Bacteriological, physicochemical and mineral analysis of water used in abattoirs in Ado-Ekiti, Southwest Nigeria

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1 Journal of Microbiology and Biotechnology Research Scholars Research Library J. Microbiol. Biotech. Res., 2011, 1 (2): ( ISSN : CODEN (USA) : JMBRB4 Bacteriological, physicochemical and mineral analysis of water used in abattoirs in Ado-Ekiti, Southwest Nigeria * 1 Odeyemi, A.T., 2 Dada, A.C., 3 Akinjogunla, O.J., 4 Agunbiade O.R 1 Department of Microbiology, University of Ado-Ekiti, P.M.B 5363, Ado Ekiti, Nigeria. 2 School of Biosciences and Biotechnology, National University of Malaysia, Bangi 3 Department of Microbiology, University of Uyo, Akwa Ibom 4 Department of Zoology, University of Ado-Ekiti, Nigeria ABSTRACT Bacteriological, physicochemical and mineral analysis of water used in the months of January, February and March 2008, in two major abattoirs in Ado-Ekiti was determined. The bacteriological analysis of water used in two major abattoirs (Atikankan and Adere abattoirs) in Ado-Ekiti was assessed using standard microbiological techniques. Physicochemical and mineral constituents were also determined for the collected water samples. Results from the bacteriological analysis indicated that all the samples collected were highly contaminated with pathogenic organisms, Escherichia coli having the highest observed prevalence (26%) while Enterobacter aerogenes had the least observed prevalence (4%) among the encountered isolates. Highest mean bacterial count observed during the study was 8.5 x 10 7 cfu/ml. Recorded ph and temperature values ranged between and C C respectively. The mineral values obtained were Ca ( mg/l), Mg ( mg/l), Na ( mg/l) and K ( mg/l), while iron, copper, zinc, and manganese had values which ranged from mg/l, mg/l, mg/l and mg/l respectively. The need for improved sanitary conditions in abattoirs in Nigeria is emphasized. Key words: Bacteriological, Abattoir, Physicochemical, Sanitary condition. INTRODUCTION Abattoir is a slaughter house derived from the French word abattre meaning to strike down [1]. It is a place where animals such as cattle, goats, and so on are killed, dressed and distributed for consumption and other industrial purposes. Abattoir operation produces a characteristic highly organic waste with relatively high levels of suspended solid, liquid, and fat. The liquid waste generated is usually composed of dissolved solids, blood, gut contents, urine and water. 14

2 The continuous drive to increase meat production for the protein needs of the ever increasing world population comes with some pollution problems attached. In many countries, pollution arising from activities in meat production is as result of failure adhering to Good Manufacturing (GMP) and Good Hygiene Practices (GHP) [2]. Consideration is hardly given to safety practices during animal transport to the abattoir, during slaughter and during dressing. Yet, contamination from slaughter slabs and within the abattoir is of a high significance as it can occur at each step employed during the carcass dressing. Human micro biota could also contaminate the carcasses during slaughtering and distribution [3]. Also the animal involved, such as cow, sheep, goats and birds; can also serve as sources of contaminants. Microorganisms such as Enterobacter aerogenes, faecal Streptococcus, and Escherichia coli could come from human (butcher) microbiota, the knife used, or even from animal itself while Bacillus subtilis could emanate from the abattoir ground [4]. Apart from contamination of the meat, contaminations from hides, hooves and content of alimentary tract during evisceration could negatively impact the environment [4]. Added to the complex situation is the dilemma of having to manage wastewater from abattoirs without subsequent contamination of nearby water sources. As the population grows and more pressure as a result of urbanization is put on the demand for meat, demand for water for use also increases while more wastewater is generated. Consequently, a greater amount of organic and inorganic wastes spread back into the neater sources so that less portable water eventually becomes available [5]. This could thus warrant a shift to source waters of less quality for use in meat processing. As the water used in the washing of carcasses could serve as a good source of contaminant., water used for cleaning procedures must thus meet drinking water standards [6] and by definition this water should not contain chemical substances or microorganism in amounts that could cause hazards to health [1]. Historically water has played a significant role in the transmission of human disease, such as typhoid fever, cholera, infectious hepatitis, bacillary and amoebic dysenteries and many varieties of gastro-intestinal diseases [7]. Bacteriological examination of water has thus been considered a powerful and foremost tool to foreclose the presence of microorganisms that might constitute a health hazard. This forms the basis for quality studies on water available for abattoir use in Ekiti State. The two major abattoirs in Ado-Ekiti are Atikankan and Adere abattoirs serving the meat protein (beef) needs of about 65% of the populace of Ado-Ekiti. About cows are sacrificed daily in Atikankan abattoir while cows are sacrificed in Adere abattoir daily. The study was carried out to ascertain the microbiological and chemical quality of water available for use in two major abattoirs in Ado-Ekiti, a south western town in Nigeria. MATERIALS AND METHODS Collection of Water Sample: Water samples were collected aseptically with the aid of a sterilized sampling bottle and transported in ice to the Microbiology laboratory for analysis within 4-6 hrs after collection. Samples were collected at three different sites where well water is made available for use in the abattoirs. Seven samples were collected at each site at interval of every eight (8) days. Preparation of Culture Media and Samples: The media used for this research study were; Nutrient agar, MacConkey, Salmonella-Shigella agar, Bacillus cereus agar and Eosin Methylene Blue Agar all which were prepared according to 15

