[Journal of Public Health in Africa 2017; 8:679] [page 23]

Field application of the MicroBiological Survey method forthe assessment of the microbi-ological safety of differentwater sources in Horn of Africaand the evaluation of the effec-tiveness of Moringa oleifera indrinking water purificationFrancesca Losito,1 Alyexandra Arienzo,2Daniela Somma,2 Lorenza Murgia,2Ottavia Stalio,2 Paolo Zuppi,3Elisabetta Rossi,4 Giovanni Antonini1,21INBB Interuniversity Consortium ofStructural and Systems Biology, Rome;2Department of Sciences, Roma TreUniversity; 3Department ofEndocrinology, San Camillo-ForlaniniHospital, Rome; 4Policlinic AgostinoGemelli, Sacro Cuore CatholicUniversity, Rome, Italy

Abstract

Water monitoring requires expensiveinstrumentations and skilled technicians. Indeveloping Countries as Africa, the severeeconomic restrictions and lack of technologymake water safety monitoring approachesapplied in developed Countries, still not sus-tainable. The need to develop new methodsthat are suitable, affordable, and sustainable inthe African context is urgent. The simple, eco-nomic and rapid Micro Biological Survey(MBS) method does not require an equippedlaboratory nor special instruments and skilledtechnicians, but it can be very useful for rou-tine water analysis. The aim of this work wasthe application of the MBS method to evaluatethe microbiological safety of different watersources and the effectiveness of differentdrinking water treatments in the Horn ofAfrica. The obtained results have proved thatthis method could be very helpful to monitorwater safety before and after various purifica-tion treatments, with the aim to control water-borne diseases especially in developingCountries, whose population is the mostexposed to these diseases. In addition, it hasbeen proved that Moringa oleifera water treat-ment is ineffective in decreasing bacterial loadof Eritrea water samples.

Introduction

Contamination of water is one of the

major issues of concern for public safety. Itis a serious environmental problem thatadversely affects human health and biodi-versity in the aquatic ecosystems.1 Most ofthe rural communities in developingCountries are poverty-stricken and lackaccess to potable water supplies. In order toobtain drinking water, the population main-ly relies on rivers, unprotected wells andcisterns, which are often highly contaminat-ed with waterborne pathogens. In mostcases, water from these sources is usedwithout any preliminary treatment, since theunavailability of energy sources makes sim-ple procedures as boiling or heating waterdifficult to achieve. A significant part of thepopulation is continuously exposed towater-borne diseases and their potentialcomplications.2,3 The main risk associatedwith the consumption of unsafe drinkingwater is microbiological. Monitoringmicrobial safety of water is therefore not anoption, but an imperative to provide safewater.4 Traditional methods currently usedto test microbiological water safety are lab-oratory-based assessments that are timeconsuming and require expensive equip-ment. Since the number of specialized labo-ratories is exiguous, water safety control indeveloping Countries is extremely restrict-ed. In these rural areas microbiologicalmethods of analysis to ensure an effectivewater safety monitoring, should be portable,low cost, fast and simple to use.5 In this con-text, Roma Tre University, Italy, developedthe colorimetric Micro Biological Survey(MBS) method, which is an easy-to-use andlow-cost method for microbiological analy-sis of food and water.6,7

Differently from traditional methodsthat measure the capability of cells to repli-cate, creating visible colonies on solidmedia, the MBS method measures the cat-alytic activity of redox enzymes of the mainmetabolic pathways of bacteria allowing anunequivocal correlation between theobserved enzymatic activity and the bacte-ria concentration present in the samples.The MBS analysis is performed in dispos-able, ready-to-use reaction vials that containthe specific reagent for the analysis to per-form. The test results are easy to interpretbecause they simply require the observationof a color change of the reaction vials, thatoccurs in times that are inversely propor-tional to the bacterial charge in the sample:higher is the number of bacteria present intothe sample, shorter is the time required forcolor change. After analyses, the reactionvials can be sterilized by pressing on theperforable cap that releases a bactericidesubstance that completely sterilizes the vialcontent in 5-10 minutes. The simple analyt-ical procedure, the reduced labor and

automation, positively affect the analyticalperformance of the MBS method, whichdisplays greater reproducibility and repeata-bility compared to traditional methods.8 Theeffectiveness of the MBS method as analternative method for microbiologicalanalysis of drinking water was demonstrat-ed in Arienzo et al., 2015.9 The MBSmethod was applied to evaluate the micro-biological quality of dug and drilled wellsin Douala, Cameroon. It was also demon-strated that the simple evaluation of totalcoliforms in 1 mL of water simples, insteadof 100 mL as required by law, could beeffective to roughly assess water particular-ly in developing countries in the absence ofspecific facilities and instrumentations.9

