Antibiotic Resistance and Pathogenomics of Staphylococci Circulating in Novosibirsk, Russia

Abstract

A total of 394 strains of staphylococci found in humans and pets in Novosibirsk, Siberian Russia, were characterized in terms of antibiotic resistance and corresponding genes. Two coagulase-positive and 17 coagulase-negative species were identified. The majority of isolates, with the exception of S. haemolyticus and hospital S. epidermidis isolates, were sensitive to most of the tested antibiotics, and isolates from pets displayed the lowest level of resistance. Nevertheless, methicillin-resistant (MRS) and/or multidrug-resistant (MDR) isolates were found in all prevailed species, including coagulase-negative. A set of genes corresponding to the detected resistance was identified: mecA (beta-lactam resistance), aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, ant(4′)-Ia (aminoglycoside-modifying enzymes), ermA/ermC, and msrA (macrolide resistance). Complete genome analysis for ten MDR S. epidermidis and five MDR S. haemolyticus isolates revealed additional antibiotic resistance genes mphC, qacA/qacB, norA, dfrC/dfrG, lnuA, BseSR, and fosB. NorA, dfrC, and fosB were present in all S. epidermidis genomes, whereas mphC and msrA were identified in all S. haemolyticus ones. All investigated MDR S. epidermidis and four of five S. haemolyticus strains were moderate or strong biofilm producers, whereas multiple genes responsible for this function and for virulence and pathogenicity were identified mostly in S. epidermidis, but were less frequently represented in S. haemolyticus.

Bacteriophage St_134 and its Endolysin as a Potential Staphy-lococcus Biofilm-Removing Biological Agent

“…Notably, LysSte134_1 showed even higher efficacy against S. epidermidis cells and biophilms that against S. aureus ones. Although it is believed that S. epidermidis is a less virulent pathogen than S. aureus, in recent years the proportion of S. epidermidis strains with MDR is significantly higher than that for S. aureus at least in some regions [3]. In addition, S. epidermidis, being a normal skin commensal, is capable of forming biofilms, which is a serious problem in intensive care units and especially in surgery.…”

“…Staphylococcus species was determined by sequencing the 16S rRNA gene fragment (~1400 bp). Antibiotic resistance has been previously tested using the disk-diffusion method (Oxoid™, Thermo Fisher Scientific, Waltham, MA, USA) in accordance with the EUCAST recommendations [3]. All bacterial strains were cultivated in Luria Bertani (LB) media/agar (1.5% w/v) (10 g/L peptone, 5 g/L yeast extract, 10 g/L NaCl, pH: 7.0, Becton Dickinson, Franklin Lakes, NJ, USA).…”

“…Staphylococcus aureus that is resistant to methicillin and vancomycin (MRSA and VRSA) was assigned to the high priority group [2]. Given the faster growth of MDR among nosocomial strains of Staphylococcus epidermidis [3] and its increased ability to form biofilms [4][5][6], an assessment of the antibacterial activity of new drugs against both S. aureus, S. epidermidis and other coagulase-negative staphylococci is required.…”

“…There are three large groups of phage lysins: (1) tail-associated murein lytic enzymes (TAME) that provide genome DNA penetration when the phage adsorbs the host cell; (2) endolysins, which are produced inside the infected cell providing the release of new phage particles; and (3) depolymerases that are able to cleave polysaccharide chains [20][21][22]. Notably, endolysins can hydrolyze peptidoglycans of the cell wall, being outside.…”

Bacteriophage vB_SepP_134 and Endolysin LysSte_134_1 as Potential Staphylococcus-Biofilm-Removing Biological Agents

“…Staphylococcus aureus strains, which are resistant to methicillin and vancomycin (MRSA and VRSA), were assigned to the high-priority group [ 2 ]. Given the increasing incidence of MDR among nosocomial strains of Staphylococcus epidermidis [ 3 ] and their ability to form biofilms [ 4 , 5 , 6 ], an assessment of the antibacterial activity of new drugs against both S. aureus and S. epidermidis, and other coagulase-negative staphylococci is required.…”