy that could be used to disinfect water. A minimum of 6 hours solar exposure is generally required for effective disinfection of water and photocatalytic nanomaterials such as titanium dioxide (TiO2) have subsequently been employed to improve SODIS efficiency by decreasing the treatment time. Research has however, indicated that while SODIS is effective in significantly reducing the concentration of microbial contaminants in water sources, various pathogens and opportunistic pathogens employ survival strategies and persist after treatment. A combination of physical, chemical and biological treatments, which target these persistent organisms directly, should therefore be investigated. For the purpose of this dissertation, the use of Bdellovibrio bacteriovorus (B. bacteriovorus), a Gram-negative predatory bacterium, was investigated. The primary aim of Chapter 2 (published in Microbiological Research, 2019) was thus to isolate B. bacteriovorus from wastewater and investigate the interaction of this predator with Gram-negative and Gram-positive prey using culture-based (spread plating and double-layer agar overlays) and molecular methods [ethidium monoazide quantitative polymerase chain reaction (EMA-qPCR)]. The predation activity of B. bacteriovorus on the different prey cells was assessed and compared in a nutrient poor [diluted nutrient broth (DNB)] and nutrient deficient medium (HEPES buffer). A B. bacteriovorus isolate (PF13) was subsequently co-cultured with Pseudomonas fluorescens (P. fluorescens), Pseudomonas aeruginosa (P. aeruginosa), Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus) and Enterococcus faecium (E. faecium). Results indicated that P. fluorescens (maximum log reduction of 4.21) and K. pneumoniae (maximum log reduction of 5.13) were sensitive to predation in DNB and HEPES buffer, while E. faecium (maximum log reduction of 2.71) was sensitive to predation in DNB and S. aureus (maximum log reduction of 1.80) was sensitive to predation in HEPES buffer. Predation of Gram-positive prey by B. bacteriovorus was thus dependent on the specific prey cells used and the media employed to assess these interactions. In contrast, for P. aeruginosa, while the culture-based analysis indicated that the cell counts were reduced, the EMA-qPCR analysis indicated that the concentration of P. aeruginosa was not significantly reduced in DNB or HEPES buffer. The use of EMA-qPCR can thus aid in accurately monitoring and quantifying both predator and prey cells during co-culture experiments in a time-effective manner. The aim of Chapter 3 (published in Water Research, 2020) was to subsequently apply B.bacteriovorus PF13 as a pre-treatment to SODIS and solar photocatalytic disinfection. Thephotocatalyst used was immobilised titanium-dioxide reduced graphene oxide (TiO2-rGO). Synthetic rainwater was seeded with K. pneumoniae and E. faecium, with results indicating that the use of B. bacteriovorus pre-treatment in combination with solar photocatalysis resulted in the greatest reduction in K. pneumoniae concentrations in the shortest treatment time, with the cell counts reduced by 9.30 logs to below the detection limit (BDL) within 120 min. In contrast, for E. faecium the most effective treatment was solar photocatalysis or SODIS without the B. bacteriovorus pre-treatment, as the viable counts of E. faecium were reduced by 8.00 logs to BDL (within 210 min) and the gene copies were reduced by ~3.39 logs after 240 min. It was thus evident that the application of B. bacteriovorusmay specifically enhance the disinfection of Gram-negative bacteria. Additionally, the use of the photocatalyst further enhanced the disinfection of the Gram-negative bacteria, while the same trend was not observed for E. faecium. Recirculating the water in solar photocatalytic reactors may, however, enhance disinfection of Gram-positive bacteria, by exerting mechano-osmotic stress