During a 3-year study period, 32,741 urine samples were analyzed for the presence of members of the Staphylococcus sciuri group (S. sciuri, S. lentus, and S. vitulinus), and 13 isolates were identified. They presented 0.79% of the total number of coagulase-negative staphylococci isolated. One case of symptomatic urinary tract infection and five possible cases of asymptomatic bacteriuria caused by these bacteria were established. It is noteworthy, however, that over 50% of the isolates originated from hospitalized patients.Coagulase-negative staphylococci (CoNS), with the exception of Staphylococcus saprophyticus, are generally considered to be bacteria of doubtful pathogenicity in the urinary tract (1,14). However, a few recent studies proposed that significance of some CoNS species as uropathogens may have been somewhat underestimated (6, 7).Members of the Staphylococcus sciuri group, S. sciuri, S. lentus, S. vitulinus, and S. pulvereri (15), are principally animal species (3,11,17,21), but they may colonize humans, and their isolation from various human clinical specimens has been reported (2,11,13,16,17,22). Moreover, S. sciuri has been associated with serious infections in humans, such as endocarditis (8), peritonitis (24), septic shock (10), and wound infections (20). Several investigators have reported isolation of S. sciuri (4, 6, 16) and S. lentus (6) from urine. However, they did not specify whether the strains isolated were recovered in pure or mixed culture, the colony counts were not reported, and the relationship between the isolates obtained from urine and urinary tract infections (UTIs) was not discussed. The objectives of the present study were to determine the frequency of isolation of the members of S. sciuri group from urine and to evaluate the significance of these isolates as potential ethiological agents of UTIs.Study population. Urine samples were collected from 32,741 hospitalized patients as well as outpatients examined at three hospitals in the region of Příbram The medical records of patients with urine cultures positive for the members of the S. sciuri group were reviewed for symptoms and signs of UTI (dysuria, urinary frequency, urinary urgency, and costovertebral tenderness), underlying medical disorders, and antimicrobial treatment. S. sciuri group isolation and identification.Approximately 95% of samples were cultured on a Uricult dipslide (Orion Diagnostica, Helsinki, Finland), and the remaining specimens were inoculated on Columbia agar supplemented with 5% sheep blood and MacConkey agar. The plates were examined after overnight incubation at 35°C. Any colony that resembled staphylococci was subcultured and further tested. Preliminary identification of an isolate as a member of the S. sciuri group was based upon microscopical characteristics, positive catalase reaction, positive oxidase test, and resistance to novobiocin. Identification to the species level was done with a STAPHYtest 16 kit (Pliva-Lachema, Brno, Czech Republic) and additional biochemical characterization accordi...

Clinical treatment of the infections caused by various staphylococcal species differ depending on the actual cause of infection. Therefore, it is necessary to develop a fast and reliable method for identification of staphylococci. Raman spectroscopy is an optical method used in multiple scientific fields. Recent studies showed that the method has a potential for use in microbiological research, too. Our work here shows a possibility to identify staphylococci by Raman spectroscopy. We present a method that enables almost 100% successful identification of 16 of the clinically most important staphylococcal species directly from bacterial colonies grown on a Mueller-Hinton agar plate. We obtained characteristic Raman spectra of 277 staphylococcal strains belonging to 16 species from a 24-hour culture of each strain grown on the Mueller-Hinton agar plate using the Raman instrument. The results show that it is possible to distinguish among the tested species using Raman spectroscopy and therefore it has a great potential for use in routine clinical diagnostics.

