Diamond nanoparticles (DNPs) of various types have been recently reported to possess antibacterial properties. Studies have shown a decrease of the colony forming ability on agar plates of the bacteria that had been previously co-incubated with DNPs in the suspension. Before plating, bacteria with DNPs were adequately diluted in order to obtain a suitable number of colony forming units. However, residual DNPs were still present on an agar plate, concentrated on the surface during the plating process; this introduces a potential artifact which might affect colony growth. The effect of DNPs remaining on the surface, alongside growing bacteria, has not been previously investigated. In this work, we present the experiments designed to investigate the effect of DNPs on bacterial survival and on the growth of the bacterial colony on a solid media. We employed Escherichia coli and Bacillus subtilis as models of Gram-negative and Gram-positive bacteria, respectively, and Proteus mirabilis as a model of bacterium exhibiting swarming motility on the surfaces. We analyzed the number, area, and weight of bacterial colonies grown on the agar surface covered with DNPs. We did not observe any bactericidal effect of such applied DNPs. However, in all bacterial species used in this work, we observed the appreciable reduction of colony area, which suggests that DNPs obstruct either bacterial growth or motility. The most obvious effect on colony growth was observed in the case of motile P. mirabilis. We show that DNPs act as the mechanical barrier blocking the lateral colony growth.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- Bacillus subtilis účinky léků růst a vývoj MeSH
- Bacteria cytologie účinky léků růst a vývoj MeSH
- diamant chemie farmakologie MeSH
- Escherichia coli účinky léků růst a vývoj MeSH
- mikrobiální testy citlivosti MeSH
- nanočástice chemie MeSH
- povrchové vlastnosti MeSH
- Proteus mirabilis účinky léků růst a vývoj MeSH
- velikost částic MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Increasing bacterial resistance to antibiotics is one of the most serious problems in current medicine. An important factor contributing to the growing prevalence of multiresistant bacteria is application of antibiotics. This study aimed at analyzing the development of resistance of Enterobacteriaceae to selected beta-lactam, fluoroquinolone and aminoglycoside antibiotics in the University Hospital Olomouc and assessing the effect of selection pressure of these antibiotics. METHODS: For the period between 1 January 2000 and 31 December 2011, resistance of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Proteus mirabilis to third- and fourth-generation cephalosporins, meropenem, piperacillin/tazobactam, fluoroquinolones and aminoglycosides was retrospectively studied. For the assessment of selection pressure of antibiotics, a parameter of defined daily dose in absolute annual consumption (DDDatb) based on the ATC/DDD classification and in relative annual consumption (RDDDatb) as the number of defined daily doses per 100 bed-days was used. The relationship between frequency of strains resistant to a particular antibiotic and antibiotic consumption was assessed by linear regression analysis using Spearman's correlation. The level of statistical significance was set at p < 0.05. RESULTS: A total of 113,027 isolates from the Enterobacteriaceae family were analyzed. There was a significant effect of selection pressure of the primary antibiotic in the following cases: piperacillin/tazobactam in Klebsiella pneumoniae, gentamicin in Klebsiella pneumoniae and Escherichia coli and amikacin in Escherichia coli and Enterobacter cloacae. Also, there was significant correlation between resistance to ceftazidime and consumption of piperacillin/tazobactam in Klebsiella pneumoniae and Escherichia coli. No relationship was found between consumption of third- and fourth-generation cephalosporins and resistance to ceftazidime or between fluoroquinolone consumption and resistance to ciprofloxacin. CONCLUSION: The study showed the effects of both direct and indirect selection pressure on increasing resistance to gentamicin, amikacin, piperacillin/tazobactam and ceftazidime. Given the fact that no correlation was found between resistance to fluoroquinolones and consumption of either primary or secondary antibiotics, we assume that the increasing resistance to fluoroquinolones is probably due to circulation of resistance genes in the bacterial population and that this resistance was not affected by reduced use of these antibiotics.