In this study we investigate the possibil-ity to use the MBS method as a point of usetest to assess water quality and evaluate theeffectiveness of different drinking watertreatments in Eritrea, Horn of Africa.

Two microbiological parameters wereconsidered in this study: Total Viable Countat 22°C and total coliforms. Total ViableCount at 22°C is a parameter used to evalu-

Journal of Public Health in Africa 2017 ; volume 8:679

Correspondence: Giovanni Antonini,Department of Sciences, Roma Tre University,Viale Guglielmo Marconi 446, 00146 Rome(RM), Italy.Tel.: +39.329.0570913.E-mail: giovanni.antonini@uniroma3.it

Key words: Water microbiological analysis;Drinking water; Africa; Alternative microbio-logical method.

Contributions: GA coordinated the research,participated to the design of the study and crit-ically revised the manuscript for intellectualcontent. ER and PZ conceived the study andparticipated to its design. FL and DS per-formed the experimental work. AA, OS andLM contributed to the interpretation of data.FL and AA drafted the manuscript. Allauthors read and approved the final version ofthe manuscript.

Conflicts of interest: the authors declare nopotential conflict of interest.

Funding: this work has been financially sup-ported by Consulcesi Onlus (Rome, Italy) andby MBS s.r.l. (Rome, Italy).

Received for publication: 11 April 2017.Accepted for publication: 10 June 2017.

This work is licensed under a CreativeCommons Attribution NonCommercial 4.0License (CC BY-NC 4.0).

©Copyright F. Losito et al., 2017Licensee PAGEPress, ItalyJournal of Public Health in Africa 2017; 8:679doi:10.4081/jphia.2017.679

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ate the concentration of‘ heterotrophic bac-teria that grow at 20-28°C. This parameterincludes all aerobic bacteria that use organicnutrients to grow and are universally pres-ent in all types of water, food, soil, vegeta-tion, and air. The Total Viable Count is thusa useful tool to monitor the general bacteri-ological safety of water samples and to ver-ify the effectiveness of water treatments.10

A significant presence of heterotrophic bac-teria can be considered worrisome for pub-lic health, indicating the possible presenceof viruses or parasites that are more resist-ant than bacteria to chemical disinfec-tants.11,12 Total coliforms are a group ofbacteria that include a wide range of aerobicand facultative anaerobic, Gram-negative,non-spore-forming bacilli. These bacteriacan occur in faces of human and otherwarm-blooded animals, but some can bealso found in soil, on various plants, includ-ing grains and trees, and in certain industrialwastes. Total coliforms are an indicator ofsanitary safety of water and their presenceindicates a existing risk of contamination bypathogenic bacteria having oral-fecal trans-mission. They are moderately sensitive tochemical disinfectants, but they can surviveand grow in water distribution systems, par-ticularly in presence of biofilms, so theirpresence can also be used to assess thecleanliness and integrity of distribution sys-tems.11,13 The effectiveness of Moringaoleifera (M. oleifera) in drinking waterpurification was also investigated. M.oleifera is a multipurpose tree native toNorthern India that now grows widelythroughout the tropics.14 The active compo-nent of the dried crushed seeds (powder) ofM. oleifera is a soluble protein, a naturalcationic polyelectrolyte that causes coagu-lation. Research over the last four decadeshas primarily focused on testing M. oleiferafor the removal of turbidity but there is poorevidence about its efficacy in the reductionof bacterial load in different drinking watersources.15 In addition, the efficiency ofthree different household water disinfectiontreatments already in use in Eritrea wasexamined: i) filtration and ultraviolet (UV)purification; ii) chlorination using an empir-ical dosage (about 0.1-0.2 mg/L) and iii)chlorination using sodium hypochlorite pro-duced by an electrolytic device.