on the cells and should be investigated in future research. As conflicting results regarding the interaction between B. bacteriovorus and Gram-positive bacteria have been reported, the aim of Chapter 4 (published in Microbiological Research, 2020) was to monitor and compare the expression of attack phase (AP) and growth phase (GP) genes of B. bacteriovorus in co-culture with Gram-positive and Gram-negative prey. Bdellovibrio bacteriovorus PF13 was thus co-cultured with Escherichia coli (E. coli; control), K. pneumoniae and E. faecium. Relative qPCR analysis indicated that the AP genes bd0108 (type IVa pili retraction/extrusion) and merRNA (massively expressed riboswitch RNA) were highly expressed in the B. bacteriovorus AP cells, whereafter expression in co-culture with all the prey strains was reduced. The fliC1 gene (flagellar filament) was also expressed at a high level in the AP cells, however, after 240 min of co-culture with E. faecium the expression of fliC1 remained low (at 0.759-fold), while in the presence of the Gram-negative prey, fliC1 expression increased (in comparison to the expression recorded after 30 min) to 4.62 (E. coli) and 2.69-fold (K. pneumoniae). In addition, bd0816 (peptidoglycan-modifying enzyme) and groES1 (chaperone protein) were not induced in the presence of E. faecium, however, after exposure to the Gram-negative prey, bd0816 expression increased during the early GP, while groES1 expression gradually increased during the early GP and GP. It was thus concluded that B. bacteriovorus senses the presence of potential prey when exposed to Gram-positive and Gram-negative prey however, the GP genes were not induced when B. bacteriovorus was co-cultured with E. faecium. This indicates that B. bacteriovorus may not actively grow in the presence of E. faecium and the second predatory cue (which induces active growth of B. bacteriovorus) may be lacking under the conditions employed in this study. Limited information on the expression of predatory-specific genes of B. bacteriovorus in co-culture with Gram-positive prey cells is available. Recent studies have however, indicated that B. bacteriovorus can prey on Gram-positive bacteria and investigating the expression of these predatory-specific genes may elucidate the genetic mechanisms this predator employs to survive in the presence of these atypical prey.AFRIKAANSE OPSOMMING: Geoeste reënwater is geïdentifiseer as ʼn addisionele varswater bron wat gebruik kan word om munisipale water gebruik aan te vul, veral in areas waar water skaars is. Verskeie studies het egter gewys dat die mikrobiese kwaliteit van hierdie water nie op standaard is nie. Hierdie mikrobes kan ʼn beduidende gesondheidsrisiko vir verbruikers inhou en daarom moet water behandeling sisteme geïmplementeer word om die vlakke van hierdie mikroörganismes te verlaag. Sonkrag ontsmetting is aangewys as ʼn maklike en goedkoop strategie om water te suiwer. Vir effektiewe suiwering, moet die water vir 6 ure aan sonlig blootgestel word en daarom word fotokatalitiese nanomaterial soos titaandioksied (TiO2) dikwels gebruik om die proses te versnel en sodoende die effektiwiteit van sonkrag ontsmetting te verbeter. Navorsing dui egter daarop dat alhoewel sonkrag ontsmetting mikroörganismes in water verminder, baie patogene en opportunistiese patogene oorlewingsmeganismes gebruik om hierdie tipe behandeling te oorleef. ʼn Kombinasie van fisiese, chemiese en biologiese behandelings moet dus ondersoek word om hierdie oorlewende patogene te teiken. Die gebruik van Bdellovibrio bacteriovorus (B. bacteriovorus), ʼn Gram-negatiwe roofbakterium, is dus vir hierdie dissertasie ondersoek. Die oorhoofse doel van Hoofstuk 2 (gepubliseer in “Microbiological Research”, 2019) was dus om B. bacteriovorus uit riool te isoleer en die interaksie tussen hierdie roofbakterium en Gram-negatiewe en Gram-positiewe prooi te ondersoek deur