Phage Biocontrol of Pseudomonas aeruginosa in Water

Bacteriophage control of harmful or pathogenic bacteria has aroused growing interest, largely due to the rise of antibiotic resistance. The objective of this study was to test phages as potential agents for the biocontrol of an opportunistic pathogen Pseudomonas aeruginosa in water. Two P. aeruginosa bacteriophages (vB_PaeM_V523 and vB_PaeM_V524) were isolated from wastewater and characterized physically and functionally. Genomic and morphological characterization showed that both were myoviruses within the Pbunavirus genus. Both had a similar latent period (50–55 min) and burst size (124–134 PFU/infected cell), whereas there was variation in the host range. In addition to these environmental phages, a commercial Pseudomonas phage, JG003 (DSM 19870), was also used in the biocontrol experiments. The biocontrol potential of the three phages in water was tested separately and together as a cocktail against two P. aeruginosa strains; PAO1 and the environmental strain 17V1507. With PAO1, all phages initially reduced the numbers of the bacterial host, with phage V523 being the most efficient (>2.4 log10 reduction). For the environmental P. aeruginosa strain (17V1507), only the phage JG003 caused a reduction (1.2 log10) compared to the control. The cocktail of three phages showed a slightly higher decrease in the level of the hosts compared to the use of individual phages. Although no synergistic effect was observed in the host reduction with the use of the phage cocktail, the cocktail-treated hosts did not appear to acquire resistance as rapidly as hosts treated with a single phage. The results of this study provide a significant step in the development of bacteriophage preparations for the control of pathogens and harmful microbes in water environments.

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F-type Pyocins are Diverse Non-Contractile Phage Tail-Like Weapons for Killing Pseudomonas aeruginosa

10.1101/2021.02.16.431561 ◽

2021 ◽

Author(s):

Senjuti Saha ◽

Chidozie D. Ojobor ◽

Erik Mackinnon ◽

Olesia I. North ◽

Joseph Bondy-Denomy ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Bactericidal Activity ◽

Pathogenic Bacteria ◽

Therapeutic Potential ◽

Experimental Studies ◽

Opportunistic Pathogen ◽

Multidrug Resistant ◽

Antibiotic Resistant ◽

Genes Encoding ◽

Intraspecies Competition

ABSTRACTMost Pseudomonas aeruginosa strains produce bacteriocins derived from contractile or non-contractile phage tails known as R-type and F-type pyocins, respectively. These bacteriocins possess strain-specific bactericidal activity against P. aeruginosa and likely increase evolutionary fitness through intraspecies competition. R-type pyocins have been studied extensively and show promise as alternatives to antibiotics. Although they have similar therapeutic potential, experimental studies on F-type pyocins are limited. Here, we provide a bioinformatic and experimental investigation of F-type pyocins. We introduce a systematic naming scheme for genes found in R- and F-type pyocin operons and identify 15 genes invariably found in strains producing F-type pyocins. Five proteins encoded at the 3’-end of the F-type pyocin cluster are divergent in sequence, and likely determine bactericidal specificity. We use sequence similarities among these proteins to define 11 distinct F-type pyocin groups, five of which had not been previously described. The five genes encoding the variable proteins associate in two modules that have clearly re-assorted independently during the evolution of these operons. These proteins are considerably more diverse than the specificity-determining tail fibers of R-type pyocins, suggesting that F-type pyocins emerged earlier or have been subject to distinct evolutionary pressures. Experimental studies on six F-type pyocin groups show that each displays a distinct spectrum of bactericidal activity. This activity is strongly influenced by the lipopolysaccharide O-antigen type, but other factors also play a role. F-type pyocins appear to kill as efficiently as R-type pyocins. These studies set the stage for the development of F-type pyocins as anti-bacterial therapeutics.IMPORTANCEPseudomonas aeruginosa is an opportunistic pathogen that causes a broad spectrum of antibiotic resistant infections with high mortality rates, particularly in immunocompromised individuals and cystic fibrosis patients. Due to the increasing frequency of multidrug-resistant P. aeruginosa infections, there is great interest in the development of alternative therapeutics. One alternative is protein-based antimicrobials called bacteriocins, which are produced by one strain of bacteria to kill other strains. In this study, we investigate F-type pyocins, bacteriocins naturally produced by P. aeruginosa that resemble non-contractile phage tails. We show that they are potent killers of P. aeruginosa, and distinct pyocin groups display different killing specificities. We have identified the probable specificity determinants of F-type pyocins, which opens up the potential to engineer them to precisely target strains of pathogenic bacteria. The resemblance of F-type pyocins to well characterized phage tails will greatly facilitate their development into effective antibacterials.

