RESUMO
BACKGROUND: In the hospital environment, carbapenemase-producing Pseudomonas aeruginosa (CPPA) may lead to fatal patient infections. However, the transmission routes of CPPA often remain unknown. Therefore, this case study aimed to trace the origin of CPPA ST357, which caused a hospital-acquired pneumonia in a repatriated critically ill patient suffering from Guillain-Barré Syndrome in 2023. METHODS: Antimicrobial susceptibility of the CPPA isolate for 30 single and combination therapies was determined by disk-diffusion, Etest or broth microdilution. Whole-genome sequencing was performed for three case CPPA isolates (one patient and two sinks) and four distinct CPPA ST357 patient isolates received in the Dutch CPPA surveillance program. Furthermore, 193 international P. aeruginosa ST357 assemblies were collected via three genome repositories and analyzed using whole-genome multi-locus sequence typing in combination with antimicrobial resistance gene (ARG) characterization. RESULTS: A Dutch patient who carried NDM-1-producing CPPA was transferred from Kenya to the Netherlands, with subsequent dissemination of CPPA isolates to the local sinks within a month after admission. The CPPA case isolates presented an extensively drug-resistant phenotype, with susceptibility only for colistin and cefiderocol-fosfomycin. Phylogenetic analysis showed considerable variation in allelic distances (mean = 150, max = 527 alleles) among the ST357 isolates from Asia (n = 92), Europe (n = 58), Africa (n = 21), America (n = 16), Oceania (n = 2) and unregistered regions (n = 4). However, the case isolates (n = 3) and additional Dutch patient surveillance program isolates (n = 2) were located in a sub-clade of isolates from Kenya (n = 17; varying 15-49 alleles), the United States (n = 7; 21-115 alleles) and other countries (n = 6; 14-121 alleles). This was consistent with previous hospitalization in Kenya of 2/3 Dutch patients. Additionally, over half of the isolates (20/35) in this sub-clade presented an identical resistome with 9/17 Kenyan, 5/5 Dutch, 4/7 United States and 2/6 other countries, which were characterized by the blaNDM-1, aph(3')-VI, ARR-3 and cmlA1 ARGs. CONCLUSION: This study presents an extensively-drug resistant subclone of NDM-producing P. aeruginosa ST357 with a unique resistome which was introduced to the Netherlands via repatriation of critically ill patients from Kenya. Therefore, the monitoring of repatriated patients for CPPA in conjunction with vigilance for the risk of environmental contamination is advisable to detect and prevent further dissemination.
Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas , Pseudomonas aeruginosa , Sequenciamento Completo do Genoma , beta-Lactamases , Humanos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/enzimologia , Países Baixos/epidemiologia , beta-Lactamases/genética , beta-Lactamases/metabolismo , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/epidemiologia , Infecções por Pseudomonas/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/farmacologia , Quênia/epidemiologia , Tipagem de Sequências Multilocus , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , MasculinoRESUMO
Carbapenem-resistant Acinetobacter baumannii (CRAb) is an important pathogen causing serious nosocomial infections. We describe an outbreak of CRAb in an intensive care unit in the Netherlands in 2021. During an outbreak of non-resistant A. baumannii, while infection control measures were in place, CRAb isolates carrying highly similar bla NDM-1 - and tet(x3)-encoding plasmids were isolated from three patients over a period of several months. The chromosomal and plasmid sequences of the CRAb and non-carbapenemase-carrying A. baumannii isolates cultured from patient materials were analysed using hybrid assemblies of short-read and long-read sequences. The CRAb isolates revealed that the CRAb outbreak consisted of two different strains, carrying similar plasmids. The plasmids contained multiple antibiotic resistance genes including the tetracycline resistance gene tet(x3), and the bla NDM-1 and bla OXA-97 carbapenemase genes. We determined minimal inhibitory concentrations (MICs) for 13 antibiotics, including the newly registered tetracycline antibiotics eravacycline and omadacycline. The CRAb isolates showed high MICs for tetracycline antibiotics including eravacycline and omadacycline, except for minocycline which had a low MIC. In this study we show the value of sequencing multidrug-resistant A. baumannii for outbreak tracking and guiding outbreak mitigation measures.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Infecção Hospitalar , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Tetraciclinas , beta-Lactamases , Acinetobacter baumannii/genética , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Acinetobacter baumannii/enzimologia , Humanos , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/epidemiologia , Tetraciclinas/farmacologia , Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , beta-Lactamases/genética , Países Baixos/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Plasmídeos/genética , Surtos de Doenças , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Unidades de Terapia IntensivaRESUMO
