Antimicrobial Use and Pathogens Sensitivity among Smallholder Dairy Herds around Nakuru Peri-Urban Areas, Kenya

Abstract

Inappropriate Antimicrobial Use (AMU) leads to antimicrobial residues and antimicrobial resistance (AMR) development. The risk can be high in peri-urban smallholder dairy herds, where with intensification, mastitis infections become prevalent, inducing frequent AMU, but sometimes inappropriately. This study (i) assessed farmers‟ Knowledge, Attitude and Practices (KAPs) about AMU and AMR, (ii) quantified use frequency and dosage of veterinary antimicrobial use, and (iii) tested for antimicrobial sensitivity levels of pathogenic bacteria species causing mastitis. A cross-sectional survey was conducted in four peri-urban wards of Nakuru city, Kenya where change from free-grazing to semi-zero-grazing and to zero-grazing dairy management represent increasing intensification. Data on KAPs was obtained from 124 farmers and a sample of 210 lactating cows positive for mastitis were examined for use frequency and dosage of antimicrobial drug, then milk samples bacteriologically cultured to test for antimicrobial sensitivity. The associations between KAPs and dairy intensification and antimicrobial sensitivity of different pathogenic bacteria species were tested using Chi-square test statistics. The drug use frequency and dosage were quantified using general linear models. Among the sample farmers, at least six in ten had intensified dairy management, marketed milk through informal outlets and were using antimicrobial drugs. Compliance with the withdrawal period, training on prudent antimicrobial use, positive attitudes and good practices in AMU increased (p>0.05) with increasing dairy intensification. Disease incidences decreased with intensification from free grazing (42.9) to semi grazing (29.4) and to zero grazing (25.8) percent. Farmers more frequently used antimicrobial drugs to treat mastitis (47.1) than (p<0.05) to treat East Coast fever (14.3), parasitic infections (11.8), or other diseases (26.8) percent. Only a few antimicrobials used were identified: gentamicin (13.9), tetracycline (11.5), penicillin G (4.9), and sulfamethoxazole (3.3) percent. The average use frequency of AMU was 2.2 times per year at a dose of 20mg/kg body weight and 8.405mg/cow/year. From the positive milk samples, Staphylococcus aureus (100), Escherichia coli (14.7), Clostridum (16.2), Corynebacterium (14.) and Entetrococcus (4.4) percent were isolated. Staphylococcus aureus and Escherichia coli showed high resistance to ampicillin (97.4), kanamycin (70.8), and penicillin G (91.7), and high susceptibility to ciprofloxacin (96.8), gentamicin (98.7), sulfamethoxazole (71.8), and streptomycin (79.5) percent. In conclusion, improving dairy management can lead to more responsible antibiotic use in livestock. The study findings indicate that milk from peri-urban cows may serve as a reservoir for multi-drug-resistant.