Antibiotic resistance is an ever-increasing global problem. Major commercial antibiotics often fail to fight common bacteria, and some pathogens have become multi-resistant. Polymyxins are potent bactericidal antibiotics against gram-negative bacteria. Known resistance to polymyxin includes intrinsic, mutational and adaptive mechanisms, with the recently described horizontally acquired resistance mechanisms. In this review, we present several strategies for bacteria to develop enhanced resistance to polymyxins, focusing on changes in the outer membrane, efflux and other resistance determinants. Better understanding of the genes involved in polymyxin resistance may pave the way for the development of new and effective antimicrobial agents. We also report novel in silico tested primers for PCR assay that may be able distinguish colistin-resistant isolates carrying the plasmid-encoded mcr genes and will assist in combating the spread of colistin resistance in bacteria.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence účinky léků genetika MeSH
- bakteriální proteiny účinky léků genetika MeSH
- gramnegativní bakteriální infekce farmakoterapie genetika MeSH
- kolistin farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- polymyxiny farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of two hospitals between May 2007 and August 2013. Altogether, 52 Cronobacter spp. isolates were analyzed. Although MALDI-TOF mass spectrometry recognized all Cronobacter sakazakii and Cronobacter malonaticus strains, it could not identify Cronobacter muytjensii strain. Nevertheless, all strains were identified as Cronobacter spp. using multilocus sequence typing (MLST). Strains were tested against 17 types of antibiotics, using the standard microdilution method according to the 2018 European Committee on Antimicrobial Susceptibility Testing criteria. Three Cronobacter species were identified as C. sakazakii (n = 33), C. malonaticus (n = 18), and C. muytjensii (n = 1); all isolates were susceptible to all tested antibiotics. All strains were PCR-negative for blaTEM, blaSHV, and blaCTX-M β-lactamase genes, as well. Even though the results of this study showed that Cronobacter spp. isolates were pan-susceptible, continued antibiotic resistance surveillance is warranted.Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of two hospitals between May 2007 and August 2013. Altogether, 52 Cronobacter spp. isolates were analyzed. Although MALDI-TOF mass spectrometry recognized all Cronobacter sakazakii and Cronobacter malonaticus strains, it could not identify Cronobacter muytjensii strain. Nevertheless, all strains were identified as Cronobacter spp. using multilocus sequence typing (MLST). Strains were tested against 17 types of antibiotics, using the standard microdilution method according to the 2018 European Committee on Antimicrobial Susceptibility Testing criteria. Three Cronobacter species were identified as C. sakazakii (n = 33), C. malonaticus (n = 18), and C. muytjensii (n = 1); all isolates were susceptible to all tested antibiotics. All strains were PCR-negative for blaTEM, blaSHV, and blaCTX-M β-lactamase genes, as well. Even though the results of this study showed that Cronobacter spp. isolates were pan-susceptible, continued antibiotic resistance surveillance is warranted.
- MeSH
- antibakteriální látky farmakologie MeSH
- Cronobacter sakazakii klasifikace účinky léků genetika MeSH
- Cronobacter klasifikace účinky léků MeSH
- genotyp MeSH
- gramnegativní bakteriální infekce mikrobiologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- mnohočetná bakteriální léková rezistence MeSH
- multilokusová sekvenční typizace MeSH
- polymerázová řetězová reakce MeSH
- techniky typizace bakterií MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Polsko MeSH
BACKGROUND: Various food-producing animals have been recognized in recent years as a potential reservoir for the spread of antibiotic resistant bacteria that may pose a risk to human health and therefore their dissemination in the food production chain needs to be assessed. METHODS: In this study, 450 boot swabs from chicken farms were analyzed for the presence of antimicrobial resistance with a focus on β-lactams resistance in Acinetobacter species. RESULTS: Two β-lactamase-encoding genes were first time identified in Acinetobacter lwoffii and Acinetobacter schindleri isolates. The deduced amino acid sequence of OXA-496 shared 93.8% identity with OXA-363. The second OXA-134-like enzyme, OXA-537, had the highest sequence identity (97.8%) with OXA-235 and OXA-237. CONCLUSIONS: The results of this study illustrate the occurrence of new OXA-134-like β-lactamases, called OXA-496 and OXA-537, carrying strains of Acinetobacter lwoffii and Acinetobacter schindleri in chicken farm litter, and highlight the possible role of Acinetobacter as a reservoir of resistance genes.
