Virulence Factors and Antibiotic Resistance of Enterobacterales

A special issue of Microorganisms (ISSN 2076-2607). This special issue belongs to the section "Antimicrobial Agents and Resistance".

Deadline for manuscript submissions: closed (31 May 2022) | Viewed by 38267

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Institute of Animal Physiology, Centre of Biosciences of the Slovak Academy of Sciences, 040 01 Košice, Slovakia
Interests: Enterobacterales; virulence factors; antibiotic resistance; biofilm; quorum sensing
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Guest Editor
Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, dr Subotica 1, 11000 Belgrade, Serbia
Interests: Enterobacterales; antimicrobial resistance; biofilm; human medicine
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The heterogeneous group of Gram-negative bacteria such as Escherichia coli and non-Escherichia coli Enterobacterales (e.g., Klebsiella, Enterobacter, Citrobacter) that can colonize the gastrointestinal tract of humans and animals and persist as gut commensals without inducing any infections in the environment with balanced microbiota (colonization resistance) also harbor features responsible for virulence and pathogenicity, including “fitness factors” or phenotypes that may result in severe health concerns, such as biofilm formation and/or multidrug resistance. Pathogenic Enterobacterales isolated from infected patients are the most often investigated, but also fecal isolates from healthy subjects including food, companion, and wild animals and/or food or environmental strains should be a more frequent target, aiming to determine the pathogenic potential of a wider biodiversity reservoir.

This Special Issue invites researchers interested in Enterobacterales characterization concerning the presence of genes associated with virulence (adhesins; surface cellulose structures and curli; siderophores, e.g., enterobactin, aerobactin, and yersiniabactin; protectines; invasins or toxins), and, furthermore, bacterial-biofilm-associated phenotypes. Although not directly involved in pathogenicity, the acquisition of multiple antibiotic resistances strongly supports the success of opportunistic Enterobacterales pathogens in invasion, survival, and spread and markedly complicates the treatment of infections. Not only pathogens but also commensal bacteria, considered harmless and part of the normal microbiota, are exposed to selection pressure and can be a reservoir of mobile genetic elements carrying antibiotic resistance genes. Therefore, the occurrence of drug-resistant bacteria within a commensal population and the possibility to exchange genetic material through horizontal gene transfer may represent a major health concern. Research papers, up-to-date review articles, and commentaries dealing with resistance, virulence, and biofilm in Enterobacterales are all welcome.

Dr. Dobroslava Bujňáková
Prof. Dr. Nikola Puvača
Prof. Ivana Ćirković
Guest Editors

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Keywords

  • enterobacterales
  • virulence factors
  • antibiotic resistance
  • biofilm
  • healthy and sick animals
  • commensal and pathogenic bacteria

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Published Papers (12 papers)

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Editorial

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3 pages, 215 KiB  
Editorial
Virulence Factors and Antibiotic Resistance of Enterobacterales
by Dobroslava Bujňáková, Nikola Puvača and Ivana Ćirković
Microorganisms 2022, 10(8), 1588; https://doi.org/10.3390/microorganisms10081588 - 7 Aug 2022
Cited by 7 | Viewed by 2977
Abstract
In the class Gammaproteobacteria, Enterobacterales are Gram-negative, facultatively anaerobic bacteria [...] Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)

