Over the period 1983-1985, investigators from the Institute of Hygiene and Epidemiology, Prague, and the Central Research Institute of Epidemiology, USSR Ministry of Public Health, Moscow, carried out a joint study of drug resistance in S. aureus strains in relation to their enterotoxigenic properties and phage group specificity. Altogether 277 strains were explored which had been isolated at random from the clinical material from infant and adult inpatients. Most of the isolated strains featured multiple resistance to antibiotics: PNC (77.9%), CMP (52.7%), TET (21.6%), ERY (17.6%) and LIN (11.9%). The strains isolated from infants were most frequently resistant to TET and ERY. No correlation was found between the incidence of antimicrobial drugs resistance and toxigenic properties of the isolated strains.

• MeSH
• antibakteriální látky farmakologie   MeSH
• antibiotická rezistence MeSH
• dítě MeSH
• dospělí MeSH
• enterotoxiny biosyntéza   MeSH
• lidé MeSH
• stafylokokové infekce mikrobiologie   MeSH
• Staphylococcus aureus účinky léků   patogenita   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Moskva MeSH
• Názvy látek
• antibakteriální látky MeSH
• enterotoxiny MeSH

Staphylococcus aureus is one of the most frequent pathogens infecting the respiratory tract of patients with cystic fibrosis (CF). This study was the first to examine S. aureus isolates from CF patients in the Czech Republic. Among 100 S. aureus isolates from 92 of 107 observed patients, we found a high prevalence of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (56%). More than half of the resistant strains (29 of 56) carried a mutation in the MLS(B) target site. The emergence of MLS(B) resistance and mutations conferring resistance to MLS(B) antibiotics was associated with azithromycin treatment (p=0.000000184 and p=0.000681, respectively). Methicillin resistance was only detected in 3% of isolates and the rate of resistance to other antibiotics did not exceed 12%. The prevalence of small-colony variant (SCV) strains was relatively low (9%) and eight of nine isolates with the SCV phenotype were thymidine dependent. The study population of S. aureus was heterogeneous in structure and both the most prevalent community-associated and hospital-acquired clonal lineages were represented. Of the virulence genes, enterotoxin genes seg (n=52), sei (n=49), and sec (n=16) were the most frequently detected among the isolates. The PVL genes (lukS-PV and lukF-PV) have not been revealed in any of the isolates.

• MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• azithromycin terapeutické užití   MeSH
• bakteriální léková rezistence genetika   MeSH
• cystická fibróza mikrobiologie   MeSH
• dlouhodobá péče MeSH
• infekce spojené se zdravotní péčí mikrobiologie   MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• mutace genetika   MeSH
• ribozomy genetika   MeSH
• stafylokokové infekce farmakoterapie   mikrobiologie   MeSH
• Staphylococcus aureus účinky léků   genetika   MeSH
• thymidin genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• antibakteriální látky MeSH
• azithromycin MeSH
• thymidin MeSH

The previous use of fresh porcine xenografts at the Prague Burn Centre had raised concerns over the transmission of zoonotic pathogens. This study examines the risk of zoonotic Staphylococcus aureus colonisation of burn patients from fresh porcine skin xenografts. Samples were collected from the nares, skin and perineum of commercial pigs (n=101) and were screened for methicillin sensitive S. aureus (MSSA) and resistant S. aureus (MRSA). The efficacy of the antibiotic wash used in decontamination of the pigskin was tested against planktonic- and biofilm-grown isolates. The spa type of each isolate was also confirmed. All pig swabs were negative for MRSA but 86% positive for MSSA. All planktonic-grown isolates of MSSA were sensitive to chloramphenicol and nitrofurantoin and 44% of isolates were resistant to streptomycin. Isolates grown as biofilm exhibited higher rates of antimicrobial resistance. Sequence analysis revealed three distinct spa types of the MRSA ST398 clonal type. This finding demonstrates the existence of a MSSA reservoir containing spa types resembling those of well-known MRSA strains. These MSSA exhibit resistance to antibiotics used for decontamination of the pigskin prior to xenograft. Amended use of procurement could allow the use of fresh pigskin xenografts to be reinstated.

