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Clinical Infectious Diseases : An... May 2015Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae present an ever-growing burden in the hospital and community settings, across all ages and... (Review)
Review
Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae present an ever-growing burden in the hospital and community settings, across all ages and demographics. Infections due to ESBL-containing pathogens continue to be associated with significant morbidity and mortality worldwide. With widespread empiric broad-spectrum β-lactam use creating selective pressure, and the resultant emergence of stable, rapidly proliferating ESBL-producing clones with continued horizontal gene transfer across genera, addressing this issue remains imperative. Although well characterized in adults, the epidemiology, risk factors, outcomes, therapies, and control measures for ESBL-producing bacteria are less appreciated in children. This analysis provides a brief summary of ESBL-producing Enterobacteriaceae in children, with a focus on recent clinical and molecular data regarding colonization and infection in nonoutbreak settings.
Topics: Adult; Anti-Bacterial Agents; Child; Child, Preschool; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Humans; Infection Control; Microbial Sensitivity Tests; Risk Factors; beta-Lactamases
PubMed: 25595742
DOI: 10.1093/cid/civ020 -
Virulence May 2017
Topics: Anti-Bacterial Agents; Carbapenem-Resistant Enterobacteriaceae; Enterobacteriaceae Infections; Humans
PubMed: 28402724
DOI: 10.1080/21505594.2017.1306621 -
Journal of Bacteriology Jan 2018Attaching and effacing (AE) pathogens colonize the gut mucosa using a type three secretion system (T3SS) and a suite of effector proteins. The locus of enterocyte... (Review)
Review
Attaching and effacing (AE) pathogens colonize the gut mucosa using a type three secretion system (T3SS) and a suite of effector proteins. The locus of enterocyte effacement (LEE) is the defining genetic feature of the AE pathogens, encoding the T3SS and the core effector proteins necessary for pathogenesis. Extensive research has revealed a complex regulatory network that senses and responds to a myriad of host- and microbiota-derived signals in the infected gut to control transcription of the LEE. These signals include microbiota-liberated sugars and metabolites in the gut lumen, molecular oxygen at the gut epithelium, and host hormones. Recent research has revealed that AE pathogens also recognize physical signals, such as attachment to the epithelium, and that the act of effector translocation remodels gene expression in infecting bacteria. In this review, we summarize our knowledge to date and present an integrated view of how chemical, geographical, and physical cues regulate the virulence program of AE pathogens during infection.
Topics: Attachment Sites, Microbiological; Enterobacteriaceae; Escherichia coli; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Genes, Bacterial; Host-Pathogen Interactions; Phosphoproteins; Quorum Sensing; Type III Secretion Systems; Virulence
PubMed: 28760850
DOI: 10.1128/JB.00336-17 -
Antimicrobial Resistance and Infection... Jun 2022Sepsis due to multidrug resistant (MDR) bacteria is a growing public health problem mainly in low-income countries.
BACKGROUND
Sepsis due to multidrug resistant (MDR) bacteria is a growing public health problem mainly in low-income countries.
METHODS
A multicenter study was conducted between October 2019 and September 2020 at four hospitals located in central (Tikur Anbessa and Yekatit 12), southern (Hawassa) and northern (Dessie) parts of Ethiopia. A total of 1416 patients clinically investigated for sepsis were enrolled. The number of patients from Tikur Anbessa, Yekatit 12, Dessie and Hawassa hospital was 501, 298, 301 and 316, respectively. At each study site, blood culture was performed from all patients and positive cultures were characterized by their colony characteristics, gram stain and conventional biochemical tests. Each bacterial species was confirmed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI TOF). Antimicrobial resistance pattern of bacteria was determined by disc diffusion. Logistic regression analysis was used to assess associations of dependent and independent variables. A p-value < 0.05 was considered as statistically significant. The data was analyzed using SPSS version 25.