- MeSH
- aminoglykosidy terapeutické užití MeSH
- antibakteriální látky terapeutické užití MeSH
- beta-laktamy terapeutické užití MeSH
- Enterobacter cloacae účinky léků izolace a purifikace fyziologie MeSH
- enterobakteriální infekce farmakoterapie mikrobiologie MeSH
- Escherichia coli účinky léků izolace a purifikace fyziologie MeSH
- fluorochinolony terapeutické užití MeSH
- Klebsiella pneumoniae účinky léků izolace a purifikace fyziologie MeSH
- lidé MeSH
- lineární modely MeSH
- mikrobiální testy citlivosti MeSH
- mnohočetná bakteriální léková rezistence účinky léků MeSH
- Proteus mirabilis účinky léků izolace a purifikace fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- bakteriální léková rezistence * MeSH
- cefalosporiny terapeutické užití MeSH
- Enterobacter cloacae účinky léků MeSH
- Escherichia coli účinky léků MeSH
- Klebsiella pneumoniae účinky léků MeSH
- lidé MeSH
- Proteus mirabilis účinky léků MeSH
- retrospektivní studie MeSH
- spotřeba léčiv MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Cíl práce: Stanovení citlivosti k antibiotikům a průkaz tvorby biofilmu u kmenů Proteus mirabilis izolovaných z moči v letech 2008 až 2010. Materiál a metody: U kmenů P. mirabilis izolovaných z moči pacientů Fakultní nemocnice u svaté Anny v Brně s diagnózou infekce močových cest v období od dubna 2008 do dubna 2010 byla stanovena citlivost na antibiotika. Byla použita metoda diskového difuzního testu a sledována tvorba β-laktamáz. Následně byla zjišťována kvalitativní tvorba biofilmu pomocí modifikované Christensenovy metody. Výsledky: Bylo vyšetřeno celkem 213 kmenů P. mirabilis, z nichž bylo 82 (38,5 %) kmenů rezistentních k ampicilinu, k cefalotinu 49 (23,0 %), k sulfamethoxazolu/trimetoprimu 83 83 (39,0 %), k ciprofloxacinu 75 (35,2 %), ke kyselině oxoUnové 95 (44,6 %), ke gentamicinu 54 (25,4 %), k chloramfenikoíu 72 (33^8 %). Mnoohem menší rezistenci vykazovah kmeny k cefotaximu - 8 (3,8 %), ceftazidimu - 8 (3,8%), amoxicilinu s klavulanátem - 17 (8,0 %) a aztreonamu - 8 (3,8 %). Nebyl nalezen žádný kmen rezistentní ke karbapenemům. Produkce širokospektré β-laktamázy ESBL byla prokázána u 8 kmenů P. mirabilis. Z celkového počtu 213 kmenů tvořilo biofilm 28 (13,1 %) kmenů P. mirabilis. Závěr: Výrazně častěji se P. mirabilis objevoval v močích starších pacientů a u mužů. Tvorba biofilmu u močových kmenů P. mirabilis byla poměrně nízká. Zkoumané kmeny vykazovaly rezistenci hlavně k beta-laktamovým antibiotikům a chinolonům, v případě ostatních antibiotik byla rezistence nižší.
Background: In the rather rare urinary pathogen Proteus mirabilis resistance to antibiotics and ability to form biofilm were studied. Material and methods: The strains Proteus mirabilis were isolated from urine samples from ambulatory and hospitalized patients diagnosed with urinary tract infection (UTI) between April 2008 and April 2010. Resistance to antibiotics was investigated using a disk diffusion antimicrobial susceptibility test. Biofilm formation was demonstrated by modified Christensen method. Results: Two hundred and thirteen of P. mirabilis strains were tested. Eighty-two (38.5 %) strains were resistant to ampicillin, 49 (23.0 %) to cefalotin, 83 (39.0 %) to sulfamethoxazole/trimetoprim, 75 (35.2 %) to ciprofloxacin, 95 (44.6 %) to oxolinic acid, 54 (25.4 %) to gentamicin, and 72 (33.8 %) to chloramphenicol. There was significantly lower resistance to cefotaxime - 8 strains (3.8 %), ceftazidime - 8 (3.8 %), amoxicillin/clavulanic acid 17 (8.0 %) and aztreonam - 8 (3.8 %). No resistance to imipenem as well as to meropenem was found. Eight P. mirabiJis strains were found to produce extended-spectrum beta-lactamase (ESBL). From the total of 213 strains tested, 28 (13.1 %) were able to form a biofilm. Conclusions: P. mirabiJis was found to be more frequent in urine of men and older patients. Biofilm formation in urinary P. mirabilis strains was relatively low. The strains showed higher resistance to beta-lactams and quinolones; in the other cases, resistance was low.