• Klíčová slova
• Infection, MRSA, MSSA, Porcine skin,
• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální léková rezistence MeSH
• biologické krytí mikrobiologie   MeSH
• chloramfenikol farmakologie   MeSH
• kůže mikrobiologie   MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus účinky léků   genetika   izolace a purifikace   MeSH
• mikrobiální testy citlivosti MeSH
• nitrofurantoin farmakologie   MeSH
• nos mikrobiologie   MeSH
• perineum mikrobiologie   MeSH
• popálení terapie   MeSH
• prasata mikrobiologie   MeSH
• Staphylococcus aureus účinky léků   genetika   izolace a purifikace   MeSH
• streptomycin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• chloramfenikol MeSH
• nitrofurantoin MeSH
• streptomycin MeSH

Methicillin-resistant Staphylococcus aureus (MRSA) is the causal agent of multiple nosocomial infections worldwide, including catheter-associated bacteremia in hemodialysis patients. The purposes of this work were to genetically characterize a group of MRSA isolates from catheter-related infections of ambulatory Mexican hemodialysis patients and to determine whether the strains are the same as those carried by the patients in their anterior nares. Sixteen pairs of MRSA isolates from the catheter (cat) and anterior nares (N) of hemodialysis patients were compared using pulsed-field gel electrophoresis (PFGE), PCR detection of adhesion genes and other virulence markers, and an antibiogram. Three pairs of N/cat MRSA isolates (18.7 %) with identical resistograms also showed the same combination of PCR-detected markers and PFGE pattern; one additional pair showed only an identical electrophoretic PFGE pattern. Of the MRSA isolates, 75 % (n = 24) were resistant to ≥ 7 antibiotics, 4 isolates were resistant to 11 antibiotics, and 7 isolates were resistant to the 12 antibiotics tested. The most frequent virulence marker combination found was spa, clfA, clfB, cna, bbp, ebps, map/eap, sdrC, sdrD, sdrE, ica, agr (65.6 %, n = 21). The SCCmec alleles of the 32 MRSA isolates were IV (n = 20), I (n = 7), II (n = 4), and V (n = 1), and no SCCmec type III MRSA was found. The genotypic characterization of the MRSA isolates studied in this work will contribute to a better understanding of the virulence gene makeup of catheter-colonizing S. aureus strains and will help to lower the infection risk in these patients.

• MeSH
• dialýza ledvin MeSH
• DNA bakterií chemie   genetika   MeSH
• dospělí MeSH
• faktory virulence genetika   MeSH
• katétry mikrobiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus genetika   izolace a purifikace   MeSH
• mikrobiální testy citlivosti MeSH
• polymerázová řetězová reakce MeSH
• pulzní gelová elektroforéza MeSH
• rozdělení chí kvadrát MeSH
• senioři MeSH
• stafylokokové infekce mikrobiologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Mexiko MeSH
• Názvy látek
• DNA bakterií MeSH
• faktory virulence MeSH

