Water In Tunisia Research Articles

Phylogenetic analysis and assessment of the pathogenic potential of the first H9N2 avian influenza viruses isolated from wild birds and Lagoon water in Tunisia

H9N2 avian influenza virus (AIV) has been isolated from various species of wild birds and domestic poultry worldwide. It has been reported since the late 1990s, that H9N2 AIV has infected humans as reported in some Asian and North African countries. This subtype has already been circulating and constituting a serious threat to the poultry industry in Tunisia back in 2009. To investigate zoonotic potential and pathogenicity of H9N2 AIV in chickens and mice in Tunisia, five strains have been isolated during the period from 2014 to 2018. Samples were withdrawn from several wild bird species and environment (Lagoon water) of Maamoura and Korba Lagoons as well as Kuriat Island. Phylogenetic analyzes demonstrated that the isolated H9N2 strains belonged to the G1-like sublineage and were close to AIV H9N2 poultry viruses from North Africa, West Africa and the Middle East. All strains carried in their hemagglutinin the residue 226 L, which is an important marker for avian-to-human viral transmission. The hemagglutinin cleavage site has several motifs: PSKSSR/G, PARSSR/G and HARSSR/G. The neuraminidase showed S372A and R403W substitutions that have been previously detected in H3N2 and H2N2 viruses that were reported in human pandemics. Many mutations associated with mammalian infections have been detected in internal proteins. Pathogenicity evaluation in chickens showed that GF/14 replicates effectively in the lungs, tracheas, spleens, kidneys and brains and that it was transmitted among contact chickens. However, GHG/18 replicates poorly in chickens and has not an efficient transmission in contact chickens. GF/14 and GHG/18 could not kill mice though they replicated in their respiratory tract and caused a significant body weight loss (p < 0.05). This study highlights the importance of H9N2 AIV monitoring in both migratory birds and the environment to prevent virus transmission to humans.

Organochlorine pesticide residues in agricultural draining water in Tunisia

Organochlorines pesticides (OCPs) are persistent organic pollutants known by their persistence, their ability to bioaccumulate in the food chain and by their toxicity. This work aims to analyze pesticides in draining water samples taken from two different regions from Tunisia. A liquid-liquid extraction method proposed by the International Atomic Energy Agency (IAEA) has been adopted for the extraction of OCPs from draining water. The analysis of these compounds was carried out with a gas chromatography coupled to mass spectrometry. Eight draining water sample was analyzed from the region of Kebili and levels of OCPs ranged between ND and 3.415 ng L−1. Four draining water samples were sampled from the region of Cap Bon and levels of OCPs in draining water varied between 14.955 and 59.305 ng L−1. The concentration of OCPs in draining water didn’t exceed the limits standardized by the regulations for drainage water, which makes possible the reuse of this water for agricultural purposes after having undergone a secondary treatment.

How to Manage the Value of Drinking Water by Using Extension on the Contingent Valuation Method

This paper examines an explanatory policy in the management of drinking water in Tunisia. Indeed, the price variable, while is considered, in general way, as a confident indicator in the regulation of drinking water consumption, it seems to be insufficient since the management of drinking water is influenced by other set of variables such as: the revenue level of households, the consumption of bottled water, the alternative sources, the household size and, above all, the quality variable, which presents an enormous variability inter- and intra-regions. Through our study, we have shown, that the variation in willingness to pay (WTP) is essentially due to psychological and subjective consideration (the degree of importance of these variables in the scale of preferences of consumers).

Micro-economic analysis of domestic water demand: application of the pseudo-panel approach

The main purpose of the work is twofold. First, we tried to identify the main determinants that may explain the consumption of residential water in Tunisia using the pseudo panel method. This technique proved its effectiveness to overcome the lack of panel data. Moreover, the comparison between the obtained results using this method and those calculated based on the cross-sectional data showed the robustness of the pseudo-panel estimators. In the second step, our goal examined the policies and strategic orientations that seemed to be useful to manage water consumption in Tunisia. Estimation results reveal that the income elasticity of Tunisian residential demand for water is of about 1.18% and price elasticity is around 0.34 confirming that residential water demand in Tunisia is inelastic. This analysis consolidates the assumptions highlighting a coupling between Economic Status and drinking water consumption, the synergy between the equipment rate and water demand, and the synergy between the type of housing structure and the drinking water demand. In addition, it also emphasized the coupling between the socio-professional category of the household head and water consumption, the coupling between household size and water consumption, and the classical economic assumption confirming that price elasticity is negative.