kultuur- (spreiplate en dubbellaag-oorlegsels) en molekulêre metodes [ethidium monoasied kwantitatiewe polimerase ketting reaksie (EMA-kPKR)] te gebruik. Hierdie interaksies is ook in ʼn voedingstof-arm medium [verdunde voedingstof boeljon (VVB)] en ʼn medium sonder voedingstowwe (HEPES buffer) waargeneem en vergelyk. ʼn B. bacteriovorus isolaat (PF13) is dus saam met Pseudomonas fluorescens (P. fluorescens), Pseudomonas aeruginosa (P. aeruginosa), Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus) en Enterococcus faecium (E. faecium) geïnokuleer en toegelaat om te groei. Die resultate het aangedui dat P. fluorescens (maksimum log vermindering van 4.21) en K. pneumoniae (maksimum log vermindering van 5.13) sensitief was vir predasie in VVB en HEPES buffer, terwyl E. faecium (maksimum log vermindering van 2.71) sensitief was vir predasie in VVB en S. aureus (maksimum log vermindering van 1.80) sensitief was vir predasie in HEPES buffer. Predasie op die Gram-positiewe bakterieë was dus afhanklik van die spesifieke prooi selle en die medium wat gebruik is om die interaksies te ondersoek. In teenstelling, vir P. aeruginosa het die resultate gewys dat die seltellings beduidende verminder is in VVB en HEPES buffer, maar die EMA-kPKR analises het gewys dat die konsentrasie van hierdie organisme nie beduidend afgeneem het nie. Daarom is die gebruik van EMA-kPKR voordelig omdat dit die konsentrasie en lewensvatbaarheid van beide die prooi en roofbakterium kan monitor in tweeledige kulture, op ‘n relatiewe vinnige manier. In Hoofstuk 3 (gepubliseer in “Water Research”, 2020) was die doel om B. bacteriovorus PF13 dan te gebruik as ʼn voorbehandeling vir sonkrag ontsmetting en fotokatalitiese ontsmetting. Titaandioksied gereduseerde grafeen oksied (TiO2-rGO) is as die fotokatalis gebruik. Sintetiese reënwater is met K. pneumoniae en E. faecium geϊnokuleer. Die resultate het aangedui dat die beste kombinasie vir K. pneumoniae ontsmetting die fotokatalise met B. bacteriovorus voorbehandeling was, aangesien die plaattellings met 9.30 log verminder is tot onder die opsporingslimiet binne 120 min. In teenstelling was die beste behandeling vir E. faecium sonkrag ontsmetting of fotokatalitiese ontsmetting sonder die B. bacteriovorus voorbehandeling, aangesien die plaattellings verminder is met 8.00 log tot onder die opsporingslimiet (binne 210 min) en die geen kopieë met ~3.39 log verminder is binne 240 min van behandeling. Dit was dus duidelik dat die gebruik van B. bacteriovorus die ontsmetting van Gram-negatiewe bakterieë kan verbeter. Die gebruik van die fotokatalis het ook die ontsmetting van die Gram-negatiewe bakterieë verbeter, terwyl dieselfde nie waargeneem is vir E. faecium nie. Om die water in die fotokatalitiese behandeling sisteem te sirkuleer mag die ontsmetting van Gram-positiewe bakterieë verbeter deur megano-osmotiese stres op die selle te plaas. Hierdie aspek moet in toekomstige studies ondersoek word. Teenstrydige resultate aangaande die interaksie tussen B. bacteriovorus en Gram-positiewe bakterieë is in die verlede weergegee en daarom was die doel van Hoofstuk 4 (gepubliseer in “Microbiological Research”, 2020) om die gene wat in die aanvallingsfase (AF) en die groeifase (GF) van B. bacteriovorus uitgedruk word, te monitor en te vergelyk terwyl B. bacteriovorus aan Gram-positiewe prooi en Gram-negatiewe prooi blootgestel word. Bdellovibrio bacteriovorus PF13 is daaropvolgens saam met Escherichia coli (E. coli; kontrole), K. pneumoniae en E. faecium in tweeledige kulture geϊnokuleer. Relatiewe kPKR analise het daarna aangedui dat die AF gene bd0108 (tipe IVa pili retraksie) en merRNA (massief uitgedrukte riboskakelaar RNA) teen hoë vlakke uitgedruk word in die AF selle, en dat die uitdrukking van hierdie gene daarna afneem in die teenwoordigheid van al die prooi selle. Die fliC1 geen (filament van die flagella) is ook teen hoë vlakke in die AF selle