BackgroundThe war in Ukraine led to migration of Ukrainian people. Early 2022, several European national surveillance systems detected multidrug-resistant (MDR) bacteria related to Ukrainian patients.AimTo investigate the genomic epidemiology of New Delhi metallo-ß-lactamase (NDM)-producing Providencia stuartii from Ukrainian patients among European countries.MethodsWhole-genome sequencing of 66 isolates sampled in 2022-2023 in 10 European countries enabled whole-genome multilocus sequence typing (wgMLST), identification of resistance genes, replicons, and plasmid reconstructions. Five bla NDM-1-carrying-P. stuartii isolates underwent antimicrobial susceptibility testing (AST). Transferability to Escherichia coli of a bla NDM-1-carrying plasmid from a patient strain was assessed. Epidemiological characteristics of patients with NDM-producing P. stuartii were gathered by questionnaire.ResultswgMLST of the 66 isolates revealed two genetic clusters unrelated to Ukraine and three linked to Ukrainian patients. Of these three, two comprised bla NDM-1-carrying-P. stuartii and the third bla NDM-5-carrying-P. stuartii. The bla NDM-1 clusters (PstCluster-001, n = 22 isolates; PstCluster-002, n = 8 isolates) comprised strains from seven and four countries, respectively. The bla NDM-5 cluster (PstCluster-003) included 13 isolates from six countries. PstCluster-001 and PstCluster-002 isolates carried an MDR plasmid harbouring bla NDM-1, bla OXA-10, bla CMY-16, rmtC and armA, which was transferrable in vitro and, for some Ukrainian patients, shared by other Enterobacterales. AST revealed PstCluster-001 isolates to be extensively drug-resistant (XDR), but susceptible to cefiderocol and aztreonam-avibactam. Patients with data on age (n = 41) were 19-74 years old; of 49 with information on sex, 38 were male.ConclusionXDR P. stuartii were introduced into European countries, requiring increased awareness and precautions when treating patients from conflict-affected areas.
Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos , Providencia , Sequenciamento Completo do Genoma , beta-Lactamases , Humanos , Ucrânia/epidemiologia , beta-Lactamases/genética , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/genética , Providencia/genética , Providencia/isolamento & purificação , Providencia/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Europa (Continente)/epidemiologia , Plasmídeos/genética , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Idoso , Adulto JovemRESUMO
During 2015-2022, a genetic cluster of OXA-48-producing uropathogenic Escherichia coli sequence type 127 spread throughout the Netherlands. The 20 isolates we investigated originated mainly from urine, belonged to Clermont phylotype B2, and carried 18 genes encoding putative uropathogenicity factors. The isolates were susceptible to first-choice antimicrobial drugs for urinary tract infections.
Assuntos
Infecções por Escherichia coli , Infecções Urinárias , Escherichia coli Uropatogênica , Humanos , Infecções por Escherichia coli/epidemiologia , Escherichia coli Uropatogênica/genética , Países Baixos/epidemiologia , Infecções Urinárias/epidemiologia , Antibacterianos , Fatores de Virulência/genética , beta-Lactamases/genéticaRESUMO
BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) strains are of particular concern, especially strains with mobilizable carbapenemase genes such as blaKPC, blaNDM or blaOXA-48, given that carbapenems are usually the last line drugs in the ß-lactam class and, resistance to this sub-class is associated with increased mortality and frequently co-occurs with resistance to other antimicrobial classes. OBJECTIVES: To characterize the genomic diversity and international dissemination of CRKP strains from tertiary care hospitals in Lisbon, Portugal. METHODS: Twenty CRKP isolates obtained from different patients were subjected to WGS for species confirmation, typing, drug resistance gene detection and phylogenetic reconstruction. Two additional genomic datasets were included for comparative purposes: 26 isolates (ST13, ST17 and ST231) from our collection and 64 internationally available genomic assemblies (ST13). RESULTS: By imposing a 21 SNP cut-off on pairwise comparisons we identified two genomic clusters (GCs): ST13/GC1 (nâ=â11), all bearing blaKPC-3, and ST17/GC2 (nâ=â4) harbouring blaOXA-181 and blaCTX-M-15 genes. The inclusion of the additional datasets allowed the expansion of GC1/ST13/KPC-3 to 23 isolates, all exclusively from Portugal, France and the Netherlands. The phylogenetic tree reinforced the importance of the GC1/KPC-3-producing clones along with their rapid emergence and expansion across these countries. The data obtained suggest that the ST13 branch emerged over a decade ago and only more recently did it underpin a stronger pulse of transmission in the studied population. CONCLUSIONS: This study identifies an emerging OXA-181/ST17-producing strain in Portugal and highlights the ongoing international dissemination of a KPC-3/ST13-producing clone from Portugal.