Isolation and characterization of a halophilic Modicisalibacter sp. strain Wilcox from produced water

We report the isolation a halophilic bacterium that degrades both aromatic and aliphatic hydrocarbons as the sole sources of carbon at high salinity from produced water. Phylogenetic analysis of 16S rRNA-gene sequences shows the isolate is a close relative of Modicisalibacter tunisiensis isolated from an oil-field water in Tunisia. We designate our isolate as Modicisalibacter sp. strain Wilcox. Genome analysis of strain Wilcox revealed the presence of a repertoire of genes involved in the metabolism of aliphatic and aromatic hydrocarbons. Laboratory culture studies corroborated the predicted hydrocarbon degradation potential. The strain degraded benzene, toluene, ethylbenzene, and xylenes at salinities ranging from 0.016 to 4.0 M NaCl, with optimal degradation at 1 M NaCl. Also, the strain degraded phenol, benzoate, biphenyl and phenylacetate as the sole sources of carbon at 2.5 M NaCl. Among aliphatic compounds, the strain degraded n-decane and n-hexadecane as the sole sources of carbon at 2.5 M NaCl. Genome analysis also predicted the presence of many heavy metal resistance genes including genes for metal efflux pumps, transport proteins, and enzymatic detoxification. Overall, due to its ability to degrade many hydrocarbons and withstand high salt and heavy metals, strain Wilcox may prove useful for remediation of produced waters.

Long-term evaluation of soil salinization risks under different climate change scenarios in a semi-arid region of Tunisia

Abstract The project ‘Research and Training on Irrigation with Saline Water in Tunisia’, with the project report published by UNESCO in 1970, was set up to specify Tunisian standards for the use of saline water and to mitigate their effects on crop yields. The objective of this study is to assess the risk of long-term soil salinization by considering the agricultural practices mentioned in the project for the ‘Water Quality’ experiment in the semi-arid region of Cherfech (Tunisia). A Hydrus-1D model was used to simulate the movement of water and the transfer of salts. Soil hydraulic and solute transport parameters were estimated using inverse modeling. Calibration and validation of the model were made for the water and salt profiles carried out with four irrigation qualities QA, QB, QC and QD. Four scenarios over 50 years were studied: (i) S1 with rainfall (400 mm) only; (ii) S2 with rainfall and irrigation (1,400 mm); (iii) S3 with a 2 °C increase in temperature; (iv) S4 with the addition of 100 mm·d−1 of rainfall. The four scenarios highlighted the high risk of soil salinization, especially for the QB, QC and QD qualities after 20 years of irrigation and the deep dynamics of water and salts beyond the root zone which increases the risk of groundwater salinization.

First report of cross resistance to silver and antibiotics in Klebsiella pneumoniae isolated from patients and polluted water in Tunisia

AbstractKlebsiella pneumoniae, ubiquitously found in a variety of environmental sources, is an important pathogen in burn wounds and nosocomial infections. Burn wounds have been commonly treated with silver compounds, which are also used in a multitude of (non)medical products. As the latter increased silver discharge into different environments, we evaluated and compared silver resistance in K. pneumoniae isolates collected from patients hospitalized at the Charles‐Nicolle hospital (Tunis, Tunisia) with isolates collected from different metal polluted waters in the north and south of Tunisia. All K. pneumoniae isolates harboured blaTEM‐1 and blaSHV‐1. In addition, all clinical isolates showed a multidrug phenotype and harboured the blaCTX‐M‐15, blaOXA‐1 and blaNDM‐1. Furthermore, all isolates showed resistance to silver nitrate. The silver resistance determinant, screened via the silE gene, was located for all isolates on a large plasmid with a size similar to pMG101. This study showed cross‐resistance between silver and beta‐lactams in clinical as well as environmental K. pneumoniae isolates from Tunisia and showed for the first time that NDM‐1‐producing K. pneumoniae developed resistance to silver.