Materials and Methods

The study areaEritrea is situated in the Horn of Africa

and lies north of the equator between lati-tudes 12°22′ N and 18°02′. Eritrea is acountry of contrasts with land rising from

below sea level to 3000 meters above sealevel. In this region climate ranges from hotand arid near the Red Sea, to temperate sub-humid in the eastern highlands. The averageannual rainfall is of about 380 millimeters(mm/year), varying from less than 50 mm toover 1000 mm. Over 90% of the total areareceives less than 450 mm and only 1%receives more than 650 mm of annual rain-falls. Rainfalls are torrential, of high inten-sity and short duration, and vary greatlyfrom year to year. The rainy season goesfrom June to September. Mean temperaturevaries between the agro-ecological zonesranging from 18°C in the highlands to 35°Cin the lowlands.16 Figure 1 shows the mapof the study area that was downloaded fromGoogle Maps. The regions of Eritrea underconsideration are highlighted: Asmara,Cheren, Akrur and Saganèiti.

Application of the Micro BiologicalSurvey method on field to evaluatethe microbiological safety of differ-ent water samples

Samples collectionA total of 16 water samples were collect-

ed from different water sources and analyzedover a period of fifteen days (October toNovember, 2014) in Eritrea, Horn of Africa.In particular, the samples were collected inAsmara, Cheren, Akrur and Saganèiti. Out ofall samples, 3 were bottled water samplesdistributed by different Eritrea industries, 2were tap water samples coming from publicdistribution systems in Asmara and Cheren,3 were household treated water samples col-lected respectively in a house in Asmara, areligious institute in Asmara and an orphan-age near Akrur, 5 were water samples com-ing from public (1 sample) and private cis-terns (4 samples) in Saganèiti, Asmara andAkrur and 3 were river water samples col-lected from the Anseba river in three differ-ent sites in Eritrea.

Microbiological safety assessment of watersamples using the Micro Biological Surveymethod

Safety assessment of water samplesusing the MBS method was performed usingTVC (Total Viable Count) and COLI (Totalcoliforms) vials for the quantification of het-erotrophic bacteria and Total coliformsrespectively. All vials were produced byMBS srl, Rome, Italy. All samples were ana-lyzed in duplicate. Analysis were performedon 1 mL both for Total Viable Count andTotal coliforms in accordance to the resultsobtained by Arienzo et al., 2015.9

The TVC and COLI vials were filledwith 10 mL of sterile distilled water and 1mL of water samples was added to each vial.

After inoculation, vials were incubated for48 hours at room temperature (22±°C) andfor 24 hours at 37±0.5°C in a bench thermo-stat for TVC and COLI vials respectively.The starting color is blue for TVC vials andred for COLI vials. In the presence ofmicroorganisms, the vials’ color changes toyellow, indicating a positive result. The per-sistence of the initial color after 36 hours forTVC vials and 24 hours for COLI vials indi-cates the absence of tested microorganisms,and consequently a negative result. The colorchange was monitored by visual inspectionat different times after inoculation. The timefor color change was used to determine thebacterial load in the sample, using specificMBS correlation tables between time(expressed as hour) and bacterial concentra-tion (expressed as CFU/mL) (Tables 1 e 2).

Evaluation of the effectiveness ofMoringa oleifera seeds in drinkingwater purification

Samples collectionA total of 9 from 16 water samples col-

lected for the evaluation of the microbiolog-ical safety were analyzed also after the treat-ment with Moringa oleifera. Out of all sam-ples, 2 were tap water samples coming frompublic distribution systems in Asmara andCheren, 4 were water samples coming fromprivate cisterns in Saganèiti, 3 were riverwater samples collected from the Ansebariver in three different sites in Eritrea.

Water purification treatment usingMoringa oleifera seeds

Water samples were treated with 60 g/Lof M. oleifera seeds, reduced to flour using amortar. The seeds were obtained from localagricultural productions. The operating pro-cedure used in this study was developed tomeet all the requirements of drinking wateron-field treatment in developing countries,such as the absence of facilities and instru-mentations. Water was collected in plasticbottles. The M. oleifera flour was added inthe bottles that were then immediately shak-en for at least 5 minutes to ensure a homog-enous distribution and promote the interac-tion between the active components of M.oleifera and bacteria. Water samples wereleft still in order to allow flocculation andsedimentation and filtered after 1 hour, usinga clean cotton cloth.

