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Health agencies recommend using hand sanitisers as protection against the coronavirus. Thus far, the emphasis on hand sanitiser studies is limited to an analysis of disinfectant content only. This study aims to provide an extended analysis of 60 off-the-shelf alcohol-based hand sanitisers by using gas chromatography to report on alcohol content and the presence of impurities, a recombinant yeast estrogen screen to assess estrogenic activity, and an investigation into labelling compliance with the South African National Standard. Fifty hand sanitisers had an alcohol content of ≥60% v/v alcohol; however, most contained skin irritants and substances that could harm human and environmental health. Estrogenic activity was detected in 29 hand sanitisers and none of the products complied with all the labelling requirements. Since off-the-shelf hand sanitisers in South Africa are not regulated and monitored, evidence-based public awareness programmes on hand sanitiser quality and safety should become a priority.
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COVID-19 , Desinfectantes para las Manos , Humanos , COVID-19/prevención & control , Sudáfrica , Pandemias/prevención & control , Desinfectantes para las Manos/química , Etanol/químicaRESUMEN
AIMS: To investigate the influence of irrigation water microbial quality on leafy green vegetables produced in commercial and small-scale farms as well as homestead gardens using pyrosequencing. METHODS AND RESULTS: Next generation sequencing analysis of the V1-V3 hypervariable region of bacterial 16S rDNA was used to compare bacterial diversity in irrigation water sources and on leafy vegetables. In all samples (12) analysed, the phylum Proteobacteria (64·5%), class Gammaproteobacteria (56·6%) and genus Aeromonas (14·4%) were found to be dominant. Of the total Escherichia sequences detected in tested samples, lettuce (16·3%) from the one commercial farm harboured more sequences than cabbage from the small-scale farm (1·3%) or homestead gardens (1·9%). Escherichia sequences were detected in both irrigation water (4·6%) and on cabbage (1·3%) samples from the small-scale farm. The genus Salmonella was absent in borehole water but was detected in the holding dam water (<1%) from commercial farm A. Salmonella sequences were present in river water (<1%) and on cabbages (1·9%) from the small-scale farm but were not detected on cabbage samples from the one commercial farm or the homestead gardens. CONCLUSION: Water sources quality used for irrigation greatly influences the microbial dynamics of the irrigated crop. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbial biomes in irrigation water and on leafy greens were described with pyrosequencing and revealed insights into prevalence of potential and opportunistic pathogens across different production systems.
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Riego Agrícola , Verduras/microbiología , Microbiología del Agua , Aeromonas/genética , Aeromonas/aislamiento & purificación , Brassica/microbiología , Ecosistema , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Granjas , Agua Dulce/microbiología , Gammaproteobacteria/genética , Gammaproteobacteria/aislamiento & purificación , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactuca/microbiología , Proteobacteria/genética , Proteobacteria/aislamiento & purificación , Salmonella/genética , Salmonella/aislamiento & purificación , Calidad del AguaRESUMEN
AIMS: To investigate the effect of commercial citrus packhouse processing steps on the fruit surface microbiome of Clementines and Palmer navel oranges. METHODS AND RESULTS: Viable bacteria, yeast and fungi counts, and the pyrosequencing analysis of the 16S rRNA and ITS were used to evaluate the community structure and population dynamics of phylloepiphytic bacteria and fungi associated with commercial postharvest processing. Drenching significantly reduced microbial counts in all cases except for yeasts on navels, while the extent of degreening effects varied between the citrus varieties. Pyrosequencing analysis showed a total of 4409 bacteria and 5792 fungi nonchimeric unique sequences with an average of 1102 bacteria and 1448 fungi reads per sample. Dominant phyla on the citrus carpoplane were Proteobacteria (53·5%), Actinobacteria (19·9%), Bacteroidetes (5·6%) and Deinococcus-Thermus (5·4%) for bacteria and Ascomycota (80·5%) and Basidiomycota (9·8%) for fungi. Beginning with freshly harvested fruit fungal diversity declined significantly after drenching, but had little effect on bacteria and populations recovered during degreening treatments, including those for Penicillium sp. CONCLUSION: Packhouse processing greatly influences microbial communities on the citrus carpoplane. SIGNIFICANCE AND IMPACT OF THE STUDY: A broad orange biome was described with pyrosequencing and gave insight into the likely survival and persistence of pathogens, especially as they may affect the quality and safety of the packed product. A close examination of the microbiota of fruit and the impact of intervention strategies on the ecological balance may provide a more durable approach to reduce losses and spoilage.
