Bovine mastitis caused by rapid-growth environmental mycobacteria

• DOI: 10.46419/vs.53.5.11
• Publication Date: 2022-01-07T11:23:41Z
• Authors: Luka Cvetnić; Miroslav Benić; Željko Cvetnić; Sanja Duvnjak; Irena Reil; Maja Zdelar-Tuk; Marija Cvetnić; Vera Katalinić-Ja...; Boris Habrun; Gordan Kompes; Silvio Špičić
• Keywords: Mycobacterium fortuitum; rpoB

Rapid-growth mycobacteria were isolated from two cases of cow mastitis with similar clinical appearance and within a narrow time frame. Mycobacteria on blood esculine agar. The Gram stained, Ziehl-Nielsen stained tested for growth at 25°C, 37°C 42°C, iron uptake, Löwenstein-Jensen (LJ) agar without 5% NaCl, arylsulphatase (3 days), tween 80 hydrolysis, tellurite reduction, nitrate reductase niacin synthesis. Molecular identification was performed using the GenoType CM AS tests (Hain Diagnostika, Nehren, Germany). One isolate additionally sequenced hsp65, rpoB, 16S rRNA gene sequence transcribed spacer (ITS) DNA. Susceptibility testing isolates Sensititre Rapmycol plate (TREK Diagnostic Systems Ltd.) trimethoprim/sulfamethoxasole, linezolid, ciprofloxacin, imipenem, moxifloxacin, cefepime, cefoxitin, amoxicillin / clavulanic acid, amikacin, ceftriaxone, doxycycline, minocycline, tigecycline, tobramycine clarythromycine. Gram-positive acid-resistant rods observed in smears. Both strains grew 42°C LJ medium, medium containing 5 % NaCl. conventional biochemical Tween reduction positive, while test negative. identified by Mycobacterium as fortuitum II/ mageritense, application kit both belonging to species smegmatis. Analysis sequences (strain DS) ribosomal RNA confirmed 100% identical result smegmatis strain INHR2. According CLSI criteria, sensitive sulfametoxazole/trimethoprim, doxicycline, amikacin tobramycin. differed their sensitivity cefoxitim, resistant clarithromycin. There strong difference between toward cefoxitime tigecycline.