Next Issue
Previous Issue

Table of Contents

Pathogens, Volume 3, Issue 3 (September 2014), Pages 499-790

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-17
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Molecular Identification of Isolated Fungi from Unopened Containers of Greek Yogurt by DNA Sequencing of Internal Transcribed Spacer Region
Pathogens 2014, 3(3), 499-509; doi:10.3390/pathogens3030499
Received: 28 April 2014 / Revised: 11 June 2014 / Accepted: 19 June 2014 / Published: 25 June 2014
Cited by 2 | PDF Full-text (247 KB) | HTML Full-text | XML Full-text
Abstract
In our previous study, we described the development of an internal transcribed spacer (ITS)1 sequencing method, and used this protocol in species-identification of isolated fungi collected from the manufacturing areas of a compounding company known to have caused the multistate fungal meningitis outbreak
[...] Read more.
In our previous study, we described the development of an internal transcribed spacer (ITS)1 sequencing method, and used this protocol in species-identification of isolated fungi collected from the manufacturing areas of a compounding company known to have caused the multistate fungal meningitis outbreak in the United States. In this follow-up study, we have analyzed the unopened vials of Greek yogurt from the recalled batch to determine the possible cause of microbial contamination in the product. A total of 15 unopened vials of Greek yogurt belonging to the recalled batch were examined for the detection of fungi in these samples known to cause foodborne illness following conventional microbiological protocols. Fungi were isolated from all of the 15 Greek yogurt samples analyzed. The isolated fungi were genetically typed by DNA sequencing of PCR-amplified ITS1 region of rRNA gene. Analysis of data confirmed all of the isolated fungal isolates from the Greek yogurt to be Rhizomucor variabilis. The generated ITS1 sequences matched 100% with the published sequences available in GenBank. In addition, these yogurt samples were also tested for the presence of five types of bacteria (Salmonella, Listeria, Staphylococcus, Bacillus and Escherichia coli) causing foodborne disease in humans, and found negative for all of them. Full article
(This article belongs to the Special Issue Foodborne Pathogens)
Open AccessArticle Fitness of Outbreak and Environmental Strains of Escherichia coli O157:H7 in Aerosolizable Soil and Association of Clonal Variation in Stress Gene Regulation
Pathogens 2014, 3(3), 528-548; doi:10.3390/pathogens3030528
Received: 16 May 2014 / Revised: 20 June 2014 / Accepted: 24 June 2014 / Published: 30 June 2014
Cited by 3 | PDF Full-text (671 KB) | HTML Full-text | XML Full-text
Abstract
Airborne dust from feedlots is a potential mechanism of contamination of nearby vegetable crops with Escherichia coli O157:H7 (EcO157). We compared the fitness of clinical and environmental strains of EcO157 in <45 µm soil from a spinach farm. Differences in survival were observed
[...] Read more.
Airborne dust from feedlots is a potential mechanism of contamination of nearby vegetable crops with Escherichia coli O157:H7 (EcO157). We compared the fitness of clinical and environmental strains of EcO157 in <45 µm soil from a spinach farm. Differences in survival were observed among the 35 strains with D-values (days for 90% decreases) ranging from 1–12 days. Strains that survived longer, generally, were from environmental sources and lacked expression of curli, a protein associated with attachment and virulence. Furthermore, the proportion of curli-positive (C+) variants of EcO157 strains decreased with repeated soil exposure and the strains that were curli-negative (C) remained C post-soil exposure. Soil exposure altered expression of stress-response genes linked to fitness of EcO157, but significant clonal variation in expression was measured. Mutations were detected in the stress-related sigma factor, rpoS, with a greater percentage occurring in parental strains of clinical origin prior to soil exposure. We speculate that these mutations in rpoS may confer a differential expression of genes, associated with mechanisms of survival and/or virulence, and thus may influence the fitness of EcO157. Full article
(This article belongs to the Special Issue Foodborne Pathogens)
Figures

Open AccessArticle Mycobacterium avium Subspecies paratuberculosis: Human Exposure through Environmental and Domestic Aerosols
Pathogens 2014, 3(3), 577-595; doi:10.3390/pathogens3030577
Received: 30 April 2014 / Revised: 1 July 2014 / Accepted: 11 July 2014 / Published: 16 July 2014
Cited by 4 | PDF Full-text (874 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Mycobacterium avium subspecies paratuberculosis (Map) causes Johne’s disease in animals and is significantly associated with Crohn’s disease (CD) in humans. Our previous studies have shown Map to be present in U.K. rivers due to land deposition from chronic livestock infection and
[...] Read more.
