George Botsaris

Pipe Scales and Biofilms in Drinking-Water Distribution Systems: Undermining Finished Water Quality

Safety and security are two important features of urban drinking-water distribution systems (UDWDS), worldwide, that are often compromised by a suite of physical, hydraulic, and chemical factors adversely impacting quality of potable water reaching consumer taps. Growth of scales and biofilm conglomerates (SBC) coupled with sorption of water chemicals and planktonic microorganisms by SBC has been increasingly recognized as underestimated contaminant sources in aging pipe networks of UDWDS. The main objective of this study was to provide an updated review of factors and processes associated with the increasing frequency of deteriorated finished water quality incidences as a result of SBC effects in UDWDS. This critical review integrated scattered knowledge on the effects of either pipe scales or pipe-anchored biofilm systems on contaminant destabilization and subsequent release into water. It was emphasized that little information exists on combined or concomitantly studied effects of SBC on finished water quality. Important synergistic SBC effects on finished water quality were identified as: (i) those promoting chemical release from pipe scales due to biofilm-induced alterations at the pipe surface/water interface, (ii) the synergistic SBC action on promoting increased release rates of pathogens or toxic chemicals into water, and (iii) the microbially enhanced corrosive phenomena on pipe scales and their constituents. Substantial room for improvement is anticipated for the water and global health research agenda by formulating innovative hypotheses and research designs that water authorities could benefit from as they strive towards further securing access to safe water in urban settings.

Detection of Mycobacterium avium subsp. paratuberculosis in bulk tank milk by combined phage-PCR assay: Evidence that plaque number is a good predictor of MAP

Conventional culture and a rapid phage-PCR method were used to detect Mycobacterium avium subsp. paratuberculosis (MAP) in bulk tank milk (BTM) samples. Only two of 225 samples (0.9%) were found to contain MAP by culture whereas 50 (22%) MAP-positive samples were identified using the phage-PCR assay, including both samples that were MAP-culture positive. Results using the phage-based method for independently tested duplicate samples indicated that the assay is very reproducible (r(2)=0.897), especially when low levels of mycobacteria are present. A relationship was established between plaque number and the presence of MAP in a sample. A cut-off value was determined allowing identification of MAP-positive samples based on plaque number alone (90% sensitivity, 99% specificity; area under the curve=0.976). These results indicate that the assay is a robust method for screening BTM, providing results within 24 h.

Detection of viable Mycobacterium avium subspecies paratuberculosis in powdered infant formula by phage-PCR and confirmed by culture

Surveys from different parts of the world have reported that viable Mycobacterium avium subsp. paratuberculosis (MAP) can be cultured from approximately 2% of samples of retail pasteurised milk samples. Pasteurised milk is used for the production of powdered infant formula (PIF) and therefore there is a concern that MAP may also be present in these products. Several studies have previously reported the detection of MAP in PIF using PCR-based assays. However, culture-based surveys of PIF have not detected viable MAP. Here we describe a phage amplification assay coupled with PCR (page-PCR) that can rapidly detect viable MAP in PIF. The results of a small survey showed that the phage-PCR assay detected viable MAP in 13% (4/32) of PIF samples. Culture detected viable MAP in 9% (3/32) PIF samples, all of which were also phage-PCR positive. Direct IS900 PCR detected MAP DNA in 22% (7/32) of PIF samples. The presence of viable MAP in PIF indicates that MAP either survived PIF manufacturing or that post-production contamination occurred. Irrespective of the route of MAP contamination, the presence of viable MAP in PIF is a potential public health concern.

Adherence to the Mediterranean Diet and Lifestyle Characteristics of University Students in Cyprus: A Cross-Sectional Survey

Objective. To assess dietary-related habits among young adults. Design and Setting. Dietary habits were assessed cross-sectionally, using a self-completed questionnaire in 193 students enrolled in public and private universities in Cyprus. Adherence to the Mediterranean diet was evaluated using the validated KIDMED index. BMI was estimated based on weight and height measurements. Results. The mean BMI was 23.31 (±3.98). The mean adherence score to the Mediterranean diet was 6.0 (IQR 4 to 8), with 26.9% of students being classified as high adherers and 21.8% as low adherers to the Mediterranean diet. About 32% of students consumed a second serving of fruit and vegetables more than once a day, whereas 26% reported going more than once a week to a fast-food restaurant and 31% consumed sweets and candy several times a day. On the other hand, 76% of participants reported consumption of at least two dairy products daily and 88% use olive oil at home. The majority consume coffee 2-3 times per day. Conclusions. Results support a shift from traditional healthy diets to more unhealthy eating patterns. However, we also report a high dairy intake and use of olive oil. Tailored-made strategies targeting the young adult population could be warranted.

The Use of Phage for Detection, Antibiotic Sensitivity Testing and Enumeration

Bacteriophage are bacterial viruses which may attack and destroy bacterial cells. While many have a narrow host range and are used in sub-typing techniques, some infect many members of a genus or species and these have been used to develop rapid detection methods for a variety of bacterial pathogens (Rees and Loessner, 2008). The use of bacteriophage (or phage) in assays for detecting bacteria was first reported over half a century ago when an assay to detect Salmonella using phage Felix 01 was described by Cherry et al. (1954). Since then other bacteriophage-based detection methods have been developed that take advantage of the specificity of the host-phage interaction and its ability, once inside the host, to replicate rapidly. This is particularly useful when studying slowgrowing organisms such as Mycobacterium tuberculosis and other slow growing mycobacteria such as Mycobacterium avium subsp. paratuberculosis (see Stanley et al., 2007; Grant & Rees, 2009, Botsaris et al., 2010). This chapter will provide an introduction to phage biology and will then describe the different phage-based detection methods that have been described for M. tuberculosis – including one that has been developed into a commercial product. In addition adaptations of the phage test are described that allow the antibiotic sensitivity of isolates to be rapidly determined, and also how a further modification can be used to allow rapid estimation of viable cell number. However, all these indirect methods have their limitations and these too will be discussed in each case.