Research

Jump to: Editorial

14 pages, 2558 KiB  
Article
Pheromone Activity after Stimulation with Ampicillin in a Plasmid-Free Enterococcus faecalis Strain
by José Arellano-Galindo, Sergio Zavala-Vega, Rosario Vázquez-Larios, Sara A. Ochoa, Ariadnna Cruz-Córdova, Adolfo Sierra-Santoyo, Lourdes López-González, Rigoberto Hernández-Castro, Silvia Giono-Cerezo and Juan Xicohtencatl-Cortes
Microorganisms 2022, 10(11), 2294; https://doi.org/10.3390/microorganisms10112294 - 19 Nov 2022
Cited by 1 | Viewed by 1732
Abstract
Enterococci exhibit clumping under the selective pressure of antibiotics. The aim of this study was to analyze the effect of supernatants from a plasmid-free clone (C29) of Enterococcus faecalis subjected to 0.25×, 0.5×, and 0.75× of the minimal inhibitory concentration (MIC) of ampicillin [...] Read more.
Enterococci exhibit clumping under the selective pressure of antibiotics. The aim of this study was to analyze the effect of supernatants from a plasmid-free clone (C29) of Enterococcus faecalis subjected to 0.25×, 0.5×, and 0.75× of the minimal inhibitory concentration (MIC) of ampicillin on the expression of an aggregation substance (AS) by a donor plasmid clone (1390R). A clumping assay was performed. The relative expression of prgB (gene that encodes AS) was determined and semiquantified in 1390R, and iad1 expression was determined and semiquantified in C29. AS expression was analyzed in the stimulated 1390R cells by confocal microscopy, flow cytometry, and ELISA. Adherence was also measured. Maximal clumping was observed with the pheromone medium 0.25×. Only the 1390R strain stimulated with the C29 supernatant without ampicillin and with 0.25× was able to express prgB. No expression of prgB was observed at 0.5× and 0.75×. The difference in relative expression (RE) of 1390R without ampicillin and with 0.25× was 0.5-fold. AS expression in 1390R showed the greatest increase upon stimulation with 0.25×. When 1390R was stimulated with 0.5× and 0.75×, AS expression was also observed but was significantly lower. Ampicillin stimulated C29 switch-off pheromone expression in recipient cells, which in turn switched off AS expression in donor cells. We observed that although prgB was switched off after 0.5× stimulation in C29, the supernatants induced expression in certain 1390R strains. In conclusion, ampicillin was able to modulate pheromone expression in free plasmid clones which, in turn, modulated AS expression in plasmid donor cells. The fact that PrgB gene expression was switched off after the ampicillin stimulus at 0.5× MIC, whereas AS proteins were present on the surface of the bacteria, suggested that a mechanism of rescue associated with mechanism pheromone sensing may be involved. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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9 pages, 1001 KiB  
Article
Pandemic Clones of CTX-M-15 Producing Klebsiella pneumoniae ST15, ST147, and ST307 in Companion Parrots
by Yamê Miniero Davies, Marcos Paulo Vieira Cunha, Milena Dropa, Nilton Lincopan, Vasco Túlio Moura Gomes, Luisa Zanoli Moreno, Maria Inês Zanoli Sato, Andrea Micke Moreno and Terezinha Knöbl
Microorganisms 2022, 10(7), 1412; https://doi.org/10.3390/microorganisms10071412 - 13 Jul 2022
Cited by 6 | Viewed by 2004
Abstract
Psittacine birds are commonly kept as companion birds and the maintenance of these birds in captivity may represent a zoonotic risk and contribute to the propagation of multidrug-resistant and β-lactamase extended-spectrum (ESBLs)-producing pathogens. This study aimed to identify and characterize strains of the [...] Read more.
Psittacine birds are commonly kept as companion birds and the maintenance of these birds in captivity may represent a zoonotic risk and contribute to the propagation of multidrug-resistant and β-lactamase extended-spectrum (ESBLs)-producing pathogens. This study aimed to identify and characterize strains of the Klebsiella pneumoniae complex isolated from diseased psittacine birds, determining virulence and resistance profiles. K. pneumoniae strains were isolated from 16 birds (16/46). All strains carried more than three virulence genes, with a high frequency of fimH and kpn (93.75%), uge (87.52%), and irp-2 (81.25%) genes. The antimicrobial susceptibility revealed that 3/16 strains were ESBL producers. Genomic analysis revealed that CTX-M-15-positive strains belonged to sequence types (STs) ST15, ST147, and ST307, characterized as international clones associated with outbreaks of healthcare-associated infections (HAIs) worldwide. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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16 pages, 2644 KiB  