A total of 28 staphylococcal isolates from human clinical specimens belonging to the Staphylococcus sciuri group were identified and characterized. The API Staph and ID32 STAPH correctly identified S. sciuri and S. lentus but not S. vitulinus strains. Identification to the subspecies level was possible only by a PCR-based method.Members of the Staphylococcus sciuri group are widespread in nature, and they can be isolated from a variety of farm animals, pets, and wild animals, as well as from various food products of animal origin (6,9,12,14,22,26 (12,26). Staphylococcus pulvereri was a member of the S. sciuri group until recently, when it was shown that S. pulvereri is only a synonym of S. vitulinus (originally S. vitulus) (15, 23). Although they are principally associated with animals, members of the S. sciuri group may colonize humans, and it has been estimated that they may constitute 0.79 to 4.3% of the total number of coagulase-negative staphylococci isolated from clinical samples (8,20). However, they have been associated with serious infections such as endocarditis (10), peritonitis (25), septic shock (11), urinary tract infection (20), endophthalmitis (1), pelvic inflammatory disease (21), and, most frequently, wound infections (16,19). The aim of this study was to compare phenotypic (conventional, API Staph, ID32 Staph) and genotypic (PCR) methods for identification of isolates of the S. sciuri group.A total of 28 isolates belonging to the S. sciuri group, recovered from 1998 to 2003 from clinical samples at the Institute of Microbiology, School of Medicine, Belgrade, Serbia, and Regional Hospital Příbram, Příbram, Czech Republic, were analyzed (Table 1). Half of them were isolated from urine samples. Some of these strains have been reported previously (18-21) but not investigated for the characteristics presented in this study. All the isolates were previously identified by conventional methods (5,12,18,26) as S. sciuri (23 strains), S. lentus (3 strains), or S. vitulinus (2 strains).Staphylocoagulase (free coagulase) activity was determined with rabbit plasma (Torlak, Belgrade, Serbia) by using the tube method (5). Oxidase activity was determined with oxidase diagnostic tablets (Rosco, Taastrup, Denmark). Novobiocin susceptibility was determined on Mueller-Hinton agar (Oxoid Limited, Basingstoke, Hampshire, United Kingdom) with a disk containing 5 g of novobiocin (Bioanalyse, Ankara, Turkey). Strains were considered to be resistant to novobiocin if the zone of inhibition was Յ16 mm. Commercial identification kits, namely, API Staph and ID32 STAPH (bioMérieux, Marcy-l'Etoile, France), were used according to the manufacturer's instructions. All the strains were coagulase negative and oxidase positive. In addition, the disk diffusion method with the 5-g novobiocin disk confirmed that all strains were resistant to novobiocin. However, only three S. sciuri strains showed resistance to novobiocin by use of the ID32 STAPH kit. The problem with determination of resistance to novobiocin by ID32 STAPH was also ...

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The genus Macrococcus is a close relative of the genus Staphylococcus. Whilst staphylococci are widespread as human pathogens, macrococci have not yet been reported from human clinical specimens. Here we investigated Gram-positive and catalase-positive cocci recovered from human clinical material and identified as Macrococcus sp. by a polyphasic taxonomic approach and by comparative genomics. Relevant phenotypic, genotypic and chemotaxonomic methods divided the analyzed strains into two separate clusters within the genus Macrococcus. Comparative genomics of four representative strains revealed enormous genome structural plasticity among the studied isolates. We hypothesize that high genomic variability is due to the presence of a com operon, which plays a key role in the natural transformation of bacilli and streptococci. The possible uptake of exogenous DNA by macrococci can contribute to a different mechanism of evolution from staphylococci, where phage-mediated horizontal gene transfer predominates. The described macrococcal genomes harbor novel plasmids, genomic islands and islets, as well as prophages. Capsule gene clusters, intracellular protease, and a fibronectin-binding protein enabling opportunistic pathogenesis were found in all four strains. Furthermore, the presence of a CRISPR-Cas system with 90 spacers in one of the sequenced genomes corresponds with the need to limit the burden of foreign DNA. The highly dynamic genomes could serve as a platform for the exchange of virulence and resistance factors, as was described for the methicillin resistance gene, which was found on the novel composite SCCmec-like element containing a unique mec gene complex that is considered to be one of the missing links in SCC evolution. The phenotypic, genotypic, chemotaxonomic and genomic results demonstrated that the analyzed strains represent one novel subspecies and three novel species of the genus Macrococcus, for which the names Macrococcus caseolyticus subsp. hominis subsp. nov. (type strain CCM 7927T = DSM 103682T), Macrococcus goetzii sp. nov. (type strain CCM 4927T = DSM 103683T), Macrococcus epidermidis sp. nov. (type strain CCM 7099T = DSM 103681T), and Macrococcus bohemicus sp. nov. (type strain CCM 7100T = DSM 103680T) are proposed. Moreover, a formal description of Macrococcus caseolyticus subsp. caseolyticus subsp. nov. and an emended description of the genus Macrococcus are provided.

