Naslov
Mastitis in cows caused by Mycobacterium fortuitum – a new moment in diagnostics and treatment

Autori
Špičić, Silvio ; Benić, Miroslav ; Kompes, Gordan ; Katalinić-Janković, Vera ; Zdelar-Tuk, Maja ; Reil, Irena ; Duvnjak, Sanja ; Pate, Mateja ; Cvetnić, Luka ; Cvetnić, Željko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
36th Annual Congress of the European Society of Mycobacteriology : Scientific Program including Abstracts / Niemann, Stefan - Selm : Agency KONSENS Ltd., 2015, 63-64

ISBN
978-3-00-049915-9

Skup
Annual Congress of the European Society of Mycobacteriology (36 ; 2015)

Mjesto i datum
Riga, Latvija, 28.06.2015. - 01.07.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Mycobacterium fortuitum; cattle; mastitis

Sažetak
Mycobacterium (M.) fortuitum is recognized as the etiological agent of mastitis in cattle and is considered to be species the most commonly associated with mastitis among nontuberculous mycobacteria (NTM). The bacterium has also been isolated from raw-milk samples collected from bulk tanks and from milk samples from tuberculin test positive cows . During February and March 2015, bacteriological investigation targeting the causative agents of mastitis was carried out on samples from two older pregnant Simmental cows from two different herds. In both cases, the anamnestic data coincided: the mastitis was persistent and resistant to treatment with antimicrobials routinely used for mastitis treatment. In one case, the therapy was repeated several times using antimicrobials of different groups. Scarce clinical signs included positive reaction to mastitis test. The milk samples were inoculated onto esculin-blood agar plate. In both cases, the culture growth dynamics was identical: the first tiny dust-like colonies became visible after 48 hours of incubation at 37°C and reached a diameter of 1-2 mm after 72 hours. Gram-stained smear revealed blue bacilli while Ziehl-Neelsen staining showed the presence of acid fast bacilli. Culture for acid‐fast bacilli was done using a BACTEC MGIT culture system (Becton Dickinson, Maryland, USA), which showed a positive signal after 5 days, and the bacteria were subsequently subcultured on to Löwenstein–Jensen (LJ) medium in duplicate. The culture grew at 25 and 37 °C and at 42 °C on LJ medium, and on LJ medium containing 5 % NaCl. The conventional biochemical tests for iron uptake, aryl sulphatase (3 days), Tween 80 hydrolysis, tellurite reduction and nitrate reductase were positive, whilst niacin was negative. The isolates were also investigated using conventional PCR and GenoType Mycobacterium CM (Hain Lifescience) kit. The latter identified both isolates as M. fortuitum while the GenoType assay results corresponded to M. fortuitum II/M. mageritense hybridization pattern. Both strains were additionally tested on minimal inhibitory concentrations by SENSITITRE, RAPMYCOI (Trek Diagnostic Systems, USA) to trimethoprim / sulfamethoxazole, ciprofloxacin, moxifloxacin, cefoxitin, Amikacin, doxycycline, tigecycline, clarithromycin, linezolid, imipenem, cefepime, amoxicillin / clavulanic acid 2:1 ratio, ceftriaxone, minocycline and tobramycin. Evaluation of results were performed due to Susceptibility testing of mycobacteria, nocardiae and other aerobic actinomycetes standard (Clinical and Laboratory Standards Institute, USA). Resistance in both isolates were found only to clarithromycin, intermediate for cefoxitin, while on all other antimicrobials isolates were found susceptible. Interpretation in standard were not found for cefepime, amoxicillin / clavulanic acid and ceftriaxone, but both strains grew in all wells in microtitre plate with these antimicrobials. The finding of udder infection with a rapidly growing NTM species shows an increasing importance of mycobacteria in milk production pathology. Each case of udder infections with the evidence of long-lasting treatment should be suspicious to NTM involvement, especially because of high antimicrobial resistance.

Izvorni jezik
Engleski

Znanstvena područja
Javno zdravstvo i zdravstvena zaštita, Veterinarska medicina

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