Theses and Dissertations (Veterinary Public Health)

Chemical Composition, Bacterial Load and Prevalance of Verotoxigenic Escherichia Coli in Donkey Meat Sold at Ezzamgbo, Ebonyi State Nigeria

2017-06-05T00:00:00Z

Chemical Composition, Bacterial Load and Prevalance of Verotoxigenic Escherichia Coli in Donkey Meat Sold at Ezzamgbo, Ebonyi State Nigeria Olorunleke, Solomon This study was carried out to evaluate the chemical composition and bacterial load of donkey meat as well as the prevalence of verotoxigenic Escherichia coli (VTEC). The study adopted the survey and experimental designs. A questionnaire, which comprised three sections, was developed to elicit information on the demographics, source of meat, and factors that influence choice of meat consumed by the respondents. The instrument for data collection was validated by three experts. A pilot study was conducted and the Cronbach Alpha Reliability Coefficient of 77.5% was determined. Four hundred and fifty copies of the questionnaire were administered to respondents in Ezzamgbo who were selected by a simple random sampling technique. This comprised meat sellers (117), butchers (36), farmers (72), civil servants (130), students (68), artisans (18) and donkey hide sellers (9). Systematic random sampling was employed to select 60 donkeys at slaughter. From each of the selected donkeys, three meat cuts (shank, sirloin and ribs) giving a total of 180 meat samples were collected and processed for chemical composition and bacteriological analysis. The meat cuts were analysed for mineral content, percentage moisture, protein, fat and ash. The bacterial load of the meat was evaluated by mean aerobic plate count (APC) on nutrient agar and mean coliform count (MCC) on MacConkey agar. Suspected E. coli isolates were characterized by conventional biochemical tests and Analytical Profile Index (API). Confirmed E. coli were presumptively identified as VTEC on sorbitol MacConkey agar (SMAC). The prevalence of VTEC O157 and non O157 was determined using specific latex agglutination test. The resistance profiles of the isolates to commonly used antibiotics were evaluated using the disc diffusion method. The chemical composition and bacteriological survey were subjected to one way analysis of variance and significant means were separated using Duncan’s multiple range test at the significance level of p < 0.05. The factors that influence the preference for meat type were affordability, tenderness and flavour. The brightness of the meat, availability and religious and cultural restrictions had no direct influence on the choice of meat type. Forty-four, forty-one and forty-nine percent of the respondents indicated that beef, donkey and chevon, respectively are cheap and affordable. Seventy-four percent of the respondents indicated that the hike in price of beef was influenced by the insurgence in Northern Nigeria while Fifty-three percent indicated that the insurgence in the North has influenced the price of donkey meat and chevon. Sixty nine, forty and sixty-eight percent of the respondents indicated that beef, donkey meat and chevon, respectively are soft and tender but eighty percent indicated that chevon have good aroma or flavour while sixty-two and thirty-five percent stated that beef and donkey meat have good aroma. There were no significant differences (p > 0.05) in the iron content and percentage moisture and protein between the various meat cuts. There were significant differences (p > 0.05) in zinc, magnesium, calcium and phosphorus contents and percentage ash and fat between the meat cuts. The mean values of the chemical composition of donkey meat were 74.11±1.20% moisture, 1.73±0.50% ash, 21.37±0.79% protein and 2.30±0.22% fat, 3.76±0.47 mg/100 g zinc, 4.27±0.30 mg/100 g calcium, 3.04±0.21 mg/100 g magnesium, 0.60±0.06 ppm iron and 0.046±0.01 ppm phosphorus. The mean APC for the meat cuts were 1.2 x 108 ±2.35 x 107 cfu/g, 9.16 x 107 ±2.01 x 107 cfu/g and 1.08 x 108 ±2.27 x 107cfu/g for the shank, sirloin and ribs respectively. There were no significant (p > 0.05) differences in the mean APC values between the different meat cuts. The MCC of the rib (2.47 x 107 ± 5.26 x 106cfu/g) was significantly higher than those of the shank (1.94 x 107 ± 4.28 x 106cfu/g) and sirloin (9.90 x 106 ± 2.16 x 106 cfu/g). A total of 108 E. coli isolates, comprised 52 from the shank, 30 from the sirloin and 26 from the rib, were obtained from the 180 meat samples. Thirty-seven of these isolates were sorbitol negative out of which 28 were confirmed VTEC O157:H7 while 16 were confirmed non-O157: H7. The overall prevalence rate of VTEC O157:H7 was 15.56%. Resistance to ampicillin, streptomycin, amoxicillin/clavulanic acid and tetracycline were exhibited by 100, 85.71, 78.5 and 42.86%, respectively of the VTEC O157:H7 strains. It was concluded that the factors that influence individuals’ choice of meat are availability, price, flavor, brightness, and health related issues. Religious and cultural sentiments had little influence on the consumption of meat generally. Donkey meat is frequently masked as beef and sold to unsuspecting consumers. Donkey meat is nutritional wholesome as it contains high protein, ash, zinc, calcium, magnesium, phosphorus and iron. Donkey meat sold at Nkwo-Jaki is unsafe for human consumption using the bench mark of microbial standard. The contamination of the meat is associated with the health status of the animal, the environment and the personnel handling the meat. The prevalence of 15.56% of VTEC and 8.89% of non-O157 makes donkey meat sold at Nkwo-Jaki unsafe and may pose a threat to the health of individuals who consumes the meat. The high level of resistance of the bacterial isolate in this study shows that there is possibility of indiscriminate use of antibiotics in donkeys or the personnel handling the meat are infected with bacteria that have developed resistance to most of the antibiotics used.