RESULTS
Among 1416 blood cultures performed, 40.6% yielded growth. Among these, 27.2%, 0.3% and 13.1%, were positive for pathogenic bacteria, yeast cells and possible contaminants respectively. Klebsiella pneumoniae (26.1%), Klebsiella variicola (18.1%) and E. coli (12.4%) were the most frequent. Most K. variicola were detected at Dessie (61%) and Hawassa (36.4%). Almost all Pantoea dispersa (95.2%) were isolated at Dessie. Rare isolates (0.5% or 0.2% each) included Leclercia adecarboxylata, Raoultella ornithinolytica, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, Burkholderia cepacia, Kosakonia cowanii and Lelliottia amnigena. Enterobacteriaceae most often showed resistance to ampicillin (96.2%), ceftriaxone (78.3%), cefotaxime (78%), cefuroxime (78%) and ceftazidime (76.4%). MDR frequency of Enterobacteriaceae at Hawassa, Tikur Anbessa, Yekatit 12 and Dessie hospital was 95.1%, 93.2%, 87.3% and 67.7%, respectively. Carbapenem resistance was detected in 17.1% of K. pneumoniae (n = 111), 27.7% of E. cloacae (n = 22) and 58.8% of Acinetobacter baumannii (n = 34).
CONCLUSION
Diverse and emerging gram-negative bacterial etiologies of sepsis were identified. High multidrug resistance frequency was detected. Both on sepsis etiology types and MDR frequencies, substantial variation between hospitals was determined. Strategies to control MDR should be adapted to specific hospitals. Standard bacteriological services capable of monitoring emerging drug-resistant sepsis etiologies are essential for effective antimicrobial stewardship.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Ethiopia; Hospitals; Humans; Klebsiella pneumoniae; Microbial Sensitivity Tests; Referral and Consultation; Sepsis
PubMed: 35698179
DOI: 10.1186/s13756-022-01122-x -
World Journal of Microbiology &... Jul 2017Acute oak decline (AOD) is a relatively newly described disorder affecting native oak species in Britain. Symptomatic trees are characterised by stem bleeds from... (Review)
Review
Acute oak decline (AOD) is a relatively newly described disorder affecting native oak species in Britain. Symptomatic trees are characterised by stem bleeds from vertical fissures, necrotic lesions in the live tissue beneath and larval galleries of the two spotted oak buprestid (Agrilus biguttatus). Several abiotic and biotic factors can be responsible for tree death, however the tissue necrosis and stem weeping is thought to be caused by a combination of bacterial species. Following investigations of the current episode of AOD which began in 2008, numerous strains belonging to several different bacteria in the family Enterobacteriaceae have been consistently isolated from symptomatic tissue. The majority of these enterobacteria were found to be novel species, subspecies and even genera, which have now been formally classified. The most frequently isolated species from symptomatic oak are Gibbsiella quercinecans, Brenneria goodwinii and Rahnella victoriana. Identification of these bacteria is difficult due to similarities in colony morphology, phenotypic profile and 16S rRNA gene sequences. Current identification relies heavily on gyrB gene amplification and sequencing, which is time consuming and laborious. However, newer techniques based on detection of single nucleotide polymorphisms show greater promise for rapid and reliable identification of the bacteria associated with AOD.
Topics: DNA Barcoding, Taxonomic; DNA, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Phylogeny; Plant Diseases; Polymorphism, Single Nucleotide; Quercus
PubMed: 28623563
DOI: 10.1007/s11274-017-2296-4 -
EcoSal Plus Feb 2019CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against invasion by bacteriophages and other mobile genetic elements. Short fragments of invader... (Review)
Review
CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against invasion by bacteriophages and other mobile genetic elements. Short fragments of invader DNA are stored as immunological memories within CRISPR (clustered regularly interspaced short palindromic repeat) arrays in the host chromosome. These arrays provide a template for RNA molecules that can guide CRISPR-associated (Cas) proteins to specifically neutralize viruses upon subsequent infection. Over the past 10 years, our understanding of CRISPR-Cas systems has benefited greatly from a number of model organisms. In particular, the study of several members of the Gram-negative family, especially and , have provided significant insights into the mechanisms of CRISPR-Cas immunity. In this review, we provide an overview of CRISPR-Cas systems present in members of the . We also detail the current mechanistic understanding of the type I-E and type I-F CRISPR-Cas systems that are commonly found in enterobacteria. Finally, we discuss how phages can escape or inactivate CRISPR-Cas systems and the measures bacteria can enact to counter these types of events.
