Identification and Determination of Antibiotic Susceptibilities of Brucella Strains Isolated from Patients in Van, Turkey by Conventional and Molecular Methods

Abstract

Purpose: Brucellosis is a worldwide zoonotic disease and still constitutes a major public health problem. In this study, we aimed to identify biovars of Brucella strains isolated from clinical specimens taken from brucellosis patients from the Eastern Anatolia region as well determine the susceptibility of these isolates to tigecycline and azithromycin, drugs that may serve as alternatives to the conventional drugs used in the therapy.Materials and methods: Seventy-five Brucella spp. isolates were included in the study. All strains were identified by both conventional and molecular methods. Brucella Multiplex PCR kit (FC-Biotech, Code: 0301, Turkey) and B. melitensis biovar typing PCR kit (FC-Biotech, Code: 0302, Turkey) were used for molecular typing. Antimicrobial susceptibilities of all strains were determined by E-tests.Results: By conventional biotyping, 73 strains were identified as B. melitensis biovar 3 and two strains as B. abortus biovar 3. Molecular typing results were compatible with conventional methods. The MIC50 and MIC90 values of doxycycline were 0.047 and 0.094; tigecycline 0.094 and 0.125; trimethoprim/sulfamethoxazole 0.064 and 0.19; ciprofloxacin 0.19 for both; streptomycin 0.75 and 1; rifampin 1 and 2 and azithromycin 4 and 8. According to the MIC values, doxycycline was found to be the most effective antibiotic, followed by tigecycline, trimethoprim-sulfamethoxazole and ciprofloxacin.Conclusion: Currently recommended antibiotics for the treatment of brucellosis such as doxycycline, rifampin, streptomycin, trimethoprim-sulfamethoxazole and ciprofloxacin were found to be still effective. While our results showed that tigecycline can be used an alternative agent in the treatment of brucellosis, azithromycin has not been confirmed as an appropriate agent for the treatment.

Molecular Investigation of the Transmission Dynamics of Brucellosis Observed Among Children in the Province of South - East Anatolia, Turkey

“…In vitro determination of antibiotic efficacy against Brucella strains is based on detection of minimal inhibitory concentration (MIC) values. For this purpose, in the current study, the E -test method was used as it is a reliable, reproducible, less labor-intensive, less time -consuming, and more practical micro -dilution method (12). To determine the MIC, 0.5 McFarland turbidity suspension of bacteria was spread on Mueller Hinton agar medium supplemented with 5% sheep and E -test strips (AB Biodisk, Solna, Sweden) for Gentamicin (GM), Rifampicin (RIF), and Doxycycline (DC), Tigecycline (TC), and Ceftriaxone (CRO), trimethoprim -Sulfamethoxazole (SXT) were placed on the agar plates (12,13).…”

“…were interpreted as recommended by the clinical and laboratory standards institute (CLSI) guidelines for slowgrowing bacteria, such as Haemophilus spp. (12)(13)(14). Since the breakpoints value for tigecycline have not been determined by CLSI, ≤ 0.25 as sensitive was considered as interpretive MIC breakpoints for tigecycline (12,15).…”

Isolation of Brucella melitensis strains from Syrian bovine milk samples

“…For the isolation, identification and typing of Brucella spp., 2YTA (20 g agar, 10 g peptone, 5 g sodium chloride, 5 g meat extract, 1 L distilled water) plates with 5% sterile horse serum, polymyxin B (5 U/mL), bacitracin (25 U/mL) and cycloheximide (100 μg/mL) were used (Parlak et al, 2013). To prepare solid selective media, the basal medium was melted and then cooled to 56 °C in a water bath and stock solutions of the antibiotics were added.…”

“…Typing of Brucella isolates was made according to the CO 2 requirement, H 2 S production, growth in the presence of dyes (thionin and basic fuchsin), and reaction with monospecific sera anti-A, anti-M and anti-R (Parlak et al, 2013). The laboratory personnel working with these isolates wore impermeable protective clothing, gloves, and a face mask during contact with the organism.…”

Seguimiento clínico, serológico y mediante la reacción de polimerasa en cadena de una familia con brucelosis

“…En nuestro reporte, el padre, la tía y la prima, quienes tomaron doxiciclina y rifampicina como segunda terapia mostraron resultados negativos en serología y RPC al final del seguimiento. Resultados parecidos fueron reportados por Buzgan y cols., en pacientes con complicaciones ostearticulares 33 , en contraste con los hallazgos de otros autores quienes reportaron que esta combinación fue la menos efectiva en el tratamiento de casos humanos 34,35 . En los casos de las pacientes con DM2 no mostraron mejoría después del tratamiento con doxiciclina y rifampicina.…”