Bacterial Pathogens Resistance and Virulence

A special issue of Antibiotics (ISSN 2079-6382). This special issue belongs to the section "Genetic and Biochemical Studies of Antibiotic Activity and Resistance".

Deadline for manuscript submissions: closed (31 May 2020) | Viewed by 26055

Special Issue Editors

Research and Reference Laboratory on Antimicrobial Resistance and Healthcare Infections, National Microbiology Center, Majadahonda, Madrid, Spain
Interests: antimicrobial resistance; pathogenicity; infectious diseases; genomics; metagenomics; epidemiology
Special Issues, Collections and Topics in MDPI journals
Department of Medical Microbiology and Infection prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
Interests: antimicrobial resistance; whole genome sequencing; anaerobic bacteria; MALDI-TOF MS; antimicrobial resistance mechanisms; taxonomy

Special Issue Information

Dear Colleagues,

Bacteria are causative agents of multitude of infections, they can be classified as opportunistic or primary pathogens, and some of them are capable of infecting a wide range of hosts whereas others are highly adapted. The capacity of a bacterium to cause disease is related to its pathogenicity and the host immune response. Pathogenic mechanisms include invasion of the host, disease induction, and the evasion of host defenses. Some of the most studied virulence factors are adherence and invasion factors, toxins, capsules and siderophores. They can be encoded on chromosomes, plasmids, transposons, or temperate bacteriophages DNA; the latter two can also be integrated in the bacterial chromosome.

In the course of a bacterial infection, the outcome will depend not only on the virulence profile and host susceptibility, but also on an effective antimicrobial treatment. Antimicrobial resistance challenges our ability to treat these bacterial infections and leads to higher rates of mortality and morbidity. Due to the difficulties on developing new antimicrobials, it is necessary to develop new strategies to combat bacterial infections. This has to be done in addition to worldwide implementation of antimicrobial stewardship programs to ensure a prudent use of our current antimicrobials. Understanding the mechanisms of pathogenesis may help to design novel approaches to mitigate the severity of an infection of even to reverse the bacterial pathogenicity.

The purpose of the Special Issue is to gather information on bacterial pathogenicity, its transmissibility and co-existence with other bacterial advantageous determinants such as antimicrobial resistance.  

Dr. Silvia García Cobos
Dr. Alida Veloo
Guest Editors

Manuscript Submission Information

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Keywords

  • bacterial pathogenesis
  • antimicrobial resistance
  • virulence

Published Papers (8 papers)