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Bacterias/aislamiento & purificación , Citrus sinensis/microbiología , Frutas/microbiología , Hongos/aislamiento & purificación , Microbiota , Bacterias/genética , Manipulación de Alimentos , Hongos/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
AIMS: To determine fungal communities that characterize table grapes during berry development. METHODS AND RESULTS: Two agro-ecologically different table grape commercial farms (site A and B) were used in this study. Samples were collected at full bloom, pea size and mature stages, from three positions (inside centre, eastern and western peripheral ends) per site. Total DNA extraction, Illumina sequencing and analysis of 18 pooled samples for fungal diversity targeting ITS1-2 generated a total of 2 035 933 high-quality sequences. The phylum Ascomycota (77.0%) and Basidiomycota (23.0%) were the most dominant, while the genera, Alternaria (33.1%) and Cladosporium (24.2%) were the overall dominant postharvest decay causing fungi throughout the developmental stages. Inside centre of site A were more diverse at full bloom (3.82) than those at the peripheral ends (<3.8), while at site B, the peripheral ends showed better diversity, particularly the eastern part at both full bloom (3.3) and pea size (3.7). CONCLUSION: Fungal population diversity varies with different phenological table grape growth stages and is further influenced by site and vine position within a specific vineyard. SIGNIFICANCE AND IMPACT OF THE STUDY: The information on fungal diversity and succession in table grapes during preharvest growth stages is critical in the development of a more targeted control strategy, to improve postharvest quality of table grapes.
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Frutas/crecimiento & desarrollo , Hongos/aislamiento & purificación , Vitis/microbiología , Biodiversidad , Frutas/microbiología , Hongos/clasificación , Hongos/genética , Filogenia , Sudáfrica , Vitis/crecimiento & desarrolloRESUMEN
Microbial dynamics on commercially grown white button mushrooms is of importance in terms of food safety assurance and quality control. The purpose of this study was to establish the microbial profile of fresh white button mushrooms. The total microbial load was determined through standard viable counts. Presence and isolation of Gram-negative bacteria including coagulase-positive Staphylococci were performed using a selective enrichment approach. Dominant and presumptive organisms were confirmed using molecular methods. Total mushroom microbial counts ranged from 5·2 to 12·4 log CFU per g, with the genus Pseudomonas being most frequently isolated (45·37% of all isolations). In total, 91 different microbial species were isolated and identified using Matrix-assisted laser desorption ionization-time of flight mass spectrophotometry, PCR and sequencing. Considering current food safety guidelines in South Africa for ready-to-eat fresh produce, coliform counts exceeded the guidance specifications for fresh fruit and vegetables. Based on our research and similar studies, it is proposed that specifications for microbial loads on fresh, healthy mushrooms reflect a more natural microbiome at the point-of-harvest and point-of-sale. SIGNIFICANCE AND IMPACT OF THE STUDY: Presence and persistence of micro-organisms within the microbiome of fresh produce is important when identifying a potential niche for foodborne pathogens. Most foodborne outbreaks can be attributed to microbial imbalances or lack of diversity within the associated host surface and residing microbial population. Agaricus bisporus samples analysed during this study showed a higher microbial load (5·2 up to 12·4 log CFU per g) compared to known values for other fresh produce. These mushrooms were considered to carry microbial loads representing a healthy and safe product, fit for consumption, despite showing a high indicator incidence. Although foodborne pathogens may be associated on occasion with fresh mushrooms, it remains a low-risk commodity; therefore, this study provides insight and experimental evidence identifying microbial population dynamics of fresh and packed mushrooms.
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Agaricus , Microbiología de Alimentos , Inocuidad de los Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Microbiota , Pseudomonas/aislamiento & purificación , Carga Bacteriana , Frutas/microbiología , Sudáfrica , Verduras/microbiologíaRESUMEN
Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced here. Citation: Crous PW, Sandoval-Denis M, Costa MM, Groenewald JZ, van Iperen AL, Starink-Willemse M, Hernández-Restrepo M, Kandemir H, Ulaszewski B, de Boer W, Abdel-Azeem AM, Abdollahzadeh J, Akulov A, Bakhshi M, Bezerra JDP, Bhunjun CS, Câmara MPS, Chaverri P, Vieira WAS, Decock CA, Gaya E, Gené J, Guarro J, Gramaje D, Grube M, Gupta VK, Guarnaccia V, Hill R, Hirooka Y, Hyde KD, Jayawardena RS, Jeewon R, Jurjevic Z, Korsten L, Lamprecht SC, Lombard L, Maharachchikumbura SSN, Polizzi G, Rajeshkumar KC, Salgado-Salazar C, Shang Q-J, Shivas RG, Summerbell RC, Sun GY, Swart WJ, Tan YP, Vizzini A, Xia JW, Zare R, González CD, Iturriaga T, Savary O, Coton M, Coton E, Jany J-L, Liu C, Zeng Z-Q, Zhuang W-Y, Yu Z-H, Thines M (2022). Fusarium and allied fusarioid taxa (FUSA). 1. Fungal Systematics and Evolution 9: 161-200. doi: 10.3114/fuse.2022.09.08.
