Prevalence, Risk Factors, and Antibiogram of Bacteria Isolated from Milk of Goats with Subclinical Mastitis in Thika East Subcounty, Kenya

Abstract

A cross-sectional study was carried out to determine the prevalence and risk factors of subclinical mastitis in dairy goats in Thika East Subcounty, Kenya. Further the bacterial pathogens and their antibiogram were investigated. Farm level data on risk factors were obtained from 41 farmers using questionnaires. Milk was obtained from 110 lactating dairy goats and tested for submastitis using California Mastitis Test (CMT). The prevalence of subclinical mastitis at goat level was estimated to be at 50.9% using CMT, out of which 86.5% yielded bacteria on culture. The significant risk factors associated with the occurrence of subclinical mastitis were cleaning schedule (p=0.022, OD=1.047) and parity of the goat (p=0048, OD=1.37). Higher prevalence of subclinical mastitis was observed for goats residing in houses cleaned at least once a fortnight. Does in the first parity were least affected. 169 bacterial isolates were obtained from culture, of which 52 isolates from major classes of isolated bacteria were tested for antibiotic sensitivity to six antibiotics. Fourteen different bacteria were isolated and identified from the milk samples. Coagulase-negative Staphylococci (20.7%), Serratia spp. (19.5%), Citrobacter spp. (16%), Klebsiella spp. (11%), Staphylococcus aureus (10.7%), Enterobacter spp. (6.5%), Escherichia coli (5.9%), Proteus spp. (3%), Corynebacterium spp. (1.8%), Morganella spp. (1.8%), Streptococcus spp. (1.2%), Providencia spp. (0.6%), Micrococcus spp. (0.6%), and Staphylococcus intermedius (0.6%) were isolated and identified from the samples. All the isolates were resistant to Penicillin G, while 98% of the isolates were sensitive to Streptomycin. In conclusion, the study showed that a large proportion of goats were affected by subclinical mastitis, with the main bacteria being Staphylococci spp. and coliforms, and that most of the tested antibiotics can be used in the treatment of mastitis. Farmers need to be trained on improved control of mastitis through adoption of good dairy husbandry and milking practices.

Occurrence of mastitis and methicillin resistant <i>Staphylococcus aureus</i> in goats in Zaria, Kaduna State, Nigeria

“…The susceptibility of the isolates to ampicillin was within the range reported by Widianingrum et al in 2016. The resistance observed for ampicillin (100%) is also in agreement with the reports by Mahlangu et al (2018) who observed a resistivity of 100% to ampilcillin in a study carried out in Zaria. The resistance (40.63%) of the isolates to tetracycline in this study may reflect the excessive use of the drug in treatment in the study area.…”

“…The increase in prevalence of mastitis with age may be due to the fact that older goats are long term nannies that have stayed longer in the herd and hence are at higher risk of coming into contact with mastitis causing organisms than the younger does. Old age and multiple parturitions have been reported to produce stress on animals and as a result, such animals become susceptible to infectious agents due to low immunity level (Mahlangu et al, 2018). The result of this study differs from the findings of the study of Mahlangu et al (2018) who reported that goats of age 1year had a prevalence of SCM of 67% as compared to older goats of 2 and 3 years which had a prevalence of 46% and 50% respectively.…”

“…Old age and multiple parturitions have been reported to produce stress on animals and as a result, such animals become susceptible to infectious agents due to low immunity level (Mahlangu et al, 2018). The result of this study differs from the findings of the study of Mahlangu et al (2018) who reported that goats of age 1year had a prevalence of SCM of 67% as compared to older goats of 2 and 3 years which had a prevalence of 46% and 50% respectively. A higher prevalence of subclinical mastitis was found in goats raised under the semi-intensive system of management (62.5%) compared with goats kept under the intensive management system (57.8%).…”

“…The result of this study is lower than the result of Wang et al (Dore et al, 2016;Makau et al, 2017). This could be linked to the wide distribution of S. aureus inside the mammary glands and the skin of teats and udders (Mahlangu et al, 2018) and the fact that the organism has adapted to survive in the udder to establish chronic and subclinical infections (Mahlangu et al, 2018). The prevalence of S. aureus in this study is in agreement with the 10.65% prevalence of S. aureus reported by Mahlangu et al (2018) from milk of goats with subclinical mastitis in Thika East subcounty, Kenya.…”

“…This could be linked to the wide distribution of S. aureus inside the mammary glands and the skin of teats and udders (Mahlangu et al, 2018) and the fact that the organism has adapted to survive in the udder to establish chronic and subclinical infections (Mahlangu et al, 2018). The prevalence of S. aureus in this study is in agreement with the 10.65% prevalence of S. aureus reported by Mahlangu et al (2018) from milk of goats with subclinical mastitis in Thika East subcounty, Kenya. The high prevalence of S. aureus intramammary infection can be of veterinary and public health concern because it is an important zoonotic bacterial pathogen which can also be transmitted to humans through raw milk of goats or sheep and can cause food borne intoxication associated with enterotoxin production.…”