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Reservoirs of resistance: polymyxin resistance in veterinary-associated companion animal isolates of Pseudomonas aeruginosa

Veterinary Record ◽

10.1136/vr.105075 ◽

2019 ◽

Vol 185 (7) ◽

pp. 206-206 ◽

Cited By ~ 1

Author(s):

Andrea Scott ◽

Sian Pottenger ◽

Dorina Timofte ◽

Matthew Moore ◽

Laura Wright ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Pathogenic Bacteria ◽

Inhibitory Concentration ◽

Respiratory Infections ◽

Companion Animals ◽

Opportunistic Pathogen ◽

Polymyxin B ◽

Potential Reservoir ◽

Human Infections ◽

Animal Isolates

BackgroundPseudomonas aeruginosa is an opportunistic pathogen and a major cause of infections. Widespread resistance in human infections are increasing the use of last resort antimicrobials such as polymyxins. However, these have been used for decades in veterinary medicine. Companion animals are an understudied source of antimicrobial resistant P. aeruginosa isolates. This study evaluated the susceptibility of P. aeruginosa veterinary isolates to polymyxins to determine whether the veterinary niche represents a potential reservoir of resistance genes for pathogenic bacteria in both animals and humans.Methods and resultsClinical P. aeruginosa isolates (n=24) from UK companion animals were compared for antimicrobial susceptibility to a panel of human-associated isolates (n=37). Minimum inhibitory concentration (MIC) values for polymyxin B and colistin in the companion animals was significantly higher than in human isolates (P=0.033 and P=0.013, respectively). Genotyping revealed that the veterinary isolates were spread throughout the P. aeruginosa population, with shared array types from human infections such as keratitis and respiratory infections, suggesting the potential for zoonotic transmission. Whole genome sequencing revealed mutations in genes associated with polymyxin resistance and other antimicrobial resistance-related genes.ConclusionThe high levels of resistance to polymyxin shown here, along with genetic similarities between some human and animal isolates, together suggest a need for sustained surveillance of this veterinary niche as a potential reservoir for resistant, clinically relevant bacteria in both animals and humans.

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The flavanone naringenin reduces the production of quorum sensing-controlled virulence factors in Pseudomonas aeruginosa PAO1

Microbiology ◽

10.1099/mic.0.049338-0 ◽

2011 ◽

Vol 157 (7) ◽

pp. 2120-2132 ◽

Cited By ~ 123

Author(s):

Olivier M. Vandeputte ◽

Martin Kiendrebeogo ◽

Tsiry Rasamiravaka ◽

Caroline Stévigny ◽

Pierre Duez ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Pathogenic Bacteria ◽

Opportunistic Pathogen ◽

Homoserine Lactone ◽

Gene Products ◽

Strain Pao1 ◽

Preliminary Screening ◽

Mutant Strains

Preliminary screening of the Malagasy plant Combretum albiflorum for compounds attenuating the production of quorum sensing (QS)-controlled virulence factors in bacteria led to the identification of active fractions containing flavonoids. In the present study, several flavonoids belonging to the flavone, flavanone, flavonol and chalcone structural groups were screened for their capacity to reduce the production of QS-controlled factors in the opportunistic pathogen Pseudomonas aeruginosa (strain PAO1). Flavanones (i.e. naringenin, eriodictyol and taxifolin) significantly reduced the production of pyocyanin and elastase in P. aeruginosa without affecting bacterial growth. Consistently, naringenin and taxifolin reduced the expression of several QS-controlled genes (i.e. lasI, lasR, rhlI, rhlR, lasA, lasB, phzA1 and rhlA) in P. aeruginosa PAO1. Naringenin also dramatically reduced the production of the acylhomoserine lactones N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) and N-butanoyl-l-homoserine lactone (C4-HSL), which is driven by the lasI and rhlI gene products, respectively. In addition, using mutant strains deficient for autoinduction (ΔlasI and ΔrhlI) and LasR- and RhlR-based biosensors, it was shown that QS inhibition by naringenin not only is the consequence of a reduced production of autoinduction compounds but also results from a defect in the proper functioning of the RlhR–C4-HSL complex. Widely distributed in the plant kingdom, flavonoids are known for their numerous and determinant roles in plant physiology, plant development and in the success of plant–rhizobia interactions, but, as shown here, some of them also have a role as inhibitors of the virulence of pathogenic bacteria by interfering with QS mechanisms.