Mycobacterium avium subspecies paratuberculosis (Map) causes Johne’s disease in animals and is significantly associated with Crohn’s disease (CD) in humans. Our previous studies have shown Map to be present in U.K. rivers due to land deposition from chronic livestock infection and runoff driven by rainfall. The epidemiology of CD in Cardiff showed a significant association with the River Taff, in which Map can be detected on a regular basis. We have previously hypothesized that aerosols from the river might influence the epidemiology of CD. In this preliminary study, we detected Map by quantitative PCR in one of five aerosol samples collected above the River Taff. In addition, we examined domestic showers from different regions in the U.K. and detected Map in three out of 30 independent samples. In detecting Map in river aerosols and those from domestic showers, this is the first study to provide evidence that aerosols are an exposure route for Map to humans and may play a role in the epidemiology of CD. Full article
Open AccessArticle Small Animal Models for Human Metapneumovirus: Cotton Rat is More Permissive than Hamster and Mouse
Pathogens 2014, 3(3), 633-655; doi:10.3390/pathogens3030633
Received: 3 March 2014 / Revised: 13 June 2014 / Accepted: 30 June 2014 / Published: 24 July 2014
Cited by 4 | PDF Full-text (8085 KB) | HTML Full-text | XML Full-text
Abstract
Human metapneumovirus (hMPV) is the second most prevalent causative agent of pediatric respiratory infections worldwide. Currently, there are no vaccines or antiviral drugs against this virus. One of the major hurdles in hMPV research is the difficulty to identify a robust small animal
[...] Read more.
Human metapneumovirus (hMPV) is the second most prevalent causative agent of pediatric respiratory infections worldwide. Currently, there are no vaccines or antiviral drugs against this virus. One of the major hurdles in hMPV research is the difficulty to identify a robust small animal model to accurately evaluate the efficacy and safety of vaccines and therapeutics. In this study, we compared the replication and pathogenesis of hMPV in BALB/c mice, Syrian golden hamsters, and cotton rats. It was found that BALB/c mice are not permissive for hMPV infection despite the use of a high dose (6.5 log10 PFU) of virus for intranasal inoculation. In hamsters, hMPV replicated efficiently in nasal turbinates but demonstrated only limited replication in lungs. In cotton rats, hMPV replicated efficiently in both nasal turbinate and lung when intranasally administered with three different doses (4, 5, and 6 log10 PFU) of hMPV. Lungs of cotton rats infected by hMPV developed interstitial pneumonia with mononuclear cells infiltrates and increased lumen exudation. By immunohistochemistry, viral antigens were detected at the luminal surfaces of the bronchial epithelial cells in lungs. Vaccination of cotton rats with hMPV completely protected upper and lower respiratory tract from wildtype challenge. The immunization also elicited elevated serum neutralizing antibody. Collectively, these results demonstrated that cotton rat is a robust small animal model for hMPV infection. Full article
(This article belongs to the Special Issue Animal Model to Study Viral Immunity)
Figures

Open AccessArticle Development and Validation of a Rapid Turbidimetric Assay to Determine the Potency of Cefuroxime Sodium in Powder for Dissolution for Injection
Pathogens 2014, 3(3), 656-666; doi:10.3390/pathogens3030656
Received: 4 June 2014 / Revised: 16 July 2014 / Accepted: 24 July 2014 / Published: 30 July 2014
Cited by 3 | PDF Full-text (283 KB) | HTML Full-text | XML Full-text
Abstract
The cefuroxime sodium is a second generation cephalosporin indicated for infections caused by Gram-positive and Gram-negative microorganisms. Although this drug is highly studied and researched regarding the antimicrobial activity, pharmacokinetics and pharmacodynamics, there are few studies regarding the development of analytical methodology for
[...] Read more.