uitgedruk, maar na 240 min se groei saam met E. faecium was die vlak van fliC1 uitdrukking laag (0.759-voud), terwyl die fliC1 uitdrukking saam met die Gram-negatiewe bakterieë gestyg het (in vergelykking met die vlakke by 30 min) na 4.62- (E. coli) en 2.69-voud (K. pneumoniae). Verder is die bd0816 (peptidoglikaan modifiserende ensiem) en groES1 (chaperone proteϊen) gene nie geïnduseer terwyl B. bacteriovorus aan E. faecium blootgestel is nie, maar na die roofbakterium aan die Gram-negatiewe bakterieë blootgestel is, het die vlakke van bd0816 en groES1 beduidend toegeneem in onderskeidelik die vroeë GF en GF. Hierdie resultate het dus aangedui dat B. bacteriovorus waarneem dat moontlike prooi selle naby is wanneer dit blootgestel word aan beide Gram-negatiewe en Gram-positiewe prooi, maar dat die GF gene nie geïnduseer word in die teenwoordigheid van E. faecium nie. Dit kan daarop dui dat B. bacteriovorus nie kan groei met E. faecium as prooi nie en dat die tweede sein (wat aktiewe groei van B. bacteriovorus bewerkstellig) afwesig is in hierdie toestande. Beperkte inligting is beskikbaar vir die interaksies tussen B. bacteriovorus en Gram-positiewe bakterieë en daarom moet hierdie interaksies op ʼn genetiese vlak bestudeer word om vas te stel hoe hierdie roofbakterium oorleef in die teenwoordigheid van hierdie atipiese prooi.Doctora

Basidiobolomycosis of colon: Case report"

Basidiobolomycosis of the colon is a very rare fungal infection disease. We report here primary colonic Basidiobolomycosis as the first female case in Iraq. A 48 years old Insulin dependent diabetic patient presented with abdominal pain , right side abdominal mass and weight loss for few months duration. CT scan revealed caecal wall thickening without intestinal obstruction. Colonoscopy revealed large fungative ulcerated mass in caecum but the mucosal biopsy was negative for malignancy and in favour of chronic inflammation .Laparotomy with right hemicolectomy and ilio-transverse anastomosis done. Histopathological examination of the excised specimen prove Basidiobolomycosis of colon for which she received 6 months course of oral Itraconazole . She recovered well from the disease with no sequela or recurrence

Effects of Propofol on Left Ventricular Mechanoenergetics in the Excised Cross-circulated Canine Heart

Although propofol is commonly used for general anesthesia, its direct effects on left ventricular (LV) contractility and energetics remain unknown. Accordingly, we studied the effects of intracoronary propofol on excised cross-circulated canine hearts using the framework of the Emax (a contractility index)-PVA (systolic pressure-volume area, a measure of total mechanical energy)-Vo2 (myocardial oxygen consumption per beat) relationship. We obtained 1) the Vo2-PVA relationship of isovolumic contractions with varied LV volumes at a constant Emax, 2) the Vo2-PVA relationship with varied LV volumes at a constant intracoronary concentration of propofol, and 3) the Vo2-PVA relationship under increased intracoronary concentrations of either propofol or CaCl2 at a constant LV volume to assess the cardiac mechanoenergetic effects of propofol. We found that propofol decreased Emax dose-dependently. The slope of the linear Vo2-PVA relationship (oxygen cost of PVA) remained unchanged by propofol. The PVA-independent Vo2-Emax relationship (oxygen cost of Emax) was the same for propofol and Ca2＋. In conclusion, propofol showed a direct negative inotropic effect on LV. At its clinical concentrations, decreases in contractility by propofol were relatively small. Propofol shows mechanoenergetic effects on the LV that are similar to those of Ca2＋ blockers or ß-antagonists—i.e., it exerts negative inotropic effects without changing the oxygen costs of Emax and PVA

Decreased risk of catheter infection in infants and children using subcutaneous tunneling for continuous caudal anesthesia.