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BACKGROUND: Radical cystectomy with pelvic lymph node dissection is the recommended treatment in non-metastatic muscle-invasive bladder cancer (MIBC). In randomised trials, robot-assisted radical cystectomy (RARC) showed non-inferior short-term oncological outcomes compared with open radical cystectomy (ORC). Data on intermediate and long-term oncological outcomes of RARC are limited. OBJECTIVE: To assess the intermediate-term overall survival (OS) and recurrence-free survival (RFS) of patients with MIBC and high-risk non-MIBC (NMIBC) who underwent ORC versus RARC in clinical practice. METHODS AND MATERIALS: A nationwide retrospective study in 19 Dutch hospitals including patients with MIBC and high-risk NMIBC treated by ORC (nâ¯=â¯1086) or RARC (nâ¯=â¯386) between January 1, 2012 and December 31, 2015. Primary and secondary outcome measures were median OS and RFS, respectively. Survival outcomes were estimated using Kaplan-Meier curves. A multivariable Cox regression model was developed to adjust for possible confounders and to assess prognostic factors for survival including clinical variables, clinical and pathological disease stage, neoadjuvant therapy and surgical margin status. RESULTS: The median follow-up was 5.1 years (95% confidence interval ([95%CI] 5.0-5.2). The median OS after ORC was 5.0 years (95%CI 4.3-5.6) versus 5.8 years after RARC (95%CI 5.1-6.5). The median RFS was 3.8 years (95%CI 3.1-4.5) after ORC versus 5.0 years after RARC (95%CI 3.9-6.0). After multivariable adjustment, the hazard ratio for OS was 1.00 (95%CI 0.84-1.20) and for RFS 1.08 (95%CI 0.91-1.27) of ORC versus RARC. Patients who underwent ORC were older, had higher preoperative serum creatinine levels and more advanced clinical and pathological disease stage. CONCLUSION: ORC and RARC resulted in similar intermediate-term OS and RFS in a cohort of almost 1500 MIBC and high-risk NMIBC.
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Cistectomía/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Robótica/métodos , Neoplasias de la Vejiga Urinaria/cirugía , Anciano , Femenino , Humanos , Masculino , Países Bajos , Estudios Retrospectivos , Análisis de Supervivencia , Neoplasias de la Vejiga Urinaria/mortalidad , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
AIMS: A Bacillus amyloliquefaciens strain, surviving epiphytically on the surface of fruit, was isolated while searching for naturally occurring biological control agents. This bacterial strain was characterized for its antifungal activity against seven selected fungal postharvest pathogens of citrus. METHODS AND RESULTS: To understand the antifungal activity, seven postharvest fungal pathogens were screened for growth inhibition by B. amyloliquefaciens strain. Assays using B. amyloliquefaciens lipopeptide extracts showed a strong inhibitive activity. The inhibitory effect was observed in abnormal conidial germination and germ tube development when conidia were treated with different lipopeptide extract concentrations. Further analysis using PCR and chromatography confirmed the presence of fengycin, iturin and surfactine, of which iturin A showed the strongest and most common inhibitory effect. The results are supported by site-directed mutagenesis analysis, targeted to suppress the biosynthesis of iturin A production. Fruit trials confirmed disease development inhibition when the antagonist was applied 1 day prior to or 1 day after fungal application. CONCLUSIONS: We conclude that the iturin family of lipopeptides are vital in the antagonism of B. amyloliquefaciens against the seven citrus postharvest pathogenic fungi tested. SIGNIFICANCE AND IMPACT OF THE STUDY: We elucidated the principal mechanism used by B. amyloliquefaciens PPCB004 to suppress postharvest disease development on stored fruits.