Article
Investigating Morphological Changes of T-lymphocytes after Exposure with Bacterial Determinants for Early Detection of Septic Conditions
by Kari Lavinia vom Werth, Theresa Wörmann, Björn Kemper, Philipp Kümpers, Stefanie Kampmeier and Alexander Mellmann
Microorganisms 2022, 10(2), 391; https://doi.org/10.3390/microorganisms10020391 - 8 Feb 2022
Cited by 8 | Viewed by 2207
Abstract
Sepsis is a leading cause of morbidity and mortality, annually affecting millions of people worldwide. Immediate treatment initiation is crucial to improve the outcome but despite great progress, early identification of septic patients remains a challenge. Recently, white blood cell morphology was proposed [...] Read more.
Sepsis is a leading cause of morbidity and mortality, annually affecting millions of people worldwide. Immediate treatment initiation is crucial to improve the outcome but despite great progress, early identification of septic patients remains a challenge. Recently, white blood cell morphology was proposed as a new biomarker for sepsis diagnosis. In this proof-of-concept study, we aimed to investigate the effect of different bacteria and their determinants on T-lymphocytes by digital holographic microscopy (DHM). We hypothesize that species- and strain-specific morphological changes occur, which may offer a new approach for early sepsis diagnosis and identification of the causative agent. Jurkat cells as a model system were exposed to different S. aureus or E. coli strains either using sterile determinants or living bacteria. Time-lapse DHM was applied to analyze cellular morphological changes. There were not only living bacteria but also membrane vesicles and sterile culture supernatant-induced changes of cell area, circularity, and mean phase contrast. Interestingly, different cellular responses occurred depending on both the species and strain of the causative bacteria. Our findings suggest that investigation of T-lymphocyte morphology might provide a promising tool for the early identification of bacterial infections and possibly discrimination between different causative agents. Distinguishing gram-positive from gram-negative infection would already offer a great benefit for the proper administration of antibiotics. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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17 pages, 4321 KiB  
Article
Alteration of Salmonella enterica Virulence and Host Pathogenesis through Targeting sdiA by Using the CRISPR-Cas9 System
by Momen Askoura, Ahmad J. Almalki, Amr S. Abu Lila, Khaled Almansour, Farhan Alshammari, El-Sayed Khafagy, Tarek S. Ibrahim and Wael A. H. Hegazy
Microorganisms 2021, 9(12), 2564; https://doi.org/10.3390/microorganisms9122564 - 11 Dec 2021
Cited by 39 | Viewed by 4432
Abstract
Salmonella enterica is a common cause of many enteric infections worldwide and is successfully engineered to deliver heterologous antigens to be used as vaccines. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) RNA-guided Cas9 endonuclease is a promising genome editing tool. In the current [...] Read more.
Salmonella enterica is a common cause of many enteric infections worldwide and is successfully engineered to deliver heterologous antigens to be used as vaccines. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) RNA-guided Cas9 endonuclease is a promising genome editing tool. In the current study, a CRISPR-Cas9 system was used to target S.enterica sdiA that encodes signal molecule receptor SdiA and responds to the quorum sensing (QS) signaling compounds N-acylhomoserine lactones (AHLs). For this purpose, sdiA was targeted in both S.enterica wild type (WT) and the ΔssaV mutant strain, where SsaV has been reported to be an essential component of SPI2-T3SS. The impact of sdiA mutation on S. enterica virulence was evaluated at both early invasion and later intracellular replication in both the presence and absence of AHL. Additionally, the influence of sdiA mutation on the pathogenesis S. enterica WT and mutants was investigated in vivo, using mice infection model. Finally, the minimum inhibitory concentrations (MICs) of various antibiotics against S. enterica strains were determined. Present findings show that mutation in sdiA significantly affects S.enterica biofilm formation, cell adhesion and invasion. However, sdiA mutation did not affect bacterial intracellular survival. Moreover, in vivo bacterial pathogenesis was markedly lowered in S.enterica ΔsdiA in comparison with the wild-type strain. Significantly, double-mutant sdiA and ssaV attenuated the S. enterica virulence and in vivo pathogenesis. Moreover, mutations in selected genes increased Salmonella susceptibility to tested antibiotics, as revealed by determining the MICs and MBICs of these antibiotics. Altogether, current results clearly highlight the importance of the CRISPR-Cas9 system as a bacterial genome editing tool and the valuable role of SdiA in S.enterica virulence. The present findings extend the understanding of virulence regulation and host pathogenesis of Salmonellaenterica. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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21 pages, 2727 KiB  
Article
Bacterial Morphotypes as Important Trait for Uropathogenic E. coli Diagnostic; a Virulence-Phenotype-Phylogeny Study
by Manuel G. Ballesteros-Monrreal, Margarita M. P. Arenas-Hernández, Edwin Barrios-Villa, Josue Juarez, Maritza Lizeth Álvarez-Ainza, Pablo Taboada, Rafael De la Rosa-López, Enrique Bolado-Martínez and Dora Valencia
Microorganisms 2021, 9(11), 2381; https://doi.org/10.3390/microorganisms9112381 - 18 Nov 2021
Cited by 16 | Viewed by 4931
Abstract
Urinary tract infections (UTIs) belong to the most common pathologies in Mexico and are mainly caused by Uropathogenic Escherichia coli (UPEC). UPEC possesses a wide diversity of virulence factors that allow it to carry out its pathogenesis mechanism in the urinary tract (UT). [...] Read more.
Urinary tract infections (UTIs) belong to the most common pathologies in Mexico and are mainly caused by Uropathogenic Escherichia coli (UPEC). UPEC possesses a wide diversity of virulence factors that allow it to carry out its pathogenesis mechanism in the urinary tract (UT). The development of morphotypes in UT represents an important feature of UPEC because it is associated with complications in diagnosis of UTI. The aim of this study was to determine the presence of bacterial morphotypes, virulence genes, virulence phenotypes, antibiotic resistant, and phylogenetic groups in clinical isolates of UPEC obtained from women in Sonora, Mexico. Forty UPEC isolates were obtained, and urine morphotypes were observed in 65% of the urine samples from where E. coli was isolated. Phylogenetic group B2 was the most prevalent. The most frequent virulence genes were fimH (100%), fliCD (90%), and sfaD/focC (72%). Biofilm formation (100%) and motility (98%) were the most prevalent phenotypes. Clinical isolates showed high resistance to aminoglycosides and β-lactams antibiotics. These data suggest that the search for morphotypes in urine sediment must be incorporated in the urinalysis procedure and also that clinical isolates of UPEC in this study can cause upper, lower, and recurrent UTI. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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18 pages, 2917 KiB  
Article
Phenotypic and Molecular Characterization of Commensal, Community-Acquired and Nosocomial Klebsiella spp.
by Marta Gómez, Arancha Valverde, Rosa del Campo, Juan Miguel Rodríguez and Antonio Maldonado-Barragán
Microorganisms 2021, 9(11), 2344; https://doi.org/10.3390/microorganisms9112344 - 12 Nov 2021
Cited by 17 | Viewed by 3266
Abstract
Klebsiella spp. is a relevant pathogen that can present acquired resistance to almost all available antibiotics, thus representing a serious threat for public health. While most studies have been focused on isolates causing community-acquired and nosocomial infections, little is known about the commensal [...] Read more.