Participation in the Implementation of the Human Right to Water in Tunisia

This article analyses the implementation of the human right to water in Tunisia, focusing on the procedural indicator on ‘participation’. The article looks at the functioning of local Water User Associations as the lowest institutional level of water management and reviews theperformance criteria for participation within these associations as applied by the Tunisian government against the background of the legal norms for the human right to water and the indicator on participation within Sustainable Development Goal 6 on water and sanitation, i.e. SDG 6.b.

Feasibility of water desalination for irrigation: the case of the coastal irrigated area of Dyiar-Al-Hujjej, Tunisia

AbstractIrrigation in Tunisia is threatened all over the country. The irrigated coastal area of Dyiar-Al-Hujjej has observed a drop in agricultural activity following a seawater intrusion. Thus, yields have become disrupted in direct relation to the quantities of fresh water supplied and transferred over a distance of 100 km. For the sustainability of this area, the feasibility of using desalinated water to stabilize the irrigation water supply was analyzed. When all crop water requirements are to be met with desalinated water, the net income is negative for crops currently grown, except strawberry. All the open-field crops remain unprofitable even in the case of agro-industrial development, except tomatoes. A blending between desalinated seawater and aquifer saltwater also leads to a negative income for the main crops. The introduction of greenhouses to replace the same open-season crops is beneficial when desalinated water is used. The use of desalinated water in irrigation faces the high cost of desalination (0.5 US $/m3) while the average price of irrigation water in Tunisia is 0.05 US $/m3. Desalination can be recommended only in the case of crops with low need for water and high added value.

Genetic characterization of ESBL-producing Escherichia coli and Klebsiella pneumoniae isolated from wastewater and river water in Tunisia: predominance of CTX-M-15 and high genetic diversity.

Aquatic environments are crucial hotspots for the dissemination of antibiotic resistant microorganisms and resistance genes. Thus, the purpose of this study was to investigate the occurrence and the genetic characterization of cefotaxime-resistant (CTXR) Enterobacteriaceae at a Tunisian semi-industrial pilot plant with biological treatment (WWPP) and its receiving river (Rouriche River, downstream from WWPP) located in Tunis City, during 2017-2018. We collected 105 and 15 water samples from the WWPP and the Rouriche River, respectively. Samples were screened to recover ESBL-producing Enterobacteriaceae (ESBL-E) and isolates were characterized for phenotype/genotype of antimicrobial resistance, integrons, plasmid types and molecular typing (multilocus sequence typing, MLST). Among 120 water samples, 33 and 4 contained ESBL-producing E. coli and K. pneumoniae isolates, respectively. Most isolates were multidrug resistant and produced CTX-M-15 (28 isolates), CTX-M-1 (4 isolates), CTX-M-55 (2 isolates), CTX-M-27 (one isolate), SHV-12 (one isolate) and VEB beta-lactamases (one isolate). All K. pneumoniae were CTX-M-15-positive. Four colistin-resistant isolates were found (MIC 4-8μg/ml), but they were negative for the mcr genes tested. Class 1 integrons were detected in 21/25 trimethoprim/sulfamethoxazole-resistant isolates, and nine of them carried the gene cassette arrays: aadA2 + dfrA12 (n = 4), aadA1 + dfrA15 (n = 2), aadA5 + dfrA17 (n= 2) and aadA1/2 (n = 1). The IncP and IncFIB plasmids were found in 30 and 16 isolates, respectively. Genetic lineages detected were as follows: E. coli (ST48-ST10 Cplx, ST2499, ST906, ST2973 and ST2142); K. pneumoniae: (ST1540 and ST661). Our findings show a high rate of CTX-M-15 and high genetic diversity of ESBL-E isolates from WWPP and receivingriver water.