Evidence of arsenic release promoted by disinfection by-products within drinking-water distribution systems

Changes in disinfectant type could trigger a cascade of reactions releasing pipe-anchored metals/metalloids into finished water. However, the effect of pre-formed disinfection by-products on the release of sorbed contaminants (arsenic-As in particular) from drinking water distribution system pipe scales remains unexplored. A bench-scale study using a factorial experimental design was performed to evaluate the independent and interaction effects of trihalomethanes (TTHM) and haloacetic acids (HAA) on arsenic (As) release from either scales-only or scale-biofilm conglomerates (SBC) both anchored on asbestos/cement pipe coupons. A model biofilm (Pseudomonas aeruginosa) was allowed to grow on select pipe coupons prior experimentation. Either TTHM or HAA individual dosing did not promote As release from either scales only or SBC, detecting <6 μg AsL(-1) in finished water. In the case of scales-only coupons, the combination of the highest spike level of TTHM and HAA significantly (p<0.001) increased dissolved and total As concentrations to levels up to 16 and 95 μg L(-1), respectively. Similar treatments in the presence of biofilm (SBC) resulted in significant (p<0.001) increase in dissolved and total recoverable As up to 20 and 47 μg L(-1), respectively, exceeding the regulatory As limit. Whether or not, our laboratory-based results truly represent mechanisms operating in disinfected finished water in pipe networks remains to be investigated in the field.

Health-Promoting Effects of Pistacia Resins: Recent Advances, Challenges, and Potential Applications in the Food Industry

Pistacia resins are a complex mixture comprising of different bioactive compounds, with the presence of triterpenes and essential oils being characteristic for these resins. Since ancient times, Pistacia resins have been used in traditional medicine of Mediterranean and Middle Eastern countries as herbal remedies. There is accumulating evidence that suggests that Pistacia resins may contribute to the reduction of many chronic diseases, such as gastrointestinal disorders, cardiovascular diseases, and some forms of cancer, while in parallel promoting oral health and other physiological functions such as antimicrobial and antioxidant activities. This review aims at presenting and critically reviewing the health effects from the consumption of Pistacia resins whilst revealing future challenges and potential applications in the food industry.

Adherence to the Mediterranean diet and lifestyle characteristics of university students in Cyprus: A cross-sectional survey

Objective. To assess dietary-related habits among young adults. Design and Setting. Dietary habits were assessed cross-sectionally, using a self-completed questionnaire in 193 students enrolled in public and private universities in Cyprus. Adherence to the Mediterranean diet was evaluated using the validated KIDMED index. BMI was estimated based on weight and height measurements. Results. The mean BMI was 23.31 (±3.98). The mean adherence score to the Mediterranean diet was 6.0 (IQR 4 to 8), with 26.9% of students being classified as high adherers and 21.8% as low adherers to the Mediterranean diet. About 32% of students consumed a second serving of fruit and vegetables more than once a day, whereas 26% reported going more than once a week to a fast-food restaurant and 31% consumed sweets and candy several times a day. On the other hand, 76% of participants reported consumption of at least two dairy products daily and 88% use olive oil at home.Themajority consume coffee 2-3 times per day. Conclusions. Results support a shift from traditional healthy diets to more unhealthy eating patterns. However, we also report a high dairy intake and use of olive oil. Tailored-made strategies targeting the young adult population could be warranted.

Bacteriophage-Based Techniques for Detection of Foodborne Pathogens

This article is a revision of the previous edition article by Richard J. Mole, Vinod K. Dhir, Stephen P. Denyer, Gordon S.A.B. Stewart (dec), volume 1, pp 203–210,

Mapping drinking water and quality of life aspects in urban settings: an application of the urban exposome

Cities face rapid changes leading to increasing inequalities and emerging public health issues that require cost-effective interventions. The urban exposome framework constitutes a novel approach in tackling city-wide challenges, such as those of drinking water quality and quality of life. In this proof-of-concept study, we presented part of the urban exposome of Limassol (Cyprus) focusing on chemical and microbial drinking water quality parameters and their association with urban neighborhood indicators. A perceptions study and an urban population study was conducted. We mapped the water quality parameters and participants’ opinions on city life (i.e. neighborhood life, health care and green space access) using quarters (small administrative areas) as the reference unit of the city. In an exploratory environment-wide association study analysis, we used all variables (questionnaire responses and water quality metrics) to describe correlations between them accounting, also, for self-reported health status. Overall, urban drinking-water quality using conventional indicators of chemical (disinfection byproducts-trihalomethanes) and microbial (coliforms, E. coli, and Enterococci) quality did not raise particular concerns. The general health and chronic health status of the urban participants were significantly (all >FDR corrected p value of 0.1) associated with different health conditions such as hypertension and asthma, or having financial issues in access to dental care. Additionally, correlations between trihalomethanes and participant characteristics (e.g. household cleaning, drinking water habits) were documented. This proof-of-concept study showed the potential of using integrative approaches to develop urban exposomic profiles and identifying within-city differentiated environmental and health indicators. The characterization of the urban exposome of Limassol will be expanded via the inclusion of biomonitoring tools and untargeted metabolomics platforms.