The functional analysis of microbial genomes often requires gene inactivation. We constructed a set of cassettes consisting of single antibiotic resistance genes flanked by the attL and attR sites resulting from site-specific integration of the Streptomyces pSAM2 element. These cassettes can easily be used to inactivate genes by in-frame deletion in Streptomyces by a three-step strategy. In the...

Combined parenteral and intramammary treatment of mastitis caused by Staphylococcus aureus was compared to parenteral treatment only. Cows with clinical mastitis (166 mastitic quarters) caused by S. aureus treated by veterinarians of the Ambulatory Clinic of the Faculty of Veterinary Medicine during routine farm calls were included. Treatment was based on in vitro susceptibility testing of the ...

Sir: Microbial conversion of antibiotically inactive macrocyclic lactones to active compounds is an important approach in the search for new macrolide antibiotics. Mutational biosynthesis originally proposed by SHIER et al.1) was proved useful also for constructing new macrolide antibiotics and many new derivatives were obtained. However, these were virtually inactive,2-1) or weakly active and ...

AIM The aim of this study is to identify antibiogram and heavy metal resistance pattern of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp.) coinfected with motile aeromonas septicemia and edwardsiellosis in four commercial fish farms. MATERIALS AND METHODS A. hydrophila and E. tarda were isolated using glutamate starch phenol red and xylose lysin...