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Klebsiella , Humanos , Klebsiella pneumoniae , Filogenia , Portugal/epidemiologia , beta-Lactamases/genética , Proteínas de Bactérias/genética , Carbapenêmicos , Genômica , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/epidemiologia , Antibacterianos/farmacologia , Chaperonas Moleculares/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
OBJECTIVES: MRSA carrying the mecC gene (mecC-MRSA) have been found in humans and animals worldwide. A high carriage rate of mecC-MRSA has been described among hedgehogs in different countries. We performed genomic comparison of mecC-MRSA from hedgehogs and humans using next-generation sequencing (NGS) to investigate possible zoonotic transmission in the Netherlands. METHODS: Nasal swabs from hedgehogs (nâ=â105) were cultured using pre-enrichment and selective plates. Isolates were sequenced using Illumina NGS platforms. These data were compared with sequence data of mecC-MRSA (nâ=â62) from the Dutch national MRSA surveillance in humans. RESULTS: Fifty hedgehogs were found to be MRSA positive, of which 48 carried mecC. A total of 60 mecC-MRSA isolates derived from 50 hedgehogs were compared with the human isolates. Fifty-nine mecC-MRSA from hedgehogs and all but one isolate from humans belonged to clonal complexes CC130 and CC1943. The mecC gene was located within the SCCmec XI element. Most mecC-MRSA did not carry other resistance genes besides mecC and blaZ. Two human isolates carried erm(C). Isolates differed in the presence of various virulence genes, which were linked to distinct STs and clonal complexes. Some isolates had up to 17 virulence genes, which underlines their pathogenic potential. No genetic clusters of hedgehog and human isolates were found. CONCLUSIONS: mecC-MRSA from hedgehogs and humans mainly belonged to the same two clonal complexes, indicating a common source. No firm evidence for recent zoonotic transmission was found. Further studies are needed to investigate the role of hedgehogs in the occurrence of mecC-MRSA in humans.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Países Baixos/epidemiologia , Proteínas de Bactérias/genética , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/veterinária , Proteínas Hedgehog , Genômica , Testes de Sensibilidade MicrobianaRESUMO
Whole genome sequencing data of 874 Escherichia coli isolates carrying bla NDM-5 from 13 European Union/European Economic Area countries between 2012 and June 2022 showed the predominance of sequence types ST167, ST405, ST410, ST361 and ST648, and an increasing frequency of detection. Nearly a third (30.6%) of these isolates were associated with infections and more than half (58.2%) were predicted to be multidrug-resistant. Further spread of E. coli carrying bla NDM-5 would leave limited treatment options for serious E. coli infections.
Assuntos
Infecções por Escherichia coli , Escherichia coli , Humanos , beta-Lactamases/genética , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , União Europeia , Testes de Sensibilidade Microbiana , Europa (Continente)/epidemiologiaRESUMO
Infections with hypervirulent Klebsiella pneumoniae (hvKp) commonly presents with primary liver infection, bacteremia, and metastatic abscesses. Here, we present 2 cases of severe community-acquired pulmonary infections by hvKp in patients in the Netherlands without recent travel history. Both bacterial isolates are closely related to an archetype ST23 hvKp reference isolate. Based on these findings, surveillance programs on hvKp may consider to include isolates from community-acquired pneumonia by K. pneumoniae.
Assuntos
Infecções Comunitárias Adquiridas , Infecções por Klebsiella , Pneumonia , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae , Países Baixos , VirulênciaRESUMO
Since March 2022, there has been an emergence of multidrug-resistant organisms (MDRO) in the Netherlands in patients originating from Ukraine (58 patients, 75 isolates). For about half of these patients, recent hospitalisation in Ukraine was reported. Genomic surveillance revealed that the majority of the MDRO represent globally spread epidemic lineages and that 60% contain New Delhi metallo-ß-lactamase (NDM) genes. Professionals should be aware of an increase in such MDRO associated with migration and medical evacuation of people from Ukraine.
Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Humanos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Países Baixos/epidemiologia , Ucrânia/epidemiologia , Bactérias Gram-Negativas , beta-Lactamases/genética , Testes de Sensibilidade MicrobianaRESUMO
Polyphosphate is an inorganic polymer that can potentiate several interactions in the blood coagulation system. Blood platelets contain polyphosphate, and the secretion of platelet-derived polyphosphate has been associated with increased thrombus formation and activation of coagulation factor XII. However, the small polymer size of secreted platelet polyphosphate limits its capacity to activate factor XII in vitro. Thus, the mechanism by which platelet polyphosphate contributes to thrombus formation remains unclear. Using live-cell imaging, confocal and electron microscopy, we show that activated platelets retain polyphosphate on their cell surface. The apparent polymer size of membrane-associated polyphosphate largely exceeds that of secreted polyphosphate. Ultracentrifugation fractionation experiments revealed that membrane-associated platelet polyphosphate is condensed into insoluble spherical nanoparticles with divalent metal ions. In contrast to soluble polyphosphate, membrane-associated polyphosphate nanoparticles potently activate factor XII. Our findings identify membrane-associated polyphosphate in a nanoparticle state on the surface of activated platelets. We propose that these polyphosphate nanoparticles mechanistically link the procoagulant activity of platelets with the activation of coagulation factor XII.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/metabolismo , Polifosfatos/metabolismo , Plaquetas/química , Plaquetas/ultraestrutura , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Fator XII/metabolismo , Humanos , Nanopartículas/química , Polifosfatos/farmacologiaAssuntos
Infecções por Escherichia coli , Escherichia coli , Humanos , Países Baixos/epidemiologia , Escherichia coli/genética , beta-Lactamases/genética , Proteínas de Bactérias/genética , Infecções por Escherichia coli/epidemiologia , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
The microbiome and the phage meta-genome within the human gut are influenced by antibiotic treatments. Identifying a novel mechanism, here we demonstrate that bacteria use the universal communication molecule AI-2 to induce virulence genes and transfer them via phage release. High concentrations (i.e. 100 µM) of AI-2 promote dispersal of bacteria from already established biofilms, and is associated with release of phages capable of infecting other bacteria. Enterococcus faecalis V583ΔABC harbours 7 prophages in its genome, and a mutant deficient in one of these prophages (i.e. prophage 5) showed a greatly reduced dispersal of biofilm. Infection of a probiotic E. faecalis strain without lytic prophages with prophage 5 resulted in increased biofilm formation and also in biofilm dispersal upon induction with AI-2. Infection of the probiotic E. faecalis strain with phage-containing supernatants released through AI-2 from E. faecalis V583ΔABC resulted in a strong increase in pathogenicity of this strain. The polylysogenic probiotic strain was also more virulent in a mouse sepsis model and a rat endocarditis model. Both AI-2 and ciprofloxacin lead to phage release, indicating that conditions in the gastrointestinal tract of hospitalized patients treated with antibiotics might lead to distribution of virulence genes to apathogenic enterococci and possibly also to other commensals or even to beneficial probiotic strains.