Application of the Micro Biological Surveymethod to evaluate the effectiveness ofMoringa oleifera seeds in drinking waterpurification

The concentration of heterotrophic bac-teria in water samples, before and after thetreatment with M. oleifera, was determined

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using the MBS method, according to the pre-viously described procedure.

Evaluation of the effectiveness of dif-ferent water disinfection systems

Samples collectionDifferent water samples were collected

before and after disinfection treatments.Three water samples were collected in ahouse in Asmara, where water coming fromthe civil aqueduct is treated with filtrationand Ultraviolet (UV) purification before use.Other three water sample were collected in areligious institute in Asmara, where water,coming both from rainfall and from the civilaqueduct, is collected in a cistern and it isempirically treated with chlorine by addingbleaching powder to the cistern (about 0.1-0.2 mg/L). The last three water samples werecollected in an orphanage near Akrur, wherewater is collected from a river, stored in a cis-tern and chlorinated before use with the elec-trolytic device Clorel T50.

Application of the Micro Biological Surveymethod to evaluate the effectiveness of dif-ferent water disinfection systems

For all water samples, collected beforeand after disinfection treatments, concentra-

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Figure 1. Map of the study area: Eritrea, Horn of Africa. Spot A marks Asmara (N15°19’22.332’’, E38°55’30.1792’’); spot B marksCheren (N15°46'48.0360", E38°27'12.3840"); spot B marks Akrur (N15°3’17.77’’, E39°15’48.803’’); spot C marks Saganèiti(N15°3'38.848", E39°11'26.785").

Table 1. Correlation table for TVC vials for the detection of Total Viable Count (22±2°C).Correlation between the time for color change (expressed as hour) and samples contam-ination (expressed as CFU/mL). In the presence of bacterial load the color of the TVCvials changes from blue to yellow.

Contamination, (CFU/mL) Total Viable Count (22±2°C) Time for color change (hours) Final color

>105 8 Yellow104 14 Yellow103 20 Yellow102 25 Yellow10 31 Yellow0 >36 Blue

Table 2. Correlation table for COLI vials for the detection of total coliforms (37±0.5°C).Correlation between the time for color change (expressed as hour) and samples contam-ination (expressed as CFU/mL). In the presence of coliforms the color of the COLI vialschanges from blue to yellow.

Contamination (CFU/mL)Total coliforms (37°C± 0.5°C) Time for color change (hours) Final color

>105 3 Yellow104 9 Yellow103 15 Yellow102 21 Yellow10 27 Yellow0 >33 Red

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tions of heterotrophic bacteria and total col-iforms were determined using the MBSmethod, according to the previouslydescribed procedure.

Statistical analysisStatistical analysis of data was per-

formed using Student’s t-test.

Results

Application of the Micro BiologicalSurvey method on field in the evalu-ation of the microbiological safety ofdifferent water sources

The primary objective of the study wasthe application of the MBS method for theassessment of the microbiological safety ofdifferent water sources used as drinkingwater from local population: bottled water,tap water, household treated water, cisternwater and river water. Figure 2 shows thelevel of contamination for both heterotroph-ic bacteria at 22°C and Total coliformsfound in the different water sources ana-lyzed.

Bottled water resulted not contaminat-ed. Tap water samples were not contaminat-ed by coliforms, according to the WorldHealth Organization (WHO) microbiologi-cal standards for drinking water. These sam-ples however displayed a Total ViableCount that exceeds the limit of 100CFU/mL. Household treated water did notresult suitable for human consumption.Finally, both cistern and river water samplesshowed a Total Viable Count that exceededthe standard level of 100 CFU/mL and avery high contamination by coliforms.

