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In vitro susceptibility of Mycoplasma iowae isolates to antimicrobial agents
Dominika Buni1, Lilla Udvari1, Dorottya Földi1
1Veterinary Medical Research Institute, Eötvös Loránd Research Network, Budapest, Hungary.
Abstract:
ABSTRACTMycoplasma iowae, a potential re-emerging avian pathogen mainly affecting turkeys, has been reported from many parts of the world. Poor hatchability, embryonic death, joint and skeletal abnormalities, poor ossification, runting-stunting, poor feathering and airsacculitis may be observed in infected flocks. The reduction of the severity of clinical signs and short-term control of M. iowae are performed by antibiotic treatment. However, M. iowae develops resistance more rapidly and is considered to be more resistant to antimicrobials than other avian pathogenic mycoplasmas. The aim of the present study was to determine the in vitro susceptibility of 101 M. iowae isolates and strains to ten clinically important antimicrobial agents, and to analyse and compare the susceptibility patterns of isolates of various origins and from a wide time-period. The examined reference strains showed high susceptibility to all antimicrobials except for spectinomycin. Low concentrations of tiamulin, florfenicol and oxytetracycline inhibited the growth of the clinical isolates. Nevertheless, slow tendency of increasing minimum inhibitory concentration (MIC) values was observed over time in the case of the above mentioned agents, while MIC values of enrofloxacin showed relatively rapid changes. Spiramycin, erythromycin, tilmicosin, tylosin, lincomycin and spectinomycin did not inhibit the bacterial growth in most of the cases. Isolates originating from captive game birds showed similar susceptibility profiles to isolates from industrial turkey hosts. The widely detected low susceptibility of M. iowae isolates to macrolides, lincomycin and spectinomycin, and the increase of MIC values of frequently used antimicrobials against this pathogen, emphasize the importance of targeted antibiotic therapy.RESEARCH HIGHLIGHTSAntimicrobial susceptibilities of 101 Mycoplasma iowae isolates were determined.Minimum inhibitory concentrations were determined by broth micro-dilution method.Tiamulin, oxytetracycline and florfenicol showed low MIC values.Isolates rapidly adapted to antimicrobial pressure.
Insights
Antimicrobial resistance in Mycoplasma iowae is a growing concern. This study found that while some antibiotics are effective, resistance is increasing, necessitating targeted antibiotic therapy for avian mycoplasmosis control.
Area of Science:
- Veterinary Microbiology
- Antimicrobial Resistance
- Avian Pathology
Background:
- Mycoplasma iowae is an avian pathogen causing significant economic losses in turkey production.
- Existing antibiotic treatments for M. iowae are challenged by the pathogen's rapid development of antimicrobial resistance.
- Understanding in vitro antimicrobial susceptibility is crucial for effective disease management.
Purpose of the Study:
- To determine the in vitro antimicrobial susceptibility of 101 Mycoplasma iowae isolates.
- To analyze and compare susceptibility patterns across different origins and time periods.
- To inform targeted antibiotic therapy strategies against M. iowae.
Main Methods:
- Broth micro-dilution method was employed to determine minimum inhibitory concentrations (MICs).
- Susceptibility testing was performed against ten clinically relevant antimicrobial agents.
- Isolates were sourced from various origins and collected over a wide time frame.
Main Results:
- Reference strains showed high susceptibility to most agents, except spectinomycin.
- Tiamulin, florfenicol, and oxytetracycline demonstrated low MICs against clinical isolates.
- Increasing MIC values were observed over time for key agents, with rapid changes noted for enrofloxacin; macrolides, lincomycin, and spectinomycin showed widespread low susceptibility.
Conclusions:
- Mycoplasma iowae isolates exhibit increasing resistance to frequently used antimicrobials.
- Widespread low susceptibility to macrolides, lincomycin, and spectinomycin was observed.
- Targeted antibiotic selection and monitoring of antimicrobial resistance are essential for controlling M. iowae infections in poultry.