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14 pages, 3612 KiB  
Article
Functional Analysis of the Acinetobacter baumannii XerC and XerD Site-Specific Recombinases: Potential Role in Dissemination of Resistance Genes
by David L. Lin, German M. Traglia, Rachel Baker, David J. Sherratt, Maria Soledad Ramirez and Marcelo E. Tolmasky
Antibiotics 2020, 9(7), 405; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9070405 - 13 Jul 2020
Cited by 18 | Viewed by 3644
Abstract
Modules composed of a resistance gene flanked by Xer site-specific recombination sites, the vast majority of which were found in Acinetobacter baumannii, are thought to behave as elements that facilitate horizontal dissemination. The A. baumannii xerC and xerD genes were cloned, and [...] Read more.
Modules composed of a resistance gene flanked by Xer site-specific recombination sites, the vast majority of which were found in Acinetobacter baumannii, are thought to behave as elements that facilitate horizontal dissemination. The A. baumannii xerC and xerD genes were cloned, and the recombinant clones used to complement the cognate Escherichia coli mutants. The complemented strains supported the resolution of plasmid dimers, and, as is the case with E. coli and Klebsiella pneumoniae plasmids, the activity was enhanced when the cells were grown in a low osmolarity growth medium. Binding experiments showed that the partially purified A. baumannii XerC and XerD proteins (XerCAb and XerDAb) bound synthetic Xer site-specific recombination sites, some of them with a nucleotide sequence deduced from existing A. baumannii plasmids. Incubation with suicide substrates resulted in the covalent attachment of DNA to a recombinase, probably XerCAb, indicating that the first step in the recombination reaction took place. The results described show that XerCAb and XerDAb are functional proteins and support the hypothesis that they participate in horizontal dissemination of resistant genes among bacteria. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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14 pages, 1194 KiB  
Article
In Vitro Efficacy of Essential Oils from Melaleuca Alternifolia and Rosmarinus Officinalis, Manuka Honey-based Gel, and Propolis as Antibacterial Agents Against Canine Staphylococcus Pseudintermedius Strains
by Gabriele Meroni, Elena Cardin, Charlotte Rendina, Valentina Rafaela Herrera Millar, Joel Fernando Soares Filipe and Piera Anna Martino
Antibiotics 2020, 9(6), 344; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9060344 - 19 Jun 2020
Cited by 6 | Viewed by 3394
Abstract
Essential oils (EOs) and honeybee products (e.g., honey and propolis) are natural mixtures of different volatile compounds that are frequently used in traditional medicine and for pathogen eradication. The aim of this study was to evaluate the antibacterial properties of tea tree ( [...] Read more.
Essential oils (EOs) and honeybee products (e.g., honey and propolis) are natural mixtures of different volatile compounds that are frequently used in traditional medicine and for pathogen eradication. The aim of this study was to evaluate the antibacterial properties of tea tree (Melaleuca alternifolia) EO (TTEO), Rosmarinus officinalis EO (ROEO), manuka-based gel, and propolis against 23 strains of Staphylococcus pseudintermedius (SP) isolated from canine pyoderma. Antimicrobial resistance screening was assessed using a panel of nine antimicrobial agents coupled with a PCR approach. An aromatogram was done for both EOs, using the disk diffusion method. The minimum inhibitory concentration (MIC) was determined for all the compounds. Among the 23 SP strains, 14 (60.9%) were multidrug-resistant (MDR), 11 strains (47.8%) were methicillin-resistant (MRSP), and 9 (39.1%) were non-MDR. The mean diameter of the inhibition zone for Melaleuca and Rosmarinus were 24.5 ± 8.8 mm and 15.2 ± 8.9 mm, respectively, resulting as statistically different (p = 0.0006). MIC values of TTEO and ROEO were similar (7.6 ± 3.2% and 8.9 ± 2.1%, respectively) and no statistical significances were found. Honeybee products showed lower MIC compared to those of EOs, 0.22 ± 0.1% for Manuka and 0.8 ± 0.5% for propolis. These findings reveal a significant antibacterial effect for all the tested products. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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16 pages, 3889 KiB  
Article
Characterization of Extremely Drug-Resistant and Hypervirulent Acinetobacter baumannii AB030
by Manu Singh, P. Malaka De Silva, Yasser Al-Saadi, Jacek Switala, Peter C. Loewen, Georg Hausner, Wangxue Chen, Ismael Hernandez, Santiago Castillo-Ramirez and Ayush Kumar
Antibiotics 2020, 9(6), 328; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9060328 - 17 Jun 2020
Cited by 8 | Viewed by 3802
Abstract
Acinetobacter baumannii is an important nosocomial bacterial pathogen. Multidrug-resistant isolates of A. baumannii are reported worldwide. Some A. baumannii isolates display resistance to nearly all antibiotics, making treatment of infections very challenging. As the need for new and effective antibiotics against A. baumannii [...] Read more.
