Sensitivity of biofilms of vaccine and freshly isolated <i>Bordetella pertussis</i> strains to antibiotics

Abstract

Aim. To study the sensitivity of biofilms of vaccine and freshly isolated strains of Bordetella pertussis to antibiotics.Materials and methods. Vaccine and freshly isolated strains of B. pertussis were used. Cultures of strains grown on dense nutrient medium were used as inoculate for biofilms production. The intensity of biofilm formation in round-bottomed polystyrene 96-well plates was estimated by staining with 0.1% gentian-violet solution. The following antibiotics were used in experiments: penicillins (ampicillin), cephalosporins (ceftriaxone), aminoglycosides (gentamicin), macrolides (erythromycin).Results. The highest resistance to antibiotics was demonstrated by the vaccine strain No. 305 and freshly isolated strain No. 211, sensitive only to erythromycin. Vaccine strain No. 703 was sensitive to gentamicin and ampicillin and showed resistance to erythromycin and ceftriaxone. Vaccine strain No. 475 was sensitive to all tested antibiotics. The Tohama 1 strain was resistant to ampicillin and sensitive to other antibiotics. Freshly isolated strains No. 178 and No. 162 were resistant to ceftriaxone and sensitive to gentamicin, erythromycin and penicillin. Minimal inhibitory concentrations of tested antibiotics ranged from 0.2 μg/ml to 5.0 μg/ml.Conclusion. These data indicate the heterogeneity of vaccine and freshly isolated strains of B. pertussis in sensitivity to antibiotics. The greatest activity was shown by erythromycin, which suppressed the growth of biofilms of 6 out of 7 strains. The least effective was ceftriaxone, which suppressed the growth of biofilms of only 2 strains.

Antimicrobial Resistance of Listeria monocytogenes Strains Isolated from Humans, Animals, and Food Products in Russia in 1950–1980, 2000–2005, and 2018–2021

“…All strains belonged to the phylogenetic lineages I and II, there were no strains that belonged to the lineages III or IV (Figure 1B). The lineage II strains prevailed (97 vs. 23 strains for lineage II and lineage I, respectively) which is in line with the previously demonstrated prevalence of lineage II strains in the territory of the European part of Russia [15][16][17][18].…”

“…The lineage I serotype 4b strains are the most frequent causative agents of outbreaks among humans and severe neurological disease in domestic animals [13,14]. Lineage II strains and particularly the clonal complex CC7 are historically prevalent in the territory of Russia including pristine environments with natural foci of the infection [15][16][17][18].…”