scholarly journals Formation, Development, and Cross-Species Interactions in Biofilms

2022 ◽  
Vol 12 ◽  
Author(s):  
Aihua Luo ◽  
Fang Wang ◽  
Degang Sun ◽  
Xueyu Liu ◽  
Bingchang Xin
Keyword(s):  
Species Interactions ◽  
Bacterial Infections ◽  
Early Stage ◽  
Microbial Interactions ◽  
Bacterial Survival ◽  
Chronic Infections ◽  
Immune Attack ◽  
Biofilm Development ◽  
Natural Settings ◽  
Harmful Effects

Biofilms, which are essential vectors of bacterial survival, protect microbes from antibiotics and host immune attack and are one of the leading causes that maintain drug-resistant chronic infections. In nature, compared with monomicrobial biofilms, polymicrobial biofilms composed of multispecies bacteria predominate, which means that it is significant to explore the interactions between microorganisms from different kingdoms, species, and strains. Cross-microbial interactions exist during biofilm development, either synergistically or antagonistically. Although research into cross-species biofilms remains at an early stage, in this review, the important mechanisms that are involved in biofilm formation are delineated. Then, recent studies that investigated cross-species cooperation or synergy, competition or antagonism in biofilms, and various components that mediate those interactions will be elaborated. To determine approaches that minimize the harmful effects of biofilms, it is important to understand the interactions between microbial species. The knowledge gained from these investigations has the potential to guide studies into microbial sociality in natural settings and to help in the design of new medicines and therapies to treat bacterial infections.

Quorum-sensing regulation of virulence factors in bacterial biofilm

2021 ◽  
Author(s):  
Anjali Warrier ◽  
Kapaettu Satyamoorthy ◽  
Thokur Sreepathy Murali
Keyword(s):  
Quorum Sensing ◽  
Defense Mechanisms ◽  
Bacterial Infections ◽  
Bacterial Biofilm ◽  
Treatment Modalities ◽  
Chronic Infections ◽  
Treatment Regimens ◽  
Life Threatening ◽  
Diagnostic Modalities ◽  
Biofilm Development

Chronic polymicrobial wound infections are often characterized by the presence of bacterial biofilms. They show considerable structural and functional heterogeneity, which influences the choice of antimicrobial therapy and wound healing dynamics. The hallmarks of biofilm-associated bacterial infections include elevated antibiotic resistance and extreme pathogenicity. Biofilm helps bacteria to evade the host defense mechanisms and persist longer in the host. Quorum-sensing (QS)-mediated cell signaling primarily regulates biofilm formation in chronic infections and plays a major role in eliciting virulence. This review focuses on the QS mechanisms of two major bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa and explains how they interact in the wound microenvironment to regulate biofilm development and virulence. The review also provides an insight into the treatment modalities aimed at eradicating polymicrobial biofilms. This information will help us develop better diagnostic modalities and devise effective treatment regimens to successfully manage and overcome severe life-threatening bacterial infections.

The role of microbial interactions in infectious disease

1982 ◽  
Vol 297 (1088) ◽  
pp. 551-561 ◽  
Keyword(s):  
Infectious Disease ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Microbial Interactions ◽  
Protective Mechanisms ◽  
Successful Infection ◽  
Full Complement ◽  
Significant Disease ◽  
Harmful Effects

The occurrence of infectious disease is affected by interaction between microorganisms in three ways. The indigenous flora (commensal microorganisms) of some mucous surfaces provide one of the main protective mechanisms against infection by pathogens (disease-producing microbes). The commensal populations interfere with the establishment of pathogens on mucous membranes by evoking anaerobic conditions, by competing for space and nutrients and by producing inhibitors. How, at the beginning of successful infection, pathogens in relatively small numbers overcome this protective activity of the commensal population is unknown. Although not a general phenomenon, some pathogens exacerbate the effects ofothers. The best examples are the potentiation of bacterial infections by existing viral infections: mucosal adherence and penetration by bacteria are enhanced and phagocytic defences against them weakened. Some microorganisms that are unable to produce significant disease on their own may combine with others to cause serious sickness. The harmful effects of these combinations of microorganisms can be explained by the multifactorial nature of pathogenicity (virulence), i.e. the capacity to produce disease. Although each member of the mixed population cannot alone produce the full complement of factors needed for disease production, the complement can be attained by combining contributions from different members.