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Antibiosis , Antifúngicos/farmacología , Bacillus/química , Hongos Mitospóricos/efectos de los fármacos , Péptidos Cíclicos/farmacología , Antifúngicos/aislamiento & purificación , Bacillus/genética , Bacillus/aislamiento & purificación , Citrus/microbiología , Frutas/microbiología , Germinación/efectos de los fármacos , Lipopéptidos/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Mutagénesis Sitio-Dirigida , Péptidos Cíclicos/aislamiento & purificación , Enfermedades de las Plantas/prevención & control , Reacción en Cadena de la Polimerasa/métodos , Esporas Fúngicas/efectos de los fármacosRESUMEN
Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by 'Candidatus Liberibacter africanus', a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, 'Ca. L. asiaticus'. A 'Ca. L. africanus' subspecies, 'Ca. L. africanus subsp. capensis', has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, 'Ca. L. americanus', and the spread of 'Ca. L. asiaticus' to a number of additional countries over the last few years prompted us to assess whether only 'Ca. L. africanus' is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of 'Ca. L. americanus' infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate 'Ca. L. africanus' Nelspruit sequence in GenBank. No instance of 'Ca. L. asiaticus' or 'Ca. L. africanus subsp. capensis' sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only 'Ca. L. africanus' is associated with citrus greening in commercial citrus in South Africa.
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If South African citrus exporters wish to retain their competitive edge in the European market and access new markets such as the United States of America, it is of quarantine importance to distinguish between the citrus black spot pathogen, Guignardia citricarpa, and the harmless endophyte, G. mangiferae. The endophyte is not a sanitary or phytosanitary concern. This paper describes the design of species-specific primers that are able to detect and distinguish between these two Guignardia species. Application of the primer set CITRIC1 and CAMEL2 in conjunction with the ITS4 primer yielded polymerase chain reaction (PCR) amplicons of approximately 580 bp and 430 bp for G. citricarpa and G. mangiferae, respectively. Results obtained with these primers are in accordance with sequence data, and repeated tests verified accuracy and sensitivity. A BLAST search revealed no matches other than G. citricarpa and G. mangiferae, and no positive PCR results were obtained with Colletotrichum gloeosporioides, which is the most common contaminant in black spot lesions. We are, therefore, able to distinguish G. citricarpa and G. mangiferae unequivocally using a PCR-based method. This method was further improved to directly isolate DNA from fruit lesions by means of the DNeasy Plant Mini Kit (Qiagen). This eliminates the prior need for culturing the slow-growing organism, thereby shortening the time required to one day to test for and verify the presence or absence of the pathogenic G. citricarpa in export consignments.
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Six years of pesticide residue data from fresh produce destined for the export market were analyzed for the period 2009 to 2014. A total of 37,838 fruit (99.27%) and vegetable (0.73%) data sets analyzed for the presence of 73 pesticides were compared. Pesticides were detected on 56.46% of samples, of which 0.78% had multiple residues. Noncompliances detected were because of the use of unregistered pesticides (0.73%), values that exceeded established maximum residue levels (MRLs) (0.32%), or the combination of values that exceeded MRLs and the use of unregistered pesticide residues (0.003%). The most commonly detected pesticides that exceeded established MRLs were imazalil (37.71%), prochloraz (28.69%), and iprodione (5.74%). The unregistered pesticide most often found on grapes and avocados was also imazalil (62.23%) and, on nectarines and avocados, diphenylamine (11.15%). Exceedances of MRL values were mostly associated with oranges (43.44%), avocados (27.87%), grapefruits (7.38%), and lemons (6.56%). Residual pesticide monitoring on fruits and vegetables is a key tool to ensure conformity with regulatory requirements and compliance with good agricultural practices and the trade requirements set by the importing country.
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Residuos de Plaguicidas , Verduras/química , Aminoimidazol Carboxamida/análogos & derivados , Contaminación de Alimentos , Frutas/química , Hidantoínas , PlaguicidasRESUMEN
Bacteria, filamentous fungi, and yeasts were enumerated on the mango phylloplane by indirect leaf impression and washing- and dilution plating. The phylloplane microbial community was qualitatively and quantitatively related to leaf age, position in the tree canopy, seasonality, and chemical spraying. Filamentous fungi and yeasts were more abundant during winter and spring, whereas bacterial population densities increased during autumn. Community density and diversity increased progressively with leaf age. The western tree aspect sustained the least diverse bacterial, filamentous fungal, and yeast communities. Chemical sprays reduced bacterial, filamentous fungal, and yeast community diversities. Gram-positive bacteria (Bacillus spp. and coryneform spp.) exceeded gram-negative bacteria. The most common fungal genera isolated were Cladosporium and Alternaria. Yeasts prevalent in the mango phylloplane were of the genera Aureobasidium, Cryptococcus, and Sporobolomyces.
