Incidence of uterine infections, major bacteria and antimicrobial resistance in postpartum dairy cows in southern Ethiopia.

BACKGROUND: Uterine infections, primarily caused by bacterial pathogens, pose a significant problem for dairy farmers worldwide, leading to poor reproductive performance and economic losses. However, the bacteria responsible for uterine infections have not been adequately studied, nor has the antibiotic susceptibility of the causative bacteria been frequently tested in Ethiopia. This study aims to estimate the cumulative incidence of uterine infections in postpartum dairy cows, identify bacterial causes and determine antimicrobial susceptibility profile of the isolated bacteria. METHODS: A prospective cohort study was conducted in which 236 cows from 74 dairy farms were monitored biweekly from calving to 90 days postpartum for metritis, endometritis and other disorders. Aseptic uterine swab samples were collected from 40 cows with uterine infections. The samples were cultured, and the isolated bacteria were tested for antimicrobial susceptibility using the disk diffusion method. RESULTS: Out of 236 cows monitored during the postpartum phase, 45 (19.1%) were found to have contracted uterine infection. The cumulative incidence of metritis was 11.4% (n = 27), while the cumulative incidence of endometritis was 7.6% (n = 18). Of the 40 cultured swab samples, 29 (72.5%) had one or more bacteria isolated. The most commonly isolated bacteria were Escherichia coli (45%), coagulase-positive staphylococci (30%), and Klebsiella spp. (22.5%). Other bacterial spp, including Arcanobacterium pyogenes (12.5%), Fusobacterium spp. (12.5%), Enterobacter aerogenes (12.5%), coagulase-negative staphylococci (12.5%), Streptococcus spp. (7.5%), Salmonella spp, (5%) Proteus spp (5%) and Pasteurella spp (2.5%) were also isolated. All of the isolated bacteria demonstrated resistance to at least one of the antimicrobials tested. Multidrug resistance was observed in E. coli, Klebsiella spp., A. pyogenes, and Fusobacterium spp. Gentamicin was found to be the most effective antimicrobial against all bacteria tested, while tetracycline was the least effective of all. CONCLUSION: The study found that a significant proportion of cows in the population were affected by uterine infections and the isolated bacteria developed resistance to several antimicrobials. The study emphasizes the need for responsible use of antimicrobials to prevent the emergence of antimicrobial resistance. It also highlights the importance of raising awareness among dairy farmers to avoid the indiscriminate use of antibiotics and its consequences.

Characterization of Salmonella isolated from apparently healthy slaughtered cattle and retail beef in Hawassa, southern Ethiopia.

The present study was conducted to determine the occurrence, serotype distribution and antimicrobial resistance of Salmonella serotypes in slaughtered cattle, slaughterhouse environment and retail beef. Cecal content (CC), mesenteric lymph nodes (MLN), spleen and carcass swab (CS) samples (each, n=150) were collected from 150 cattle slaughtered at Hawassa municipality slaughterhouse. Floor swab specimens (SHFS) were collected on 11 occasions from the slaughterhouse, and 100 beef samples were collected from 100 butcher shops. The samples were cultured for Salmonella, following standard procedures. A total of 14 Salmonella isolates belonging to 3 serotypes namely Salmonella enterica serotype Muenchen (4 isolates), S. enterica serotype 1,4,5,12:i:- (5) and S. enterica serotype Korovi (5) were recovered. All of the 5 S. enterica serotype 1,4,5,12:i:- isolates belonged to phage type 120. Four (2.7%) of the slaughtered cattle carried Salmonella in their CC and/or MLN, while none of the spleen samples were positive for Salmonella. Salmonella was isolated from four (2.7%) CC and two (1.3%) MLN samples. Out of the total of 150 CS samples, two (1.3%) were found contaminated with Salmonella, while 4 (4%) of the 100 beef samples obtained from butcher shops yielded Salmonella. Two of the 11 (18%) SHFS were positive for Salmonella. All the four isolates from beef were S. enterica serotype Muenchen, while both of the isolates from MLN were S. enterica serotype1,4,5,12:i:-. Both S. enterica serotype1,4,5,12:i:- and S. enterica serotype Korovi were isolated from CC, CS and slaughterhouse environment. All the 14 isolates recovered during the study were tested and found pan-susceptible to a panel of 14 antimicrobials. The present study helped to update the information on the occurrence, serotype distribution and antibiogram of Salmonella in slaughter cattle and beef in Ethiopia.

Brucellosis and associated risk factors in dairy cattle of eastern Ethiopia.

Knowing the status of Bovine brucellosis and associated risk factors is a crucial step in formulating evidence based control scheme. In this study, a total of 967 dairy cows from 307 dairy farms in eastern Ethiopia were serologically tested for Brucella antibodies. The screening was done first using RBPT and positive samples were subsequently subjected to CFT for confirmation. A pre-tested structured questionnaire was used to collect relevant data from 307 dairy cattle owners or attendants to assess their awareness and routine practice. The data were run using univariable logistic regression analysis using STATA version 11.0 for Windows. Accordingly, herd and individual animal seroprevalence were found to be 6.8% (95% CI = 4.28-10.28) and 1.3% (95% CI = 0.72-2.29), respectively. The prevalence of sero-reactors among local breeds was observed to be higher compared to cross breed (p < 0.05). Herd level analysis of the risk factors indicated that in farms with large herd size (>20 animals), the odds ratio (OR) = 9.13, p = 0.00, CI = 3.01-27.69 of having brucellosis was 9.13 times higher than smaller size herds (<20 animals). Intensively managed herds had shown the highest seroprevalence (20.8%) than extensive (6.7%) and semi-intensive (4.2%). Experience of dairy handlers about the disease that cause abortion in late pregnancy was significantly associated (p < 0.001) with the occurrence of brucellosis in the herds. However, about 91% of the dairy cattle owners/attendants lack awareness about disease(s) that causes abortion in late pregnancy. Similarly risk of having brucellosis in those herds experiencing abortion was 6.3 times higher (OR = 6.3, p < 0.001, CI = 2.50-15.92). This study identified some of the handling practices for aborted and retained fetal materials to be risky. Therefore, the study highlights the need of comprehensive brucellosis surveillance in animal and human and institutions of public education and on farm biosafety measures in shaping proper disease control scheme.

Bovine trypanosomosis and Glossina distribution in selected areas of southern part of Rift Valley, Ethiopia.

Cross-sectional study was conducted in 9 selected districts of the southern part the Rift Valley, Ethiopia to estimate the dry period prevalence of bovine trypanosomosis as well as assessment of Glossina species. From a total of 1838 cattle examined for trypanosomosis by buffy coat technique 133 (7.2%) were found infected by trypanosome species. From the total positive animals 66.9 and 33.1% of them accounted to Trypanosoma congolense and Trypanosoma vivax, respectively. Significantly higher prevalence (19.4%., P<0.05) was recorded at Arba-Mnch district. Black colored cattle were the most highly affected (χ(2)=79.35, P<0.05) animals. The overall average PCV value for parasitaemic and aparasitaemic animals was 22.2 (95% CI=21.6-22.7) and 27% (95% CI=26.8-27.2), respectively. The fly caught per trap per day was 1.4 for Glossina species and 2.8 for other biting flies. Two species of Glossina identified namely Glossina pallidipes and Glossina fuscipes.