Klebsiella spp. is a relevant pathogen that can present acquired resistance to almost all available antibiotics, thus representing a serious threat for public health. While most studies have been focused on isolates causing community-acquired and nosocomial infections, little is known about the commensal isolates colonizing healthy subjects. We describe the molecular identification and the phenotypic characterization of commensal Klebsiella spp. from breast milk of healthy women and faeces from healthy breast-fed infants, which were compared with isolates from community-acquired infections and from a nosocomial NICU outbreak. The phylogenetic analysis of a 454-bp sequence of the rpoB gene was useful for species identification (K. pneumoniae, K. variicola, K. quasipneumoniae, K. oxytoca, K. grimontii, K. michiganensis, Raoultella planticola and R. ornithinolytica), previously misidentified as K. pneumoniae or K. oxytoca by biochemical methods. Globally, we report that commensal strains present virulence traits (virulence genes, siderophores and biofilms) comparable to community-acquired and NICU-infective isolates, thus suggesting that the human microbiota could constitute a reservoir for infection. Isolates causing NICU outbreak were multi-drug resistant (MDR) and ESBLs producers, although an imipenem-resistant commensal MDR K. quasipneumoniae isolate was also found. A commensal K. pneumoniae strain showed a potent bacteriocin-like inhibitory activity against MDR Klebsiella isolates, thus highlighting the potential role of commensal Klebsiella spp. in health and disease. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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13 pages, 16840 KiB  
Article
Outer Membrane Protein F Is Involved in Biofilm Formation, Virulence and Antibiotic Resistance in Cronobacter sakazakii
by Jianxin Gao, Zhonghui Han, Ping Li, Hongyan Zhang, Xinjun Du and Shuo Wang
Microorganisms 2021, 9(11), 2338; https://doi.org/10.3390/microorganisms9112338 - 11 Nov 2021
Cited by 17 | Viewed by 2430
Abstract
In some Gram-negative bacteria, ompF encodes outer membrane protein F (OmpF), which is a cation-selective porin and is responsible for the passive transport of small molecules across the outer membrane. However, there are few reports about the functions of this gene in Cronobacter [...] Read more.
In some Gram-negative bacteria, ompF encodes outer membrane protein F (OmpF), which is a cation-selective porin and is responsible for the passive transport of small molecules across the outer membrane. However, there are few reports about the functions of this gene in Cronobacter sakazakii. To investigate the role of ompF in detail, an ompF disruption strain (ΔompF) and a complementation strain (cpompF) were successfully obtained. We find that OmpF can affect the ability of biofilm formation in C. sakazakii. In addition, the variations in biofilm composition of C. sakazakii were examined using Raman spectroscopy analyses caused by knocking out ompF, and the result indicated that the levels of certain biofilm components, including lipopolysaccharide (LPS), were significantly decreased in the mutant (ΔompF). Then, SDS-PAGE was used to further analyze the LPS content, and the result showed that the LPS levels were significantly reduced in the absence of ompF. Therefore, we conclude that OmpF affects biofilm formation in C. sakazakii by reducing the amount of LPS. Furthermore, the ΔompF mutant showed decreased (2.7-fold) adhesion to and invasion of HCT-8 cells. In an antibiotic susceptibility analysis, the ΔompF mutant showed significantly smaller inhibition zones than the WT, indicating that OmpF had a positive effect on the influx of antibiotics into the cells. In summary, ompF plays a positive regulatory role in the biofilm formation and adhesion/invasion, which is achieved by regulating the amount of LPS, but is a negative regulator of antibiotic resistance in C. sakazakii. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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10 pages, 262 KiB  
Article
K1 Antigen Is Associated with Different AST Profile in Escherichia coli: A One-Month-Long Pilot Study
by Maelys Proquot, Lovasoa Najaraly Jamal, Chloe Plouzeau-Jayle, Anthony Michaud, Lauranne Broutin, Christophe Burucoa, Julie Cremniter and Maxime Pichon
