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A single soil application of Bacillus amyloliquefaciens strain S suppressed tomato bacterial wilt caused by Ralstonia solanacearum, a soilborne bacterial pathogen , through production of antibiotics augmented possibly by induction of systemic acquired resistance. Soil application also controlled tomato powdery mildew disease through induction of systemic acquired resistance. S showing bifunctional activity with a single application to soil may be an innovative biological control agent against bacterial wilt and powdery mildew in tomato.

Occurrence and antibacterial susceptibility pattern of bacterial pathogens isolated from diarrheal patients in Pakistan. To determine the occurrence of bacterial pathogens responsible for diarrhea and to engender information regarding the effectiveness of commonly used antibiotic against diarrhea. This cross-sectional study was conducted between April and July The differential and selective media were used to isolate bacterial pathogens , which were identified through cultural characteristics, microscopy, and biochemical tests.

Disc diffusion assay was carried out using Muller Hinton agar medium, and minimum inhibitory concentration was determined using broth dilution method against isolated pathogens. Frequency of occurrence was Bacillus cereus B. Typhi Single pathogen was detected in 20 Bacillus cereus and E. Typhi, P. Pseudomonas aeruginosa showed resistance against Amoxicillin and Cefotaxime, whereas S. Statistical analysis using one way Analysis of Variance revealed that Ofloxacin and Gentamicin had significant p less than 0.

Genetic reprogramming of host cells by bacterial pathogens. During the course of infection, pathogens often induce changes in gene expression in host cells and these changes can be long lasting and global or transient and of limited amplitude. Defining how, when, and why bacterial pathogens reprogram host cells represents an exciting challenge that opens up the opportunity to grasp the essence of pathogenesis and its molecular details.

Pathogenicity of Bacillus thuringiensis variety kurstaki to Ixodes scapularis Acari: Pathogenicity of the entomopathogenic bacterium Bacillus thuringiensis var. Bacillus thuringiensis shows considerable potential as a microbial control agent for the management of Ixodes scapularis. Bacterial Pathogens versus Autophagy: Implications for Therapeutic Interventions. Research in recent years has focused significantly on the role of selective macroautophagy in targeting intracellular pathogens for lysosomal degradation, a process termed xenophagy.

In this review we evaluate the proposed roles for xenophagy in controlling bacterial infection, highlighting the concept that successful pathogens have evolved ways to subvert or exploit this defense, minimizing the actual effectiveness of xenophagy in innate immunity. Instead, studies in animal models have revealed that autophagy-associated proteins often function outside of xenophagy to influence bacterial pathogenesis.

In light of current efforts to manipulate autophagy and the development of host-directed therapies to fight bacterial infections, we also discuss the implications stemming from the complicated relationship that exists between autophagy and bacterial pathogens. Effects of Mentha longifolia L. In the face of emerging new pathogens and ever-growing health-conscious customers, food preservation technology remains on the top agenda of food industry.

This study was aimed at determining the effects of the essential oil of Mentha longifolia L. Over species of resident flora in the class of bacteria are known to be associated with humans. These conventional flora compositions is often determined by factors which may not be limited to genetics, age, sex, stress and nutrition of humans. Man is constantly in contact with bacteria through media such as air, water, soil and food. This paper reviews the concept of bacterial pathogenesis from the sequential point of colonization to tissue injury.

In terms of pathogenicity which of course is the capacity to cause disease in animals, requires that the attacking bacterial strain is virulent, and has ability to bypass the host immune defensive mechanisms. In order to achieve or exhibit pathogenicity , the virulence factors required by microorganisms include capsule, pigments, enzymes, iron acquisition through siderophores.

Bacterial Pathogenicity Islands as a distinct concept in bacterial pathogenesis are just loci on the chromosome or extra chromosomal units which are acquired by horizontal gene transfer within pathogens in a microbial community or biofilm. However, in the recent paradigms shift, the use of proteomics, metagenomics, phylogenetic tree analyses, spooligotyping, and finger printing etc. Evaluating bacterial pathogen DNA preservation in museum osteological collections.

Reports of bacterial pathogen DNA sequences obtained from archaeological bone specimens raise the possibility of greatly improving our understanding of the history of infectious diseases. However, the survival of pathogen DNA over long time periods is poorly characterized, and scepticism remains about the reliability of these data. In order to explore the survival of bacterial pathogen DNA in bone specimens, we analysed samples from 59 eighteenth and twentieth century individuals known to have been infected with either Mycobacterium tuberculosis or Treponema pallidum.

No reproducible evidence of surviving pathogen DNA was obtained, despite the use of extraction and PCR-amplification methods determined to be highly sensitive. These data suggest that previous studies need to be interpreted with caution, and we propose that a much greater emphasis is placed on understanding how pathogen DNA survives in archaeological material, and how its presence can be properly verified and used.