Medical students are exposed to the hospital environment and patients during their studies, increasing the risk of exposure to virulent and antibiotic-resistant isolates of Staphylococcus aureus. The aim of the study is to determine the prevalence of Staphylococcus aureus among medical students who have varying levels of exposure to the hospital environment to provide valuable insights into the risk of colonization and transmission. Nasal swabs and fingerprints were obtained and cultured on a selective medium for staphylococci. The obtained isolates were confirmed as methicillin-sensitive S. aureus (MSSA) or methicillin-resistant (MRSA) using PCR. Antibiotic resistance, the presence of virulence genes including enterotoxin encoding genes, and spa typing were performed. Among pre-clinical students, MSSA was detected on the nose in 45.2% and on the fingerprints in 10.6% of the participants. Among clinical students, MSSA was detected on the nose in 42.0% and on the fingerprints in 25.4%. Only one MRSA isolate was obtained. Genes seg and sei were the most frequently detected in both student groups, with their presence in over 40% of isolates among clinical students. The eta and etb genes were mainly detected from the nose in both student groups. In pre-clinical students, S. aureus carrying eta gene occurred in 6.4% and etb in 8.5%. In clinical students, the occurrence was 5.1% for eta and 8.5% for etb. The tst gene was identified only in the nose and fingerprints of the clinical student group. The most frequently observed resistance was to clindamycin and erythromycin. In total 58 different spa types were identified. High rates of asymptomatic MSSA carriage were observed in both groups of medical students. Detected MSSA strains showed a high degree of genetic variability, with a number of them carrying the virulence and antibiotic resistance genes. Although students do not exhibit increased risk to their patient's, increased hygiene is required in asymptomatic carriage personnel. The overall prevalence of MRSA was low, with a minimal risk of spread.

• Klíčová slova
• Spa type, Staphylococcus aureus, Antibiotic resistance, MRSA, Medical students, Virulence genes,
• MeSH
• antibakteriální látky farmakologie   MeSH
• asymptomatické infekce epidemiologie   MeSH
• bakteriální léková rezistence MeSH
• dospělí MeSH
• faktory virulence genetika   MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus genetika   izolace a purifikace   MeSH
• mikrobiální testy citlivosti MeSH
• mladý dospělý MeSH
• nos mikrobiologie   MeSH
• přenašečství * mikrobiologie   epidemiologie   MeSH
• prevalence MeSH
• stafylokokové infekce * mikrobiologie   epidemiologie   MeSH
• Staphylococcus aureus * genetika   izolace a purifikace   účinky léků   klasifikace   MeSH
• studenti lékařství * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• faktory virulence MeSH

Bacterial variants of Staphylococcus aureus called small colony variants (SCVs) originate by mutations in metabolic genes, resulting in emergence of auxotrophic bacterial subpopulations. These variants are not particularly virulent but are able to persist viable inside host cells. SCVs show their characteristic auxotrophic growth deficiency and depressed α-cytotoxin activity. Environmental pressure such as antibiotics, select for isogenic SCV cells that are frequently found coexisting with their parent wild-type strains in a mixed bacterial culture. SCV strains often grow on blood agar as non-pigmented or pinpoint pigmented colonies and their key biochemical tests are often non-reactive. Their altered metabolism or auxotrophism can result in long generation time and thus SCV phenotype, more often than not SCV can be overgrown by their wild-type counterparts and other competitive respiratory flora. This could affect laboratory detection. Thus, molecular methods, such as 16S rRNA partial sequencing or amplification of species-specific DNA targets (e.g. coagulase, nuclease) directly from clinical material or isolated bacterial colonies, become the method of choice. Patients at risk of infection by S. aureus SCVs include cystic fibrosis patients (CF), patients with skin and foreign-body related infections and osteomyelitis, as they suffer from chronic staphylococcal infections and are subject to long-term antibiotic therapy. Molecular evidence of SCV development has not been found except for some random mutations of the thymidylate synthase gene (thyA) described in SCV S. aureus strains of CF patients. These variants are able to bypass the antibiotic effect of folic acid antagonists such as sulfonamides and trimethoprim. Resistance to gentamicin and aminoglycosides in the hemin or menadione auxotrophic SCVs was hypothesized as being due to decreased influx of the drugs into cells as a result of decreased ATP production and decreased electrochemical gradient on cell membranes.