Sequence of Colonization Determines the Composition of Mixed Biofilms by Escherichia coli O157:H7 and O111:H8 Strains†

2015 ◽  
Vol 78 (8) ◽  
pp. 1554-1559 ◽  
Author(s):  
RONG WANG ◽  
NORASAK KALCHAYANAND ◽  
JAMES L. BONO
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Early Stage ◽  
Critical Role ◽  
The United States ◽  
Food Samples ◽  
E Coli ◽  
Cell Percentage ◽  
Composition And Structure ◽  
Biofilm Development

Bacterial biofilms are one of the potential sources of cross-contamination in food processing environments. Shiga toxin–producing Escherichia coli (STEC) O157:H7 and O111:H8 are important foodborne pathogens capable of forming biofilms, and the coexistence of these two STEC serotypes has been detected in various food samples and in multiple commercial meat plants throughout the United States. Here, we investigated how the coexistence of these two STEC serotypes and their sequence of colonization could affect bacterial growth competition and mixed biofilm development. Our data showed that E. coli O157:H7 strains were able to maintain a higher cell percentage in mixed biofilms with the co-inoculated O111:H8 companion strains, even though the results of planktonic growth competition were strain dependent. On solid surfaces with preexisting biofilms, the sequence of colonization played a critical role in determining the composition of the mixed biofilms because early stage precolonization significantly affected the competition results between the E. coli O157:H7 and O111:H8 strains. The precolonizer of either serotype was able to outgrow the other serotype in both planktonic and biofilm phases. The competitive interactions among the various STEC serotypes would determine the composition and structure of the mixed biofilms as well as their potential risks to food safety and public health, which is largely influenced by the dominant strains in the mixtures. Thus, the analysis of mixed biofilms under various conditions would be of importance to determine the nature of mixed biofilms composed of multiple microorganisms and to help implement the most effective disinfection operations accordingly.

scholarly journals Bacterial defenses against a natural antibiotic promote collateral resilience to clinical antibiotics

2020 ◽  
Author(s):  
Lucas A. Meirelles ◽  
Elena K. Perry ◽  
Megan Bergkessel ◽  
Dianne K. Newman
Keyword(s):  
Antibiotic Resistance ◽  
Opportunistic Pathogen ◽  
Antimicrobial Treatment ◽  
Bacterial Survival ◽  
Human Pathogens ◽  
Opportunistic Pathogens ◽  
Chronic Infections ◽  
Antibiotic Resistant ◽  
Lung Infections ◽  
Environmental Microbes

SummaryAs antibiotic-resistant infections become increasingly prevalent worldwide, understanding the factors that lead to antimicrobial treatment failure is essential to optimizing the use of existing drugs. Opportunistic human pathogens in particular typically exhibit high levels of intrinsic antibiotic resistance and tolerance1, leading to chronic infections that can be nearly impossible to eradicate2. We asked whether the recalcitrance of these organisms to antibiotic treatment could be driven in part by their evolutionary history as environmental microbes, which frequently produce or encounter natural antibiotics3,4. Using the opportunistic pathogen Pseudomonas aeruginosa as a model, we demonstrate that the self-produced natural antibiotic pyocyanin (PYO) activates bacterial defenses that confer collateral tolerance to certain synthetic antibiotics, including in a clinically-relevant growth medium. Non-PYO-producing opportunistic pathogens isolated from lung infections similarly display increased antibiotic tolerance when they are co-cultured with PYO-producing P. aeruginosa. Furthermore, we show that beyond promoting bacterial survival in the presence of antibiotics, PYO can increase the apparent rate of mutation to antibiotic resistance by up to two orders of magnitude. Our work thus suggests that bacterial production of natural antibiotics in infections could play an important role in modulating not only the immediate efficacy of clinical antibiotics, but also the rate at which antibiotic resistance arises in multispecies bacterial communities.

scholarly journals An ultra-sensitive, ultra-fast whole blood monocyte CD169 assay for COVID-19 screening