Topics: Archaea; Bacteriophages; CRISPR-Cas Systems; Enterobacteriaceae; Escherichia coli; Host Microbial Interactions; Pectobacterium
PubMed: 30724156
DOI: 10.1128/ecosalplus.ESP-0008-2018 -
Microbial Biotechnology Mar 2017
Topics: Enterobacteriaceae; Fimbriae, Bacterial; Hair; Humans; Microbiota; Scalp
PubMed: 28244275
DOI: 10.1111/1751-7915.12694 -
Revista Argentina de Microbiologia 2019Colistin resistance can occur by chromosomal mutations and by acquisition of plasmid-carrying determinants, mainly mcr-1. In the recent years, we have observed the... (Review)
Review
Colistin resistance can occur by chromosomal mutations and by acquisition of plasmid-carrying determinants, mainly mcr-1. In the recent years, we have observed the outburst of this resistance gene in our region. Due to the risk of the rapid dissemination of mcr-1, this finding has worried and alerted different actors from the health field and has become one of the most prolific topics. Our review compiles available reports of well-documented mcr-1-positive strains of Enterobacteriaceae, obtained from different samples in Argentina and other countries of Latin America. Furthermore, it addresses the association of mcr-1 with ESBL resistance markers and outlines the platforms involved in their dissemination.
Topics: Bacterial Proteins; Colistin; Drug Resistance, Bacterial; Enterobacteriaceae; Latin America; Plasmids
PubMed: 29945744
DOI: 10.1016/j.ram.2018.05.001 -
F1000Research 2018The spread of extended-spectrum β-lactamase (ESBL)-producing (ESBL-PE) has dramatically increased worldwide, and this "evolving crisis" is currently regarded as one of... (Review)
Review
The spread of extended-spectrum β-lactamase (ESBL)-producing (ESBL-PE) has dramatically increased worldwide, and this "evolving crisis" is currently regarded as one of the most important public health threats. The growing problem of ESBL-PE antimicrobial resistance seems to have a dual face between "Scylla and Charybdis": on one hand the potential for rapid spread and dissemination of resistance mechanisms and on the other hand the injudicious overuse of antimicrobial agents and the inadequate infection control measures, especially in the health-care setting. Given the World Health Organization's warning against a "post antibiotic era", health-care providers are at a critical standpoint to find a "balance" between safe and effective ESBL-PE treatment and avoidance of inducing further resistance mechanisms. The aim of the review is to summarize the updated published knowledge in an attempt to answer basic everyday clinical questions on how to proceed to effective and the best ESBL-PE treatment options based on the existing published data.
Topics: Anti-Bacterial Agents; Enterobacteriaceae; Enterobacteriaceae Infections; Humans; Treatment Outcome; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 30228863
DOI: 10.12688/f1000research.14822.1 -
Journal of Global Antimicrobial... Sep 2023Carbapenems are among the few effective antibiotics against multidrug-resistant Enterobacteriaceae. This study aimed at characterizing the plasmid content and resistome...
OBJECTIVES
Carbapenems are among the few effective antibiotics against multidrug-resistant Enterobacteriaceae. This study aimed at characterizing the plasmid content and resistome of clinical carbapenem-resistant Enterobacteriaceae (CRE) recovered from 2016 to 2019 from hospitalized patients in Lebanon.
METHODS
Plasmid typing and whole-genome sequencing were used to study the genomic characteristics of 65 clinical CREs including 27 Escherichia coli, 24 Klebsiella pneumoniae, one Klebsiella quasipneumoniae, three Morganella morganii, three Citrobacter freundii, five Enterobacter hormaechei, and two Serratia marcescens.
RESULTS
bla (33.8%; n = 22) and bla-like genes were among the detected resistance determinants, with two isolates co-harbouring bla. Various bla variants, bla (16.9%; n = 11), bla (9.2%; n = 6), bla (9.2%; n = 6), and bla (4.6%; n = 3), different ESBLs, and AmpC β-lactamases were detected. Carbapenem resistance determinants were linked to a variety of incompatibility groups with IncFIB(K) (43.1%; n = 28) being the most prevalent, followed by IncFIA (40.0%), IncL (35.4%), IncX3 (32.3%), IncI1 (32.3%), and IncFIIK (29.2%).
CONCLUSIONS
We analysed the clonality and resistance determinants of 65 multidrug-resistant (MDR) Enterobacteriaceae recovered in the period from 2016 to 2019 from a large tertiary hospital in Lebanon. NDM variants, OXA-48, and OXA-181 were the most prevalent detected carbapenemases and were mostly linked to the dissemination of IncL, IncX3, and IncF. This study reinforces the need to track the spread and dominance of clinically relevant carbapenemase-encoding plasmids in healthcare settings.
Topics: Humans; Carbapenem-Resistant Enterobacteriaceae; Enterobacteriaceae; Escherichia coli; Anti-Bacterial Agents; Sequence Analysis
PubMed: 37437842
DOI: 10.1016/j.jgar.2023.07.004