Microorganisms 2021, 9(9), 1884; https://doi.org/10.3390/microorganisms9091884 - 5 Sep 2021
Cited by 2 | Viewed by 2752
Abstract
Escherichia coli is responsible for diseases of varying severity. The “K” antigen designates the capsular polysaccharides on the bacterial surface, which are mostly similar to those of highly pathogenic bacteria. The K1 antigen is often found in pathogenic E. coli. Aim: While [...] Read more.
Escherichia coli is responsible for diseases of varying severity. The “K” antigen designates the capsular polysaccharides on the bacterial surface, which are mostly similar to those of highly pathogenic bacteria. The K1 antigen is often found in pathogenic E. coli. Aim: While the published studies on the AST profile of K1-positive E. coli have focused on pregnant women or newborns, this study aimed to characterize the AST profile of K1-positive E. coli independently of the clinical sample of isolation. Over a 4-week-long period, all patients hospitalized/consulting at the Poitiers University Hospital presenting a determined AST on E. coli were prospectively included to define their K1-status (Pastorex Meningitis) and to collect the clinical (age/sex) or biological metadata (AST/MIC). Among the 296 included samples, no differential representation was observed between K1 results regarding sample nature. K1-negative results were associated with multiple antibiotic-resistance (12.3% vs. 33.0%; p < 0.01). AST phenotypes differed between these groups, with a higher proportion of K1-negativity among resistant strains, especially on β-lactams (ureidopenicillin, 25.8% vs. 14.9%; and ampicillin/inhibitor, 50.0% vs. 26.8%; p < 0.05) or quinolone (19.8% vs. 7.0%) and sulfamethoxazole-trimethoprim (30.2% vs. 12.3%) (p < 0.01). This study analyzed E. coli ASTs in clinical samples of all types, regarding their K1-antigen status. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
11 pages, 291 KiB  
Article
Escherichia coli Specific Virulence-Gene Markers Analysis for Quality Control of Ovine Cheese in Slovakia
by Dobroslava Bujňáková, Lívia Karahutová and Vladimír Kmeť
Microorganisms 2021, 9(9), 1808; https://doi.org/10.3390/microorganisms9091808 - 25 Aug 2021
Cited by 6 | Viewed by 2679
Abstract
Shiga toxin-producing and extra-intestinal pathogenic Escherichia coli (E. coli) have the potential to spread through faecal waste, resulting in contamination of food and causing foodborne disease outbreaks. With the aim of characterizing unpasteurized ovine cheese in Slovakia, a total of 92 [...] Read more.
Shiga toxin-producing and extra-intestinal pathogenic Escherichia coli (E. coli) have the potential to spread through faecal waste, resulting in contamination of food and causing foodborne disease outbreaks. With the aim of characterizing unpasteurized ovine cheese in Slovakia, a total of 92 E. coli strains were examined for eleven representative virulence genes typical for (extra-)intestinal pathogenic E. coli and phylogenetic grouping. Phylogenetic groups B1 (36%) and A (32%) were the most dominant, followed by groups C (14%) and D (13%), while the lowest incidence was recorded for F (4%), and E (1%), and 43 (47%) samples carried at least one virulent gene, i.e., potential pathogens. Isolates present in groups E, F and D showed higher presence of virulence genes (100%, 75%, and 67%), versus 55%, 39%, and 28% in commensal B1, C, and A, respectively. Occurrence of papC and fyuA (both 24%) was highest, followed by tsh, iss, stx2, cnf1, kpsII, cvaC, stx1, iutA and eaeA. Nine E. coli strains (almost 10% of all tested and around 21% of our virulence-gene-associated isolates) harboured stx1, stx2 or eae. Ovine cheeses in Slovakia are highly contaminated with E. coli including potentially pathogenic strains capable of causing intestinal and/or extra-intestinal diseases, and thus may pose a threat to public health while unpasteurized. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
12 pages, 2461 KiB  
Article
Successful Dissemination of Plasmid-Mediated Extended-Spectrum β-Lactamases in Enterobacterales over Humans to Wild Fauna
by Racha Beyrouthy, Carolina Sabença, Frédéric Robin, Patricia Poeta, Giberto Igrejas and Richard Bonnet