2020 ◽  
Author(s):  
Moïse Michel ◽  
Fabrice Malergue ◽  
Inès Ait Belkacem ◽  
Pénélope Bourgoin ◽  
Pierre-Emmanuel Morange ◽  
...  
Keyword(s):  
Whole Blood ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Early Stage ◽  
Polymorphonuclear Neutrophil ◽  
Blood Monocyte ◽  
Rt Pcr ◽  
Neutrophil Cd64 ◽  
Asymptomatic Patients ◽  
Hla Dr

AbstractCoVID-19 is an unprecedented epidemic, globally challenging health systems, societies, and economy. Its diagnosis relies on molecular methods, with drawbacks revealed by current use as mass screening. Monocyte CD169 upregulation has been reported as a marker of viral infections, we evaluated a flow cytometry three-color rapid assay of whole blood monocyte CD169 for CoVID-19 screening.Outpatients (n=177) with confirmed CoVID-19 infection, comprising 80 early-stage (≤14 days after symptom onset), 71 late-stage (≥15 days), and 26 asymptomatic patients received whole blood CD169 testing in parallel with SARS-CoV-2 RT-PCR. Upregulation of monocyte CD169 without polymorphonuclear neutrophil CD64 changes was the primary endpoint. Sensitivity was 98% and 100% in early-stage and asymptomatic patients respectively, specificity was 50% and 84%. Rapid whole blood monocyte CD169 evaluation was highly sensitive when compared with RT-PCR, especially in early-stage, asymptomatic patients whose RT-PCR tests were not yet positive.Diagnostic accuracy, easy finger prick sampling and minimal time-to-result (15-30 minutes) rank whole blood monocyte CD169 upregulation as a potential screening and diagnostic support for CoVID-19. Secondary endpoints were neutrophil CD64 upregulation as a marker of bacterial infections and monocyte HLA-DR downregulation as a surrogate of immune fitness, both assisting with adequate and rapid management of non-CoVID cases.

scholarly journals Plant Developmental Stage Drives the Differentiation in Ecological Role of Plant Bacterial and Fungal Microbiomes

2021 ◽  
Author(s):  
Chao Xiong ◽  
Brajesh K. Singh ◽  
Ji-Zheng He ◽  
Yan-Lai Han ◽  
Pei-Pei Li ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Plant Development ◽  
Late Stage ◽  
Developmental Stages ◽  
Early Stage ◽  
Alpha Diversity ◽  
Microbial Interactions ◽  
Disease Suppression ◽  
Fungal Communities ◽  
Ecological Role

Abstract BackgroundPlants live with diverse microbial communities which profoundly affect multiple facets of host performance such as nutrition acquisition, disease suppression and productivity, but if and how host development impacts the assembly, functions and microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils (rhizosphere and bulk soil), plant epiphytic and endophytic niches (phylloplane, rhizoplane, leaf and root endosphere), and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.ResultsOur results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartment niches than in soils, with the strongest effect in the phylloplane. Air (represented by fake plants) was an important source of phylloplane microbiomes which were co-shaped by both plant development and seasonal environmental factors. Further, we demonstrated that bacterial and fungal communities in plant compartment niches exhibited contrasting response to host developmental stages, with higher alpha diversity and stronger deterministic assembly within bacterial microbiomes at the early stage but a similar pattern within mycobiomes at the late stage. Moreover, we found that bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity and functional genes involved in nutrient provision and disease resistance at the early stage than the late stage. ConclusionsOur results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different plant development stages. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection to meet the physiological requirement of plant developmental stages. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity.

scholarly journals Draft Genome Sequences of Two Veillonella tobetsuensis Clinical Isolates from Intraoperative Bronchial Fluids of Elderly Patients with Pulmonary Carcinoma

2019 ◽  
Vol 8 (38) ◽  
Author(s):  
Izumi Mashima ◽  
Tohru Miyoshi-Akiyama ◽  
Junko Tomida ◽  
Ryo Kutsuna ◽  
Jumpei Washio ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Early Stage ◽  
Draft Genome ◽  
Clinical Isolates ◽  
Genome Sequences ◽  
Oral Biofilm ◽  
Content Type ◽  
Pulmonary Carcinoma ◽  
Biofilm Development

To date, Veillonella tobetsuensis has been known as an oral anaerobe and a facilitator of early-stage oral biofilm development with streptococci. Here, we report the draft genome sequences of 2 strains of V. tobetsuensis first isolated from intraoperative bronchial fluids of elderly patients with pulmonary carcinoma.