Estimation of the economic loss due to irrigation water use inefficiency in Tunisia.

The main objective of this study is to estimate the total economic loss due to inefficient use of irrigation water in Tunisia. Several approaches have been used for this purpose. The optimal level of water application for different crops is calculated using the actual crop evapotranspiration which is based on FAO-56 method. The residual imputation and yield comparison methods have been used to estimate the economic value of irrigation water for different irrigated crops in different bioclimatic areas. For the empirical analysis, primary data were obtained from a series of surveys that covered 78% of the total irrigated areas and were collected within the framework of the "Virtual Water and Food Security in Tunisia project" (2013-2015). Secondary data about land distribution of crops in Tunisia were taken from the Ministry of Agriculture (2016). Around 724 farms were randomly sampled considering their bioclimatic area, farm type, and production system. The survey included the main 20 crops produced in Tunisia. Results show that most of farmers are either under or over utilizing irrigation water. The value of total direct economic losses, at the country level, of both types of water inefficiencies, was estimated to around 470 million Tunisian Dinars. Therefore, an improvement of water use efficiency at field level through dissemination of information/knowledge on irrigation scheduling and crop water requirements by extension services to farmers is needed to reduce this huge economic loss, reach higher sustainability in water use and improve food security.

Isolation and molecular identification of Acanthamoeba spp from oasis water in Tunisia

In the southern Tunisia Oasis, we conducted 211 water with drawals from various water traffic sites. This water is used for agriculture, swimming or various other human activities. Acanthamoeba genus was detected in 82% of collected samples. Sequencing of the amplification products with primers P892C/P892 has allowed us to detect genotypic variation with predominance of T4 genotype (51%) and presence of the genotypes T14, T5, T3, T16, T15, T10, T11, T9 and T7. They T4, T3, T5, T15, T11 and T10 genotypes have a high potential for pathogenicity and a very high degree of virulence due to their production of serine proteases and extracellular cysteine enzymes involved in tissue degradation of the host. T4 genotype was the most abundant in the environment as well as in infections caused by Acanthamoeba spp. T5 genotype was ranked second and T3 genotype was less abundant in the environment and its pathogenicity is discussed. Acanthamoeba strains with the genotypes T16, T9 and T7 were considered non pathogenic. In fact, they have been isolated only from the environment. However, for these strains, their role as a reservoir can be a real risk to human health.

Price Policy of Drinking Water in Tunisia: Panel Application

Price Policy of Drinking Water in Tunisia: Panel Application

The nonlinear progressive water pricing policy in Tunisia: equity and efficiency

Economic theory and recent empirical evidence show that nonlinear progressive water pricing policies are the most useful tool to reduce water demand in water stressed countries. The originality of our paper is to implement Pedroni (1999) panel cointegration tests, using databases on a breakdown of two consumption blocks (a lower and an upper block) from the Tunisian water regulator over 27 years. The results reveal that increasing block tariffs have been successful in managing scarce water in Tunisia. The authors observe that, in the long-run, proportion of subscribers in the upper water consumption block decreases when price increases, while in the lower block, which is composed essentially of low-income households characterized by inelastic water demand, proportion of subscribers is less elastic to price changes and still unchanged. This paper calls for the implementation of nonlinear progressive pricing to reduce demand by large consumers in order to promote efficiency in use and to promote the access of poor consumers to the resource in order to promote equity.

Screening and characterization of thermo-active enzymes of biotechnological interest produced by thermophilic Bacillus isolated from hot springs in Tunisia.