3 manufacturers instructions. The samples were diluted serially in ten fold (10-5 ). The samples were cultured on the respective culture media within 6 hours after collection. Enumeration of Total Bacterial and Coliform Counts: Determination of bacterial and coliform load in the water samples were done in triplicates. Bacterial plate counts were carried out using the pour plate method with nutrient agar. This method was based on the serial dilution of water sample, which were then pipetted into each sterile Petri-dish. About 20ml of molten nutrient and MacConkey agar was cooled to 45 0 C and poured into each Petri-dish containing 1ml of the wastewater sample. Plates were allowed to cool and set after which they are then incubated in inverted position at 37 0 C. After 24hrs of incubation, the plates were counted by colony counter to obtain the total bacterial and coliform counts respectively [8]. Characterization and Identification of Isolates: The isolates were classified on the basis of biochemical, physiological and morphological characteristics as described by [9]. Antibiotic Susceptibility Test: The antibiotics susceptibility of the isolates was determined by the disk diffusion method of CLSI (2005). The antibiotic multi-disc containing ampicillin (10g), chloramphenicol (30g), cloxacillin (5g), erythromycin (5g), gentamycin (10g), penicillin, streptomycin (10g), and tetracycline (10g). The inoculums was standardized by adjusting its density to equal the turbidity of a Barium sulphate (BaSO 4 ) (0.5 McFarland turbidity standard) and incubated at 35 0 C for 18hours. The diameter of the zone of clearance (including the diameter of the disk) was measured to the nearest whole millimeter and interpreted on the basis of CLSI guideline [10]. Physicochemical analysis: About 5cm 3 of concentrated HCL was added to 250cm 3 of water sample and evaporated to 25cm 3. The concentrate was transferred to 50cm 3 standard flask and diluted to the mark with distilled de-ionized water [11]. The ph was measured with a KENT EIL 7020 (Kent industrial measurement Limited, Surrey, England) ph-meter, temperature was measured with a simple thermometer calibrated in centigrade, conductivity was measured with CDM83 conductivity meter (By Radiometer A/S Copenhagen, Denmark) after standardization with KCI solution, various standard methods were used for the determination of other parameters. Total alkalinity was determined by acidometry using bromocresol green-methyl red mixed indicator; total hardness and calcium hardness by EDTA titration using Erichrome Black-T-indicator. Mineral Analysis: Zinc, iron, copper, cobalt, lead and manganese were analyzed in the three matrices using a Perkin Elmer model 306 Atomic Absorption Spectrophotometer phosphorus, sulphur and calcium were analyzed from solution obtained by means of Atomic Absorption Spectrophotometer (PYE Unicam Sp 9, Cambridge, UK) [11]. RESULTS AND DISCUSSION The total bacterial and coliform counts of water samples of both Atikankan and Adere abattoirs are illustrated in Tables1 and 2 respectively. From the tables, the total bacterial and coliform counts (TBC and TCC) of the samples from both abattoirs ranged from 1.17 x 10 7 cfu/ml to 8.05 x 10 7 cfu/ml and 1.00 x 10 5 cfu/ml to x 6.1 x 10 5 cfu/ml respectively. These figures indicate very high microbial loads. As presented in a similar study by [12], the high bacterial and coliform 16