Lytic bacteriophages are valuable therapeutic agents against bacterial infections. There is continual effort to obtain new phages to increase the effectivity of phage preparations against emerging phage-resistant strains. Here we described the genomic diversity of spontaneous host-range mutants of kayvirus 812. Five mutant phages were isolated as rare plaques on phage-resistant Staphylococcus aureus strains. The host range of phage 812-derived mutants was 42% higher than the wild type, determined on a set of 186 methicillin-resistant S. aureus strains representing the globally circulating human and livestock-associated clones. Comparative genomics revealed that single-nucleotide polymorphisms from the parental phage 812 population were fixed in next-step mutants, mostly in genes for tail and baseplate components, and the acquired point mutations led to diverse receptor binding proteins in the phage mutants. Numerous genome changes associated with rearrangements between direct repeat motifs or intron loss were found. Alterations occurred in host-takeover and terminal genomic regions or the endolysin gene of mutants that exhibited the highest lytic activity, which implied various mechanisms of overcoming bacterial resistance. The genomic data revealed that Kayvirus spontaneous mutants are free from undesirable genes and their lytic properties proved their suitability for rapidly updating phage therapeutics.

Two Gram-stain-positive, coagulase-negative staphylococcal strains were isolated from abiotic sources, stone fragments and sandy soil in James Ross Island, Antarctica. Here we describe properties of novel species of the genus that has near identical 16S rRNA gene sequence to However, compared to and the next closest relatives, the new species demonstrates considerable phylogenetic distance at whole genome level, average nucleotide identity<85 %, and inferred DNA-DNA hybridization <30%. It forms a separate branch in phylogenetic clade confirmed by multilocus sequence analysis of six housekeeping genes, ,, ,, and MALDI-TOF MS and key biochemical characteristics allowed these bacteria to be distinguished from their nearest phylogenetic neighbours. In contrast to subsp. , strains were pyrrolidonyl arylamidase- and β-glucuronidase-positive, β -galactosidase-negative, nitrate was reduced and acid produced aerobically from d-mannose. Whole genome sequencing of 2.75 Mb large chromosome revealed the presence of a number of mobile genetic elements including the 27-kb-long pseudo staphylococcus cassette chromosome (ψSCC) harboring gene, two composite phage-inducible chromosomal islands probably essential to adaptation to extreme environment, and one complete and one defective prophage. Both strains are resistant to penicillin G, ampicillin, ceftazidin, methicillin, cefoxitin, and fosfomycin. We hypothesize that antibiotic resistance might represent an evolutionary advantage against beta-lactams producers, which are common in a polar environment. Based on these results, a novel species of the genus is described and named sp. nov. The type strain is P5085 (=CCM 8730 = DSM 104441). The description of sp. nov. enables the comparison of multidrug-resistant staphylococci from human and veterinary sources evolved in the globalized world to their geographically distant relative from the extreme Antarctic environment. Although this new species was not exposed to the pressure of antibiotic treatment in human or veterinary practice, mobile genetic elements carrying antimicrobial resistance genes were found in the genome. The presented genomic characteristics elucidate the evolutionary relationships in the genus with a special focus on antimicrobial resistance, pathogenicity and survival traits. Genes encoded on mobile genetic elements were arranged in unique combinations but retained conserved locations for the integration of mobile genetic elements. These findings point to enormous plasticity of the staphylococcal pangenome shaped by horizontal gene transfer. Thus can act not only as a reservoir of antibiotic resistance in a natural environment, but also as a mediator for the spread and evolution of resistance genes.

Enterotoxins produced by Staphylococcus aureus (SA) can act as super-antigens and thus influence the course of chronic rhinosinusitis with nasal polyps (NP). The aim of this study was to determine if antibiotic treatment administered after endoscopic sinus surgery (ESS) for NP can positively influence the course of the disease compared to placebo. After ESS, 23 patients who tested positive, in a perioperative culture, for SA strains producing enterotoxins A-E and TSST-1, were randomized into two groups. Group A which in addition to standard treatment received oral anti-staphylococcal antibiotics for 3 weeks. Group B received a placebo. Both groups were compared preoperatively, and at 3 and 6 months after surgery using a symptom-specific score, an endoscopic score and the SNOT-22 quality of life questionnaire. Slightly better results were achieved in patients who received antibiotic therapy. However, the differences were not statistically significant. Regardless of post-operative treatment, approximately 30% of patients had a SA-negative culture 6 months after surgery.