Animal Physiology

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Browsing Animal Physiology by Subject "antimicrobial resistance"

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    Antimicrobial Resistance of Staphylococcus aureus and Pseudomonas aeruginosa in Fish, and Knowledge, Attitude and Hygienic Practices of Fish Handlers in Bishoftu, Ethiopia
    (Addis Ababa University, 2024) Kebadu Endeg; Takele Beyene; Dr. Liyuwork Tesfaw
    Fish, a protein-rich food, can sometimes be contaminated with bacterial pathogens like S. aureus and P. aeruginosa, known for their resistance to antimicrobials. A cross-sectional study was conducted in Bishoftu, Ethiopia, from November 2023 to May 2024. The purpose of the study was to determine the antimicrobial resistance (AMR) pattern of these pathogens, as well as assess the knowledge, attitude towards antimicrobial use (AMU) and AMR, and hygienic practices of fish handlers. The study used a purposive sampling strategy. S. aureus and P. aeruginosa were confirmed using polymerase chain reaction and their susceptibility to antibiotics was tested using the Kirby Bauer disk diffusion method. The data was analyzed using STATA version 14, using descriptive statistics, Chi-squared, likelihood ratio, and binary logistic regression. The results of the study found that 8.6% (9) of 105 samples tested positive for S. aureus and 7.6% (8) for P. aeruginosa. S. aureus isolates were 100% resistant to cefuroxime, 44.4% (4/9) to cloxacillin and penicillin G, and 33.3% (3/9) to tetracycline. P. aeruginosa isolates were 100% resistant to cefuroxime, doxycycline, erythromycin, florfenicol, kanamycin, nalidixic acid, trimethoprim/sulfamethoxazole and tetracycline. Multidrug resistance was observed in 33.3% (3/9) of S. aureus isolates and 100% of P. aeruginosa isolates. None of the S. aureus isolates were positive for mecA gene. The survey revealed that 79% (42/53) and 60% (32/53) of respondents had insufficient knowledge and desirable attitudes about AMU and AMR, respectively and 41% (22/53) had poor hygienic practices. A significant positive correlation was found between respondent’s educational level and knowledge and attitude scores. Gender also played a role in attitude and hygienic practices. The study provides insights into S. aureus and P. aeruginosa resistance in fish production and establishes a baseline understanding of knowledge, attitudes, and hygiene practices among fish handlers. Further research should focus on detecting AMR genes in aquaculture. Additionally, enhancing knowledge about AMU and AMR in aquaculture for fish handlers is of utmost importance.
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    Evaluation of short- and long-term antibiotic treatment regimens on emergence of antimicrobial resistance in mice infected with E. coli
    (Addis Ababa University, 2024) Timotiwos Wogaso; Takele Beyene
    Antimicrobial resistance (AMR) is a global issue impacting human and animal health. E. coli commonly found in gut serve as an indicator organism to monitor AMR and multidrug resistance (MDR) in commensal bacteria. This research investigates the impact of oxytetracycline and penstrep (a fixed combination of penicillin and dihydrostreptomycin) misuse on AMR emergence in mice infected with drug-susceptible E. coli, analyzing the effects of short-term and long-term ( low, optimum and high) antibiotic dosing on the AMR profiles of susceptible E. coli strains. The research was carried out on 40 two-month-old female mice at the AAU-CVMA mice rearing facility and microbiology laboratory from November 2023 to April 2024. The study involved infecting the mice with E.coli, treating them with one of those two antibiotics, sampling every seven days start from day zero, isolating E. coli from the samples, testing for phenotypic resistance to seven antibiotics using agar dilution test, and identifying resistance genes through PCR and lateral flow assays with anti-CTX-M and CARBA 5 monoclonal antibodies. The study revealed higher AMR in penstrep and oxytetracycline groups, with 31.4% and 24.7% resistance, respectively. Infected and naïve control groups had 1.9% and 0.5% resistance, indicating selection pressure effects. Low-dose long-term treatments showed more antibiotic resistance than optimum and higher doses for both oxytetracycline and penstrep. The low-dose penstrep group had the highest MDR at 100% on day 28, followed by the low-dose oxytetracycline group with 86%. Significant variation in AMR emergence was observed at different time points post-treatment, peak on day 28. PCR results showed blaTEM gene growth and detection of the E. coli gene, while the lateral flow assay indicated negative results for CARB-5 and CTX-M genes. The study suggests long-term low-dose antibiotic use increases AMR risk, especially fixed combination therapy (penstrep). It is recommended to use antibiotic alternatives in food animals to reduce AMR impact. If antibiotics are necessary, use an optimum dose within the nontoxic range for the shortest recommended duration.