Acinetobacter baumannii is an important nosocomial bacterial pathogen. Multidrug-resistant isolates of A. baumannii are reported worldwide. Some A. baumannii isolates display resistance to nearly all antibiotics, making treatment of infections very challenging. As the need for new and effective antibiotics against A. baumannii becomes increasingly urgent, there is a need to understand the mechanisms of antibiotic resistance and virulence in this organism. In this work, comparative genomics was used to understand the mechanisms of antibiotic resistance and virulence in AB030, an extremely drug-resistant and hypervirulent strain of A. baumannii that is a representative of a recently emerged lineage of A. baumannii International Clone V. In order to characterize AB030, we carried out a genomic and phenotypic comparison with LAC-4, a previously described hyper-resistant and hypervirulent isolate. AB030 contains a number of antibiotic resistance- and virulence-associated genes that are not present in LAC-4. A number of these genes are present on mobile elements. This work shows the importance of characterizing the members of new lineages of A. baumannii in order to determine the development of antibiotic resistance and virulence in this organism. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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15 pages, 2375 KiB  
Article
Genomic Characterization of Antimicrobial Resistance, Virulence, and Phylogeny of the Genus Ochrobactrum
by Yael Yagel, Stephanie Sestito, Yair Motro, Anat Shnaiderman-Torban, Boris Khalfin, Orly Sagi, Shiri Navon-Venezia, Amir Steinman and Jacob Moran-Gilad
Antibiotics 2020, 9(4), 177; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9040177 - 13 Apr 2020
Cited by 11 | Viewed by 3385
Abstract
Ochrobactrum is a ubiquitous Gram-negative microorganism, mostly found in the environment, which can cause opportunistic infections in humans. It is almost uniformly resistant to penicillins and cephalosporins through an AmpC-like β-lactamase enzyme class (OCH). We studied 130 assembled genomes, of which 5 were [...] Read more.
Ochrobactrum is a ubiquitous Gram-negative microorganism, mostly found in the environment, which can cause opportunistic infections in humans. It is almost uniformly resistant to penicillins and cephalosporins through an AmpC-like β-lactamase enzyme class (OCH). We studied 130 assembled genomes, of which 5 were animal-derived isolates recovered in Israel, and 125 publicly available genomes. Our analysis focused on antimicrobial resistance (AMR) genes, virulence genes, and whole-genome phylogeny. We found that 76% of Ochrobactrum genomes harbored a blaOCH β-lactamase gene variant, while 7% harbored another AmpC-like gene. No virulence genes other than lipopolysaccharide-associated genes were found. Core genome multilocus sequence typing clustered most samples to known species, but neither geographical clustering nor isolation source clustering were evident. When analyzing the distribution of different blaOCH variants as well as of the blaOCH-deficient samples, a clear phylogenomic clustering was apparent for specific species. The current analysis of the largest collection to date of Ochrobactrum genomes sheds light on the resistome, virulome, phylogeny, and species classification of this increasingly reported human pathogen. Our findings also suggest that Ochrobactrum deserves further characterization to underpin its evolution, taxonomy, and antimicrobial resistance. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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14 pages, 1571 KiB  
Article
Bacteriology and Antimicrobial Resistance in Vanuatu: January 2017 to December 2019
by Nicola D. Foxlee, Nicola Townell, Mary Ann L. Tosul, Lachlan McIver and Colleen L. Lau
Antibiotics 2020, 9(4), 151; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9040151 - 31 Mar 2020
Cited by 4 | Viewed by 2985
Abstract
The World Health Organization has identified surveillance as a key objective in the containment of antimicrobial resistance. Local antimicrobial resistance surveillance data are used to generate antibiograms to monitor resistance patterns and inform clinicians in the selection of the appropriate empiric treatment when [...] Read more.
The World Health Organization has identified surveillance as a key objective in the containment of antimicrobial resistance. Local antimicrobial resistance surveillance data are used to generate antibiograms to monitor resistance patterns and inform clinicians in the selection of the appropriate empiric treatment when culture results are pending, or if laboratory diagnosis is unavailable. However, producing robust bacteriology data is challenging for Pacific Island Countries and Territories with limited microbiology laboratory capacity. The aim of this study is to describe pathogen occurrence and antibiotic resistance in specimens cultured at the main referral hospital in Vanuatu. We reviewed specimen culture results for the period from January 1, 2017 to December 31, 2019. Demographic and clinical data were extracted from printed and electronic registers and described and analysed. A total of 5816 specimens were cultured, of which 21% were culture positive. Staphylococcus aureus was the predominant pathogen overall (41%), and 3% of the isolates were the methicillin-resistant Staphylococcus aureus. Escherichia coli and Klebsiella pneumoniae were the most frequently isolated gram-negative pathogens, of which 14% and 26% were extended-spectrum β-lactamase-producing, respectively. Our results suggest there is a need for other Pacific Island Countries and Territories to conduct similar studies. There are gaps in knowledge about antimicrobial resistance in Pacific Island Countries and Territories. Antibiograms based on reliable data will define and inform local and national actions for containing antimicrobial resistance. There is also a need to establish a regional surveillance network to strengthen national efforts and to link surveillance data for collaborative action against antimicrobial resistance. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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12 pages, 1699 KiB  