• MeSH
• faktory virulence metabolismus   MeSH
• genetická variace * MeSH
• lidé MeSH
• metabolické sítě a dráhy genetika   MeSH
• mutace MeSH
• stafylokokové infekce mikrobiologie   MeSH
• Staphylococcus aureus genetika   růst a vývoj   metabolismus   patogenita   MeSH
• virulence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• faktory virulence MeSH

A rather fast and complicated progression of an infection caused by some strains of Staphylococcus aureus could be associated with the expression and co-action of virulence factor complexes in these strains. This study screened the antibiotic susceptibility and prevalence of virulence markers in isolates of meticillin-resistant S. aureus (MRSA) obtained from patients hospitalized at the University Hospital in Olomouc, Czech Republic. A total of 100 isolates was screened for 13 genes encoding extracellular virulence determinants (tst, pvl, eta, etb, sea, seb, sec, sed, see, seg, seh, sei and sej) and for their distribution in sample types. Eighty-nine isolates were positive for at least one of the genes. Genes for etb, pvl, see and seh were not detected in any of the MRSA isolates. No statistically significant differences in the occurrence of the determinants studied among sample types were found.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální proteiny genetika   MeSH
• DNA bakterií analýza   izolace a purifikace   MeSH
• faktory virulence genetika   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• nemocnice univerzitní * MeSH
• polymerázová řetězová reakce MeSH
• prevalence MeSH
• pulzní gelová elektroforéza MeSH
• rezistence na methicilin * MeSH
• stafylokokové infekce epidemiologie   mikrobiologie   MeSH
• Staphylococcus aureus účinky léků   genetika   izolace a purifikace   patogenita   MeSH
• virulence genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• antibakteriální látky MeSH
• bakteriální proteiny MeSH
• DNA bakterií MeSH
• faktory virulence MeSH

BACKGROUND: The study objective was to identify changes of prevalence and resistance of important pathogens in specimens of cystic fibrosis (CF) patients within a decade. METHODS: Samples of 94 patients, who attended 2 CF centers from 2001 to 2011 were retrospectively analyzed. RESULTS: Staphylococcus aureus was the most prevalent organism (74.5% in 2011) with an increase of methicillin-resistant S. aureus in patients (0% vs. 9.6%, n = 9). Resistance of S. aureus to gentamicin decreased (41.8% vs. 21%; P < 0.001), whereas resistance to rifampicin and trimethoprim/sulfamethoxazole (P < 0.05) increased significantly with a trend to increased resistance to clindamycin and erythromycin (P = 0.063). Methicillin-resistant S. aureus isolates belonged to 6 spa types (t003, t008, t011, t034, t045, t548). There was a significant increase of Pseudomonas aeruginosa prevalence (63.8% in 2011 vs. 46.8% in 2001, P = 0.019). Resistance of P. aeruginosa increased significantly to imipenem, gentamicin, amikacin, tobramycin, ciprofloxacin and fosfomycin, whereas resistance to piperacillin-tazobactam, meropenem and aztreonam decreased. Significantly fewer Stenotrophomonas maltophilia isolates were susceptible to all the analyzed antibiotics (trimethoprim/sulfamethoxazole, ciprofloxacin and colistin) in 2011 compared with 2001 (13.5% vs. 42.1%; P = 0.023), whereas the resistance to colistin increased significantly (11.1% vs. 62.2%; P < 0.001). Burkholderia cepacia complex and nontuberculous mycobacteria were not detected in 2001 but in 2011 in 7.4% (n = 9) and 7.4% (n = 9) of patients, respectively. B. cepacia complex isolates belonged to 8 multilocus sequence types. CONCLUSIONS: Our retrospective analysis revealed an increase of important CF-related pathogens, the emergence of new pathogens and a substantial increase of multidrug-resistant CF-specific isolates. Our findings are of importance to clinicians for the alertness of local epidemiology, which may be useful for prevention and treatment strategies.