Continuous caudal anesthesia has been commonly used for intra- and post-operative analgesia in infants and children. However, it has a potential risk of bacterial infection, especially in infants in whom the catheter site is easily contaminated with loose stool. To avoid infection, the authors applied a new procedure using subcutaneous tunneling for continuous caudal anesthesia. In the 18 cases studied with subcutaneous tunneling, clinical signs of infection were absent and bacterial colonization was not found on the catheter tip after 3.9 +/- 1.4 days of catheterization. The incidence of catheter colonization after continuous caudal anesthesia without tunneling had been reported. In their reports, the incidence of catheter colonization ranged from 20% to 37%. Therefore, caudal catheterization with subcutaneous tunneling is a simple and safe method, and has proved very effective to reduce the risk of epidural infection.</p

Human pathogenic bacteria detected in rainwater : risk assessment and correlation to microbial source tracking mark and traditional indicators

Abstract: Please refer to full text to view abstract

The compatibility between the writing assignments and the grammar materials in the book “pathway to English” for grade xi a thesis in partial fulfillment of the recruitments for the sarjana pendidikan degree in English language teaching

Grammar is a set of rules about how words are composed correctly in a language. Learning English grammar will be enhanced if the learners have opportunities to meaningfully apply the learning materials in appropriate contexts. Moreover, if the learners have the chance to apply them into appropriate writing, it can reinforce their grammar mastery. In this study, the writer did analysis to find out the compatibility between the writing assignments and the grammar materials in the book “Pathway To English” For grade XI. The units selected to be analyzed are those presenting grammar materials and writing assignments; they are units 3, 5, 6, 7, 10, and 11. To find whether the writing assignments are compatible with the grammar materials, the writer examined how the grammar materials are presented, and then, she analyzed whether the writing assignments provide the learners with the opportunities to meaningfully apply the grammar materials delivered. The first finding showed that most of the grammar materials consist of the grammar explanations and related grammar exercises, and the grammar exercises are gradually delivered. The second finding showed that all of the writing assignments provide the learners with the opportunities to apply the grammar materials. From both findings, it can be stated that all of the writing assignments are compatible with the grammar materials delivered, so the course book “Pathway To English” for grade XI is good to be used to reinforce the learners grammar mastery through the writing assignments given

Identifying the primary microbial and chemical source tracking markers in harvested rainwater for the detection of faecal contamination

Thesis (MSc)--Stellenbosch University, 2017.ENGLISH ABSTRACT: Rainwater harvesting has been earmarked as an additional source of fresh water. However, research has indicated that the microbiological quality is substandard as pathogens have been detected in this water source. As it is impractical to monitor for the presence of all pathogens in a water source, indicator organisms are routinely utilised to monitor water quality and predict the presence of pathogens in contaminated environmental waters. Various research groups have however indicated that the analysis of indicator organisms in a water source may not be sufficient to accurately identify the source of contamination. Supplementary indicators are therefore required to accurately identify contamination sources, with chemical and microbial source tracking markers currently being investigated and applied to various water sources. The primary focus of