Cytosolic Access of Intracellular Bacterial Pathogens: The Shigella Paradigm. Shigella is a Gram-negative bacterial pathogen , which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events.

For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens , particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it.

Biological defense and security applications demand rapid, sensitive detection of bacterial pathogens. This work presents a novel qualitative electrochemical detection technique which is applied to two representative bacterial pathogens , Bacillus cereus as a surrogate for B. This method has the potential to be adapted for a wide variety of target organisms and sample matrices, and to become a fully portable system for routine monitoring or emergency detection of bacterial pathogens.

Recognition of bacterial plant pathogens: Bacterial pathogens can cause multiple plant diseases and plants rely on their innate immune system to recognize and actively respond to these microbes. The plant innate immune system comprises extracellular pattern recognition receptors that recognize conserved microbial patterns and intracellular nucleotide binding leucine-rich repeat NLR proteins that recognize specific bacterial effectors delivered into host cells.

Plants lack the adaptive immune branch present in animals, but still afford flexibility to pathogen attack through systemic and transgenerational resistance. Here, we focus on current research in plant immune responses against bacterial pathogens. Recent studies shed light onto the activation and inactivation of pattern recognition receptors and systemic acquired resistance. New research has also uncovered additional layers of complexity surrounding NLR immune receptor activation, cooperation and sub-cellular localizations.

Taken together, these recent advances bring us closer to understanding the web of molecular interactions responsible for coordinating defense responses and ultimately resistance. Plant- bacterial pathogen interactions mediated by type III effectors. Effectors secreted by the bacterial type III system play a central role in the interaction between Gram-negative bacterial pathogens and their host plants.

Recent advances in the effector studies have helped cementing several key concepts concerning bacterial pathogenesis, plant immunity, and plant- pathogen co-evolution. The identifications of their host targets led to the identification of novel components of plant innate immune system. Key modules of plant immune signaling pathways such as immune receptor complexes and MAPK cascades have emerged as a major battle ground for host- pathogen adaptation. These modules are attacked by multiple type III effectors, and some components of these modules have evolved to actively sense the effectors and trigger immunity.

Autophagic clearance of bacterial pathogens: Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens , as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection.

In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance. Bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. During their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases.

However, the majority of enteric infection research has been conducted under aerobic conditions. To raise awareness of the importance in understanding the impact of oxygen, or lack of oxygen, on enteric pathogenesis, we describe in this review the metabolic and physiological responses of nine bacterial enteric pathogens exposed to environments with different oxygen levels. We further discuss the effects of oxygen levels on virulence regulation to establish potential connections between metabolic adaptations and bacterial pathogenesis. While not providing an exhaustive list of all bacterial pathogens , we highlight key differences and similarities among nine facultative anaerobic and microaerobic pathogens in this review to argue for a more in-depth understanding of the diverse impact oxygen levels have on enteric pathogenesis.

Marine Bacillus spp. The pandemic bacterium Vibrio parahaemolyticus, isolated from seawater, sediment, and marine organisms, is responsible for gastroenteric illnesses in humans and also cause diseases in aquaculture industry in Chile and other countries around the world. In this study, bacterial flora with inhibitory activity against pathogenic V. A phylogenetic analysis was made, and tests for the productions of antibacterial substance were performed using the double-layer method. Forty-five morphotypes of bacterial colonies were isolated, 8 of which presented an inhibitory effect on the growth of V.

It is important to determine the nature of the antibacterial substance to evaluate their potential for use against the pathogen species V. Metabolic host responses to infection by intracellular bacterial pathogens. The interaction of bacterial pathogens with mammalian hosts leads to a variety of physiological responses of the interacting partners aimed at an adaptation to the new situation. These responses include multiple metabolic changes in the affected host cells which are most obvious when the pathogen replicates within host cells as in case of intracellular bacterial pathogens.

While the pathogen tries to deprive nutrients from the host cell, the host cell in return takes various metabolic countermeasures against the nutrient theft.

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During this conflicting interaction, the pathogen triggers metabolic host cell responses by means of common cell envelope components and specific virulence-associated factors. These host reactions generally promote replication of the pathogen. There is growing evidence that pathogen -specific factors may interfere in different ways with the complex regulatory network that controls the carbon and nitrogen metabolism of mammalian cells. Accurate results on metabolic host cell responses are often hampered by the use of cancer cell lines that already exhibit various de-regulated reactions in the primary carbon metabolism.

Hence, there is an urgent need for cellular models that more closely reflect the in vivo infection conditions. The exact knowledge of the metabolic host cell responses may provide new interesting concepts for antibacterial therapies. The studies on the biocontrol potential of pink pigmented facultative methylotrophic PPFM bacteria other than the genus Methylobacterium are scarce. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains.