The cefuroxime sodium is a second generation cephalosporin indicated for infections caused by Gram-positive and Gram-negative microorganisms. Although this drug is highly studied and researched regarding the antimicrobial activity, pharmacokinetics and pharmacodynamics, there are few studies regarding the development of analytical methodology for this cephalosporin. Thus, research involving analytical methods is essential and highly relevant to optimize its analysis in the pharmaceutical industry and guarantee the quality of the product already sold. This study describes the development and validation of a microbiological assay applying the turbidimetric method for the determination of cefuroxime, using Micrococcus luteus ATCC 9341 as micro-organism test and 3x3 parallel line assay design, with nine tubes for each assay, as recommended by the Brazilian Pharmacopoeia. The developed and validated method showed excellent results of linearity, seletivity, precision and robustness, in the concentration range from 30.0 to 120.0 mg/mL, with 100.21% accuracy and content 99.97% to cefuroxime sodium in injectable pharmaceutical form. Full article
Open AccessArticle Wild Mushroom Extracts as Inhibitors of Bacterial Biofilm Formation
Pathogens 2014, 3(3), 667-679; doi:10.3390/pathogens3030667
Received: 19 June 2014 / Revised: 11 July 2014 / Accepted: 29 July 2014 / Published: 6 August 2014
Cited by 4 | PDF Full-text (400 KB) | HTML Full-text | XML Full-text
Abstract
Microorganisms can colonize a wide variety of medical devices, putting patients in risk for local and systemic infectious complications, including local-site infections, catheter-related bloodstream infections, and endocarditis. These microorganisms are able to grow adhered to almost every surface, forming architecturally complex communities termed
[...] Read more.
Microorganisms can colonize a wide variety of medical devices, putting patients in risk for local and systemic infectious complications, including local-site infections, catheter-related bloodstream infections, and endocarditis. These microorganisms are able to grow adhered to almost every surface, forming architecturally complex communities termed biofilms. The use of natural products has been extremely successful in the discovery of new medicine, and mushrooms could be a source of natural antimicrobials. The present study reports the capacity of wild mushroom extracts to inhibit in vitro biofilm formation by multi-resistant bacteria. Four Gram-negative bacteria biofilm producers (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and Acinetobacter baumannii) isolated from urine were used to verify the activity of Russula delica, Fistulina hepatica, Mycena rosea, Leucopaxilus giganteus, and Lepista nuda extracts. The results obtained showed that all tested mushroom extracts presented some extent of inhibition of biofilm production. Pseudomonas aeruginosa was the microorganism with the highest capacity of biofilm production, being also the most susceptible to the extracts inhibition capacity (equal or higher than 50%). Among the five tested extracts against E. coli, Leucopaxillus giganteus (47.8%) and Mycenas rosea (44.8%) presented the highest inhibition of biofilm formation. The extracts exhibiting the highest inhibitory effect upon P. mirabilis biofilm formation were Sarcodon imbricatus (45.4%) and Russula delica (53.1%). Acinetobacter baumannii was the microorganism with the lowest susceptibility to mushroom extracts inhibitory effect on biofilm production (highest inhibition—almost 29%, by Russula delica extract). This is a pioneer study since, as far as we know, there are no reports on the inhibition of biofilm production by the studied mushroom extracts and in particular against multi-resistant clinical isolates; nevertheless, other studies are required to elucidate the mechanism of action. Full article
(This article belongs to the Special Issue Alternatives to Antibiotics: Current Strategies and Future Prospects)
Open AccessArticle Iron and Acinetobacter baumannii Biofilm Formation
Pathogens 2014, 3(3), 704-719; doi:10.3390/pathogens3030704
Received: 10 July 2014 / Revised: 9 August 2014 / Accepted: 12 August 2014 / Published: 18 August 2014
Cited by 6 | PDF Full-text (583 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role
[...] Read more.
Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role of iron in A. baumannii nutrition and pathogenicity, iron metabolism has been considered as a possible target for chelation-based antibacterial chemotherapy. In this study, we investigated the effect of iron restriction on A. baumannii growth and biofilm formation using different iron chelators and culture conditions. We report substantial inter-strain variability and growth medium-dependence for biofilm formation by A. baumannii isolates from veterinary and clinical sources. Neither planktonic nor biofilm growth of A. baumannii was affected by exogenous chelators. Biofilm formation was either stimulated by iron or not responsive to iron in the majority of isolates tested, indicating that iron starvation is not sensed as an overall biofilm-inducing stimulus by A. baumannii. The impressive iron withholding capacity of this bacterium should be taken into account for future development of chelation-based antimicrobial and anti-biofilm therapies. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available
Open AccessArticle Exploring Dangerous Connections between Klebsiella pneumoniae Biofilms and Healthcare-Associated Infections
Pathogens 2014, 3(3), 720-731; doi:10.3390/pathogens3030720
Received: 26 June 2014 / Revised: 4 August 2014 / Accepted: 12 August 2014 / Published: 19 August 2014
Cited by 4 | PDF Full-text (743 KB) | HTML Full-text | XML Full-text
Abstract
Healthcare-associated infections (HAI) are a huge public health concern, particularly when the etiological agents are multidrug resistant. The ability of bacteria to develop biofilm is a helpful skill, both to persist within hospital units and to increase antibiotic resistance. Although the links between
[...] Read more.
Healthcare-associated infections (HAI) are a huge public health concern, particularly when the etiological agents are multidrug resistant. The ability of bacteria to develop biofilm is a helpful skill, both to persist within hospital units and to increase antibiotic resistance. Although the links between antibiotic resistance, biofilms assembly and HAI are consensual, little is known about biofilms. Here, electron microscopy was adopted as a tool to investigate biofilm structures associated with increased antibiotic resistance. The K. pneumoniae strains investigated are able to assemble biofilms, albeit with different kinetics. The biofilm structure and the relative area fractions of bacteria and extracellular matrix depend on the particular strain, as well as the minimal inhibitory concentration (MIC) for the antibiotics. Increased values were found for bacteria organized in biofilms when compared to the respective planktonic forms, except for isolates Kp45 and Kp2948, the MIC values for which remained unchanged for fosfomycin. Altogether, these results showed that the emergence of antimicrobial resistance among bacteria responsible for HAI is a multifactorial phenomenon dependent on antibiotics and on bacteria/biofilm features. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available
Open AccessArticle Genetic Characterization of Fungi Isolated from the Environmental Swabs collected from a Compounding Center Known to Cause Multistate Meningitis Outbreak in United States Using ITS Sequencing
Pathogens 2014, 3(3), 732-742; doi:10.3390/pathogens3030732
Received: 28 April 2014 / Revised: 31 July 2014 / Accepted: 19 August 2014 / Published: 22 August 2014
Cited by 2 | PDF Full-text (218 KB) | HTML Full-text | XML Full-text
Abstract
A multistate fungal meningitis outbreak started in September of 2012 which spread in 20 states of the United States. The outbreak has been fatal so far, and has affected 751 individuals with 64 deaths among those who received contaminated spinal injections manufactured by
[...] Read more.
A multistate fungal meningitis outbreak started in September of 2012 which spread in 20 states of the United States. The outbreak has been fatal so far, and has affected 751 individuals with 64 deaths among those who received contaminated spinal injections manufactured by a Compounding Center located in Massachusetts. In a preliminary study, Food and Drug Administration (FDA) investigated the outbreak in collaboration with Centers for Disease Control and Prevention (CDC), state and local health departments, and identified four fungal and several bacterial contaminations in the recalled unopened injection vials. This follow-up study was carried out to assess DNA sequencing of the ITS1 region of rRNA gene for rapid identification of fungal pathogens during public health outbreak investigations. A total of 26 environmental swabs were collected from several locations at the manufacturing premises of the Compounding Center known to have caused the outbreak. The swab samples were initially examined by conventional microbiologic protocols and a wide range of fungal species were recovered. Species-identification of these microorganisms was accomplished by nucleotide sequencing of ITS1 region of rRNA gene. Analysis of data confirmed 14 additional fungal species in the swabs analyzed. Full article
Open AccessArticle Role of Daptomycin in the Induction and Persistence of the Viable but Non-Culturable State of Staphylococcus Aureus Biofilms
Pathogens 2014, 3(3), 759-768; doi:10.3390/pathogens3030759
Received: 26 June 2014 / Revised: 22 August 2014 / Accepted: 12 September 2014 / Published: 18 September 2014
Cited by 2 | PDF Full-text (235 KB) | HTML Full-text | XML Full-text
Abstract
We have recently demonstrated that antibiotic pressure can induce the viable but non-culturable (VBNC) state in Staphylococcus aureus biofilms. Since dormant bacterial cells can undermine anti-infective therapy, a greater understanding of the role of antibiotics of last resort, including daptomycin, is crucial. Methicillin-resistant
[...] Read more.