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Biofilm of Pseudomonas aeruginosa in Nosocomial Infection

Journal of Molecular Biology Research ◽

10.5539/jmbr.v7n1p29 ◽

2017 ◽

Vol 7 (1) ◽

pp. 29

Author(s):

Z. Mahmmudi ◽

A. A. Gorzin

Keyword(s):

Pseudomonas Aeruginosa ◽

Pathogenic Bacteria ◽

Molecular Mechanisms ◽

Matrix Material ◽

Model Organism ◽

Opportunistic Pathogen ◽

Chronic Infections ◽

Microbial Biofilms ◽

Alternative Measures ◽

Opportunistic Pathogenic

Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially, biofilm infections where P. aeruginosa plays an important role are described. Subsequently, current insights into the molecular mechanisms involved in P. aeruginosa biofilm formation and the associated antimicrobial tolerance are reviewed. And finally, based on our knowledge about molecular biofilm biology, a number of therapeutic strategies for combat of P. aeruginosa biofilm infections are presented.

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The In Vitro Antibiofilm Activity of Water Leaf Extract of Papaya (Carica papaya L.) against Pseudomonas aeruginosa

Current Biochemistry ◽

10.29244/cb.2.3.150-163 ◽

2017 ◽

Vol 2 (3) ◽

pp. 150-163

Author(s):

Ekajayanti Kining ◽

Syamsul Falah ◽

Novik Nurhidayat

Keyword(s):

Pseudomonas Aeruginosa ◽

Contact Time ◽

Cell Attachment ◽

Water Extract ◽

Opportunistic Pathogen ◽

Bacterial Biofilm ◽

Antibiofilm Activity ◽

Bacterial Survival ◽

Optimum Conditions

Pseudomonas aeruginosa is one of opportunistic pathogen forming bacterial biofilm. The biofilm sustains the bacterial survival and infections. This study aimed to assess the activity of water extract of papaya leaves on inhibition of cells attachment, growth and degradation of the biofilm using crystal violet (CV) biofilm assay. Research results showed that water extract of papaya leaves contains alkaloids, tanins, flavonoids, and steroids/terpenoids and showed antibacterial activity and antibiofilm against P. aeruginosa. Addition of extract can inhibit the cell attachment and was able to degrade the biofilm of 40.92% and 48.058% respectively at optimum conditions: extract concentration of 25% (v/v), temperature 37.5 °C and contact time 45 minutes. With a concentration of 25% (v/v), temperature of 50 °C and the contact time of 3 days, extract of papaya leaves can inhibit the growth of biofilms of 39.837% v/v.

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Microbiological quality of residues from drinking water preparation

Water Science & Technology ◽

10.2166/wst.1995.0565 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 75-79 ◽

Cited By ~ 5

Author(s):

M. Würzer ◽

A. Wiedenmann ◽

K. Botzenhart

Keyword(s):

Waste Water ◽

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Drinking Water ◽

Water Treatment ◽

Pathogenic Bacteria ◽

Waste Water Treatment ◽

Microbiological Quality ◽

Detection Limits

In Germany the application of procedures such as flocculation and filtration in the preparation of drinking water results in the annual production of an estimated 500,000 t of sediments and sludges. Some of these residues have a potential for being reused, for example in agriculture, forestry, brickworks or waste water treatment. To assess the microbiological quality of residues from waterworks methods for the detection of enterobacteria, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Legionella, poliovirus, Ascaris suis eggs and Cryptosporidium have been evaluated regarding their detection limits and were applied to various residues from German waterworks. Results show that sediments and sludges may contain pathogenic bacteria, viruses and protista. When residues from waterworks are intended to be reused in agriculture or forestry the microbiological quality should therefore be considered.