Under in vitro conditions, D.

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Under plant growth chamber condition methylotrophic bacterial isolates; D. Under greenhouse condition, D. In the current study, we first report the facultative methylotrophy in pink pigmented D. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent. Utilizing Bacillus to inhibit the growth and infection by sheath blight pathogen , Rhizoctoniasolani in rice. Rhizoctonia solani Kuhn is a common pathogen of rice.

The pathogen causes sheath blight of rice. So far, the disease however is still poorly taken care of by the farmers and researchers, so the control measures is nearly never practiced by the farmers in the fields. It due to the unavailability of effective control method of the disease. Therefore, development to control the disease is important. Bacillus is one of popular bacteria which is effective as biological control agent of a lot of pathogens in plants, but it has not been used for control sheath blight in rice yet.

The current researches were aimed to study the potential of Bacillus collected from healthy rice as candidates of biological control agent of the disease. The results showed that some isolates showed indications to inhibit significantly the growth and infection of the pathogen. We obtained at least five isolates of Bacillus collected from leaves, sheath, and stem of healthy rice fields. All of the isolates could effectively inhibit the growth of R.

Kynetic resazurin assay KRA for bacterial quantification of foodborne pathogens. Fast detection of bacterial concentrations is important for the food industry and for healthcare. Early detection of infections and appropriate treatment is essential since, the delay of treatments for bacterial infections tends to be associated with higher mortality rates. In the food industry and in healthcare, standard procedures require the count of colony-forming units in order to quantify bacterial concentrations, however, this method is time consuming and reports require three days to be completed.

An alternative is metabolic-colorimetric assays which provide time efficient in vitro bacterial concentrations. A colorimetric assay based on Resazurin was developed as a time kinetic assay KRA suitable for bacterial concentration measurements. An optimization was performed by finding excitation and emission wavelengths for fluorescent acquisition.

A comparison of two non-related bacteria, foodborne pathogens Escherichia coli and Listeria monocytogenes, was performed in 96 well plates. A metabolic and clonogenic dependence was established for fluorescent kinetic signals. Detection of mastitis pathogens by analysis of volatile bacterial metabolites. The ability to detect mastitis pathogens based on their volatile metabolites was studied.

Milk samples from cows with clinical mastitis, caused by Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis, Streptococcus dysgalactiae, and Escherichia coli were collected. In addition, samples from cows without clinical mastitis and with low somatic cell count SCC were collected for comparison. All mastitis samples were examined by using classical microbiological methods, followed by headspace analysis for volatile metabolites. Milk from culture-negative samples contained a lower number and amount of volatile components compared with cows with clinical mastitis.

Because of variability between samples within a group, comparisons between pathogens were not sufficient for classification of the samples by univariate statistics. Therefore, an artificial neural network was trained to classify the pathogen in the milk samples based on the bacterial metabolites. The trained network differentiated milk from uninfected and infected quarters very well. When comparing pathogens , Staph. Samples with coagulase-negative staphylococci and E. The 2 streptococcus species did not show significant differences between each other but could be identified as a different group from the other pathogens.

Five groups can thus be identified based on the volatile bacterial metabolites: We constructed a new real-time PCR method to detect causative pathogens in cerebrospinal fluid CSF from patient due to bacterial meningitis. The eight pathogens targeted in the PCR are Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus agalactiae, Staphylococcus aurues, Neisseria meningitides, Listeria monocytogenes, Esherichia coli, and Mycoplasma pneumoniae.

The detection rate of pathogens with PCR was significantly better than that with cultures in patients with antibiotic administration. In conclusion, detection with real-time PCR is useful for rapidly identifying the causative pathogens of meningitis and for examining the clinical course of chemotherapy. Bithionol blocks pathogenicity of bacterial toxins, ricin, and Zika virus.

Disease pathways form overlapping networks, and hub proteins represent attractive targets for broad-spectrum drugs. Using bacterial toxins as a proof of concept, we describe a new approach of discovering broad-spectrum therapies capable of inhibiting host proteins that mediate multiple pathogenic pa Current methods of species-specific bacterial detection and identification are complex, time-consuming, and often require expensive specialized equipment and highly trained personnel.

With a view towards addressing these shortcomings, we have exploited the evolutionarily conserved interactions between a bacteriophage phage and its bacterial host to develop species-specific detection methods. Phage amplification-coupled matrix assisted laser desorption time-of-flight mass spectrometry MALDI-TOF-MS was utilized to rapidly detect phage propagation resulting from species-specific in vitro bacterial infection. This novel signal amplification method allowed for bacterial detection and identification in as little as 2 h, and when combined with disulfide bond reduction methods developed in our laboratory to enhance MALDI-TOF-MS resolution, was observed to lower the limit of detection by several orders of magnitude over conventional spectroscopy and phage typing methods.