Application of the Micro Biological

Survey method in the evaluation ofthe effectiveness of Moringa oleiferaseeds in drinking water purification

Natural plant extracts have been usedfor water purification for many centuries.M. oleifera seeds (Figure 2) has beenranked as one of the best plant extracts forwater purification.14 In terms of water treat-ment applications, M. oleifera seeds haveproved to be effective at removing suspend-ed material, generate reduced sludge vol-umes in comparison to alum, soften hardwaters and act as effective absorber of cad-mium.17-19 Most studies have consideredthe removal of turbidity and rarely of bacte-ria. One study conducted on surface waterused for domestic purposes showed a 90-99% reduction in fecal coliform levels. Itwas found that the reduction in E. coli wasdirectly linked to the turbidity removalachieved during coagulation (from 50% upto 97%.).20

In this work the effectiveness of M.oleifera in the reduction of bacterial load indifferent water samples was evaluated usingthe MBS method.

The operating procedure was previouslystudied in in vitro and on field trials inLazio, Italy: a concentration of M. oleiferaequal to 60 g/L was chosen as it gave themost promising results (Table 3).

Water samples from different watersources in Eritrea, were treated with M.oleifera. Total Viable counts were assessedusing the MBS TVC vials before and afterthe treatment (Figure 3).

Table 4 shows the reduction of bacterialload in water samples collected in Eritreaafter treatment with M. oleifera.

In the analyzed samples the treatmentwith M. oleifera did not positively affect themicrobiological quality in almost all thesamples, causing an increase in the bacterial

load, on average of 75.5%. The treatmentresulted effective in reducing the bacterialload only in freshwater samples collectedfrom the Anseba river. These results com-pletely differ from the ones previouslyobtained in in vitro and on field trialsdemonstrating the inefficiency of the treat-ment in Eritrea water samples.

Application of the Micro BiologicalSurvey method on field in the evaluationof the effectiveness of different householdwater disinfection systems

Considering the inefficiency of M.oleifera in drinking water purification,another objective of the study was the appli-cation of the MBS method to evaluate theeffectiveness of three different systems ofhousehold disinfection of water that arealready in use in Eritrea: i) filtration andultraviolet (UV); ii) chlorination usingempiric dosage (about 0.1-0.2 mg/l) of thecommercially available bleaching powder(mixture of calcium hypochlorite, calciumhydroxide, and calcium chloride); iii) chlo-rination using sodium hypochlorite pro-duced by an electrolytic device, Clorel T50.For this purpose, the microbiological safetyof water was tested before and after treat-ments, considering both Total Viable Countat 22°C and Total coliforms.

Figure 4 shows the level of contamina-tion for both parameters observed beforeand after the treatment. Water treated withfiltration and Ultraviolet (UV) radiationsresulted suitable for human use, due to thetotal absence of bacterial load. Water empir-ically treated with bleaching powdershowed a reduction of bacterial load forboth parameters, that varied among thesamples, with the greatest reductionobserved for Total coliforms. Water chlori-nated using Clorel T50, was not contami-

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Table 3. Reduction of bacterial load in different water samples after treatment with Moringa oleifera. The values shown are the meansof the results obtained using the Micro Biological Survey method. For each water sample three independent analyses were performedin duplicate. Results are expressed in percentage to analyze the effectiveness of the treatment with M. oleifera in relation to the initialconcentrations.

Samples N. Total Viable Count 22°C (after treatment/before treatment) Mean (%) Max (%) Min (%)

Artificially contaminated distilled water samples (ATCC strains) 10 −75.5 −100 −61.1Freshwater samples (rivers in Lazio, Italy) 12 −48.6 −63.5 −34.1

Table 4. Reduction of bacterial load in Eritrea water samples after treatment with Moringa oleifera. The values shown are the means ofthe results obtained using the Micro Biological Survey method. For each water sample three independent analyses were performed induplicate. Results are expressed in percentage to analyze the effectiveness of the treatment with M. oleifera in relation to the initial con-centrations.

Samples N. Total Viable Count 22°C (after treatment/before treatment) Mean (%) Max (%) Min (%)

Eritrea water samples 12 +75.5 +400 −61.6

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nated by Total coliforms. However TotalViable Count did not significantly decreaseafter the treatment.