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Natural products are becoming more important in modern-day society as man is moving away from synthetic products, which can be detrimental to the environment and human health. Scientific research on the healing properties and bioactivity of natural compounds, especially of plant origin, has been extensive particularly in the Western world. However, a rich heritage of floral biodiversity is found in developing countries. South Africa, a country with a strong history of traditional healing, hosts a variety of around 30000 plant species. Indigenous bulbous plants of importance to South African traditional healers mainly belong to the Amaryllidaceae and Hyacinthaceae families. A number of these plants have particular uses as disinfectants and anti-inflammatory agents, although there is still a lack of scientific research regarding their unique pharmacological compounds.
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Enfermedades Transmisibles/tratamiento farmacológico , Medicinas Tradicionales Africanas , Plantas Medicinales , Humanos , Liliaceae , Estructuras de las Plantas , Sudáfrica/etnologíaRESUMEN
Three hundred and eighteen Colletotrichum gloeosporioides isolates from stem-end rot and anthracnose infected avocados as well as from stem-end rot/anthracnose and soft brown rot on mango, were compared using fruit inoculations. Isolates could be categorised according to lesion size and both avocado and mango isolates produced larger lesions when inoculated on their own hosts. Cross-inoculation potential of these isolates was also compared on strawberries, peppers, guavas, papayas and citrus. All isolates produced lesions on all hosts except citrus. Factors such as area of origin and symptom type from which original isolations were made, could not be correlated with lesion development on these hosts.
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Colletotrichum/fisiología , Frutas/microbiología , Mangifera/microbiología , Persea/microbiología , Enfermedades de las Plantas/microbiología , Capsicum/microbiología , Carica/microbiología , Citrus/microbiología , Colletotrichum/genética , Colletotrichum/crecimiento & desarrollo , Colletotrichum/aislamiento & purificación , ADN de Hongos/análisis , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Fragaria/microbiología , Reacción en Cadena de la Polimerasa , Psidium/microbiología , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
In 3 consecutive years, preharvest applications of Bacillus subtilis field sprays integrated with copper oxychloride or benomyl consistently reduced severity of avocado black spot (BS), caused by Pseudocercospora purpurea at Omega, Republic of South Africa. Control was equal to that obtained with copper oxychloride or benomyl-copper oxychloride in the first and third years of spraying at Omega. In the second year, only the integrated treatment controlled BS, while copper oxychloride proved ineffective. The antagonist was applied on its own or integrated with copper oxychloride sprays at two other geographically distinct locations, Westfalia Estate and Waterval. The integrated and biological treatments at these localities were less effective than copper oxychloride sprays in controlling BS disease. Integrated control was more effective than B. subtilis sprays at Westfalia. On continuation of the biological spray program at Waterval for an additional three seasons, control was as effective as copper oxychloride in the last 2 years of spraying. Sooty blotch (SB), caused by an Akaropeltopsis sp., was reduced by the integrated treatment at Omega during the second season and at Westfalia during the first season. Although the two fungicide treatments reduced SB at Omega in the first season, copper oxychloride increased it above that of the control in the third season. Only the copper oxychloride treatment reduced SB at Waterval in the third season, while the B. subtilis treatment increased disease above that of the control in the fourth season.
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Synopsis Two studies were conducted to determine the predominant micro-organisms found in spoiled cosmetic creams manufactured in South Africa. The products evaluated included facial creams and hand and body lotions. Spoiled cosmetic creams were obtained from different manufacturers and analysed microbiologically for the presence of bacteria, yeasts and moulds. The frequency and relative density (percentage) of micro-organisms isolated from naturally spoiled creams were calculated. Pseudomonas aeruginosa and Enterobacter gergoviae were the most predominant bacteria, whilst Candida parapsilosis and Aspergillus flavus were the most predominant yeast and mould, respectively. Of all the samples examined, approximately two-thirds (69%) were due to microbial spoilage. This study highlighted the importance of adopting suitable quality control guidelines for the local cosmetics industry, similar to those currently used by international cosmetics manufacturers.
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Four Xanthomonas campestris pv. mangiferaeindicae isolates from mango black spot lesions were grouped according to differences in virulence and used to raise monoclonal antibodies (mAbs). Two immunization approaches were followed. In the first, four groups of mice were immunized, each with a different isolate and the spleens from each group homogenized together for cell fusion. The second approach entailed immunization of a single group of mice with bacteria pooled from all four isolates. The resultant mAbs were characterized with regard to the antigen binding specificity and antibody class. A relationship between mAb binding specificity and virulence of the bacteria was shown by Western blot analysis.