- MeSH
- Acinetobacter genetika MeSH
- bakteriální léková rezistence genetika MeSH
- beta-laktamasy genetika MeSH
- beta-laktamová rezistence genetika MeSH
- farmy MeSH
- kur domácí MeSH
- mikrobiální testy citlivosti MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Serratospiculiasis is a parasitic disease caused by filariid nematodes of the genus Serratospiculum that parasitise the air sacs of various species of falcons, bald eagles and Cooper's hawks around the world. An infection with Serratospiculum was recently confirmed in a nonspecific host, the great tit, in Slovakia. Parasitic material from this host was fixed for molecular analysis. Nematode found in the air sacs from a captive-bred gyrfalcon was also stored. Analysis of small subunit (18S) ribosomal DNA (18S rDNA) gene indicated that sequences from Serratospiculum sp. and Serratospiculoides amaculata were closely related to a reference sequence from Serratospiculum tendo, in agreement with morphology. This study is the first to generate molecular data and infer the phylogenetic position of S. amaculata as the first representative of the genus Serratospiculoides.
- MeSH
- chov MeSH
- Falconiformes parazitologie MeSH
- fylogeneze MeSH
- infekce hlísticemi řádu Spirurida parazitologie veterinární MeSH
- nemoci ptáků parazitologie MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S genetika MeSH
- Spirurida klasifikace genetika izolace a purifikace MeSH
- vzdušné vaky parazitologie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Slovenská republika MeSH
Východiska: Akutní leukemie (AL) je heterogenní skupina maligních onemocnění hematopoézy, rozděluje se na dva základní typy, a to akutní myeloidní leukemie (AML) a akutní lymfoidní leukemie (ALL). Pacienti s těmito onemocněními patří mezi těžce imunosuprimované a je u nich velké riziko vzniku závažných infekcí. Cílem studie bylo sledování výskytu enterobakterií - původců těchto infekcí - u pacientů s AL hospitalizovanými na Hemato-onkologické klinice Fakultní nemocnice v Olomouci a zjištění jejich antibiotické rezistence. Materiál a metodika: Do studie bylo zapojeno 49 pacientů s AL, z toho 37 s AML (16 žen a 21 mužů) a 12 s ALL (6 žen a 6 mužů); průměrný věk pacientů byl 50,5 roku. V průběhu 12 měsíců (od září 2015 do srpna 2016) by od těchto pacientů získávány vzorky klinického materiálu, které byly podrobeny základnímu mikrobiologickému vyšetření. Bakteriální kmeny byly identifikovány pomocí MALDI-TOF MS. Citlivost na antibiotika byla stanovena pomocí mikrodiluční metody. Výsledky: Celkově bylo od pacientů s AL získáno 292 vzorků, které byly dále podrobeny selekci na základě několika kritérií, aby bylo zamezeno zahrnutí identických kmenů získaných od téhož pacienta. Výsledkem byl výběr 146 klinických vzorků z 9 typů klinických materiálů (47x výtěr z krku, 40x stolice, 33x moč, 11x hemokultura, 5x výtěr z dutiny ústní, 4x perianální stěr, 3x; stěr z rány, 2x sputum, 1x punktát). Nejvíce prevalentní enterobakterií byla Escherichia coli (42x), dále zástupci Klebsiella spp. (46x), a to Klebsiella pneumoniae (34x) a Klebsiella oxytoca (12x), a Enterobacter cloacae (19x). Mnohé izoláty vykazovaly rezistenci na testovaná antibiotika. Závěr: Pacienti s hematoonkologickými onemocněními jsou kolonizováni rezistentními enterobakteriemi, což pro ně představuje potenciální nebezpečí vzniku závažných infekcí. Obecně je výskyt těchto rezistentních zástupců z čeledi Enterobacteriaceae v dnešní době závažným problémem se zvyšujícím se výskytem. Tato fakta a vysoká imunosuprese jsou faktory, které hematoonkologické pacienty řadí do zvlášť ohrožené skupiny, v níž je aktivní surveillance naprosto klíčová.