Discussion

An adequate and safe supply of waterfor human use is one of the major prerequi-sites for a healthy life. Improving watersafety is significant for the country’s devel-opmental progress in terms of human

health, education and gender safety. Accessto adequate water is however restricted indeveloping Countries, resulting in a highincidence of communicable diseases thatincreases the harshness of daily life.21

Monitoring the microbiology safety ofwater for human use is one of the key chal-lenges to ensure safety in developingCountries. Surveillance is typically weakestin these countries, where the access toimproved water sources is lowest and thelikelihood of contamination is greatest.Considering this scenario the rapid, easy

and cheap colorimetric MBS method formicrobiological analysis may represent animportant tool to increase water monitoringin rural areas. The MBS method is morepractical and simple in its execution com-pared to traditional techniques. It providesreliable results diminishing the time ofanalysis, favoring procedures and interpre-tation of data, limiting cost and allowinganalysis also in absence of skilled personneland laboratory. Its features were alreadyexploited for drinking water analysis in thecity of Douala, Cameroon.9

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Figure 4. Effectiveness of three different household systems for water disinfection used in Eritrea. a) Filtration and ultraviolet (UV)purification; b) Chlorination using empiric dosage (about 0.1-0.2 mg/l) of the commercially available bleaching powder (mixture ofcalcium hypochlorite, calcium hydroxide, and calcium chloride); c) Chlorination using Clorel T50. The values shown are the means ±SD of the results obtained using the Micro Biological Survey method (expressed as log of CFU/mL) for three samples of the same typeof water analyzed in duplicate (*P<0.01, Student’s t test). Black bars show the average of the level of contamination of Total ViableCount. Grey bars show the average of the level of contamination of Total coliforms.

Figure 3. Effectiveness of the treatment with Moringa oleifera.Total Viable Count in Eritrea water samples before and after 1and 31 hours from the treatment with M. oleifera. The valuesshown are the means of the results obtained using the MicroBiological Survey method (expressed as log of CFU/mL). Foreach water sample three independent analyses were performed induplicate. Black bars show the average of the level of contamina-tion of Total Viable bacteria in the samples before treatment. Greybars show the average of the level of Total Viable bacteria 1 hourafter the treatment with M. oleifera.

Figure 2. Total Viable Count and total coliforms contaminationof different water sources in Eritrea, Horn of Africa. The valuesshown are the means ± SD of the results obtained using the MicroBiological Survey method (expressed as log of CFU/mL) for dif-ferent samples of the same type of water source. Black bars showthe average of the level of contamination of Total Viable Count at22°C. Grey bars show the average of the level of contamination oftotal coliforms. n=3 for bottled water samples; n=2 for tap watersamples; n=3 for household treated water; n=5 for cistern watersamples; n=3 for river water.

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In this study, the MBS method was usedto assess the microbiological safety of watersamples from various sources and to evalu-ate the effectiveness of different water treat-ments in Eritrea, Horn of Africa. TotalViable Count at 22°C and Total coliformswere evaluated. Safe water must be charac-terized from a low level of Total Viable bac-teria (<100 mL/CFU) and from the absenceof Total coliforms.11 It has been demonstrat-ed that the presence of heterotrophic bacte-ria (<100 CFU/mL) indicates the possiblepresence of viruses or parasites that aremore resistant than bacteria to chemical dis-infectants,11,12 while the presence of Totalcoliforms indicates a existing risk of con-tamination by pathogenic bacteria havingoral-fecal transmission.13

Most of the analyzed water samplesresulted not compliant with the current stan-dards for drinking water. Only bottled waterwas found to be always microbiologicallypure. Tap water coming from the civil aque-duct, despite the absence of coliforms,showed a high level of heterotrophic bacte-ria, that exceeded the standard limits. Thisindicates that, although the presence of apublic water distribution system should bean indicator of improved water supplies in adeveloping country, it should not beassumed that the resulting water is alwayssuitable for human consumption.22 Also thehousehold treated water resulted not suit-able for human consumption, since theamount of heterotrophic bacteria exceededthe standard level and low level of contam-ination by coliforms was detected. Theseresults highlight the importance of verifyingthe effectiveness of potabilization treat-ments. Cistern and river water also resultednot compliant with current microbiologicalstandards for drinking water underlining apotential health risk due to high concentra-tions of both heterotrophic bacteria andTotal coliforms. The use of cisterns is anancient practice to collect and store water,but they are susceptible to microbiologicalcontamination.23 Moreover, in some vil-lages, river water is adopted as the mainwater supply although it can be highly pol-luted. This contamination is a result of thesurrounding environment (e.g. contamina-tion from land and fecal material originat-ing from local animals present on the banksof the river).