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Assessing the Molecular Targets and Mode of Action of Furanone C-30 on Pseudomonas aeruginosa Quorum Sensing

Molecules ◽

10.3390/molecules26061620 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1620

Author(s):

Victor Markus ◽

Karina Golberg ◽

Kerem Teralı ◽

Nazmi Ozer ◽

Esti Kramarsky-Winter ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Quorum Sensing ◽

Conformational Changes ◽

Mode Of Action ◽

Pathogenic Bacteria ◽

Molecular Targets ◽

Resistant Bacteria ◽

Public Healthcare ◽

C 30

Quorum sensing (QS), a sophisticated system of bacterial communication that depends on population density, is employed by many pathogenic bacteria to regulate virulence. In view of the current reality of antibiotic resistance, it is expected that interfering with QS can address bacterial pathogenicity without stimulating the incidence of resistance. Thus, harnessing QS inhibitors has been considered a promising approach to overriding bacterial infections and combating antibiotic resistance that has become a major threat to public healthcare around the globe. Pseudomonas aeruginosa is one of the most frequent multidrug-resistant bacteria that utilize QS to control virulence. Many natural compounds, including furanones, have demonstrated strong inhibitory effects on several pathogens via blocking or attenuating QS. While the natural furanones show no activity against P. aeruginosa, furanone C-30, a brominated derivative of natural furanone compounds, has been reported to be a potent inhibitor of the QS system of the notorious opportunistic pathogen. In the present study, we assess the molecular targets and mode of action of furanone C-30 on P. aeruginosa QS system. Our results suggest that furanone C-30 binds to LasR at the ligand-binding site but fails to establish interactions with the residues crucial for the protein’s productive conformational changes and folding, thus rendering the protein dysfunctional. We also show that furanone C-30 inhibits RhlR, independent of LasR, suggesting a complex mechanism for the agent beyond what is known to date.

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Prevalence of metallo-β-lactamase genes among Pseudomonas aeruginosa isolated from various clinical samples in China

Journal of Laboratory Medicine ◽

10.1515/labmed-2019-0162 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Wei Wang ◽

Xiaoya Wang

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Susceptibility ◽

Ethylenediaminetetraacetic Acid ◽

Carbapenem Resistance ◽

Opportunistic Pathogen ◽

Detection Methods ◽

Clinical Samples ◽

Routine Practice ◽

Carbapenem Resistant ◽

High Prevalence

AbstractBackgroundPseudomonas aeruginosa is an opportunistic pathogen which is associated with nosocomial infections and causes various diseases including urinary tract infection, pneumonia, soft-tissue infection and sepsis. The emergence of P. aeruginosa-acquired metallo-β-lactamase (MBL) is most worrisome and poses a serious threat during treatment and infection control. The objective of this study was to identify antibiotic susceptibility, phenotypic detection of MBL production and to determine the prevalence of MBL genes in carbapenem-resistant P. aeruginosa isolated from different clinical samples.MethodsA total of 329 non-duplicate P. aeruginosa isolated from various clinical samples from two hospitals in China between September 2017 and March 2019 were included in this study. Phenotypic detection of MBL was performed by the combined detection method using imipenem and imipenem-ethylenediaminetetraacetic acid (EDTA) discs. MBL-encoding genes including blaVIM-1, blaVIM-2, blaIMP-1, blaIMP-2, blaSPM-1, blaSIM, blaNDM-1 and blaGIM were detected by polymerase chain reaction (PCR).ResultsOf the 329 P. aeruginosa, majority of the isolates were resistant to imipenem (77.5%) followed by meropenem (64.7%). Of the 270 P. aeruginosa isolates tested, 149 (55.2%) isolates were found to be positive for MBL detection. Of the different samples, 57.8% (n = 26) of P. aeruginosa isolated from blood were found to be positive for MBL production. Of the various MBL genes, blaIMP-1 (28.2%) was the most predominant gene detected followed by blaVIM-2 (18.8%), blaVIM-1 (16.1%), blaNDM-1 (9.4%), blaIMP-2 (6.7%), blaSIM (6.0%), blaSPM-1 (4.0%) and blaGIM (1.3%) genes.ConclusionsThe high resistance of P. aeruginosa toward imipenem and meropenem and the high prevalence of blaIMP-1 and blaVIM-2 set the alarm on the increasing, perhaps the increased, carbapenem resistance. In addition to routine antibiotic susceptibility testings, our results emphasize the importance of both the phenotypic and genotypic MBL detection methods in routine practice for early detection of carbapenem resistance and to prevent further dissemination of this resistant pathogen.