Article
Single Blinded Study on the Feasibility of Decontaminating LA-MRSA in Pig Compartments under Routine Conditions
by Iris Kobusch, Hannah Müller, Alexander Mellmann, Robin Köck and Marc Boelhauve
Antibiotics 2020, 9(4), 141; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9040141 - 26 Mar 2020
Cited by 8 | Viewed by 2150
Abstract
In countries with intensive pig husbandry in stables, the prevalence of livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) on such farms has remained high in the last few years or has also further increased. Simple measures to reduce the LA-MRSA among pigs have not [...] Read more.
In countries with intensive pig husbandry in stables, the prevalence of livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) on such farms has remained high in the last few years or has also further increased. Simple measures to reduce the LA-MRSA among pigs have not yet been successfully implemented. Earlier publications showed a decontamination of LA-MRSA was only possible with great effort. The aim of this study is to determine the suitability of routine cleaning and disinfection (C&D) for adequate LA-MRSA decontamination. For this purpose, at least 115 locations in a piglet-rearing compartment were examined before and after cleaning and disinfection. The sample locations were stratified according to accessibility for pigs and the difficulty of cleaning. The cleaning work was carried out routinely by farm employees, who were not informed about the sampling (single blinded). While before cleaning and disinfection, 85% of the samples from the surfaces were LA-MRSA positive, while only 2% were positive thereafter. All LA-MRSA-positive samples after cleaning and disinfection were outside the animal area. Air samples also showed no LA-MRSA after cleaning and disinfection. Conclusion: In well-managed livestock farms, decontamination of the LA-MRSA barn is quite possible; after C&D no LA-MRSA was detectable at animal height. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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13 pages, 1507 KiB  
Article
Virulence-Inhibiting Herbal Compound Falcarindiol Significantly Reduced Mortality in Mice Infected with Pseudomonas aeruginosa
by Pansong Zhang, Qiaolian Wu, Lin Chen and Kangmin Duan
Antibiotics 2020, 9(3), 136; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9030136 - 24 Mar 2020
Cited by 10 | Viewed by 3131
Abstract
Antipathogenic compounds that target the virulence of pathogenic bacteria rather than their viability offer a promising alternative approach to treat infectious diseases. Using extracts from 30 Chinese herbs that are known for treating symptoms resembling infections, we identified an active compound falcarindiol from [...] Read more.
Antipathogenic compounds that target the virulence of pathogenic bacteria rather than their viability offer a promising alternative approach to treat infectious diseases. Using extracts from 30 Chinese herbs that are known for treating symptoms resembling infections, we identified an active compound falcarindiol from Notopterygium incisum Ting ex H. T. Chang that showed potent inhibitory activities against Pseudomonas aeruginosa multiple virulence factors. Falcarindiol significantly repressed virulence-related genes, including the type III secretion system (T3SS); quorum sensing synthase genes lasIR and rhlIR; lasB; motility-related genes fliC and fliG; and phenazine synthesis genes phzA1 and phzA2. P. aeruginosa swarming motility and pyocyanin production were reduced significantly. In a burned mouse model, falcarindiol treatment significantly reduced the mortality in mice infected with P. aeruginosa, indicating that falcarindiol is a promising antipathogenic drug candidate for treating P. aeruginosa infections. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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6 pages, 222 KiB  
Case Report
Genomic Characterization of New Variant of Hydrogen Sulfide (H2S)-Producing Escherichia coli with Multidrug Resistance Properties Carrying the mcr-1 Gene in China
by Silpak Biswas, Mohammed Elbediwi, Guimin Gu and Min Yue
Antibiotics 2020, 9(2), 80; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9020080 - 13 Feb 2020
Cited by 20 | Viewed by 3084
Abstract
Colistin is considered to be a ‘last-resort’ antimicrobial for the treatment of multidrug-resistant Gram-negative bacterial infections. Identification of Enterobacteriaceae, carrying the transferable colistin resistance gene mcr-1, has recently provoked a global health concern. This report presents the first detection of a [...] Read more.
Colistin is considered to be a ‘last-resort’ antimicrobial for the treatment of multidrug-resistant Gram-negative bacterial infections. Identification of Enterobacteriaceae, carrying the transferable colistin resistance gene mcr-1, has recently provoked a global health concern. This report presents the first detection of a hydrogen sulfide (H2S)-producing Escherichia coli variant isolated from a human in China, with multidrug resistance (MDR) properties, including colistin resistance by the mcr-1 gene, which could have great implications for the treatment of human infections. Full article
(This article belongs to the Special Issue Bacterial Pathogens Resistance and Virulence)
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