As part of the contribution to the global efforts in research of thermostable enzymes being of industrial interest, we focus on the isolation of thermophilic bacteria from Tunisian hot springs. Among the collection of 161 strains of thermophilic Bacillus isolated from different samples of thermal water in Tunisia, 20% are capable of growing at 100°C and the rest grow at 70°C or above. Preliminary activity tests on media supplemented with enzyme-substrates confirmed that 35 strains produced amylases, 37 - proteases, 43 - cellulases, 31 - xylanases and 37 - mannanases. The study of the effect of temperature on enzyme activity led to determination of the optimal temperatures of activities that vary between 60 and 100°C. Several enzymes were active at high temperatures (80, 90 and 100°C) and kept their activity even at 110°C. Several isolated strains producing enzymes with high optimal temperatures of activity were described for the first time in this study. Both strains B62 and B120 are producers of amylase, protease, cellulase, xylanase, and mannanase. The sequencing of 16S DNA identified isolated strains as Geobacillus kaustophillus, Aeribacillus pallidus, Geobacillus galactosidasus and Geobacillus toebii.

Occurrence of antibiotics in pharmaceutical industrial wastewater, wastewater treatment plant and sea waters in Tunisia.

Antibiotics are among the most commonly used group of pharmaceuticals in human medicine. They can therefore reach surface and groundwater bodies through different routes, such as wastewater treatment plant effluents, surface runoff, or infiltration of water used for agricultural purposes. It is well known that antibiotics pose a significant risk to environmental and human health, even at low concentrations. The aim of the present study was to evaluate the presence of aminoglycosides and phenicol antibiotics in municipal wastewaters, sea water and pharmaceutical effluents in Tunisia. All analysed water samples contained detectable levels of aminoglycoside and phenicol antibiotics. The highest concentrations in wastewater influents were observed for neomycin and kanamycin B (16.4 ng mL(-1) and 7.5 ng mL(-1), respectively). Chloramphenicol was found in wastewater influents up to 3 ng mL(-1). It was observed that the waste water treatment plants were not efficient in completely removing these antibiotics. Chloramphenicol and florfenicol were found in sea water samples near aquaculture sites at levels up to, respectively, 15.6 ng mL(-1) and 18.4 ng mL(-1). Also aminoglycoside antibiotics were found near aquaculture sites with the highest concentration of 3.4 ng mL(-1) for streptomycin. In pharmaceutical effluents, only gentamycin was found at concentrations up to 19 ng mL(-1) over a sampling period of four months.

Morphological and molecular identification of free living amoeba isolated from hospital water in Tunisia.

Free-living amoebae (FLA) are opportunistic and ubiquitous protozoa that are widely found in various environmental sources. They are known to cause serious human infections. The aim of our study was to detect FLA and Acanthamoeba spp. in hospital water circuits. Eighty-four water samples were collected over a period of 4 months (September-December 2011) from different wards of the Sfax University Hospital (surgical services, intensive care unit, operating theater, and water storage tanks). FLA were detected in 53.5 % of samples as follows: surgical services (80 %), operating theater and surgical intensive care unit (13.3 %), medical intensive care unit (0 %), water storage tanks (6.6 %). The predominant morphotype was the acanthopodial (89 %). The others morphotypes were as follows: monopodial (40 %), dactylopodial (22 %), rugosa (62 %), eruptive (24 %), fan shaped (18 %), and polypodial (18 %). Acanthamoeba was found in 40 samples (47.6 %). 64.2 % of isolates were identified as Acanthamoeba spp. by PCR, using primers to amplify a region of 18S rDNA which showed variation in the product length. Sequence analysis of five PCR products identified Acanthamoeba sp. These isolates belong to T4, T10, and T11 genotypes, and to our knowledge this is the first report of the T10 and T11 genotype in Tunisia.The occurrence of potentially pathogenic FLA in the hospital environment may represent a health risk for patients, since these organisms can cause severe opportunistic illness and also can harbor pathogenic agents. Thus, increased awareness regarding these parasites and recognition of their importance, particularly in immunocompromised patients is crucial.