4 loads could be attributed to the poor sanitary and hygienic practices of the abattoirs management and workers, the poor state of health of the slaughtered cows and faecal and contaminations from the intestines of the slaughtered animals (Figures 1a and 1b). As observed in the study location, wastewater from the slaughtering and dressing slabs in both abattoirs is washed into open drainage which is untreated. According to [13], the water and leachates from the series of decomposition processes from the wastes percolate into underlying aquifers to contaminate hand-dug wells and other surrounding surface water bodies. This poses a danger to those working in the abattoirs and those living around them as available water sources close to them become contaminated. Added to this danger is the possibility of recontamination of meat products when such polluted water is used for processing in the same abattoir. Values obtained for the bacteriological count also show that the TBC and TCC for Adere abattoir are relatively high compared to those of Atikankan abattoir. This could be attributed to the fact that on the average, more animals are slaughtered in Adere abattoir daily as compared to that of Atikankan abattoir. Furthermore, the results obtained on Sunday were significantly lower compared to other days. This is also attributable to the lesser number of cows being slaughtered on Sundays. We can infer from here that the higher the number or cows slaughtered (in the light of currently poor manufacturing and hygiene practices), the higher the microbial load and thus, the greater the risk of contamination of surrounding water bodies and also of meat to be sold to the public. Two hundred isolates were encountered during the study and their frequency of occurrence is shown in Table 3. Escherichia coli had the highest frequency (26%) followed by Enterococcus spp. (20%), Streptococcus spp. (14%), Klebsiella spp (10%), Salmonella spp (10%), Pseudomonas spp. (8%) while Shigella spp, Bacillus spp. and Enterobacter spp. each had the least frequencies of occurrence (4%). E. coli which has the highest frequency of isolation in this study still remains a very useful indicator of faecal contamination in water bodies [14]. It becomes particularly worrisome if antibiotic resistant organisms from meat processing environments contaminate water sources in the environment causing infections among the human populace. The clinical management of such infections then becomes a major challenge. Today the age long battle against antibiotic resistance in Africa is far from being won. The physiochemical properties of the abattoir water samples were also determined and the result is presented in Table 4. Values obtained for ph ranged from 6.6 to 7.2 while temperature was between C to C. Total suspended solid (TSS) for all the samples were within the range 8.3 x 10-3 to mg/l, total dissolved solids (TDS) ranged from 3.97 x 10-2 to 3.55 x 10-1 mg/l. Also values obtained for total solids (TS) ranged from 2.62 x 10-2 mg/l to 1.15mg/L. The result of mineral analysis carried out is shown in the Table 5. The range of values obtained were 50.9 to 80.5 mg/l for sodium, 99.3 to mg/l for potassium, 60.2 to 10.6 mg/l for calcium, and 2.9 to 5.1 mg/l for zinc, magnesium ranged from 71.2 to mg/l and copper determined in the water samples had values between 0.1 and 0.2 mg/l. Values obtained for determination of Iron content fell within the range of 0.7 to 1.9 mg/l. 17

5 Table 1: Total Bacterial Count (10 5 CFU/ml) of water samples from Atikankan and Adere Abattoirs Key: Period of collection Atikankan Adere A1 A2 A3 B1 B2 B3 Week 1 Monday Week 2 Tuesday Week3 Wednesday Week 4 Thursday Week 5 Friday Week 6 Saturday Week 7 Sunday A- Atikankan abattoir, B- Adere abattoir, 1,2 and 3 represent three different samples collected at three different points. Table 2: Total Coliform Count (10 5 CFU/ml) of water samples from Atikankan and Adere Abattoirs Period of collection Atikankan Adere A1 A2 A3 B1 B2 B3 Week1 (Monday) Key: Week 2 Tuesday Week3 Wednesday Week4 Thursday Week 5 Friday Week 6 Saturday Week 7 Sunday A- Atikankan abattoir, B- Adere abattoir, 1, 2 and 3 represent three different samples collected at an interval o eight days Table 3: Frequency of Occurrence of Isolated Organisms from abattoirs Isolates No of occurrence Percentage of occurrence Escherichia coli 52 26% Enterococcus spp % Streptococcus spp % Klebsiella spp % Salmonella spp. 20 8% Pseudomonas spp. 16 4% Shigella spp. 8 4% Bacillus spp. 8 4% Enterobacter spp % Total