Assuntos
Biofilmes/crescimento & desenvolvimento , Endocardite Bacteriana/microbiologia , Enterococcus faecalis , Prófagos/fisiologia , Percepção de Quorum , Sepse/microbiologia , Fatores de Virulência/metabolismo , Liberação de Vírus/fisiologia , Animais , Biofilmes/efeitos dos fármacos , Células CACO-2 , Ciprofloxacina/farmacologia , Endocardite Bacteriana/patologia , Enterococcus faecalis/patogenicidade , Enterococcus faecalis/fisiologia , Enterococcus faecalis/virologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Wistar , Sepse/patologia , Liberação de Vírus/efeitos dos fármacosRESUMO
Currently, little is known about the in vivo human immune response against Staphylococcus aureus during a biofilm-associated infection, such as osteomyelitis, and how this relates to protein production in biofilms in vitro. Therefore, we characterized IgG responses in 10 patients with chronic osteomyelitis against 50 proteins of S. aureus, analyzed the presence of these proteins in biofilms of the infecting isolates on polystyrene (PS) and human bone in vitro, and explored the relation between in vivo and in vitro data. IgG levels against 15 different proteins were significantly increased in patients compared to healthy controls. Using a novel competitive Luminex-based assay, eight of these proteins [alpha toxin, Staphylococcus aureus formyl peptide receptor-like 1 inhibitor (FlipR), glucosaminidase, iron-responsive surface determinants A and H, the putative ABC transporter SACOL0688, staphylococcal complement inhibitor (SCIN), and serine-aspartate repeat-containing protein E (SdrE)] were also detected in a majority of the infecting isolates during biofilm formation in vitro. However, 4 other proteins were detected in only a minority of isolates in vitro while, vice versa, 7 proteins were detected in multiple isolates in vitro but not associated with significantly increased IgG levels in patients. Detection of proteins was largely confirmed using a transcriptomic approach. Our data provide further insights into potential therapeutic targets, such as for vaccination, to reduce S. aureus virulence and biofilm formation. At the same time, our data suggest that either in vitro or immunological in vivo data alone should be interpreted cautiously and that combined studies are necessary to identify potential targets.
Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/análise , Biofilmes/crescimento & desenvolvimento , Osteomielite/patologia , Infecções Estafilocócicas/patologia , Vacinas Antiestafilocócicas/imunologia , Staphylococcus aureus/imunologia , Idoso , Antígenos de Bactérias/imunologia , Doença Crônica , Humanos , Masculino , Pessoa de Meia-Idade , Staphylococcus aureus/química , Staphylococcus aureus/fisiologiaRESUMO
UNLABELLED: Vancomycin-resistant enterococci (VRE) have become a major nosocomial threat. Enterococcus faecium is of special concern, as it can easily acquire new antibiotic resistances and is an excellent colonizer of the human intestinal tract. Several clinical studies have explored the potential use of beneficial bacteria to weed out opportunistic pathogens. Specifically, the widely studied Lactobacillus rhamnosus strain GG has been applied successfully in the context of VRE infections. Here, we provide new insight into the molecular mechanism underlying the effects of this model probiotic on VRE decolonization. Both clinical VRE isolates and L. rhamnosus GG express pili on their cell walls, which are the key modulators of their highly efficient colonization of the intestinal mucosa. We found that one of the VRE pilus clusters shares considerable sequence similarity with the SpaCBA-SrtC1 pilus cluster of L. rhamnosus GG. Remarkable immunological and functional similarities were discovered between the mucus-binding pili of L. rhamnosus GG and those of the clinical E. faecium strain E1165, which was characterized at the genome level. Moreover, E. faecium strain E1165 bound efficiently to mucus, which may be prevented by the presence of the mucus-binding SpaC protein or antibodies against L. rhamnosus GG or SpaC. These results present experimental support for a novel probiotic mechanism, in which the mucus-binding pili of L. rhamnosus GG prevent the binding of a potential pathogen to the host. Hence, we provide a molecular basis for the further exploitation of L. rhamnosus GG and its pilins for prophylaxis and treatment of VRE infections. IMPORTANCE: Concern about vancomycin-resistant Enterococcus faecium causing nosocomial infections is rising globally. The arsenal of antibiotic strategies to treat these infections is nearly exhausted, and hence, new treatment strategies are urgently needed. Here, we provide molecular evidence to underpin reports of the successful clinical application of Lactobacillus rhamnosus GG in VRE decolonization strategies. Our results provide support for a new molecular mechanism, in which probiotics can perform competitive exclusion and possibly immune interaction. Moreover, we spur further exploration of the potential of intact L. rhamnosus GG and purified SpaC pilin as prophylactic and curative agents of the VRE carrier state.