Background: Acute leukemia (AL) is a heterogeneous group of malignant hematopoietic diseases and is divided into two basic types: acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Patients with these diseases are highly immunosuppressed and therefore at a high risk of serious infections. This study aimed to perform active surveillance of enterobacteria, which cause these infections, and to determine their antibiotic resistance in patients with AL who were hospitalized at the Hemato-Oncology Center of University Hospital Olomouc. Materials and methods: This study involved 49 patients with AL, of whom 37 had AML (16 women and 21 men) and 12 had ALL (6 women and 6 men). The mean age of the patients was 50.5 years. Samples of clinical material were obtained over 12 months (September 2015 to August 2016) and subjected to standard microbiological examinations. Bacterial strains were identified by MALDI-TOF MS, and their antibiotic susceptibility was established by microdilution method. Results: A total of 292 samples were obtained from patients with AL. Some of these samples were excluded from analysis to prevent the inclusion of identical strains from the same patient. Consequently, 146 clinical samples obtained from the following nine types of clinical materials were analyzed - throat swabs (n = 47), stools (n = 40), urine (n = 33), hemocultures (n = 11), buccal swabs (n = 5), perianal swabs (n = 4), wound swabs (n = 3), sputum (n = 2), and puncture fluid (n = 1). The most prevalent enterobacteria was Escherichia coli (n = 42), followed by Klebsiella spp. (n = 46), specifically Klebsiella pneumoniae (n = 34) and Klebsiella oxytoca (n = 12), and Enterobacter cloacae (n = 19). The most of enterobacteria were highly resistant to many tested antibiotics. Conclusions: Antibiotic-resistant enterobacteria colonize patients with hemato-oncological diseases and can cause serious infections. These antibiotic-resistant microorganisms are a serious and frequent problem. These findings together with the high level of immunosuppression mean that patients with hemato-oncological diseases are at a high risk of developing serious infections and consequently active surveillance is crucial.
- MeSH
- akutní lymfatická leukemie * komplikace mikrobiologie MeSH
- akutní myeloidní leukemie * komplikace mikrobiologie MeSH
- antibakteriální látky klasifikace škodlivé účinky terapeutické užití MeSH
- bakteriální léková rezistence * účinky léků MeSH
- dospělí MeSH
- Enterobacteriaceae * klasifikace patogenita MeSH
- Escherichia coli patogenita MeSH
- infekce spojené se zdravotní péčí mikrobiologie patologie prevence a kontrola MeSH
- Klebsiella patogenita MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- výzkum MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
The study aimed to determine the occurrence of Enterobacteriaceae producing broad-spectrum beta-lactamases, vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus strains in poultry in Moravia, Czech Republic, including phenotypic and genotypic analyses of the extent of resistance. Using chromogenic screening media, a total of 240 clinical samples collected from poultry and the poultry farm environment were processed. Phenotypic tests identified 23 isolates of broad-spectrum beta-lactamase-producing Escherichia coli and one VRE isolate (Enterococcus faecium with VanA resistance). Methicillin-resistant Staphylococcus aureus strains were not detected. Among the isolates producing broad-spectrum beta-lactamases, 17 produced extended-spectrum beta-lactamases, most frequently CTX-M; the remaining 6 isolates were CIT-type AmpC enzymes. No carbapenemase-producing strains were detected. Pulsed-field gel electrophoresis showed that 21 E. coli strains (91%) were genetically unrelated isolates. Increasing resistance of bacteria to antibiotic agents poses a serious issue for both human and veterinary medicine globally. For humans, a potential source of resistant bacteria may be animals or their products entering the human food chain, for example poultry. The presented study extends existing knowledge about the occurrence of resistant bacteria in poultry in Moravia and describes the phenotype and genotype of their resistance to antibiotics.
- MeSH
- bakteriální léková rezistence * MeSH
- beta-laktamasy * analýza škodlivé účinky MeSH
- drůbež * mikrobiologie MeSH
- drůbeží výrobky * mikrobiologie škodlivé účinky MeSH
- enterokoky rezistentní vůči vankomycinu patogenita MeSH
- Escherichia coli * genetika izolace a purifikace patogenita MeSH
- kontaminace potravin MeSH
- methicilin rezistentní Staphylococcus aureus MeSH
- mikrobiologické techniky MeSH
- výzkum MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Geografické názvy
- Česká republika MeSH
BACKGROUND: Planktonic stationary and exponential cultures of Pseudomonas aeruginosa are highly resistant to killing by bactericidal antimicrobials because of the presence of persisters, cells that are multidrug tolerant and play a key role in the recalcitrance of biofilm infections. AIM: The aim of this study was to investigate the formation of persister cells in P. aeruginosa stationary vs. exponential cultures using different class antimicrobials. METHODS: The susceptibilities of P. aeruginosa PAO1 wild-type and mutant strains to antimicrobials were determined by standard microtiter broth dilution method. In order to determine persister formation, dose- and time-dependent killing experiments were performed with antibiotics. RESULTS: Ceftazidime (Cephalosporin) showed little efficacy against either culture. Stationary-phase cells were more tolerant to imipenem (Carbapenem) than exponential cells, leaving a small fraction of persisters at high imipenem concentration in both populations. Polymyxin B (Polymyxin) appeared to be ineffective at low concentrations against both cell populations. Very high polymyxin B concentration completely eradicated exponential cells and regrowth was seen in a stationary population. Stationary cells were more tolerant to tobramycin (Aminoglycoside) than exponential cells but a higher concentration of tobramycin completely eliminated survivors. Ciprofloxacin (Fluoroquinolone) at a low concentration resulted in killing of both cultures of P. aeruginosa, producing persisters that were invulnerable to killing. CONCLUSIONS: Stationary cells appear to be somewhat more tolerant than exponential cells in all of these assays. We also showed that nutrient deprivation (serine starvation) regulated by stringent and general stress response, contribute to the increased tolerance of P. aeruginosa exponential and stationary planktonic cells via production of persisters.