Prevalence and Characteristics of Extended Beta-Lactamase Producing Enterobacteria in Cattle and Chickens Slaughtered at Ikpa Market, Nsukka, Enugu State

2017-06-05T00:00:00Z

Prevalence and Characteristics of Extended Beta-Lactamase Producing Enterobacteria in Cattle and Chickens Slaughtered at Ikpa Market, Nsukka, Enugu State Okpala, Angela.O This study was conducted to determine the prevalence of ESBL-producing enterobacteria in chickens and cattle slaughtered at Ikpa market, Nsukka; to identify the types of ESBL enzymes harboured by the ESBL-producing bacteria isolates and to determine the antibacterial résistance phenotype and genotype of the ESBL-producing isolates. This study adopted a survey design. It was conducted at Ikpa market, Nsukka, Enugu State Nigeria. The market was purposively selected because it is a major market in Nsukka Agricultural zone where large number of chickens and cattle are sold or slaughtered. The chickens and cattle used for the study were selected by systematic random sampling of those slaughtered. A total of 210 cloacal and rectal swab samples each were collected from slaughtered chickens and cattle, respectively, between April and June, 2012. The samples were streaked on MacConkey agar supplemented with cefotaxime (2µg/ml) and incubated at 37oC for 24 hours. Colonies on this medium were purified and identified using colonial, microscopic and biochemical characteristics following standard procedures. Detection of ESBL production among the isolates was done by the double disc synergy test using Oxoid cefpodoxime kit and in accordance with the manufacturer’s instructions. The types of ESBL enzymes in 8 of the ESBL-producing E. coli isolate were determined by screening the isolates for presence of genes encoding TEM-, OXA-, SHV- and CTX-M-type β-lactamases, by polymerase chain reaction (PCR) following standard procedures. Phenotypic resistance of the isolates to 21 antimicrobial agents was assessed using the disc diffusion method according to the Clinical Laboratory Standards Institute. Genes encoding resistance to tetracycline, streptomycin and gentamicin were studied by PCR according to standard procedures. Data generated were subjected to descriptive statistics and the results were expressed in percentages. Fifteen (7.1%) of the 210 chicken cloacal swab samples yielded microbial growth, while none (0.0%) of the 210 cattle rectal swab samples yielded microbial growth. The isolates from the 15 chickens were all positive for ESBL production. Thirteen (86.7%) of the ESBL-producing isolates were E. coli while 2 (13.3%) were Klebsiella species. The ESBL enzyme in 6 (75.0%) and 2 (33.3%) of the 8 E. coli strains characterized belonged to the CTX-M-15 and CTX-M-1 types, respectively. Three (37.5%) and 2 (33.3%) of the 8 E. coli strains characterized also haboured the TEM- and OXA-1- type β-lactamases, respectively. Both Klebsiella species contained the CTX-M-15 type ESBL enzyme, one of them also haboured SHV-81 β-lactamase. All (100.0%) the ESBL-producing E. coli strains were resistant to cefotaxime, cefuroxime, cefpodoxime, ceftriaxone, ampicillin and tetracycline while 92.3% were resistant to streptomycin and aztreonam. Resistance to trimethoprim, ciprofloxacin, nalidixic acid, norfloxacin, levofloxacin, enrofloxacin, ceftazidime and ampicillin was exhibited by 62.0% to 76.9% of the E. coli strains while 38.5% were resistant to gentamicin and tobramycin. The two ESBL-producing Klebsiella strains were resistant to norfloxacin, ciprofloxacin, enrofloxacin, nalidixic acid, streptomycin, tobramycin, cefotaxime, ampicillin, trimethoprim, chloramphenicol and tetracycline while one was resistant to levofloxacin and gentamicin. Six (40.0%) of the 15 ESBL-positive isolates demonstrated resistance to greater than 5 classes of the antimicrobial agents tested. Six (75.5%) of the 8 E. coli isolates characterized were positive for tetracycline resistance gene, tetA, while 2 (25.0%) were positive for both tetB and aminoglycoside resistance gene, aac-3. The two Klebsiella isolates were positive for both tetA and aac-3genes.This study has shown the presence of MDR ESBL-producing Esherichia coli and Klebsiella in chickens at Ikpa Market Nsukka, Nigeria.