the current study was thus to identify a toolbox of microbial source tracking (MST) and chemical source tracking (CST) markers that could be utilised to supplement indicator organism analysis of domestic rainwater harvesting (DRWH) systems. To achieve this aim, harvested rainwater (n = 60) and rooftop debris (n = 60) samples were screened for a range of MST (conventional PCR) and CST (high-performance liquid chromatography tandem mass spectrometry) markers previously utilised in literature to analyse various water sources (Chapter two). All the tank water samples collected at the Kleinmond Housing Scheme site (Kleinmond, Western Cape), were also screened for traditional indicator organisms using culture based techniques. Additionally, Escherichia coli (E. coli) and enterococci were screened for in all tank water and rooftop debris samples using quantitative PCR (qPCR) analysis. Based on the conventional PCR results, Bacteroides HF183, adenovirus, Lachnospiraceae and human mitochondrial DNA (mtDNA) were the most prevalent MST markers. These markers were subsequently quantified in the tank water and rooftop debris samples by qPCR. The HF183 marker was then detected at a mean concentration of 5.1 × 103 and 4.7 × 103 gene copies/μL in the tank water and rooftop debris, respectively. Adenovirus was detected at 3.2 × 102 and 6.4 × 103 gene copies/μL; human mtDNA was detected at 1.1 × 106 and 3.0 × 105 gene copies/μL and Lachnospiraceae was detected at 3.0 × 104 and 6.9 × 103 gene copies/μL in the tank water and rooftop debris samples, respectively. Additionally, E. coli and enterococci were quantifiable in all tank water and rooftop debris samples by qPCR analysis. The CST markers caffeine, salicylic acid, acetaminophen, triclosan, triclocarban and methylparaben were then detected at μg/L levels in all the tank water [except salicylic acid (98%)] and rooftop debris samples. A secondary aim was to establish correlations between the MST and CST markers as well as indicator organisms to ascertain which markers may be employed to supplement indicator organism analysis of DRWH systems. In the tank water samples, significant positive correlations were observed for adenovirus versus E. coli (enumerated with the culturing techniques) (p = 0.000), the HF183 marker versus E. coli (quantified by qPCR) (p = 0.023), Lachnospiraceae versus heterotrophic bacteria (p = 0.000) and human mtDNA versus enterococci (enumerated with the culturing techniques) (p = 0.026). In addition, significant positive correlations were observed for caffeine versus enterococci (quantified by qPCR) (p = 0.000); faecal coliforms (p = 0.001); total coliforms (p = 0.000) and enterococci (enumerated with culturing techniques) (p = 0.002). Salicylic acid also positively correlated with total coliforms (p = 0.024) in the tank water samples. For the rooftop debris samples, significant positive correlations were observed for E. coli (quantified by qPCR) versus methylparaben (p = 0.000) and salicylic acid (p = 0.042), respectively. Based on the results obtained, it is thus evident that faecal contamination and anthropogenic activities may be the primary sources of contamination in the DRWH systems. Moreover, the markers Bacteroides HF183, Lachnospiraceae, human mtDNA, adenovirus, caffeine, salicylic acid and methylparaben may be utilised to supplement traditional indicator organism analysis for the monitoring of harvested rainwater. It is however recommended that future studies focus on correlation analysis of the source tracking markers with pathogens frequently detected in harvested rainwater, in order to determine which source tracking markers may be utilised as surrogates for these pathogens and subsequently as supplementary indicators. Avian species are vectors of microorganisms in the environment and have been identified as major sources of faecal contamination of DRWH systems. The focus of Chapter three was thus to design and validate (on a small-scale) novel