Phage amplification has been combined with lateral flow immunochromatography LFI to develop rapid, easy-to-operate, portable, species-specific point-of-care POC detection devices. Prototype LFI detectors have been developed and characterized for Yersinia pestis and Bacillus anthracis, the etiologic agents of plague and anthrax, respectively. Comparable sensitivity and rapidity was observed when phage amplification was adapted to a species-specific handheld LFI detector, thus allowing for rapid, simple, POC bacterial detection and identification while eliminating the need for bacterial culturing or DNA isolation and amplification techniques.

Bacterial genome engineering and synthetic biology: The emergence and prevalence of multidrug resistant MDR pathogenic bacteria poses a serious threat to human and animal health globally. Nosocomial infections and common ailments such as pneumonia, wound, urinary tract, and bloodstream infections are becoming more challenging to treat due to the rapid spread of MDR pathogenic bacteria. The rise in these infections has generated an economic strain worldwide, prompting the WHO to endorse a global action plan to improve awareness and understanding of antimicrobial resistance.

This health crisis necessitates an immediate action to target the underlying mechanisms of drug resistance in bacteria. The advent of new bacterial genome engineering and synthetic biology SB tools is providing promising diagnostic and treatment plans to monitor and treat widespread recalcitrant bacterial infections.

Key advances in genetic engineering approaches can successfully aid in targeting and editing pathogenic bacterial genomes for understanding and mitigating drug resistance mechanisms. In this review, we discuss the application of specific genome engineering and SB methods such as recombineering, clustered regularly interspaced short palindromic repeats CRISPR , and bacterial cell-cell signaling mechanisms for pathogen targeting. The utility of these tools in developing antibacterial strategies such as novel antibiotic production, phage therapy, diagnostics and vaccine production to name a few, are also highlighted.

The prevalent use of antibiotics and the spread of MDR bacteria raise the prospect of a post-antibiotic era, which underscores the need for developing novel therapeutics to target MDR pathogens. The development of enabling SB technologies offers promising solutions to deliver safe and effective antibacterial therapies. Inhibitory effects of Bacillus subtilis on plant pathogens of conservatory in high latitudes.

Researching the effect of three kinds of Bacillus and their mixed strains inhibitory on common fungal diseases of conservatory vegetables. The results showed that B. Fusarium wilt, and the inhibition rate was The results revealed that Bacillus had a significant inhibitory effect on five common fungal pathogens.

Three kinds of Bacillus can be used for the prevention and control of common fungal diseases in conservatory vegetables. Gold Nanoparticles: Enteric bacterial human pathogens , i. Their structure badly affects the human immune system. It is important to explore new antibacterial agents instead of antibiotics for treatment.

This project is an attempt to explain how gold nanoparticles affect these bacteria. We investigated the important role of the mean particle size, and the inhibition of a bacterium is dose-dependent. Ultra Violet UV -visible spectroscopy revealed the size of chemically synthesized gold nanoparticle as 6—40 nm. Atomic force microscopy AFM analysis confirmed the size and X-ray diffractometry XRD analysis determined the polycrystalline nature of gold nanoparticles.

The present findings explained how gold nanoparticles lyse Gram-negative and Gram-positive bacteria. Plant immunity: Phytopathogenic bacteria inject an array of effector proteins into host cells to alter host physiology and assist the infection process. Some of these effectors can also trigger disease resistance as a result of recognition in the plant cell by cytoplasmic immune receptors. Recent progress indicates that many bacterial effector proteins use a variety of biochemical properties to directly attack key components of PAMP-triggered immunity and effector-triggered immunity, providing new insights into the molecular basis of plant innate immunity.

Emerging evidence indicate that the evolution of disease resistance in plants is intimately linked to the mechanism by which bacterial effectors promote parasitism. This review focuses on how these studies have conceptually advanced our understanding of plant- pathogen interactions. Systemic acquired tolerance to virulent bacterial pathogens in tomato. Recent studies on the interactions between plants and pathogenic microorganisms indicate that the processes of disease symptom development and pathogen growth can be uncoupled.

Thus, in many instances, the symptoms associated with disease represent an active host response to the presence of a pathogen. These host responses are frequently mediated by phytohormones. For example, ethylene and salicylic acid SA mediate symptom development but do not influence bacterial growth in the interaction between tomato Lycopersicon esculentum and virulent Xanthomonas campestris pv vesicatoria Xcv.

It is not apparent why extensive tissue death is integral to a defense response if it does not have the effect of limiting pathogen proliferation. One possible function for this hormone-mediated response is to induce a systemic defense response. We therefore assessed the systemic responses of tomato to Xcv. SA- and ethylene-deficient transgenic lines were used to investigate the roles of these phytohormones in systemic signaling.