3D-STRUCTURES WITH INTEGRATION GEOLOGICAL AND GEOPHYSICAL DATA: IMPLICATION FOR RESEARCH WATER RESOURCES IN TUNISIA: CASE OF BOTH SE JEFFARA AND UTIQUE BASIN, TUNISIA

Tunisia is enriched by many natural resources (natural water and geothermal water) that are located along the South to the North. This paper aims mainly to evaluate the resources water potential. The available remote sensing images for two typical examples (SE Jeffara basin and Utique basin) are analyzed and many seismic profiles are interpreted to delineate the surface and subsurface structures.&#x0D; The 3-D structures of Mio-Plio-Quaternary and Upper Cretaceous aquifers in South-East of Jeffara basin show an important reservoirs of water resources. The Upper Cretaceous aquifer "Complexe Terminal" is one of the most typical examples of exploitation features in hydrogeological research. It is formed by fractured limestones.&#x0D; The 3D-structure of Utique basin shows an important variation of thickness of Mio-Plio-Quaternary and Triassic series. The Mio-Plio-Quaternary series is formed by sand, clays and gypsum. The Triassic series is considered typical example for research the hydrogeological and hydrothermal water in Tunisia, especially in the North. In the subsurface, the triassic aquifer of Utique regions is formed by carbonates series. The hot spring in Utique basin is directly related to the Triassic dolostones which are extensively fractured [1].&#x0D; A geophysical survey was undertaken for groundwater in Tunisia. The interpretation of seismic reflection sections and petroleum wells allowed to precise the geometry in subsurface structure.

Diversity of enterococcal species and characterization of high-level aminoglycoside resistant enterococci of samples of wastewater and surface water in Tunisia

One hundred-fourteen samples of wastewater (n=64) and surface-water (n=50) were inoculated in Slanetz–Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 75% of tested samples in SB media (72% in wastewater; 78% in surface-water), and 85 enterococcal isolates (one/positive-sample) were obtained. Enterococcus faecium was the most prevalent species (63.5%), followed by Enterococcus faecalis (20%), Enterococcus hirae (9.4%), Enterococcus casseliflavus (4.7%), and Enterococcus gallinarum/Enterococcus durans (2.4%). Antibiotic resistance detected among these enterococci was as follows [percentage/detected gene (number isolates)]: kanamycin [29%/aph(3′)-IIIa (n=22)], streptomycin [8%/ant(6)-Ia (n=4)], erythromycin [44%/erm(B) (n=34)], tetracycline [18%/tet(M) (n=6)/tet(M)-tet(L) (n=9)], chloramphenicol [2%/cat(A) (n=1)], ciprofloxacin [7%] and trimethoprim–sulfamethoxazole [94%]. High-level-gentamicin resistant (HLR-G) enterococci were recovered from 15 samples in SB-Gen or SB plates [12/64 samples of wastewater (19%) and 3/50 samples of surface-water (6%)]; HLR-G isolates were identified as E. faecium (n=7), E. faecalis (n=6), and E. casseliflavus (n=2). These HLR-G enterococci carried the aac(6′)-Ie–aph(2″)-Ia and erm(B) genes, in addition to aph(3′)-IIIa (n=10), ant(6)-Ia (n=9), tet(M) (n=13), tet(L) (n=8) and cat(A) genes (n=2). Three HLR-G enterococci carried the esp virulence gene. Sequence-types detected among HLR-G enterococci were as follows: E. faecalis (ST480, ST314, ST202, ST55, and the new ones ST531 and ST532) and E. faecium (ST327, ST12, ST296, and the new ones ST985 and ST986). Thirty-two different PFGE patterns were detected among 36 high-level-aminoglycoside-resistant enterococci recovered in water samples. Diverse genetic lineages of HLR-G enterococci were detected in wastewater and surface-water in Tunisia. Water can represent an important source for the dissemination of these antibiotic resistant microorganisms to other environments.

A Thermo-Economic Modeling to Conceptualize a Biogas Digester Destined to Energetic Valorization of Waste Water under Products

In this work, we have developed a model that permits to study the technical efficiency and the economic income of a biogas reactor designed to valorize the waste water in energy producing. A first application to waste water issued from yeast industry and to municipal waste water in Tunisia was done. Results were well satisfying. In fact, the thermo economic evaluation of the biogas produced from the two stations shows that we can realize a gain of about 119600 DT/year for the yeast industry and about 3266000 DT/year for Charguia station with a compensation time of the cost of reactor installation between 6 and 10 years.