High Levels of Antibiotic Resistance in Isolates From Diseased Livestock

Abstract

Overuse of antimicrobials in livestock health and production beyond therapeutic needs has been highlighted in recent years as one of the major risk factors for the acceleration of antimicrobial resistance (AMR) of bacteria in both humans and animals. While there is an abundance of reports on AMR in clinical isolates from humans, information regarding the patterns of resistance in clinical isolates from animals is scarce. Hence, a situational analysis of AMR based on clinical isolates from a veterinary diagnostic laboratory was performed to examine the extent and patterns of resistance demonstrated by isolates from diseased food animals. Between 2015 and 2017, 241 cases of diseased livestock were received. Clinical specimens from ruminants (cattle, goats and sheep), and non-ruminants (pigs and chicken) were received for culture and sensitivity testing. A total of 701 isolates were recovered from these specimens. From ruminants, Escherichia coli (n = 77, 19.3%) predominated, followed by Staphylococcus aureus (n = 73, 18.3%). Antibiotic sensitivity testing (AST) revealed that E. coli resistance was highest for penicillin, streptomycin, and neomycin (77–93%). In addition, S. aureus was highly resistant to neomycin, followed by streptomycin and ampicillin (68–82%). More than 67% of E. coli isolates were multi-drug resistant (MDR) and only 2.6% were susceptible to all the tested antibiotics. Similarly, 65.6% of S. aureus isolates were MDR and only 5.5% were susceptible to all tested antibiotics. From non-ruminants, a total of 301 isolates were recovered. Escherichia coli (n = 108, 35.9%) and Staphylococcus spp. (n = 27, 9%) were the most frequent isolates obtained. For E. coli, the highest resistance was against amoxicillin, erythromycin, tetracycline, and neomycin (95–100%). Staphylococcus spp. had a high level of resistance to streptomycin, trimethoprim/sulfamethoxazole, tetracycline and gentamicin (80–100%). The MDR levels of E. coli and Staphylococcus spp. isolates from non-ruminants were 72.2 and 74.1%, respectively. Significantly higher resistance level were observed among isolates from non-ruminants compared to ruminants for tetracycline, amoxicillin, enrofloxacin, and trimethoprim/sulfamethoxazole.

Prevalence of Mastitis and Antibiotic Resistance of Bacterial Isolates from CMT Positive Milk Samples Obtained from Dairy Cows, Camels, and Goats in Two Pastoral Districts in Southern Ethiopia

“…However, recent studies have shown increased resistance against tetracycline among S. aureus [ 32 ] and E. coli isolates [ 33 ] from cases of mastitis. There is no doubt that antimicrobial usage in food animal production leads to an increase in AMR [ 34 , 35 ]. Dairy farms may serve as a source of antimicrobial-resistant human pathogenic bacteria, especially extended spectrum beta-lactamases producing E. coli [ 33 , 36 ] and colistin-resistant E. coli [ 37 ].…”

Antimicrobial Resistance Patterns and Risk Factors Associated with Salmonella spp. Isolates from Poultry Farms in the East Coast of Peninsular Malaysia: A Cross-Sectional Study

“…In low- and middle-income countries (LMICs), 73% of all antimicrobials are used in animals raised for food [ 2 ]. More specifically, in Malaysia and many other Southeast Asian countries, a wide use of antibiotics, especially in intensive production system, is linked to the higher resistance to various antibiotics [ 3 ]. Most of these antimicrobial compounds are accumulated and biomagnified through the food chain.…”

Prevalence and antimicrobial resistance profiling of Staphylococcus aureus isolated from traditional cheese in Yunnan, China

“…Besides, erythromycin and trimethoprim-sulphamethoxazole resistance was found in 34.78% of isolates. Due to the widespread and inappropriate use of penicillin and other antibiotics in infection treatment in dairy farming and healthcare, the majority of S. aureus strains are resistant to these agents (de los Santos et al 2017;Haulisah et al 2021). In this experiment, the Kirby-Bauer method using MHA standard medium demonstrated high performance to support better growth conditions to spread the suspension of S. aureus in BHI broth.…”