Virulent and avirulent Xcv did induce a systemic response as evidenced by expression of defense-associated pathogenesis-related genes in an ethylene- and SA-dependent manner. This systemic response reduced cell death but not bacterial growth during subsequent challenge with virulent Xcv. This systemic acquired tolerance SAT consists of reduced tissue damage in response to secondary challenge with a virulent pathogen with no effect upon pathogen growth.

SAT was associated with a rapid ethylene and pathogenesis-related gene induction upon challenge. SAT was also induced by infection with Pseudomonas syringae pv tomato. These data show that SAT resembles systemic acquired resistance without inhibition of pathogen growth. Bacterial pathogens of the bovine respiratory disease complex.

Pneumonia caused by the bacterial pathogens discussed in this article is the most significant cause of morbidity and mortality of the BRDC. Most of these infectious bacteria are not capable of inducing significant disease without the presence of other predisposing environmental factors, physiologic stressors, or concurrent infections. Mannheimia haemolytica is the most common and serious of these bacterial agents and is therefore also the most highly characterized.

There are other important bacterial pathogens of BRD, such as Pasteurella multocida, Histophulus somni, and Mycoplasma bovis. Mixed infections with these organisms do occur. These pathogens have unique and common virulence factors but the resulting pneumonic lesions may be similar. Although the amount and quality of research associated with BRD has increased, vaccination and therapeutic practices are not fully successful. A greater understanding of the virulence mechanisms of the infecting bacteria and pathogenesis of pneumonia, as well as the characteristics of the organisms that allow tissue persistence, may lead to improved management, therapeutics, and vaccines.

Copyright Elsevier Inc. Genome-based approaches to develop vaccines against bacterial pathogens. Bacterial infectious diseases remain the single most important threat to health worldwide. Although conventional vaccinology approaches were successful in conferring protection against several diseases, they failed to provide efficacious solutions against many others. The advent of whole-genome sequencing changed the way to think about vaccine development, enabling the targeting of possible vaccine candidates starting from the genomic information of a single bacterial isolate, with a process named reverse vaccinology.

As the genomic era progressed, reverse vaccinology has evolved with a pan-genome approach and multi-strain genome analysis became fundamental for the design of universal vaccines. This review describes the applications of genome-based approaches in the development of new vaccines against bacterial pathogens.

Investigation of magnetic microdiscs for bacterial pathogen detection. Despite strict regulations to control the presence of human pathogens in our food supply, recent foodborne outbreaks have heightened public concern about food safety and created urgency to improve methods for pathogen detection. Herein we explore a potentially portable, low-cost system that uses magnetic microdiscs for the detection of bacterial pathogens in liquid samples.

The system operates by optically measuring the rotational dynamics of suspended magnetic microdiscs functionalized with pathogen -binding aptamers. The soft ferromagnetic Ni80Fe20 microdiscs exhibit a closed magnetic spin arrangement i. With very high surface area for functionalization and volumes 10,x larger than commonly used superparamagnetic nanoparticles, these 1. This work reports a wafer-level microfabrication process for fabrication of million magnetic microdiscs per substrate and measurement of their rotational dynamics response.

Additionally, the biofunctionalization of the microdiscs with DNA aptamers, subsequent binding to E. Point detection of bacterial and viral pathogens using oral samples. Oral samples, including saliva, offer an attractive alternative to serum or urine for diagnostic testing. This is particularly true for point-of-use detection systems. The various types of oral samples that have been reported in the literature are presented here along with the wide variety of analytes that have been measured in saliva and other oral samples.

The paper focuses on utilizing point-detection of infectious disease agents, and presents work from our group on a rapid test for multiple bacterial and viral pathogens by monitoring a series of targets. It is thus possible in a single oral sample to identify multiple pathogens based on specific antigens, nucleic acids, and host antibodies to those pathogens. The value of such a technology for detecting agents of bioterrorism at remote sites is discussed. Replication of the Bacterial and Bacteriophage Genomes.

Synthesis of phage and bacterial deoxyribonucleic acid DNA was studied by sucrose gradient centrifugation and density equilibrium centrifugation of DNA extracted from induced bacteria. The distribution of DNA in the gradients was measured by differential isotope and density labeling of DNA before and after induction and by measuring the biological activity of the DNA in genetic transformation, in rescue of phage markers, and in infectivity assays.

At early times after induction, but after at least one round of replication, phage DNA remains associated with high-molecular-weight DNA, whereas, later in the infection, phage DNA is associated with material of decreasing molecular weight. Genetic linkage between phage and bacterial markers can be demonstrated in replicated DNA from induced cells. Prophage induction is shown to affect replication of the bacterial chromosome. The rate of replication of the bacterial marker phe-1 and also of nia , located close to the prophage in direction of the terminus of the bacterial chromosome, is increased in induced cells, however, relative to other bacterial markers tested.