scholarly journals Stochastic Variation in Expression of the Tricarboxylic Acid Cycle Produces Persister Cells

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Eliza A. Zalis ◽  
Austin S. Nuxoll ◽  
Sylvie Manuse ◽  
Geremy Clair ◽  
Lauren C. Radlinski ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Bacterial Infections ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Resistant Bacteria ◽  
Chronic Infections ◽  
Persister Cells ◽  
Stochastic Variation ◽  
Content Type ◽  
Atp Levels

ABSTRACT Chronic bacterial infections are difficult to eradicate, though they are caused primarily by drug-susceptible pathogens. Antibiotic-tolerant persisters largely account for this paradox. In spite of their significance in the recalcitrance of chronic infections, the mechanism of persister formation is poorly understood. We previously reported that a decrease in ATP levels leads to drug tolerance in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. We reasoned that stochastic fluctuation in the expression of tricarboxylic acid (TCA) cycle enzymes can produce cells with low energy levels. S. aureus knockouts in glutamate dehydrogenase, 2-oxoketoglutarate dehydrogenase, succinyl coenzyme A (CoA) synthetase, and fumarase have low ATP levels and exhibit increased tolerance of fluoroquinolone, aminoglycoside, and β-lactam antibiotics. Fluorescence-activated cell sorter (FACS) analysis of TCA genes shows a broad Gaussian distribution in a population, with differences of over 3 orders of magnitude in the levels of expression between individual cells. Sorted cells with low levels of TCA enzyme expression have an increased tolerance of antibiotic treatment. These findings suggest that fluctuations in the levels of expression of energy-generating components serve as a mechanism of persister formation. IMPORTANCE Persister cells are rare phenotypic variants that are able to survive antibiotic treatment. Unlike resistant bacteria, which have specific mechanisms to prevent antibiotics from binding to their targets, persisters evade antibiotic killing by entering a tolerant nongrowing state. Persisters have been implicated in chronic infections in multiple species, and growing evidence suggests that persister cells are responsible for many cases of antibiotic treatment failure. New antibiotic treatment strategies aim to kill tolerant persister cells more effectively, but the mechanism of tolerance has remained unclear until now.

scholarly journals Witch Hazel Significantly Improves the Efficacy of Commercially Available Teat Dips

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 92 ◽  
Author(s):  
Reuven Rasooly ◽  
Adel Molnar ◽  
Paula Do ◽  
Gianluca Morroni ◽  
Lucia Brescini ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Economic Loss ◽  
Toxin Production ◽  
Gram Negative Bacteria ◽  
Bacterial Survival ◽  
High Concentration ◽  
Witch Hazel ◽  
Intramammary Infections ◽  
Gram Positive Bacteria ◽  
Associated Conditions

Bovine intramammary infections (IMIs) are the main cause of economic loss in milk production. Antibiotics are often ineffective in treating infections due to antimicrobial resistance and the formation of bacterial biofilms that enhance bacterial survival and persistence. Teat dips containing germicides are recommended to prevent new IMIs and improve udder health and milk quality. IMIs are often caused by staphylococci, which are Gram-positive bacteria that become pathogenic by forming biofilms and producing toxins. As a model for a teat dip (DIP), the BacStop iodine-based teat dip (DIP) was used. Witch hazel extract (whISOBAX (WH)) was tested because it contains a high concentration of the anti-biofilm/anti-toxin phenolic compound hamamelitannin. We found that the minimal inhibitory or bactericidal concentrations of DIP against planktonic S. epidermidis cells increased up to 160-fold in the presence of WH, and that DIP was 10-fold less effective against biofilm cells. While both DIP and WH are effective in inhibiting the growth of S. aureus, only WH inhibits toxin production (tested for enterotoxin-A). Importantly, WH also significantly enhances the antibacterial effect of DIP against Gram-negative bacteria that can cause IMIs, like Escherichia coli and Pseudomonas aeruginosa. Put together, these results suggest that the antibacterial activity of DIP combined with WH is significantly higher, and thus have potential in eradicating bacterial infections, both in acute (planktonic-associated) and in chronic (biofilm-associated) conditions.

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