- Klíčová slova
- infekce močových cest,
- MeSH
- bakteriální léková rezistence MeSH
- biofilmy MeSH
- infekce bakteriemi rodu Proteus farmakoterapie mikrobiologie MeSH
- infekce močového ústrojí farmakoterapie mikrobiologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- moč mikrobiologie MeSH
- Proteus mirabilis fyziologie izolace a purifikace účinky léků MeSH
- Check Tag
- lidé MeSH
Získané ß-laktamázy AmpC poedstavují vážný klinický a epidemiologický problém. V České republice (ČR) byly dosud popsány pouze u druhu Klebsiella pneumoniae a Serratia marcescens (DHA-1). Elánek popisuje záchyt dvou kmenu druhu Proteus mirabilis produkujících ß-laktamázy CMY-2. Jedná se o první doložený poípad produkce získané AmpC odlišné skupiny než je DHA-1 v ČR u humánních vzorku.
Acquired AmpC ß-lactamases are an important clinical and epidemiological problem. In the Czech Republic, they have only been detected in Klebsiella pneumoniae and Serratia marcescens (DHA-1). This article reports the detection of two CMY-2-producing strains of Proteus mirabilis. It is the first report of acquired AmpCblactamase other than DHA-1 in human isolates from the Czech Republic.
The occurrence of positive synergy between antibiotic discs of amoxicillin/clavulanate and cefoperazone was registered in two Klebsiella pneumoniae strains, isolated from hospitals in Czech and Slovak Republic, indicating the presence of genes coding for an extended-spectrum beta-lactamase active also against cefoperazone, a broad-spectrum cephalosporin. Sulbactam inhibited the hydrolysis of cefoperazone by cell-free lysates of these strains which substantiates its use in combination with cefoperazone. Resistance to cephalothin, cefotaxime, ceftazidime, cefoperazone, cefepime and aztreonam was transferred from K. pneumoniae isolates to Escherichia coli K-12 3110 and to Proteus mirabilis P-38 recipient strains.
- MeSH
- antibakteriální látky farmakologie MeSH
- cefalosporiny farmakologie MeSH
- cefoperazon farmakologie MeSH
- Escherichia coli účinky léků genetika MeSH
- hydrolýza MeSH
- infekce bakteriemi rodu Klebsiella farmakoterapie MeSH
- infekce spojené se zdravotní péčí farmakoterapie MeSH
- Klebsiella pneumoniae účinky léků genetika patogenita MeSH
- kombinace amoxicilinu a kyseliny klavulanové farmakologie MeSH
- lékové interakce MeSH
- lidé MeSH
- mnohočetná léková rezistence * MeSH
- Proteus mirabilis účinky léků genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Slovenská republika MeSH
In this report we describe a specific transfer of carbenicillin and cephaloridine resistance determinants from two different strains of Stenotrophomonas maltophilia: No. 215 and 221 isolated from two critically ill patients treated in different Intensive Care Units of a large University Hospital in Ostrava, Czech Republic. These strains were resistant to flouroquinolones and the following beta-lactam drugs: carbenicillin, cephaloridine, cefotaxime, ceftazidime, cefepime, imipenem, meropenem and aztreonam. Both strains transferred carbenicillin and cephaloridine resistance determinants, with rather different frequency, to Proteus mirabilis P-38. All carbenicillin-selected transconjugants were found by an indirect selection method to be co-resistant to cephaloridine only. In a second cycle of transfers Proteus mirabilis R+ strains directly transferred carbenicillin and cephalothin determinants to Escherichia coli K-12 No. 185 nal+ lac+ recipient strain.
- MeSH
- antibakteriální látky farmakologie MeSH
- antiinfekční látky farmakologie MeSH
- beta-laktamasy analýza metabolismus MeSH
- beta-laktamová rezistence * MeSH
- cefaloridin farmakologie MeSH
- fluorochinolony MeSH
- jednotky intenzivní péče MeSH
- karbenicilin farmakologie MeSH
- kultivační média MeSH
- lidé MeSH
- mnohočetná léková rezistence * MeSH
- Proteus mirabilis účinky léků genetika MeSH
- Xanthomonas účinky léků genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- enterobakteriální infekce farmakoterapie patologie přenos MeSH
- epidemiologie MeSH
- infekce spojené se zdravotní péčí komplikace MeSH
- katarakta chirurgie MeSH
- lidé MeSH
- panoftalmitida epidemiologie etiologie komplikace MeSH
- Proteus mirabilis patogenita účinky léků MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