The results of these experiments suggest that the prophage is not initially excised in induced cells, but rather it is specifically replicated in situ together with adjacent parts of the bacterial chromosome. Fluorescence spectroscopy for rapid detection and classification of bacterial pathogens. This study deals with the rapid detection and differentiation of Escherichia coli, Salmonella, and Campylobacter, which are the most commonly identified commensal and pathogenic bacteria in foods, using fluorescence spectroscopy and multivariate analysis. Each bacterial sample cultured under controlled conditions was diluted in physiologic saline for analysis.

Fluorescence spectra were collected over a range of nm with 0. The synchronous scan technique was employed to find the optimum excitation lambda ex and emission lambda em wavelengths for individual bacteria with the wavelength interval Deltalambda being varied from 10 to nm. For all three bacterial genera, the same synchronous scan results were obtained. The emission spectra from the three bacteria groups were very similar, creating difficulty in classification.

However, the application of principal component analysis PCA to the fluorescence spectra resulted in successful classification of the bacteria by their genus as well as determining their concentration. These results demonstrated that fluorescence spectroscopy, when coupled with PCA processing, has the potential to detect and to classify bacterial pathogens in liquids. The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides.

However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens.

Here we tested the endophytes for in vitro antagonism dual culture assays against important soil-borne pathogens Rhizoctonia solani , Fusarium graminearum , Phytophthora capsici , Pythium aphanideratum. The endophytes were also assayed in planta leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea , the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds VOCs known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related PR proteins of plant hosts implicated in suppression of fungal pathogens , displays ribonuclease activity.

All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. These results show that seeds of cultivated. Here we tested the endophytes for in vitro antagonism dual culture assays against important soil-borne pathogens Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanidermatum.

The endophytes were also assayed in planta leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. These results show that seeds of cultivated cucurbits. Fusarium graminearum teleomorph: Ascomycota, Hypocreales, Gibberella , Gibberella zeae is a destructive fungal pathogen that threatens the production and quality of wheat and barley worldwide.

Controlling this toxin-producing pathogen is a significant challenge. In the present study, the commercially available strain Bacillus amyloliquefaciens Bacteria , Firmicutes , Bacillales , Bacillus FZB42 showed strong activity against F. Purified bacillomycin D showed strong activity against F. Analyses using scanning and transmission electron microscopy revealed that bacillomycin D caused morphological changes in the plasma membranes and cell walls of F.

Fluorescence microscopy combined with different dyes showed that bacillomycin D induced the accumulation of reactive oxygen species and caused cell death in F. Biological control experiments demonstrated that bacillomycin D exerted good control of F. In response to bacillomycin D, F. Taken together, these findings reveal the mechanism of the antifungal action of bacillomycin D. Bacillus amyloliquefaciens FZB42 is a representative of the biocontrol bacterial strains. In this work. Questions about the behaviour of bacterial pathogens in vivo. Bacterial pathogens cause disease in man and animals.

They have unique biological properties, which enable them to colonize mucous surfaces, penetrate them, grow in the environment of the host, inhibit or avoid host defences and damage the host. The bacterial products responsible for these five biological requirements are the determinants of pathogenicity virulence determinants. Current knowledge comes from studies in vitro, but now interest is increasing in how bacteria behave and produce virulence determinants within the infected host. There are three aspects to elucidate: The first is relatively easy to accomplish and, recently, new methods for doing this have been devised.

The second is not easy because of the complexity of the environment in vivo and its ever-changing face. Nevertheless, some information can be gained from the literature and by new methodology. The third aspect is very difficult to study effectively unless some events in vivo can be simulated in vitro. The objectives of the Discussion Meeting were to describe the new methods and to show how they, and conventional studies, are revealing the activities of bacterial pathogens in vivo.

This paper sets the scene by raising some questions and suggesting, with examples, how they might be answered. Bacterial growth in vivo is the primary requirement for pathogenicity. Without growth, determinants of the other four requirements are not formed. Results from the new methods are underlining this point.

The important questions are as follows. What is the pattern of a developing infection and the growth rates and population sizes of the bacteria at different stages? What nutrients are present in vivo and how do they change as infection progresses and relate to growth rates and population sizes? How are these nutrients metabolized and by what bacterial mechanisms? Which bacterial processes handle. Genomic Analysis of Bacillus sp. Bacillus sp. B25 is an effective biocontrol agent against the maize pathogenic fungus Fusarium verticillioides Fv. Previous in vitro assays have shown that B25 has protease, glucanase, and chitinase activities and siderophores production; however, specific mechanisms by which B25 controls Fv are still unknown.

