Bovine Brucellosis is enzootic and widespread in all departments of Algeria, with variable prevalence depending on the region. During the two last decades, the veterinary authorities declared an average infection rate of 1 % in cattle. All the investigations and epidemiological data were based only on serological surveys, and didn’t provide the knowledge and characteristics concerning the circulating Brucellastrains. Our study aims (i) to identify the biovars of Brucellaisolated from seropositive cattle of the department of Tizi Ouzou (centre north Algeria), and (ii) to determine the susceptibility of these isolates to antibiotics used in the therapy.
Between October 2011 and May 2014, 32 samples, including 14 milks and 18 lymph tissues (9 retropharyngeal and 9 supramammary lymph nodes) were collected from 15 infected cattle (detected during screening and slaughtered under the control program) coming from 11 farms, situated in six town of the department.
Brucellastrains characterization was performed according to the technique described by the French standard AFNOR NF U47-105. The sensitivity of the isolated strains to streptomycin, rifampicin, gentamicin, tetracycline, doxycycline and trimethoprim-sulfamethoxazole was tested by E-test method and their minimum inhibitory concentrations were determined.
A total of 11 strains of Brucellawere isolated, 3 (27%) from milks and 8 (73%) from lymph nodes (3 (27%) from retropharyngeal and 5 (45,5%) from supramammary). All isolated strains were classified to Brucella abortusbiovar 3. Seven were susceptible to all tested antibiotics, but probable resistance to streptomycin was observed among 4 (36,4%) of the isolates.
This study represents the first investigation in Algeria on the characterisation of Brucellastrains isolated from cattle. This results may contribute to establish the epidemiological map of the distribution of different Brucellabiovars prevailing in this region. This is the first report of probable resistance to streptomycin of Brucella isolates from Algeria.