A scoping study on the prevalence of Escherichia coli and Enterococcus species in harvested rainwater stored in tanks

Rainwater harvesting (RWH) is a relatively inexpensive technology that has the potential to provide safe water in communities where conventional technologies are difficult to implement. In this study, the microbiological quality of rainwater harvested from rooftops and ground-surface runoff was evaluated based on the concentrations of Escherichia coli, total coliforms and enterococci. Samples were collected from 15 roof-harvested rainwater (RHRW) tanks, 4 ground-surface runoff rainwater harvesting (GRWH) tanks, 3 rivers and 1 spring water source in the Eastern Cape Province of South Africa, and 14 RHRW tanks in Gauteng Province. In the Eastern Cape Province E. coli and enterococci were detected in 7 and 4 of the 15 RHRW tanks, respectively. Enterococci were detected only from one river whereas E. coli was detected in all three rivers; in spring water neither enterococci nor E. coli were detected. Samples from GRWH tanks were positive for E. coli and enterococci in 2 and 3 of the 4 tanks, respectively. In Gauteng Province, E. coli, coliforms and enterococci were detected from 6, 6 and 9 of the 14 rainwater tanks, respectively. On average, E. coli and enterococci were detected in 44.8% of the RHRW tanks, although enterococci concentrations were several times higher than those for E. coli. We further evaluated the significance of urban pigeons as the likely sources of contamination by isolating 156 enterococci from 30 pigeon faecal samples and 208 enterococci from RHRW samples collected from Gauteng Province. Matrix-assisted laser desorption ionisation identification of the various enterococci revealed 4 species – E. faecalis (20.5%), E. mundtii (20.51%), E. faecium (23.1%) and E. casseliflavus (17.3%) – to be dominant in faecal samples, whereas E. casseliflavus (34.6%) and E. mundtii (33.2%) were dominant in RHRW.Keywords: rainwater harvesting, contamination, indicator bacteria, health risk

Private Standards, Handling and Hygiene in Fruit Export Supply Chains: A Preliminary Evaluation of the Economic Impact of Parallel Standards

With the emergence of private food safety and quality standards in developed countries fruit exporting countries in the developing world face increasing constraints to access markets in the rich industrialised countries in the North. Producers in the South have no alternative as to make the necessary investments on farms and in pack houses to comply with the requirements of these food quality and safety standards. The export of fresh fruit is an important component of South African agricultural exports, with citrus fruit exported to markets such as Europe being of particular importance. This paper reports selected results from a large research project into the impact of private standard compliance on the quality of the fruit and the returns to farmers. The research process involved a multi-disciplinary analysis of Agricultural Economics and Microbiology / Plant pathology as we analysed the dynamics of the citrus export supply chain from the farms in South Africa to the end consumer in Europe. Sampled fruit containers were followed through the whole supply chain which allowed us to provide an exposé of the behaviour of the different actors in the citrus supply chain and obtain some evidence of poor handling and hygiene standards by means of a comparison of the experimental observations with various relevant components of the EurepGAP control points and compliance criteria for fruit and vegetables. Observations suggest that these standards are adequately applied to the production and handling of fruit at the farm and pack house levels while on the other hand the subsequent stages (mainly after the importing harbour in Europe) of the fruit supply chain are seemingly not subjected to the same strict requirements laid out for producers, leading to fruit quality deterioration and financial losses for producers. This constitutes clear parallel standards in terms of fruit safety and quality standards between upstream and downstream sections of the supply chain and questions thus the purpose of the standards and the financial return for producers making large investments to comply with these privately introduced standards.International Relations/Trade,

ELISA OPTIMISATION FOR MONITORING BACILLUS SUBTILIS IN PREHARVEST BIOCONTROL PROGRAMMES

Abstract Enzyme linked immunosorbent assay (ELISA) was optimised for more effective monitoring of Bacillus subtilis in avocado field spray programmes using natural antagonists. Parameters of the ELISA that were optimised included, incubation temperature and -time, fixatives, blocking buffers, washing buffers, antibody incubation time, conjugate concentration, conjugate incubation time and enzyme-substrate reaction time. Incubation conditions of 4ºC for 24 h gave the highest signal/background value, the baking method was found more applicable due to its 3 months storage potential without loss of ELISA signals. Bovine serum albumin gave the highest signals when used as a blocking solution. When comparing the optimised ELISA protocol with the one used previously, a higher signal/ background value were obtained with the former ELISA

Global collection of mushroom pathogens

In many places in the world, increasingly less chemical crop protection agents are available for use in mushroom cultivation. As a consequence, mushroom cultivation will loose the ability to use crop protection agents. As a consequence, good hygiene management, early detection and monitoring of pathogens (diagnostics), alternative crop protection agents and disease resistant mushroom varieties have to play an important role. The number of researchers in several mushroom producing countries is decreasing already for a number of years. For an effective use of research funds, international collaboration on topics of mutual interest is important. At the workshop of the Global Mushroom Disease Diagnostic Initiative, held in 2008 just before the ISMS conference in Cape Town, it was decided to try and build a collection of reference pathogen strains for the white button mushroom diseases present world wide. This collection will play a vital role in the development of diagnostic methods for mushroom diseases. This project was funded in part by the ISMS and in part by the Dutch Horticultural Board

Inability to Ventilate after Tube Exchange Postoperative to Pneumonectomy

We report a case of inability to ventilate a patient after completion of pneumonectomy, due to migrated tumor tissue to the contralateral side. This represents an unusual complication with a high mortality rate. We have managed to find the cause in time and were able to remove the obstructive tissue using bronchoscopy

Profiling bacterial communities of irrigation water and leafy green vegetables produced by small‑scale farms and sold in informal settlements in South Africa