Microorganisms 2021, 9(7), 1471; https://doi.org/10.3390/microorganisms9071471 - 9 Jul 2021
Cited by 4 | Viewed by 3299
Abstract
Background: The emergence of multidrug-resistant bacteria remains poorly understood in the wild ecosystem and at the interface of habitats. Here, we explored the spread of Escherichia coli containing IncI1-ST3 plasmid encoding resistance gene cefotaximase-Munich-1 (blaCTX-M-1) in human-influenced habitats and wild [...] Read more.
Background: The emergence of multidrug-resistant bacteria remains poorly understood in the wild ecosystem and at the interface of habitats. Here, we explored the spread of Escherichia coli containing IncI1-ST3 plasmid encoding resistance gene cefotaximase-Munich-1 (blaCTX-M-1) in human-influenced habitats and wild fauna using a genomic approach. Methods. Multilocus sequence typing (MLST), single-nucleotide polymorphism comparison, synteny-based analysis and data mining approaches were used to analyse a dataset of genomes and circularised plasmids. Results. CTX-M-1 E. coli sequence types (STs) were preferentially associated with ecosystems. Few STs were shared by distinct habitats. IncI1-ST3-blaCTX-M-1 plasmids are disseminated among all E. coli phylogroups. The main divergences in plasmids were located in a shuffling zone including blaCTX-M-1 inserted in a conserved site. This insertion hot spot exhibited diverse positions and orientations in a zone-modulating conjugation, and the resulting synteny was associated with geographic and biological sources. Conclusions. The ecological success of IncI1-ST3-blaCTX-M-1 appears less linked to the spread of their bacterial recipients than to their ability to transfer in a broad spectrum of bacterial lineages. This feature is associated with the diversity of their shuffling conjugation region that contain blaCTX-M-1. These might be involved in the resistance to antimicrobials, but also in their spread. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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12 pages, 823 KiB  
Article
Antibiotic Resistant and Biofilm-Associated Escherichia coli Isolates from Diarrheic and Healthy Dogs
by Lívia Karahutová, René Mandelík and Dobroslava Bujňáková
Microorganisms 2021, 9(6), 1334; https://doi.org/10.3390/microorganisms9061334 - 19 Jun 2021
Cited by 12 | Viewed by 2805
Abstract
Bacteria isolated from companion animals are attracting concerns in a view of public health including antimicrobial resistance and biofilm development, both contributing to difficult-to-treat infections. The purpose of this study was to evaluate the minimum inhibitory concentrations (MIC) of 18 antibiotics in Escherichia [...] Read more.
Bacteria isolated from companion animals are attracting concerns in a view of public health including antimicrobial resistance and biofilm development, both contributing to difficult-to-treat infections. The purpose of this study was to evaluate the minimum inhibitory concentrations (MIC) of 18 antibiotics in Escherichia coli isolated from two groups of dogs (healthy and diarrheic). Isolates were classified into phylogroups, examined for the presence of resistance genes and biofilm-formation capacity. In healthy dogs, phylogenetic analysis showed that 47.37% and 34.22% of E. coli isolates belonged to commensal groups (A; B1) in contrast to diarrheic dogs; 42.2% of isolates were identified as the B2 phylogroup, and these E. coli bacteria formed a stronger biofilm. The results of healthy dogs showed higher MIC levels for tetracycline (32 mg/L), ampicillin (64 mg/L), ciprofloxacin (8 mg/L) and trimethoprim-sulphonamide (8 mg/L) compared to clinical breakpoints. The most detected gene encoding plasmid-mediated resistance to quinolones in the healthy group was qnrB, and in dogs with diarrhea, qnrS. The resistance genes were more frequently detected in healthy dogs. The presence of the integron int1 and the transposon tn3 increases the possibility of transfer of many different cassette-associated antibiotic-resistance genes. These results suggest that dogs could be a potential reservoir of resistance genes. Full article
(This article belongs to the Special Issue Virulence Factors and Antibiotic Resistance of Enterobacterales)
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