Detection and quantification of antibiotic residues in goat milk in Mahikeng Local Municipality.

Goat milk could be used to reduce malnutrition since it is highly nutritious, and many people in rural communities in South Africa rear small ruminants for survival. However, the risk of food contamination by antibiotic residues is one of the significant problems facing public health, and is a result of the irresponsible use of veterinary drugs. One hundred goat farmers were interviewed using a questionnaire, and raw milk samples from 266 goats were collected and analysed for the presence of antibiotic residues. Screening for amoxicillin, tetracycline, sulfamethazine, erythromycin, and streptomycin residues was done using the enzymelinked immunosorbent assay (ELISA) while high-performance liquid chromatography (HPLC) was carried out for confirmation. The questionnaire shows that all (100%) of the participants acknowledged the use of antibiotics on their goats and 99% of them were aware of the possibility of antibiotic residues in milk. ELISA results for residues of erythromycin, sulfamethazine and amoxicillin exceeded the Codex Alimentarius maximum residue levels (MRLs) in 94.7%, 82.3%, and 35.3% of analysed samples, respectively. Tetracycline was present in all (100%) analysed milk samples, and streptomycin was detected in 18.7% of samples; however, these results were below the recommended MRLs. The HPLC method confirmed the presence of streptomycin and tetracycline residues in 90% and 40% of the samples analysed. However, the concentrations were below the accepted MRL standards. Approximately 76.6% of samples exceeded the established MRL for sulfamethazine and 10% for erythromycin. Amoxicillin was not detected by the HPLC method. The results obtained in this study indicate a high level of contamination of goat milk with antibiotic residues, which may harm the health of the consumers.

Bacterial contaminants and their antibiotic susceptibility patterns in ready-to-eat foods vended in Ogun state, Nigeria.

Contamination of ready-to-eat (RTE) foods by pathogenic bacteria may predispose consumers to foodborne diseases. This study investigated the presence of bacterial contaminants and their antibiotic susceptibility patterns in three locally processed RTE foods (eko, fufu and zobo) vended in urban markets in Ogun state, Nigeria. Bacteria isolated from a total of 120 RTE food samples were identified by 16S rRNA gene phylogeny while susceptibility patterns to eight classes of antibiotics were determined by the disc diffusion method. Species belonging to the genera Acinetobacter and Enterobacter were recovered from all RTE food types investigated, Klebsiella and Staphylococcus were recovered from eko and fufu samples, while those of Shigella were recovered from eko samples. Enterobacter hormaechei was the most prevalent species in all three RTE food types. Precisely 99% of 149 isolates were multidrug-resistant, suggesting a high risk for RTE food handlers and consumers. Co-resistance to ampicillin and cephalothin was the most frequently observed resistance phenotype. Results demonstrate that improved hygiene practices by food processors and vendors are urgently required during RTE processing and retail. Also, adequate food safety guidelines, regulation and enforcement by relevant government agencies are needed to improve the safety of RTE foods and ensure the protection of consumer health.

A risk assessment study of the occurrence and distribution of aflatoxigenic Aspergillus flavus and aflatoxin B1 in dairy cattle feeds in a central northern state, Nigeria.

Nigeria, being a tropical nation, characterized by favorable climatic conditions, may display high chances of feed contaminations due to aflatoxigenic Aspergillus flavus with the consequences of health risks associated with the consumption of dairy products. A cross-sectional study was conducted to examine the risks of occurrence and distribution of aflatoxigenic Aspergillus flavus (A. flavus) and aflatoxin B1 (AFB1) contamination levels based on the European Union (EU) and United States Food and Drug Administration (USFDA) set limits. Feeds (n = 144) were collected from selected conventional and traditional dairy herds; prepared and analyzed using immuno-affinity column (IAC) and high performance liquid chromatography (HPLC) respectively. Forty eight (55.8%) isolates were identified as A. flavus of the isolated Aspergilli (n = 86). Of this proportion, 12 (25.0%) were aflatoxigenic strains. An outrageous number of the tested feeds (86.8%, n = 144) were positive for AFB1 contamination. Detectable AFB1 concentrations ranged between (0.5 and 24.8) µgKg-1 and were distributed variously according to many factors of distribution. Eighty three (66.4%, n = 125) of the AFB1 contaminated feed samples showed AFB1 concentrations between 5 and ≥20 µgKg-1. All-inclusive policies are key to reducing the health risks posed to the consumers of dairy products.

The effect of temperature and effluent recycle rate on hydrogen production by undefined bacterial granules.

Biohydrogen production in an anaerobic fluidized granular bed bioreactor was strongly dependent on temperature and effluent recycle rates. At 45 °C as the effluent recycle rate was increased from 1.3 to 3.5 L/min, the total H2 output for the bioreactor increased from 10.6 to 43.2 L/h. Volumetric H(2) productivity also increased from 2.1 to 8.7 L H2/L/h. At 70°C as the effluent recycle was increased from 1.3 to 3.5 L/min, the total H2 output for the bioreactor increased from 13.8 to 73.8L/h. At 70 °C volumetric H(2) productivities increased from 2.8 to 14.8L H2/L/h as the effluent recycle rate was increased from 1.3 to 3.5 L/min. At 45 °C % H2 was 45% and reached 67% at 70 °C. Maximum hydrogen yields at 45 °C were 1.24 and 2.2 mol H2/mol glucose at 70 °C.