We have recently demonstrated that antibiotic pressure can induce the viable but non-culturable (VBNC) state in Staphylococcus aureus biofilms. Since dormant bacterial cells can undermine anti-infective therapy, a greater understanding of the role of antibiotics of last resort, including daptomycin, is crucial. Methicillin-resistant S. aureus 10850 biofilms were maintained on non-nutrient (NN) agar in the presence or absence of the MIC of daptomycin until loss of culturability. Viable cells were monitored by epifluorescence microscopy and flow cytometry for 150 days. All biofilms reached non-culturability at 40 days and showed a similar amount of viable cells; however, in biofilms exposed to daptomycin, their number remained unchanged throughout the experiment, whereas in those maintained on NN agar alone, no viable cells were detected after 150 days. Gene expression assays showed that after achievement of non-culturability, 16S rDNA and mecA were expressed by all biofilms, whereas glt expression was found only in daptomycin-exposed biofilms. Our findings suggest that low daptomycin concentrations, such as those that are likely to obtain within biofilms, can influence the viability and gene expression of non-culturable S. aureus cells. Resuscitation experiments are needed to establish the VBNC state of daptomycin-exposed biofilms. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available

Review

Jump to: Research

Open AccessReview Perturbation of the Human Microbiome as a Contributor to Inflammatory Bowel Disease
Pathogens 2014, 3(3), 510-527; doi:10.3390/pathogens3030510
Received: 26 March 2014 / Revised: 6 June 2014 / Accepted: 9 June 2014 / Published: 30 June 2014
Cited by 9 | PDF Full-text (223 KB) | HTML Full-text | XML Full-text
Abstract
The human microbiome consist of the composite genome of native flora that have evolved with humanity over millennia and which contains 150-fold more genes than the human genome. A “healthy” microbiome plays an important role in the maintenance of health and prevention of
[...] Read more.
The human microbiome consist of the composite genome of native flora that have evolved with humanity over millennia and which contains 150-fold more genes than the human genome. A “healthy” microbiome plays an important role in the maintenance of health and prevention of illness, inclusive of autoimmune disease such as inflammatory bowel disease (IBD). IBD is a prevalent spectrum of disorders, most notably defined by Crohn’s disease (CD) and ulcerative colitis (UC), which are associated with considerable suffering, morbidity, and cost. This review presents an outline of the loss of a normal microbiome as an etiology of immune dysregulation and IBD pathogenesis initiation. We, furthermore, summarize the knowledge on the role of a healthy microbiome in terms of its diversity and important functional elements and, lastly, conclude with some of the therapeutic interventions and modalities that are now being explored as potential applications of microbiome-host interactions. Full article
(This article belongs to the Special Issue Gut Microbiome)
Open AccessReview Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens
Pathogens 2014, 3(3), 549-562; doi:10.3390/pathogens3030549
Received: 8 April 2014 / Revised: 18 June 2014 / Accepted: 23 June 2014 / Published: 30 June 2014
Cited by 3 | PDF Full-text (920 KB) | HTML Full-text | XML Full-text
Abstract
Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of
[...] Read more.
Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens. Full article
(This article belongs to the Special Issue Animal Model to Study Viral Immunity)
Open AccessReview Exploring the Therapeutic Potentials of iNKT Cells for Anti-HBV Treatment
Pathogens 2014, 3(3), 563-576; doi:10.3390/pathogens3030563
Received: 15 April 2014 / Revised: 23 June 2014 / Accepted: 23 June 2014 / Published: 3 July 2014
PDF Full-text (342 KB) | HTML Full-text | XML Full-text
Abstract
CD1d-restricted invariant NKT (iNKT) cells are a group of innate-like regulatory T cells that recognize lipid antigens. Both mouse modeling experiments and human clinical studies have suggested a key role for iNKT cells in anti-HBV immunity and these potent T cells can be
[...] Read more.