To determine the genetic traits involved in biocontrol, B25 genome was sequenced and analyzed. Some of these genes are shared with some biocontrol agents of the Bacillus genus and less with Pseudomonas and Serratia strains. We performed a genomic comparison between B25 and five Bacillus spp. B25 contains genes involved in a wide variety of antagonistic mechanisms including chitinases, glycoside hydrolases, siderophores, antibiotics, and biofilm production that could be implicated in root colonization.

This is the first comparative genome analysis between strains belonging to the B. These results are the starting point for further studies on B25 gene expression during its interaction with Fv. Biodegradation of crude oil by a defined co-culture of indigenous bacterial consortium and exogenous Bacillus subtilis. The aim of this work was to study biodegradation of crude oil by defined co-cultures of indigenous bacterial consortium and exogenous Bacillus subtilis.

Through residual oil analysis, it is apparent that the defined co-culture displayed a degradation ratio Long-chain n-alkanes could be degraded markedly by Bacillus subtilis. Result analysis of the bacterial community showed that a decrease in bacterial diversity in the defined co-culture and the enrichment of Burkholderiales order The research results revealed that the promising potential of the defined co-culture for application to degradation of crude oil. Antimicrobial inflammasomes: Inflammasomes - molecular platforms for caspase-1 activation - have emerged as common hubs for a number of pathways that detect and respond to bacterial pathogens.

In this review we discuss signal transduction leading to 'canonical' and 'non-canonical' activation of caspase-1 through the involvement of upstream caspases. Recent studies have identified a growing number of regulatory networks involving guanylate binding proteins, protein kinases, ubiquitylation and necroptosis related pathways that modulate inflammasome responses and immunity to bacterial infection. By being able to respond to extracellular, vacuolar and cytosolic bacteria, their cytosolic toxins or ligands for cell surface receptors, inflammasomes have emerged as important sentinels of infection.

Hospital-acquired pneumonia HAP is one of the most serious complications in patients staying in intensive care units. This multicenter study of Czech patients with HAP aimed at assessing the clonality of bacterial pathogens causing the condition. Bacterial isolates were compared using pulsed-field gel electrophoresis. Included in this study were patients hospitalized between May 1, and December 31, at departments of anesthesiology and intensive care medicine of four big hospitals in the Czech Republic.

A total of bacterial isolates were obtained, of which were classified as etiological agents causing HAP. Similarity or identity was assessed in bacterial isolates most frequently obtained from HAP patients. Over the study period, no significant clonal spread was noted. Most isolates were unique strains, and the included HAP cases may therefore be characterized as mostly endogenous. Yet there were differences in species and potential identical isolates between the participating centers. In three hospitals, Gram-negative bacteria Enterobacteriaceae and Pseudomonas aeruginosa prevailed as etiological agents, and Staphylococcus aureus was most prevalent in the fourth center.

Copper and zinc homeostasis systems in pathogenic bacteria are required to resist host efforts to manipulate the availability and toxicity of these metal ions. Central to this microbial adaptive response is the involvement of metal-trafficking and -sensing proteins that ultimately exercise control of metal speciation in the cell.

Cu- and Zn-specific metalloregulatory proteins regulate the transcription of metal-responsive genes while metallochaperones and related proteins ensure that these metals are appropriately buffered by the intracellular milieu and delivered to correct intracellular targets. Microbiological food safety issues in Brazil: The globalization of food supply impacts patterns of foodborne disease outbreaks worldwide, and consumers are having increased concern about microbiological food safety.

In this sense, the assessment of epidemiological data of foodborne diseases in different countries has not only local impact, but it can also be of general interest, especially in the case of major global producers and exporters of several agricultural food products, such as Brazil. In this review, the most common agents of foodborne illnesses registered in Brazil will be presented, compiled mainly from official databases made available to the public.

In addition, some representative examples of studies on foodborne bacterial pathogens commonly found in Brazilian foods are provided. Relationship between lactobacilli and opportunistic bacterial pathogens associated with vaginitis.

Vaginitis, is an infectious inflammation of the vaginal mucosa, which sometimes involves the vulva. The balance of the vaginal flora is maintained by the Lactobacilli and its protective and probiotic role in treating and preventing vaginal infection by producing antagonizing compounds which are regarded as safe for humans.

The aim of this study was to evaluate the protective role of Lactobacilli against common bacterial opportunistic pathogens in vaginitis and study the effects of some antibiotics on Lactobacilli isolates. In this study vaginal swabs were obtained from women suffering from vaginitis who admitted to Babylon Hospital of Maternity and Paediatrics in Babylon province, Iraq. The study involved the role of intrauterine device among married women with vaginitis and also involved isolation of opportunistic bacterial isolates among pregnant and non pregnant women.