Assuntos
Enterococcus faecium/fisiologia , Fímbrias Bacterianas/metabolismo , Lacticaseibacillus rhamnosus/fisiologia , Interações Microbianas , Muco/microbiologia , Probióticos/metabolismo , HumanosRESUMO
The current epidemic of infections caused by antibiotic-resistant gram-positive bacteria requires the discovery of new drug targets and the development of new therapeutics. Lipoteichoic acid (LTA), a cell wall polymer of gram-positive bacteria, consists of 1,3-polyglycerol-phosphate linked to glycolipid. LTA synthase (LtaS) polymerizes polyglycerol-phosphate from phosphatidylglycerol, a reaction that is essential for the growth of gram-positive bacteria. We screened small molecule libraries for compounds inhibiting growth of Staphylococcus aureus but not of gram-negative bacteria. Compound 1771 [2-oxo-2-(5-phenyl-1,3,4-oxadiazol-2-ylamino)ethyl 2-naphtho[2,1-b]furan-1-ylacetate] blocked phosphatidylglycerol binding to LtaS and inhibited LTA synthesis in S. aureus and in Escherichia coli expressing ltaS. Compound 1771 inhibited the growth of antibiotic-resistant gram-positive bacteria and prolonged the survival of mice with lethal S. aureus challenge, validating LtaS as a target for the development of antibiotics.
Assuntos
Antibacterianos/farmacologia , Inibidores Enzimáticos/farmacologia , Lipopolissacarídeos/biossíntese , Bibliotecas de Moléculas Pequenas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Ácidos Teicoicos/biossíntese , Aciltransferases/antagonistas & inibidores , Aciltransferases/metabolismo , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Domínio Catalítico , Modelos Animais de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/uso terapêutico , Camundongos , Testes de Sensibilidade Microbiana , Mutação/genética , Fosfatidilgliceróis/metabolismo , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/patologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/enzimologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/ultraestrutura , Relação Estrutura-Atividade , Análise de SobrevidaRESUMO
The lipid II-binding N-terminus of nisin, comprising the so-called A/B ring system, was synthetically modified to provide antibacterially active and proteolytically stable derivatives. A variety of lipids were coupled to the C-terminus of the nisin A/B ring system to generate semisynthetic constructs that display potent inhibition of bacterial growth, with activities approaching that of nisin itself. Most notable was the activity observed against clinically relevant bacterial strains including MRSA and VRE. Experiments with membrane models indicate that these constructs operate via a lipid II-mediated mode of action without causing pore formation. A lipid II-dependent mechanism of action is further supported by antagonization assays wherein the addition of lipid II was found to effectively block the antibacterial activity of the nisin-derived lipopeptides.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Lipopeptídeos/química , Lipopeptídeos/farmacologia , Nisina/química , Uridina Difosfato Ácido N-Acetilmurâmico/análogos & derivados , Antibacterianos/síntese química , Antibacterianos/metabolismo , Estabilidade de Medicamentos , Enterococcus faecium/efeitos dos fármacos , Humanos , Lipopeptídeos/síntese química , Lipopeptídeos/metabolismo , Proteólise , Lipossomas Unilamelares/metabolismo , Uridina Difosfato Ácido N-Acetilmurâmico/químicaRESUMO
For transmission to new hosts, Yersinia pestis, the causative agent of plague, replicates as biofilm in the foregut of fleas that feed on plague-infected animals or humans. Y. pestis biofilm formation has been studied in the rat flea; however, little is known about the cat flea, a species that may bridge zoonotic and anthroponotic plague cycles. Here, we show that Y. pestis infects and replicates as a biofilm in the foregut of cat fleas in a manner requiring hmsFR, two determinants for extracellular biofilm matrix. Examining a library of transposon insertion mutants, we identified the LysR-type transcriptional regulator YfbA, which is essential for Y. pestis colonization and biofilm formation in cat fleas.
Assuntos
Biofilmes/crescimento & desenvolvimento , Ctenocephalides/microbiologia , Fatores de Transcrição/metabolismo , Yersinia pestis/fisiologia , Animais , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Elementos de DNA Transponíveis , Trato Gastrointestinal/microbiologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutagênese Insercional , Fatores de Transcrição/genética , Yersinia pestis/genéticaRESUMO
Biofilm formation is a critical step in the pathogenesis of difficult-to-treat Gram-positive bacterial infections. We identified that YajC, a conserved membrane protein in bacteria, plays a role in biofilm formation of the clinically relevant Enterococcus faecium strain E1162. Deletion of yajC conferred significantly impaired biofilm formation in vitro and was attenuated in a rat endocarditis model. Mass spectrometry analysis of supernatants of washed ΔyajC cells revealed increased amounts in cytoplasmic and cell-surface-located proteins, including biofilm-associated proteins, suggesting that proteins on the surface of the yajC mutant are only loosely attached. In Streptococcus mutans YajC has been identified in complex with proteins of two cotranslational membrane protein-insertion pathways; the signal recognition particle (SRP)-SecYEG-YajC-YidC1 and the SRP-YajC-YidC2 pathway, but its function is unknown. In S. mutans mutation of yidC1 and yidC2 resulted in impaired protein insertion in the cell membrane and secretion in the supernatant. The E. faecium genome contains all homologous genes encoding for the cotranslational membrane protein-insertion pathways. By combining the studies in S. mutans and E. faecium, we propose that YajC is involved in the stabilization of the SRP-SecYEG-YajC-YidC1 and SRP-YajC-Yid2 pathway or plays a role in retaining proteins for proper docking to the YidC insertases for translocation in and over the membrane.