Antimikrobiálna rezistencia nozokomiálnych patogénov sa ukázala v novom tisícročí ako jeden z najvýznamnejších problémov v zdravotnej starostlivosti. V tomto prehľade uvádzame nové metódy na testovanie citlivosti baktérií na antibiotiká založené na detekcii markerov antibiotikami sprostredkovanej bunkovej smrti, ktoré by sa mohli stať v blízkej budúcnosti cennými alternatívami k už existujúcim fenotypovým metódam.
Antimicrobial resistance among nosocomial pathogens has emerged as one of the most important health care problems in the new millennium. In this review, we present new methods for bacterial antimicrobial susceptibility testing, based on the detection of antibiotic-mediated cell death markers that could provide valuable alternatives to existing phenotypic approaches in the very near future.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence MeSH
- buněčná smrt * účinky léků MeSH
- kvantitativní polymerázová řetězová reakce * metody MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- Pseudomonas aeruginosa MeSH
- reaktivní formy kyslíku MeSH
- volné radikály MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Za posledné dve desaťročia pozorujeme rýchly nárast infekcií spôsobených mikroorganizmami s mnohonásobnou rezistenciou. Naše možnosti antibiotickej terapie sú vystavené obrovskému nebezpečenstvu v dôsledku šírenia rezistentných patogénov. Mnoho štúdií dokazuje, že včasné poskytnutie primeranej antibiotickej liečby je nesmierne dôležité pri záchrane života. Momentálne sa lekári spoliehaju na klinické, epidemiologické a demografické údaje, ktoré im napomáhajú pri výbere empirickej terapie, nakoľko výsledky kultivácie a testovania citlivosti na antibiotiká môžu trvať až 48 hod. a dlhšie. A preto je nevyhnutný záujem o skorú a citlivejšiu detekciu rezistentných baktérií. V tomto prehľade poskytujeme zhrnutie najpokročilejších metód (techniky založené na PCR, prietoková cytometria, hmotnostná spektrometria, mikročipy a iné) určených na rýchlu detekciu antibiotickej rezistencie u baktérií, ktoré by sa mohli stať vo veľmi blízkej budúcnosti cennými alternatívami k už existujúcim metódam (fenotypové metódy).
The past two decades have witnessed increasing infections due to multidrug-resistant bacteria. Therefore, transmission of these pathogens could limit the antibiotic therapy options. Many reports suggest that initiation of appropriate antimicrobial therapy can be lifesaving. Physicians rely on combination of clinical, epidemiological and demographic data to guide empirical therapy because results of culture and antimicrobial susceptibility testing may require 48 hours or longer. Therefore, an ongoing effort for the development of earUer and more sensitive detection of resistant bacteria is inevitable. This review presents a summary of the most advanced methods (e.g. PCR-based techniques, flow cytometry, mass spectrometry, microarrays and others) that are able to rapidly detect antibiotic resistance in bacterial pathogens which have the potential to become valuable alternatives to the existing methods (standard phenotypic resistance testing) in the very near future.
- Klíčová slova
- MALDI-TOF, vážení mikrobiálních buněk pomocí vibrujících konzol, izotermická mikrokalorimetrie, magnetická rotace kuliček,
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence MeSH
- časové faktory MeSH
- kalorimetrie metody MeSH
- lidé MeSH
- magnety MeSH
- mikrobiální testy citlivosti * metody trendy MeSH
- mikrofluidní analytické techniky metody MeSH
- mikrotechnologie MeSH
- nanotechnologie MeSH
- průtoková cytometrie MeSH
- RNA genetika MeSH
- rotace MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