MST markers for the detection of avian faecal contamination in the DRWH systems. Three primer sets [AVF1 and AVR (designated AV1); AVF2 and AVR (designated AV2); and ND5F and ND5R (designated ND5)] were subsequently designed to target regions of the NADH dehydrogenase subunit 5 mitochondrial DNA gene of avian species. Mitochondrial DNA is abundant in animal faecal matter and may thus be readily detected. Conventional PCR assays were optimised for each of the three primer sets. Avian and non-avian faecal samples were then screened to validate the host-specificity and host-sensitivity of the mtDNA markers. The mtDNA markers AV1, AV2 and ND5 displayed a host-sensitivity of 1.00, 0.892 and 0.622, respectively. While the host-specificity of each assay was equal to 0.316, 0.0526 and 0.237 for AV1, AV2 and ND5, respectively. Tank water samples (n = 60) and rooftop debris (n = 60) were then screened for the prevalence of the three markers. Overall, AV1 was the dominant marker detected in the tank water (85%) and rooftop debris (90%) samples. Bayes’ theorem then indicated that there was an 89.2% and 92.9% probability that the AV1 marker detected true avian faecal contamination in the tank water and rooftop debris samples, respectively. The AV1 marker thus exhibited the greatest potential as an avian mtDNA marker for the detection of avian faecal contamination in DRWH systems. However, based on the low host-specificity obtained for all three primer sets (AV1, AV2 and ND5), further optimisation should include the use of a Taqman™ probe to increase the specificity of this marker.AFRKAANSE OPSOMMING: Geoeste reënwater is geïndentifiseer as ‘n addisionele vars waterbron, maar navorsing het bewys dat die mikrobiese kwaliteit substandaard is aangesien ‘n verskeidenheid patogene al in geoeste reënwater gevind is. Aangesien dit onprakties is om vir alle patogene in ‘n waterbron te toets, word indikator organismes algemeen gebruik om die kwaliteit van waterbronne te monitor en om die teenwoordigheid van patogene in die water te voorspel. Verskeie navorsingsgroepe het egter gewys dat om vir indikator organismes te toets, nie voldoende is om die bron van kontaminasie te identifiseer nie. Daar is dus ‘n behoefte aan aanvullende indikators om die bronne van kontaminasie te identifiseer. Daarom word chemiese en mikrobiese bron spoor merkers deesdae nagevors en toegepas op verskeie waterbronne. Die primêre doel van die huidige studie was dus om ‘n versameling mikrobiese bron spoor (MBS) en chemiese bron spoor (CBS) merkers te identifiseer wat gebruik mag word om die analise van indikator organismes in huishoudelike reënwater oesting (HRWO) sisteme, aan te vul. Hierdie doel is behaal deur geoeste reënwater monsters (n = 60) en detritus monsters vanaf die dakoppervlak (n = 60) te toets vir ‘n paneel MBS (konvensionele PKR) en CBS (hoë-verrigting vloeistof chromatografie tandem massaspektrometrie) merkers, wat voorheen in die literatuur aangewend is om water te analiseer (Hoofstuk twee). Die tenk water monsters wat by die Kleinmond Behuisings-skema (Kleinmond, Wes-Kaap) geneem is, is ook getoets vir tradisionele indikator organismes deur gebruik te maak van groei-gebaseerde tegnieke. Daarby is daar ook vir Escherichia coli ( E. coli) en enterokokkie met kwantitatiewe PKR (kPKR) in die tenk water en detritus monsters getoets. Die konvensionele PKR resultate het getoon dat Bacteroides HF183, adenovirus, Lachnospiraceae en menslike mitokondriale DNS (mtDNS) die mees algemene MBS merkers in die monsters was. Hierdie merkers is dus gekwantifiseer in die tenk water en detritus monsters met behulp van kPKR. Die HF183 merker is toe teen ‘n gemiddelde konsentrasie van 5.1 × 103 en 4.7 × 103 geen kopieë/μL in die tenk water en detritus monsters gekry. Adenovirus is teen 3.2 × 102 en 6.4 × 103 geen kopieë/μL; menslike mtDNS is teen 1.1 × 106 en 3.0 × 105 geen kopieë/μL en Lachnospiraceae is teen 3.0 × 104 en 6.9 × 103 geen kopieë/μL in onderskeidelik