RESUMO
Objectives: We describe the clonal spread of New Delhi metallo-ß-lactamase (NDM) 1-producing Pseudomonas aeruginosa isolates belonging to the ST773 clone in Spain and the Netherlands, associated with the transfer of Ukrainian patients during the war. Methods: Between March and December 2022, nine NDM-1-producing P. aeruginosa ST773 isolates were recovered from nine Ukrainian patients evacuated to two Spanish (n = 3) and five Dutch (n = 6) hospitals. Antimicrobial susceptibility testing was studied (Sensititre, Microscan, EUCAST-2023). Whole genome sequencing (Illumina, Oxford-Nanopore) was used to analyze the genetic relatedness, the resistome, and the prophage content. Results: All NDM-1-producing P. aeruginosa ST773 isolates exhibited resistance to all tested antimicrobials except colistin, aztreonam, and cefiderocol. Genomic analysis revealed that all isolates had an identical resistome and a chromosomally encoded integrative conjugative element carrying the bla NDM-1 gene. The core genome multilocus sequence typing and core genome single nucleotide polymorphisms analysis showed highly related isolates, irrespective of country of isolation, distant from other NDM-1-ST773 P. aeruginosa not collected in Ukraine. Both analysis revealed two closely related clusters, spanning the Spanish and Dutch isolates. In addition, a high content of prophages was identified in all strains, most of them in more than one isolate simultaneously, regardless of their origin country. Moreover, an identical phage tail-like bacteriocin cluster was identified in all NDM-1-ST773 P. aeruginosa. Conclusions: We report a clonal dissemination of NDM-producing P. aeruginosa ST773 to the Netherlands and Spain associated with patients from Ukraine. Our work highlights the importance of genomic surveillance and to understand the dynamics of resistance in multidrug-resistant bacteria after the transfer of patients from conflict zones. International collaboration is crucial to address global antimicrobial resistance.
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BACKGROUND: Vancomycin-resistant Enterococcus faecium (VREfm) is an opportunistic pathogen, which can cause outbreaks in hospitals. In the Netherlands, several national guidelines and guidance documents on different aspects of VREfm-management are available. Most available guidelines are written towards the hospital setting and only few on long-term care facilities (LTCFs). Moreover, not all aspects of VREfm-management are covered, recommendations differ and the level of compliance to these guidelines is unknown. The aim of this study was to get insight into the routine VREfm-policies in Dutch healthcare facilities with regard to screening, diagnostics and infection control measures. MATERIALS AND METHODS: Online questionnaires were sent to representatives of Dutch hospitals and long-term care facilities (LTCFs). The questionnaire included questions regarding the definition of VRE, screening, diagnostics, patient isolation, cleaning procedures, VREfm-clearance and VREfm-outbreaks. RESULTS: The questionnaire was completed by 61 hospitals with a response rate of 84.1% and 57 LTCFs, mostly nursing homes. Most hospitals reported VRE-outbreaks in the previous decade, whereas only one LTCFs reported an outbreak. Of the hospitals, 87% perform VREfm-screening versus 50% of the LTCFs. VRE-positive patients are isolated in 98% of hospitals and 83% of LTCFs. Protocols regarding how to unlabel VRE-positive patients are in place in 84% of the hospitals and in 51% of LTCFs. The details of these measures differ substantially between healthcare facilities. CONCLUSION: This study has shown that most hospitals and some LTCFs in the Netherlands have standard procedures for VREfm-management to some level, although the comprehensiveness and details of the measures differ per hospital. More uniform policies would improve comparability of VREfm data on a regional/national level.