CD1d-restricted invariant NKT (iNKT) cells are a group of innate-like regulatory T cells that recognize lipid antigens. Both mouse modeling experiments and human clinical studies have suggested a key role for iNKT cells in anti-HBV immunity and these potent T cells can be explored as a novel therapeutic target for anti-HBV treatment. We aim to humanize mice in the CD1d/iNKT cell lipid presentation system and provide new research tools for identifying novel anti-HBV agents. Full article
(This article belongs to the Special Issue Animal Model to Study Viral Immunity)
Open AccessReview Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation
Pathogens 2014, 3(3), 596-632; doi:10.3390/pathogens3030596
Received: 29 May 2014 / Revised: 10 July 2014 / Accepted: 14 July 2014 / Published: 18 July 2014
Cited by 19 | PDF Full-text (1109 KB) | HTML Full-text | XML Full-text
Abstract
Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps
[...] Read more.
Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl), pellicle Formation (Pel) and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides) that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available
Open AccessReview Pseudomonas aeruginosa Diversification during Infection Development in Cystic Fibrosis Lungs—A Review
Pathogens 2014, 3(3), 680-703; doi:10.3390/pathogens3030680
Received: 1 July 2014 / Revised: 11 August 2014 / Accepted: 12 August 2014 / Published: 18 August 2014
Cited by 17 | PDF Full-text (442 KB) | HTML Full-text | XML Full-text
Abstract
Pseudomonas aeruginosa is the most prevalent pathogen of cystic fibrosis (CF) lung disease. Its long persistence in CF airways is associated with sophisticated mechanisms of adaptation, including biofilm formation, resistance to antibiotics, hypermutability and customized pathogenicity in which virulence factors are expressed according
[...] Read more.
Pseudomonas aeruginosa is the most prevalent pathogen of cystic fibrosis (CF) lung disease. Its long persistence in CF airways is associated with sophisticated mechanisms of adaptation, including biofilm formation, resistance to antibiotics, hypermutability and customized pathogenicity in which virulence factors are expressed according the infection stage. CF adaptation is triggered by high selective pressure of inflamed CF lungs and by antibiotic treatments. Bacteria undergo genetic, phenotypic, and physiological variations that are fastened by the repeating interplay of mutation and selection. During CF infection development, P. aeruginosa gradually shifts from an acute virulent pathogen of early infection to a host-adapted pathogen of chronic infection. This paper reviews the most common changes undergone by P. aeruginosa at each stage of infection development in CF lungs. The comprehensive understanding of the adaptation process of P. aeruginosa may help to design more effective antimicrobial treatments and to identify new targets for future drugs to prevent the progression of infection to chronic stages. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available
Open AccessReview Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae
Pathogens 2014, 3(3), 743-758; doi:10.3390/pathogens3030743
Received: 10 July 2014 / Revised: 2 September 2014 / Accepted: 3 September 2014 / Published: 5 September 2014
Cited by 14 | PDF Full-text (3639 KB) | HTML Full-text | XML Full-text
Abstract
The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent
[...] Read more.
The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae. Full article
(This article belongs to the Special Issue Biofilm-Based Nosocomial Infections) Print Edition available
Open AccessReview Early Development of the Gut Microbiota and Immune Health
Pathogens 2014, 3(3), 769-790; doi:10.3390/pathogens3030769
Received: 18 December 2013 / Revised: 29 August 2014 / Accepted: 19 September 2014 / Published: 24 September 2014
Cited by 9 | PDF Full-text (241 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, the increase in human microbiome research brought about by the rapidly evolving “omic” technologies has established that the balance among the microbial groups present in the human gut, and their multipronged interactions with the host, are crucial for health. On
[...] Read more.
In recent years, the increase in human microbiome research brought about by the rapidly evolving “omic” technologies has established that the balance among the microbial groups present in the human gut, and their multipronged interactions with the host, are crucial for health. On the other hand, epidemiological and experimental support has also grown for the ‘early programming hypothesis’, according to which factors that act in utero and early in life program the risks for adverse health outcomes later on. The microbiota of the gut develops during infancy, in close interaction with immune development, and with extensive variability across individuals. It follows that the specific process of gut colonization and the microbe-host interactions established in an individual during this period have the potential to represent main determinants of life-long propensity to immune disease. Although much remains to be learnt on the progression of events by which the gut microbiota becomes established and initiates its intimate relationships with the host, and on the long-term repercussions of this process, recent works have advanced significatively in this direction. Full article
(This article belongs to the Special Issue Gut Microbiome)

Journal Contact

MDPI AG
Pathogens Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
pathogens@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Pathogens
Back to Top