Antibiotic susceptibility of mycobacteria isolated from ornamental fish

Abstract

Introduction Nontuberculous mycobacteria (NTM) are increasingly recognised as causative agents of opportunistic infections in humans for which effective treatment is challenging. There is very little information on the prevalence of NTM drug resistance in Poland. This study was aimed to evaluate the susceptibility to antibiotics of NTM, originally isolated from diseased ornamental fish. Material and Methods A total of 99 isolates were studied, 50 of them rapidly growing mycobacteria (RGM) (among which three-quarters were Mycobacterium chelonae, M. peregrinum, and M. fortuitum and the rest M. neoaurum, M. septicum, M. abscessus, M. mucogenicum, M. salmoniphilum, M saopaulense, and M. senegalense). The other 49 were slowly growing mycobacteria (SGM) isolates (among which only one was M. szulgai and the bulk M. marinum and M. gordonae). Minimum inhibitory concentrations for amikacin (AMK), kanamycin (KAN), tobramycin (TOB), doxycycline (DOX), ciprofloxacin (CIP), clarithromycin (CLR), sulfamethoxazole (SMX), isoniazid (INH) and rifampicin (RMP) were determined. Results The majority of the isolates were susceptible to KAN (95.95%: RGM 46.46% and SGM 49.49%), AMK (94.94%: RGM 45.45% and SGM 49.49%), CLR (83.83%: RGM 36.36% and SGM 47.47%), SMX (79.79%: RGM 30.30% and SMG 49.49%), CIP (65.65%: RGM 24.24% and SGM 41.41%), and DOX (55.55%: RGM 9.06% and SGM 46.46%). The majority were resistant to INH (98.98%: RGM 50.50% and SGM 48.48%) and RMP (96.96%: RGM 50.50% and SGM 46.46%). Conclusion The drug sensitivity of NTM varies from species to species. KAN, AMK, CLR and SMX were the most active against RGM isolates, and these same four plus DOX and CIP were the best drugs against SGM isolates.

Antimicrobial Susceptibility Testing Using the MYCO Test System and MIC Distribution of 8 Drugs against Clinical Isolates of Nontuberculous Mycobacteria from Shanghai

“…In addition, compared with the three most prevalent SGM, M. kansasii , M. avium , and M. intracellulare , the MIC of M. abscessus was generally increased. Treatment of RGM infection is very difficult because the bacterium is resistant to a wider variety of drugs than SGM ( 27 ).…”

Review of methods for detection and characterization of non-tuberculous mycobacteria in aquatic organisms

“…Nine antimicrobials were tested against 99 NTM isolates from diseased ornamental fish, and M. abscessus , M. chelonae , M. fortuitum , M. mucogenicum , M. saopaulense , and M. szulgai isolates had multidrug resistance profile with ≥ 3 different classes of antimicrobials. 28 In that same study, the growth of most NTM isolates was inhibited by amikacin and kanamycin, with only a few isolates with a multidrug resistance profile that rendered these antimicrobials ineffective. Therapeutic strategies for treating NTM infections are yet to be standardized.…”

Combined antimicrobial action of streptomycin and terpenes against atypical mycobacteria isolated from fish

“…The minimum inhibitory concentrations (MIC) of the terpenoids and streptomycin (in the presence and absence of terpenoids) for each strain were determined using the resazurin microtiter assay (REMA), as previously described by Guz and Puk (2022). A growth control containing terpene without antibiotics and a sterility control without inoculum were included in each plate.…”