This study also demonstrated the impor-tance of verifying the effectiveness of sev-eral water treatments.

Coagulation is a common process usedfor removing suspended matter from water.Recently, a resurgence of interest in naturalcoagulants has emerged. Various plantbased materials have been identified aseffective coagulants. The major merits of

plant-derived coagulant materials whenused as point-of-use (POU) technology inwater treatment methods are obvious: theseare less expensive, do not alter the pH oftreated water, and the sludge they produce isless voluminous and readily biodegradable.Of all plant materials investigated, M.oleifera has drawn special attention as ittreats water by acting both as a coagulantand antimicrobial agent.24,25 M. oleifera iswidely available, easy to store, especially indeveloping countries, and has been reportedas an ecofriendly substitute to widely useddisinfectants.26

In this study, however, the treatment ofwater with M. oleifera seeds did not resulteffective in reducing the bacterial load inmost of the examined water samples.Unexpectedly in 75% of the samples theconcentration of bacteria has risen on aver-age of the 80%. This result conflicts withthose found in literature and with those pre-viously obtained treating different watersamples in in vitro and on field trials inItaly. The reasons behind such discrepancyhave been investigated. In vitro experimentsexcluded the influence of pH, cation andanion concentrations, but further experi-ments are required to understand thisbehavior.

In any case, it is important to stress that,after the treatment with M. oleifera, watersamples were indeed not suitable for humanconsumption. Apart from the worsenedmicrobiological quality, in fact, water sam-ples displayed a considerable increase ofturbidity due to a higher concentration oforganic matter, that caused odor, color andtaste issues, as previously described.27

Regarding the other water treatmentsexamined in this study it appears clear thatdespite their common use not all of them areeffective, at least not following the house-hold protocols usually implemented.

Water treated by national drinkingwater distribution companies, using filtra-tion and Ultraviolet (UV) radiation, resultedmicrobiologically acceptable for humanuse. On the contrary, the chlorination treat-ment either using empiric dosages (about0.1-0.2 mg/L) of the commercially avail-able bleaching powder (mixture of calciumhypochlorite, calcium hydroxide, and calci-um chloride) or through sodium hypochlo-rite produced by an electrolytic device,Clorel T50, did not result efficient and theobtained water was not suitable for humanuse. The amount of chlorine used followingthe household protocols was not enough todecrease the bacterial load down to accept-able levels. These results highlight that theinefficiency of chlorination is most likely toarise from human error.

ConclusionsIn conclusion, the results of this study

suggest a need to increase water monitoringin order to effectively improve water qualityand thereby reduce incidence of water-relat-ed diseases. In this context, the MBSmethod can be suitable for microbiologicalwater analysis in rural areas by local per-sonnel, operating without a microbiologicallaboratory.

References

1. Sabae SZ, Rabeh SA. Evaluation of themicrobial safety of the river Nile watersat Damietta branch, Egypt. Egypt JAquat Res 2007; 33:301-11.

2. Obi CL, Potgieter N, Bessong PO,Matsaung G. Assessment of the micro-bial safety of river water sources inrural Venda communities in SouthAfrica. Water SA 2002;28.

3. Clasen T, McLaughlin C, Nayaar N, etal. Microbiological effectiveness andcost of disinfecting water by boiling insemi-urban India. Am J Trop MedHygiene 2008:407-13.

4. Schwarzenbach RP, Egli T, HofstetterTB et al. Global water pollution andhuman health. Environ Res2010;35:109-36.

5. Chouler J, Di Lorenzo M. Water safetymonitoring in developing Countries;can microbial fuel cells be the answer?Biosensors 2015;5:450-70.

6. Bottini G, Losito F, De Ascentis A, et al.Validation of the micro biological sur-vey method for total viable count andEscherichia coli in food samples. Am JFood Technol 2011;6:951-62.