Morogo is an African indigenous term used for leafy green vegetables harvested in the wild or cultivated in small-scale farms and consumed by the local populations of the region. Small-scale farmers have gained recognition as important suppliers of morogo to informal settlements. In commercial production systems, leafy green vegetables have increasingly been reported as associated with foodborne pathogens and disease outbreaks. Little is known of the presence of these organisms on leafy green vegetables in the informal unregulated food systems. This study aimed to profile bacterial communities in irrigation water (flooding and overhead irrigation water) and leafy green vegetables (Brassica rapa L. chinensis and Brassica rapa varieties of morogo) to establish the natural bacterial flora at the water-fresh produce interface from five small-scale farms in two provinces in South Africa. Illumina MiSeq high-throughput sequencing showed that each farm exhibited a unique bacterial community composition, with an overall high relative abundance of Proteobacteria, Firmicutes and Actinobacteria, including prominent families such as Burkholderiaceae (48%), Enterobacteriaceae (34%), Bacillales Family XII (8%), Rhodobacteraceae (3%), Micrococcaceae (1.98%) and Pseudomonadaceae (1.79%). Specific Enterobacteriaceae Serratia, Enterobacter, Salmonella, Shigella, Escherichia coli, Buchnera, Citrobacter, Klebsiella and Proteus were identified, in addition to unique communities associated with plant or irrigation water source. These findings suggest that the edible plant microbiome can play an important role as transient contributor to the human gut and has the potential to affect overall health

Imazalil resistance in Penicillium digitatum and P. italicum causing citrus postharvest green and blue mould : impact and options

Citrus green and blue mould, caused by Penicillium digitatum (PD) and Penicillium italicum (PI), respectively, are mostly controlled by means of postharvest fungicide applications. Currently, IMZ is regarded as the most effective fungicide in use. Effective IMZ concentrations that inhibit 50% (EC50) growth of nine PD and five PI isolates were assessed in vitro and the various isolates categorized according to their resistance (R) factors. Effective residue levels that provided 50% curative (ER50C) and protective (ER50P) control of these isolates were determined in vivo. All the PI isolates were sensitive, having EC50 values of 0.005–0.050 mg mL 1. Three PD isolates were sensitive (0.027–0.038 mg mL 1), while one resistant isolate was categorized as low resistant (R-factor of 19), one as moderately resistant (R-factor of 33.2), three as resistant (R-factor of 50–57.6) and one as highly resistant (R-factor of 70.7). Sensitive PD isolates had mean ER50C and ER50P values on Valencia orange fruit of 0.29 and 0.20 mg g 1, and 0.33 and 0.32 mg g 1 on navel fruit, respectively. ER50 values for resistant isolates did not always correlate with EC50 values and ranged from 1.22 to 4.56 mg g 1 for ER50C and 1.00–6.62 mg g 1 for ER50P values. ER50P values for resistant isolates could not be obtained on navel orange fruit, but ER50C values (1.42– 1.65 mg g 1) were similar to those obtained on Valencia fruit. The PI isolates all behaved similar to the sensitive PD isolates with ER50C and ER50P values on navel and Valencia fruit <0.38 mg g 1. Alternative fungicides were assessed for the control of an IMZ sensitive, resistant and highly resistant PD isolate; these included sodium ortho-phenylpenate (SOPP), thiabendazole (TBZ), guazatine (GZT), imazalil (IMZ), pyrimethanil (PYR) and Philabuster1 (PLB; a combination of IMZ and PYR), fludioxonil (FLU), azoxystrobin (AZO), Graduate1A+ (GRA; a combination of FLU and AZO) and propiconazole (PPZ). Multiple fungicide resistance was shown to IMZ, GZT, TBZ and PPZ in both resistant isolates. For the sensitive isolates, IMZ, SOPP, TBZ, GZT and PLB provided best curative control, while IMZ, GZT and PLB provided best protective control. For the IMZ-resistant isolates, SOPP, PYR and PLB gave the best curative control, while none of the fungicides provided adequate protective control.Citrus Research International, Citrus Academy, Postharvest Innovation Fund (PHI) and Technology and Human Resources for Industry Programme (THRIP).http://www.elsevier.com/locate/postharvbio2016-09-30hb201

Defining asthma in children: how well do parents, doctors and spirometry agree?

Background: Because diagnosing asthma in school-aged children is challenging, a variety of proxies for asthma are used in clinical practice and research settings as indicators of this disease. We aimed to provide insight into the agreement between various asthma indicators based on parental report, medical diagnosis and spirometry. Methods: Children from the WHISTLER birth cohort performed spirometry and were followed up with parental ISAAC (International Study of Asthma and Allergies in Childhood) questionnaires about asthma at 5 and 8 years of age. Medical data were extracted from primary care records. We compared 15 asthma indicators based on parental report, medical diagnosis and spirometry using positive agreement, κ statistics and latent class cluster analysis. Results: At 5 years of age, 1007 children completed a study visit, while 803 children visited at 8 years of age. Depending on the indicator, the responder and child's age, the asthma prevalence ranged from 0.2% to 26.6%. Cluster analysis revealed classes related to the presence of recent symptoms and a decreased lung function. Agreement between parents and doctors was generally low with κ coefficients ranging from 0.07 (recent wheeze) to 0.52 (recent asthma medication). Additionally, parental report showed to be sensitive to recall bias over time. Conclusions: Dependent on the asthma indicator, the responder and the age of the child, substantial differences in agreement were observed between commonly used indicators associated with asthmatic disease in school-aged children. Most agreement between parents and doctors was seen for objective and recent indicators such as the recent use of asthma medication. We advocate caution when literature with different asthma indicators is compared