die tenk water en detritus monsters gekry. Daarbenewens was die E. coli en enterokokkie ook kwantifiseerbaar in al die tenk water en detritus monsters, onderskeidelik. Die CBS merkers kafeïen, salisielsuur, asetaminofen, metielparabeen, triklosaan en triklokarbaan is teen μg/L vlakke in al die tenk water [behalwe salisielsuur (98%)] en detritus monsters gekry. ‘n Tweede doel van hierdie studie was om korrelasies tussen die MBS en CBS merkers en indikator organismes te ondersoek, om vas te stel watter merkers gebruik mag word om indikator organisme analises aan te vul. In die tenk water monsters is daar beduidende positiewe korrelasies waargeneem vir adenovirus teenoor E. coli (groei-gebaseerd) (p = 0.000), die HF183 merker teenoor E. coli (kPKR) (p = 0.023), Lachnospiraceae teenoor heterotrofiese bakterieë (p = 0.000) en menslike mtDNS teenoor enterokokkie (groei-gebaseerd) (p = 0.026). Daaropvolglik, is beduidende positiewe korrelasies opgemerk vir kafeïen teenoor enterokokkie (kPKR) (p = 0.000); fekale koliforme (p = 0.001); totale koliforme (p = 0.000) en enterokokkie (groei-gebaseerd) (p = 0.002). Salisielsuur het ook positief gekorreleer met totale koliforme (p = 0.024) in die tenk water monsters. Vir die detritus monsters is beduidende positiewe korrelasies opgemerk vir E. coli (kPKR) teenoor metielparabeen (p = 0.000) en salisielsuur (p = 0.042), onderskeidelik. Hierdie resultate dui dan aan dat fekale kontaminasie en antropogeniese aktiwiteite die primêre bronne van kontaminasie van die HRWO sisteme is. Verder kan Bacteroides HF183, Lachnospiraceae, menslike mtDNS, adenovirus, kafeïen, salisielsuur en metielparabeen gebruik word om tradisionele indikator organisme analises aan te vul om die kwaliteit van geoeste reënwater te monitor. Daar word egter aanbeveel dat toekomstige studies op korrelasies tussen bron spoor merkers en patogene, wat gereeld in geoeste reënwater gevind word, ondersoek word om vas te stel watter bron spoor merkers as surrogate vir hierdie patogene en verder as aanvullende indikators gebruik kan word. Voël spesies is vektore van mikroorganismes in die omgewing en is geïdentifiseer as bronne van fekale kontaminasie in HRWO sisteme. Die fokus van Hoofstuk drie was dus om nuwe MBS merkers, om fekale kontaminasie van voëls in HRWO sisteme op te spoor, te ontwerp en op ‘n klein skaal te verifieer. Drie inleier stelle [AVF1 en AVR (benoem AV1); AVF2 en AVR (benoem AV2); en ND5F en ND5R (benoem ND5)] is dus ontwerp om dele van die NADH dehidrogenase subeenheid 5 mtDNS geen van voëls te teiken. Mitokondriale DNS is vollop in die fekale materiaal van diere en kan dus maklik geamplifiseer word. Konvensionele PKR toetse is vir elke inleier paar geoptimiseer. Fekale monsters van voël spesies en nie-voël spesies is gevolglik geanaliseer om die gasheer-sensitiwiteit en -spesifisiteit van die mtDNS merkers te verifieer. Die gasheer-sensitiwiteit was dus gelyk aan 1.00, 0.892 en 0.622 vir die AV1, AV2 en ND5 merkers, onderskeidelik, terwyl die gasheer-spesifisiteit gelyk was aan 0.316, 0.0526 en 0.237 vir die AV1, AV2 en ND5 merkers, onderskeidelik. Tenk water (n = 60) en detritus (n = 60) monsters is toe getoets vir die teenwoordigheid van die drie merkers. Die AV1 merker is as die dominante merker in die tenk water (85%) en detritus (90%) monsters geïdentifiseer. Bayes se stelling het aangedui dat daar ‘n 89.2% en 92.9% waarskynlikheid is dat die AV1 merker opgespoor is weens ware voël verwante kontaminasie in die tenk water en detritus monsters. Die AV1 merker het dus die grootste potensiaal om as ‘n mtDNS merker, vir die opsporing van voël verwante kontaminasie in HRWO sisteme, gebruik te kan word. As gevolg van die lae gasheer-spesifisiteit wat opgemerk is vir die drie inleier stelle (AV1, AV2 en ND5), word daar egter voorgestel dat hierdie merkers verder geoptimiseer moet word deur gebruik te maak van Taqman™ ondersoekers spesifiek vir voëls, om dan die spesifisiteit van die merkers te verbeter