7. Losito F, Bottini G, De Ascentis A, et al.Qualitative and quantitative validationof the Micro Biological Survey Methodfor Listeria spp., Salmonella spp.,Enterobactericeae and Staphylococcusaureus in food samples. Am J FoodTechnol 2012;7:340-51.

8. Arienzo A, Losito F, Stalio O, AntoniniG. Comparison of uncertainty betweentraditional and alternative methods forfood microbiological analysis. Am JFood Technol 2016;11:29-36.

9. Sobze MS, Wadoum RG, Colizzi V,Antonini G. Field application of theMicro Biological Survey method for asimple and effective assessment ofmicrobiological safety of water sourcesin developing Countries. Int J EnvironRes Public Health 2015;12:10314-28.

10. Allen MJ, Edberg SC, Reasoner DJ.

Article

Non co

mmercial

use o

nly

[Journal of Public Health in Africa 2017; 8:679] [page 29]

Heterotrophic plate count bacteria –what is their significance in drinkingwater? Int J Food Microbiol 2004;92:265-74.

11. WHO. Guidelines for drinking-watersafety. Assessment of risk and risk man-agement for water-related infectiousdisease. Geneva: World HealthOrganization; 2001.

12. Páll E, Niculae M, Kiss T, et al. Humanimpact on the microbiological waterquality of the rivers. J Med Microbiol2013;62:1635-40.

13. EPA Protocol for the review of existingnational primary drinking water regula-tions, 2003. Available from:https://www.epa.gov/sites/production/files/2014-12/documents/815r03002.pdf

14. Bhuptawat H, Folkard GK, ChaudhariSK. Innovative physico-chemical treat-ment of wastewater incorporatingMoringa oleifera seed coagulant. JHazard Mat 2007;142:477-82

15. Pritchard M, Craven T, Mkandawire T,et al. A comparison between Moringaoleifera and chemical coagulants in thepurification of drinking water – Analternative sustainable solution fordeveloping countries. Phys Chem Earth2010;35:798-805.

16. Solomon S, Quiel F. Groundwater studyusing remote sensing and geographicinformation systems (GIS) in the centralhighlands of Eritrea. Hydrogeol J2006;14:729-41.

17. Folkard GK, Sutherland JP.Development of a naturally derivedcoagulant for water and wastewatertreatment. Water Sci Technol2002;2:89-94.

18. Sharma P, Kumari P, Srivastava MM,Srivastava S. Removal of cadmiumfrom aqueous system by shelledMoringa oleifera Lam. seed powder.Biores Technol 2006;97:299-305.

19. Muyibi SA, Alfugara AMS. Treatmentof surface water with Moringa oleiferaseed extract and alum: a comparativestudy using pilot scale water treatmentplant. Intern J Environ Stud 2003;60:617-26.

20. Sengupta ME, Keraita B, Olsen A, et al.Use of Moringa oleifera seed extracts toreduce helminth egg numbers and tur-bidity in irrigation water. Water Res2012;46:e3646-56.

21. Fawell J, Nieuwenhuijsen MJ.Contaminants in drinking water. BrMed Bull 2003;68:200-8.

22. Wright J, Gundry S, Conroy R.

Household drinking water in develop-ing Countries: a systematic review ofmicrobiological contamination betweensource and household. Trop Med IntHealth 2004;9:106-17.

23. Lye JD. Microbiology of rainwater cis-tern systems: a review. J Environ SciHealth 1992:27.

24. Sánchez-Martín J, Beltrán-Heredia J,Peres JA. Improvement of the floccula-tion process in water treatment by usingMoringa oleifera seeds extract. Brazil JChem Eng 2012;29:495-501.

25. Abaliwano JK, Ghebremichael KA,Amy GL. Application of purifiedMoringa oleifera coagulant for surfacewater treatment; Water Mill WorkingPaper Series no. 5; UNESCO-IHEInstitute for Water Education: Delft,Netherlands, 2008.

26. Kansal S, Kumari A. Potential of M.oleifera for the treatment of water andwastewater. Chem Rev 2014;114:4993-5010.

27. Ndabigengesere A, Narasiah KS.Quality of water treated by coagulationusing Moringa oleifera seeds. WaterRes 1998;32:781-91.

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