The effect of crude oil pollution on soil properties, germination and height of maize (Zea mays) was investigated under natural environment in three separate pot experiments. Two crude oil types--Forcados light and Escravos light were used. In Experiment 1, the effect of crude oil application on germination using high pollution levels of 5, 15, 25 and 40 mL kg(-1) of soil was assessed. In Experiment 2, the effect of crude oil application on maize plant height using the same pollution levels was assessed. The last experiment (Experiment 3) was used to test for the effects of crude oil application on maize plant height using lower levels of pollution (1.0, 1.5, 2.0 and 2.5 mL kg(-1) of soil). Soil samples were collected before, during and after the experiment and analyzed for some physical and chemical properties. Results obtained showed variation in chemical properties of soil. % organic matter increased from 1.34 to 2.62% in polluted soils. Available P decreased from 15.00 ppm in control to between 7.34 and 5.42 in soils polluted with 'high' levels of crude oil. Statistical analysis of height data showed that crude oil inhibited the growth of maize at high pollution levels. High levels of pollution also inhibited germination and for Escravos light there was no germination at 40 mL kg(-1) soil level of crude oil pollution.

An investigation of the effects of application of poultry manure to crude oil polluted soils on the growth of maize and soil properties was carried out under natural conditions at the Ambrose Alli University, Ekpoma, Nigeria. Potted maize plants were treated to crude oil pollution at four different levels (0, 25, 50 and 75 mL) and amended with poultry manure at four rates of application (0, 50, 100 and 150 kg ha(-1)) two weeks after pollution. Results obtained showed that percent survival rate, plant height and dry matter yield decreased with increase in crude oil contamination. For example % seed germination decreased from 93 to 0% as crude oil increased from 0 to 75 mL without poultry manure application while plant height decreased from 97 to 20 cm. However when amended with poultry manure, statistical analysis showed that the highest rate of crude oil application (75 mL) and the 150 kg ha(-1) rate poultry manure application affected maize growth, dry matter yield and soil properties significantly. For example at the 75 mL crude oil application, plant height increased from 20 to 149 cm as level of manure applied increased from 0 to 150 kg ha(-1) while dry matter yield increased from 27 to 58 g.

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The study was carried out to investigate the effects of application of cassava mill effluent on bacteria and fungi types and population in a soil grown to maize (Zea Mays L.) Microbial populations were determined before pollution of soil with cassava mill effluent, six weeks after pollution with effluent and at the end of the experiment. Results obtained showed that bacteria and fungi populations increased with time as rates of pollution increased. It was also observed that some bacteria present in the soil at the beginning of the experiment and up to the sixth week after pollution with effluent became extinct at the end of the experiment.

Background:The major influences on the increase and spread of antimicrobial resistant bacteria are the use of antimicrobial agents in human medicine and their use in livestock for therapy and growth promotion. To generate baseline data to use in future risk assessment of antimicrobial resistance, a number of surveillance program on the local, continental and global scale have been initiated. The prevalence of resistance in commensal E. coli is a good indicator for the selective pressure by antibiotics use and resistance problems to be expected in pathogenic bacteria. The aim of this study was to determine and compare the occurrence of antimicrobial resistance phenotypes and genotypes among E. coli strains recovered from animal sources.Methods & Materials: Fifty-eight (58) E. coli strains were isolated from animal sources (Cattle, pig and chicken). MIC was determined according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Strains were screened and mapped by PCR methods for antimicrobial resistant genes, integrons and gene cassettes.Results: The resistance profile of E. coli for ampicillin (100%), cefotaxime (100%), ceftazidime (83%), ciprofloxacin (43%) (C), tetracycline (100%) (T), gentamicin (90%) (G), kanamycin (77%) (K), streptomycin (100%) (S), chloramphenicol (97%) (Ch) sulphamethoxazole (100%) (Su) and trimethoprime (97%) (T). Eight-Five per cent (85%) of E. coli harbored class 1 integron and variable gene cassettes were revealed. A prevalence of gene cassettes that present resistance to streptomycin and trimethoprime was observed. The resistance genes determinant present in gentamicin resistance were aac(3')-IIc, aac(6')-Ib and ant(2")-1a. The occurrence of aph(3)-Ia in kanamycin resistant strains was 68%. The prevalence of sul1 (80%) and sul2 (100%) was observed. The prevalence of tet(A) is higher than tet(B) in tetracycline-resistant strains. The gene determinants for chloramphenicol resistance (cat1 and catB) were detected. Differences in the rates and profile of resistance were observed, possibly reflecting differences in antibiotic use regimens among these strains.Conclusion: This study shows that multi-drug resistant E. coli isolates are prevalent in animal sources and a considerable proportion of E. coli strains are resistant to a variety of antimicrobial agents. Genotypic characterization revealed high number of diverse resistance determinants.http://dx.