This study also involved studying probiotic role of Lactobacilli by production of some defense factors like hydrogen peroxide, bacteriocin, and lactic acid. Results revealed that a total of bacterial isolates were obtained. Intrauterine device was a predisposing factor for vaginitis.

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The most common opportunistic bacterial isolates were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae, and Klebsiella pneumoniae. All Lactobacilli were hydrogen peroxide producers while some isolates were bacteriocin producers that inhibited some of opportunistic pathogens S. Lactobacilli were sensitive to erythromycin while Results revealed that there was an inverse relationship between Lactobacilli presence and organisms causing vaginitis.

This may be attributed to the production of defense factors by Lactobacilli. The types of antibiotics used to treat vaginitis must be very selective in order not to kill the beneficial bacteria.

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Materials and Methods: The types of antibiotics used to treat vaginitis must be very. Pathogenic bacteria are detected by pattern-recognition receptors PRRs expressed on innate immune cells, which activate intracellular signal transduction pathways to elicit an immune response. These pathways are critical for mounting an effective immune response. In order to evade detection and promote virulence, many pathogens subvert the host immune response by targeting components of these signal transduction pathways. Understanding the elaborate strategies that pathogens employ to subvert the immune response not only highlights the importance of these proteins in mounting effective immune responses, but may also identify novel approaches for treatment or prevention of infection.

Disarming Fungal Pathogens: However, it is largely unknown whether and how bacteria also interact with human fungal pathogens naturally found in the environment. Here, we identified a soil bacterium, Bacillus safensis, which potently blocked several key Cryptococcus neoformans virulence factors, including formation of the antioxidant pigment melanin and production of the antiphagocytic polysaccharide capsule. The bacterium also inhibited de novo cryptococcal biofilm formation but had only modest inhibitory effects on already formed biofilms or planktonic cell growth.

The inhibition of fungal melanization was dependent on direct cell contact and live bacteria. Specifically, dual-species interaction studies revealed that the bacterium strongly inhibited C. In particular, B. Through genetic and phenotypic analyses, we demonstrated that bacterial chitinase activity against fungal cell wall chitin is a factor contributing to the antipathogen effect of B.

Antimicrobial Resistance in Bacterial Poultry Pathogens: A Review. The passive and regulated movement of ions, solutes, and water via spaces between cells of the epithelial monolayer plays a critical role in the normal intestinal functioning. This paracellular pathway displays a high level of structural and functional specialization, with the membrane-spanning complexes of the tight junctions, adherens junctions, and desmosomes ensuring its integrity. Tight junction proteins, like occludin, tricellulin, and the claudin family isoforms, play prominent roles as barriers to unrestricted paracellular transport.

The past decade has witnessed major advances in our understanding of the architecture and function of epithelial tight junctions. While it has been long appreciated that microbes, notably bacterial and viral pathogens , target and disrupt junctional complexes and alter paracellular permeability, the precise mechanisms remain to be defined. Notably, renewed efforts will be required to interpret the available data on pathogen -mediated barrier disruption in the context of the most recent findings on tight junction structure and function.

While much of the focus has been on pathogen -induced dysregulation of junctional complexes, commensal microbiota and their products may influence paracellular permeability and contribute to the normal physiology of the gut. Finally, microbes and their products have become important tools in exploring host systems, including the junctional properties of epithelial cells. Compr Physiol 8: Quorum sensing and Bacterial Pathogenicity: From Molecules to Disease.

Quorum sensing in prokaryotic biology refers to the ability of a bacterium to sense information from other cells in the population when they reach a critical concentration i. Quorum sensing is thought to afford pathogenic bacteriaa mechanism to minimize host immune responses by delaying theproduction of tissue-damaging virulence factors until sufficientbacteria have amassed and are prepared to overwhelm host defensemechanisms and establish infection. Among the pathogenic bacteria, Pseudomonas aeruginosa is perhaps the best understood in terms of the virulence factors regulated and the role the Quorum sensing plays in pathogenicity.

This paper reviews Quorum sensing in gram positive and gram negative bacteria and its role in biofilm formation. Jeffrey R. Ralph M. Natasha Cedar Ave Brewer Keith. Elizabeth Tasker St Keough Joseph. Robert S 10th St Conte Josephine. Sarah S 4th St Cappone Natalie. Mary S 4th St Woods Jeffrey. Theresa Algon Ave Fortuna Anthony. Vann Tyson Ave Dougherty Helen. James S 11th St Wilhelm William. Sheila Elbridge St King Charles. Jean S 7th Montella Kathryn C. Phyllis Winton St Appleton Richard. Antonio N 66th St Lepping Gerald. Vincent M.

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