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Exploring Mucin as Adjunct to Phage Therapy

Microorganisms ◽

10.3390/microorganisms9030509 ◽

2021 ◽

Vol 9 (3) ◽

pp. 509

Author(s):

Amanda Carroll-Portillo ◽

Henry C. Lin

Keyword(s):

Pathogenic Bacteria ◽

Structural Changes ◽

Phage Therapy ◽

Bacterial Species ◽

Gi Tract ◽

Beneficial Bacteria ◽

Phage Cocktail ◽

Small Intestinal ◽

Gastrointestinal Dysbiosis

Conventional phage therapy using bacteriophages (phages) for specific targeting of pathogenic bacteria is not always useful as a therapeutic for gastrointestinal (GI) dysfunction. Complex dysbiotic GI disorders such as small intestinal bowel overgrowth (SIBO), ulcerative colitis (UC), or Crohn’s disease (CD) are even more difficult to treat as these conditions have shifts in multiple populations of bacteria within the microbiome. Such community-level structural changes in the gut microbiota may require an alternative to conventional phage therapy such as fecal virome transfer or a phage cocktail capable of targeting multiple bacterial species. Additionally, manipulation of the GI microenvironment may enhance beneficial bacteria–phage interactions during treatment. Mucin, produced along the entire length of the GI tract to protect the underlying mucosa, is a prominent contributor to the GI microenvironment and may facilitate bacteria–phage interactions in multiple ways, potentially serving as an adjunct during phage therapy. In this review, we will describe what is known about the role of mucin within the GI tract and how its facilitation of bacteria–phage interactions should be considered in any effort directed at optimizing effectiveness of a phage therapy for gastrointestinal dysbiosis.

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Bacteriophage Cocktail-Mediated Inhibition of Pseudomonas aeruginosa Biofilm on Endotracheal Tube Surface

Antibiotics ◽

10.3390/antibiotics10010078 ◽

2021 ◽

Vol 10 (1) ◽

pp. 78

Author(s):

Viviane C. Oliveira ◽

Ana P. Macedo ◽

Luís D. R. Melo ◽

Sílvio B. Santos ◽

Paula R. S. Hermann ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Endotracheal Tube ◽

Metabolic Activity ◽

Bacterial Colonization ◽

Multidrug Resistant ◽

Scientific Data ◽

Tube Surface ◽

Screening Assay ◽

Biofilm Growth ◽

Phage Cocktail

Although different strategies to control biofilm formation on endotracheal tubes have been proposed, there are scarce scientific data on applying phages for both removing and preventing Pseudomonas aeruginosa biofilms on the device surface. Here, the anti-biofilm capacity of five bacteriophages was evaluated by a high content screening assay. We observed that biofilms were significantly reduced after phage treatment, especially in multidrug-resistant strains. Considering the anti-biofilm screens, two phages were selected as cocktail components, and the cocktail’s ability to prevent colonization of the endotracheal tube surface was tested in a dynamic biofilm model. Phage-coated tubes were challenged with different P. aeruginosa strains. The biofilm growth was monitored from 24 to 168 h by colony forming unit counting, metabolic activity assessment, and biofilm morphology observation. The phage cocktail promoted differences of bacterial colonization; nonetheless, the action was strain dependent. Phage cocktail coating did not promote substantial changes in metabolic activity. Scanning electron microscopy revealed a higher concentration of biofilm cells in control, while tower-like structures could be observed on phage cocktail-coated tubes. These results demonstrate that with the development of new coating strategies, phage therapy has potential in controlling the endotracheal tube-associated biofilm.

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