Occurrence of Antimicrobial Residues in Broilers in Enugu Metropolis and the Effect of Temperature on the Concentration of Oxytetracycline Residue

2017-06-05T00:00:00Z

Occurrence of Antimicrobial Residues in Broilers in Enugu Metropolis and the Effect of Temperature on the Concentration of Oxytetracycline Residue Ezenduka, Ekene Vivienne The high turn-over rate and quest for white meat have given more impetus to poultry production. The need to increase production and meet the demand for poultry meat has necessitated the use of veterinary drugs, especially antimicrobials, for therapeutic, prophylactic and growth promotion purposes in poultry farming. These drugs tend to accumulate in tissues and organs as residues. The presence of drug residues in tissues above maximum residue limit (MRL) becomes violative if withdrawal periods are not observed. The consumption of violative levels of antimicrobial residues could result in the development of antibiotic-resistant strains of microorganisms, allergic reaction in sensitised individuals, distortion of activities of the intestinal flora, carcinogenesis and mutagenesis. There is evidence of excessive prescription, overuse and abuse of antimicrobial drugs in veterinary practice in Nigeria, and legislation regarding drug use in veterinary practice is hardly enforced. It has become necessary to monitor the presence and level of antimicrobial residues in poultry in Nigeria using reliable screening tests. This is imperative since there is presently no established surveillance programme for detecting drug residues. Oxytetracycline (OTC) is the most widely used antimicrobial in poultry production. Although thorough cooking is part of our food culture, studies have shown that some drugs are heat stable, hence there is need to investigate the effects of heat and freezing on the stability of this drug in tissues. The study to: (i) assessed the occurrence of antimicrobial residues in broilers retailed in Enugu metropolis, (ii) evaluated the effects of cooking methods and freezing on OTC residue, (iii) compared the sensitivity of detection of OTC residues in tissues using Three Plate Test (TPT) and Premi® test. The study involved both a cross sectional survey of broilers retailed in Enugu metropolis and two experiments. The survey was an assay of antimicrobial residues in broiler meat and organs using qualitative screening methods (TPT and Premi® Test) and a quantification of tetracycline (TC) residues using specific enzyme-linked immunosorbent assay (ELISA) technique. The three major markets (Artisan, Gariki and Ogbete) in which broilers are retailed in Enugu metropolis, were used for the study. A total of 100 broilers were proportionately selected according to the sale capacity of each of the markets as follows: Artisan (40), Gariki (30) and Ogbete (30). The birds and retailers were selected using systematic random sampling technique. Muscle, liver, kidney and gizzard were collected from each of the 100 broilers for the survey. For the experiments, TPT, Premi® Test and ELISA were used to detect OTC residue in tissues of OTC treated birds and to evaluate the effects of various cooking methods (boiling, microwave grilling and roasting) and freezing time on the level of OTC residues. Fifty 5-week old broilers were raised for 3 weeks for the experiment. Four birds were sacrificed and their organs screened for residues. In the absence of residues, the remaining 46 birds were assigned into 2 equal groups (A and B). Group A birds were injected with long acting OTC at the dose of 20mg/kg body weight and group B birds were given OTC in drinking water at the dose of 4g/l for 5 days. Their organs were screened for OTC residue 24 hours after treatment. For each organ, meat juice was extracted by maceration and centrifugation. The API50 and polymerase chain reaction (PCR) were used to identify and characterize the Bacillus subtilis used for the TPT. Premi® test and ELISA were done following the manufacturer’s instructions. Graphpad Prism 5 statistical package was used to analyse the data generated. Chi-square was used to determine associations between occurrence of residues and organ types. One way analysis of variance was used to analyse other data as appropriate. Dunn’s multiple comparism was used for post hoc analysis. Three plate test inhibition zones were correlated to OTC concentration. Significance was accepted at p < 0.05. For the survey, TPT detected antimicrobial residues in 64% of broilers and the organ distribution were as follows: kidney (60%), liver (54%), gizzard (30%) and muscle (11%). Premi® test detected residues in 60% of broilers and distribution in specific organs were: kidney (49%), liver (25%) gizzard (22%) and muscle (14%). The ELISA detected tetracycline residues in 90% of broilers and detection in specific organs were: liver (96%), muscle (96%), kidney (88%) and gizzard (82%). The residue level was above MRL in 84% of liver, 100% of gizzard and 86% of muscle, whereas residues in 100% of positive kidney samples were below the MRL. For the experimental study, microwaving, boiling and roasting significantly (p < 0.05) reduced the inhibition zones produced by raw liver in TPT. There was a significant (p < 0.05) decrease in OTC residue concentration in roasted and boiled liver samples tested with ELISA. The three cooking methods had no significant (p > 0.05) effect on residue levels in muscle samples. Freezing had no significant (p > 0.05) effect on residue levels in muscle and liver samples. Three plate test had a higher sensitivity in detecting OTC residue than Premi® test in muscle and liver of birds treated by injection and those administered OTC in drinking water. There was a positive and significant correlation (r = 0.94; p < 0.05) between the TPT inhibition zones and OTC concentration.