6 Table 4: Physiochemical values of abattoir water in Atikankan and Adere Parameters A1 A2 A3 B1 B2 B3 ph Range Temperature ( 0 C) Dissolved oxygen (mg/l) Total solid (mg/l) Total dissolved solids (mg/l) Total suspended solid (mg/l) Conductivity (ms/cm) Biochemical oxygen demand Key: A- Atikankan abattoir, B- Adere abattoir, 1,2 and 3 represent three different samples collected at three different points. Table 5: Mineral composition of abattoir water in Atikankan and Adere Key: Minerals A1 A2 A3 B1 B2 B3 Sodium (Na) Potassium (K) Magnesium (Mg) Calcium (Ca) Zinc (Zn) Copper (Cu) Iron (Fe) Manganese (Mn) 0.1 ND ND Lead (Pb) ND NR 0.1 ND A- Atikankan abattoir, B- Adere abattoir, 1,2 and 3 represent three different samples collected at three different points. Figure 1a and 1b: Manufacturing and hygiene practices during animal slaughter at Adere abattoir On-site observation of the two abattoirs shows that the sanitary conditions under which carcasses are being dressed are far from ideal, pipe borne water is not available and the wells dug in replacement for unavailable pipe borne water are not well maintained. Water is retrieved from the wells using manual drawing buckets which are left lying around in the mud or on the slaughter slabs and are re-used at will. It is suggested that more attention should be given to the quality of meat emanating from our various abattoirs by the relevant authorities with a view to providing healthy meat to the populace. The National Agency for Food and Drug Administration land Control (NAFDAC) should ensure that animals to be slaughtered are free from infection and are in healthy condition. There should be an enforcement of the adoption of microbiological criteria by the meat producers and provision of guidelines, specifications for the quality of process water, safe discharge of spent water and other standards that would ensure good manufacturing and hygiene practices. Furthermore, there should be enforcement of the regular 19

7 cleaning and disinfection of the abattoirs. In addition, the health of abattoir workers should be constantly monitored as contamination could result from human micro biota or flora. REFERENCES [1] D.O.Alonge, Textbook of meat hygiene in the tropics farmcoe press, Ibadan.1991, 58. [2] A.O.Adesemoye., B.O.Opere and S.C.O.Makinde, 2006, African Journal of Biotechnology, 2006, 5 (20), [3] A.W.Akpan, The Environmentalist, 2004, 24: [4] K.O.Amisu, A.O.Coker, S.L.W.On and R.D.Isokpehi, East Afri. Medical J, 2003, 80: [5] H.T.Shuval, Advances in water pollution Research, Oxford pergamon press, [6] L.F.L.Fonseca, Proc. Xth ISAH Maasttricht, the Netherlands, 2000, [7] P.S.Gerger and Y.Argaman (eds) Assessment of microbiology and turbidity standards for drinking water, [8] G.I.Barrow and R.K.A.Feltham, 3rd edn. Cambridge: Cambridge University Press, [9] P.O.Olutiola, O.Famurewa and H.S.Sonntag, Bolabay publication, 2000, [10] CLSI, Clinical and Laboratory Standard Institute Wayne, Pa. 2005, 25(1). [11] AOAC, 18 th Ed. Association of official Analytical Chemists, [12] O.A.Ogunseitan, World J. Microbiol. Biotechnol. 2002, 18: [13] S.S.Abiola, J. of. Ani. Prod. 1995, 5:62 [14] C.Monica, District laboratory practice in tropical countries, 2000, 2(7);