ABSTRACT
Aims@#Linezolid has become a decisive therapy in treating infections with vancomycin-resistant Enterococcus (VRE). Currently, the emergence of linezolid-resistant Enterococcus further complicates the therapeutic options and leads to global health threat not only in hospital setting but in the community. The study aimed at antimicrobial pattern of Enterococcus isolated from 6 poultry farms in Kelantan, Malaysia.@*Methodology and results@#Between February and December 2019, 300 broiler cloacal swab sample (Gallus gallus domesticus) were collected and screened for linezolid-resistant enterococci (LRE) using a standard biochemical and antimicrobial susceptibility tests. Among all the samples, 32.3% (n=97/300) grew Enterococcus, 71.1% (n=69/97) of it were identified Enterococcus casseliflavus by molecular identification, whilst remaining isolates 28.9% (n=28/97) were further identified as Enterococcus gallinarum by 16S rRNA sequencing. None of the isolates were found to exhibit high-level resistance to vancomycin. However, 3/97 (3.1%) were exhibit resistance to high-level gentamicin based on Kirby-Bauer disk diffusion test. Whereas 48/97 (49.5%) of isolates were observed to be resistant to ampicillin, 28/97 (28.9%) were resistant to penicillin. Surprisingly, among the two strains isolated, 18.6% (n=18/97) of it were resistant to linezolid. Isolates showed resistance to linezolid by disk diffusion test were verified by VITEK-2 automated system (bioMérieux, USA) with MIC ≥8 µg/mL. All antimicrobial susceptibility test and minimal inhibitory concentration (MIC) results were interpreted according to Clinical and Laboratory Standard Institute (CLSI). @*Conclusion, significance and impact of study@#In conclusion, this study has reported the prevalence of linezolid resistant Enterococcus (LRE) in highly intrinsic antibiotic resistant of E. casseliflavus and E. gallinarum in Malaysia poultry farms, alongside with the truancy of vanA strains. The emergence of LRE strains is an alarming problem to the animal husbandry and healthcare setting worldwide. This could lead to potentially untreatable and life-threatening enterococcal infections. Even more worrying is the spread of LRE to geographical regions where these strains were previously unreported, which may pose a global health threat. Antimicrobial surveillance in poultry husbandry is thus, dimly necessary to prevent wide spread of multidrug-resistant bacteria.
Subject(s)
Linezolid , Enterococcus , FarmsABSTRACT
Aims@#New therapeutics are needed to ease the prevailing waterborne disease, and one of the alternatives is by exploring the natural compounds with antimicrobial properties. Duckweed, Lemna sp. is recorded as a medicinal herb that known to have antifungal and antibacterial activities towards several fungi and bacteria. Suitability of duckweed (Lemna minor) as an antibacterial resource against selected waterborne bacteria were evaluated in terms of its antibacterial activity and toxicity.@*Methodology and results@# Antibacterial activity of the duckweed methanolic extract was tested against 11 selected waterborne bacteria using disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) assay. Brine shrimp lethality assay was used to determine the toxicity of this extract. The lethal concentrations of plant extract resulting in 50% mortality of the brine shrimp (LC50) were then determined.@*Conclusion, significance and impact of study@#Results showed that duckweed extract exhibited bacteriostatic and bactericidal against the selected bacteria activity at the concentration of MIC = 1.8-2.0 mg/mL and MBC ≥ 2.0 mg/mL. This study shows that methanolic extract of L. minor may contain bioactive compounds against bacteria and potential therapeutic effect. The crude extract is slightly toxic and may not safe to be used in high concentration but is valuable in further study as a potential antitumor agent.