• MeSH
• Bacteria klasifikace   účinky léků   izolace a purifikace   MeSH
• bakteriální infekce epidemiologie   mikrobiologie   MeSH
• bakteriální léková rezistence * MeSH
• cystická fibróza komplikace   MeSH
• dítě MeSH
• dospělí MeSH
• infekce dýchací soustavy epidemiologie   mikrobiologie   MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• předškolní dítě MeSH
• prevalence MeSH
• retrospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The carriage of multidrug-resistant (MDR) pathogens in medical students has not been studied extensively, despite the fact that they are in contact with patients and exposed to a hospital environment. AIM: To investigate the intestinal and nasal carriage of MDR pathogens among medical students and its association with their lifestyle and demographic data. METHODS: In 2021, first- and final-year medical students were invited to the study. Two rectal swabs were used for detection of extended-spectrum β-lactamase (ESBL)-producing, colistin-, tigecycline- or carbapenem-resistant Gram-negative bacteria and vancomycin-resistant enterococci. Nasal swab was used for Staphylococcus aureus culture. S. aureus isolates were characterized by spa typing; Gram-negative resistant isolates and meticillin-resistant S. aureus (MRSA) were subjected to whole-genome short and/or long sequencing. FINDINGS: From 178 students, 80 (44.9%) showed nasal carriage of S. aureus; two isolates were MRSA. In rectal swabs, seven ESBL-producing strains were detected. Sixteen students were colonized by colistin-resistant bacteria, three isolates carried the mcr-1 gene (1.7%). The mcr-9 (10.7%, 19/178) and mcr-10 (2.2%, 4/178) genes were detected by quantitative polymerase chain reaction, but only two colistin-susceptible mcr-10-positive isolates were cultured. The S. aureus nasal carriage was negatively associated with antibiotic and probiotic consumption. S. aureus and colistin-resistant bacteria were detected more frequently among students in contact with livestock. CONCLUSION: Medical students can be colonized by (multi)drug-resistant bacteria with no difference between first- and final-year students. The participation of students in self-screening increases their awareness of possible colonization by resistant strains and their potential transmission due to poor hand hygiene.

• Klíčová slova
• Bioinformatics, Chromosomally encoded, Prevalence, Resistance, Surveillance, Whole-genome sequencing,
• MeSH
• antibakteriální látky farmakologie   MeSH
• kolistin MeSH
• lidé MeSH
• methicilin rezistentní Staphylococcus aureus * genetika   MeSH
• Staphylococcus aureus genetika   MeSH
• studenti lékařství * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• kolistin MeSH

224 coagulase-negative strains of staphylococci (CNS) isolated from haemocultures of hospitalized patients were classified into 11 types. The most frequent one was S. epidermis (73.2%), S. haemolyticus (7.6%), S. lugdunensis (6.7%) and S. hominis (3.6%). In different strains virulence factors were assessed: production of mucus and delta toxin. Based on these properties the strains were classified into biotypes. Of 164 strains of S. epidermis mucus was produced by 64.6% and delta toxin by 75.0%. Of 17 strains of S. haemolyticus mucus was produced by 8 and delta toxin by 10 strains. Of 15 strains of S. lugdunensis 9 strains produced both virulence factors. Of 8 strains of S. hominis 5 strains produced mucus and 3 delta toxin. In strains S. capitis, S. sciuri, S. auricularis, S. caprae these factors were not detected. The most frequent biotypes were: subtype 3 (43.3%), 1a (26.8%) and 1b (10.3%). The sensitivity of CNS to 11 antibacterial substances was assessed quantitatively by estimating the MIC (mg/l). The most effective antibiotic was vancomycin (100%) and tetracycline (76.8%). Only 26.3% strains were sensitive to oxacillin and cefalotine. Of 224 CNS (70%) were resistant to more than 8 antibacterial substances.

• MeSH
• antibiotická rezistence MeSH
• koagulasa metabolismus   MeSH
• kultivační média MeSH
• lidé MeSH
• Staphylococcus klasifikace   účinky léků   metabolismus   MeSH
• virulence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• koagulasa MeSH
• kultivační média MeSH