Pre-Columbian Archeological Textiles: A Source of Pseudomonas aeruginosa with Virulence Attributes

Pseudomonas aeruginosa is an opportunistic pathogen associated with a broad spectrum of infections in humans. However, the pathogenicity of environmental P. aeruginosa strains, especially isolates from museums and conservation laboratories, is not widely recognized. In this study, the virulence attributes of P. aeruginosa isolated from pre-Columbian textiles were compared to those of a clinical strain. Both genetically identified environmental strains (KP842564 and KP842565) exhibited a high ability to form biofilms on abiotic surfaces and high hemolytic activity. In addition, strain KP842564 was a moderate pyocyanin producer and showed proteolytic properties toward bovine serum albumin, fibrinogen, mucin, and casein. In contrast to the clinical isolate, the environmental strains were susceptible to all the tested antimicrobial agents. The strains also showed high bioadhesion and colonization capacity on archeological textile samples, in which wool fibers were the only source of nutrients, as confirmed by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) analysis. This study highlights the need to identify microorganisms which inhabit historic objects, in order to avoid exposure to occupational hazards. Although the strain KP842565 exhibited only some of the examined virulence-related features, given that the production of pyocyanin and hemolysins as well as the formation of biofilm are important virulence factors of P. aeruginosa, the results indicate that these strains may present a potential health risk for humans.

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Local and Global Regulators Linking Anaerobiosis to cupA Fimbrial Gene Expression in Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.01344-07 ◽

2007 ◽

Vol 189 (23) ◽

pp. 8667-8676 ◽

Cited By ~ 29

Author(s):

Isabelle Vallet-Gely ◽

Josh S. Sharp ◽

Simon L. Dove

Keyword(s):

Gene Expression ◽

Pseudomonas Aeruginosa ◽

Opportunistic Pathogen ◽

Phase Variable ◽

Global Regulators ◽

Variable Expression ◽

Regulatory Cascade ◽

Abiotic Surfaces ◽

Positive Regulators ◽

Anaerobic Environment

ABSTRACT The cupA gene cluster of Pseudomonas aeruginosa encodes components and assembly factors of a putative fimbrial structure that enable this opportunistic pathogen to form biofilms on abiotic surfaces. In P. aeruginosa the control of cupA gene expression is complex, with the H-NS-like MvaT protein functioning to repress phase-variable (on/off) expression of the operon. Here we identify four positive regulators of cupA gene expression, including three unusual regulators encoded by the cgrABC genes and Anr, a global regulator of anaerobic gene expression. We show that the cupA genes are expressed in a phase-variable manner under anaerobic conditions and that the cgr genes are essential for this expression. We show further that cgr gene expression is negatively controlled by MvaT and positively controlled by Anr and anaerobiosis. Expression of the cupA genes therefore appears to involve a regulatory cascade in which anaerobiosis, signaled through Anr, stimulates expression of the cgr genes, resulting in a concomitant increase in cupA gene expression. Our findings thus provide mechanistic insight into the regulation of cupA gene expression and identify anaerobiosis as an inducer of phase-variable cupA gene expression, raising the possibility that phase-variable expression of fimbrial genes important for biofilm formation may occur in P. aeruginosa persisting in the largely anaerobic environment of the cystic fibrosis host lung.

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Pseudomonas aeruginosa in Bronchiectasis

Seminars in Respiratory and Critical Care Medicine ◽

10.1055/s-0041-1730921 ◽

2021 ◽

Vol 42 (04) ◽

pp. 587-594

Author(s):

Laia Fernández-Barat ◽

Victoria Alcaraz-Serrano ◽

Rosanel Amaro ◽

Antoni Torres

Keyword(s):

Pseudomonas Aeruginosa ◽

Chronic Infection ◽

Opportunistic Pathogen ◽

Oxygen Depletion ◽

Antimicrobial Treatment ◽

Consensus Definition ◽

Abiotic Surfaces ◽

Technological Advances ◽

Patients At Risk ◽

Definition Of

Abstract Pseudomonas aeruginosa (PA) in patients with bronchiectasis (BE) is associated with a poor outcome and quality of life, and its presence is considered a marker of disease severity. This opportunistic pathogen is known for its ability to produce biofilms on biotic or abiotic surfaces and to survive environmental stress exerted by antimicrobials, inflammation, and nutrient or oxygen depletion. The presence of PA biofilms has been linked to chronic respiratory infection in cystic fibrosis but not in BE. There is considerable inconsistency in the reported infection/eradication rates of PA and chronic PA. In addition, inadequate antimicrobial treatment may potentiate the progression from intermittent to chronic infection and also the emergence of antibiotic resistance. A better comprehension of the pathophysiology of PA infections and its implications for BE is urgently needed. This can drive improvements in diagnostic accuracy, can move us toward a new consensus definition of chronic infection, can better define the follow-up of patients at risk of PA, and can achieve more successful eradication rates. In addition, the new technological advances regarding molecular diagnostics, -omics, and biomarkers require us to reconsider our traditional concepts.

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Occupational Health Hazards in Sanitary Workers of Chandrapur City, Central India

International Journal of Environment ◽

10.3126/ije.v6i3.18095 ◽

2017 ◽

Vol 6 (3) ◽

pp. 15-24 ◽

Cited By ~ 1

Author(s):

Priyanka V. Patil ◽

R. K. Kamble

Keyword(s):

Occupational Health ◽

Central India ◽

Face Mask ◽

Health Hazards ◽

Occupational Hazards ◽

Hearing Disorder ◽

Potential Health ◽

Potential Health Risk ◽

Respiratory Problems ◽

Exposed Workers

About 198 sanitary workers work in Chandrapur Municipal Corporation, out of which 20 workers (10% of the population) was selected as a sample size (all male workers). The study was carried out from November 2015 to January 2016. Occupational health hazards of these workers were analyzed through questionnaire survey and Peak Expiratory Flow Rate (PEFR) analysis. The results of the study showed that, these workers were exposed to a number of environmental and occupational hazards leading to musculoskeletal disorders (85%), exposure to harmful gases (65%), respiratory problems (45%), headache (40%), dermatological problem (35%), gastrointestinal (10%) and leptospirosis (10%) during work. It was further observed that the workers were suffering from cough and cold (90%), skin problems (50%), allergies (15%), malaria and typhoid (15%), bronchitis lung and asthmatic problems (10%) and hearing disorder (5%) etc. after completion of work. The PEFR values were lower in exposed workers. Reduction in PEFR values was directly proportional with exposure duration. To reduce occupational health hazards, workers must be made alert and aware of potential health risk arising from their work. Reduction in exposure and use of personal protective equipments such as face mask, gloves, gum boots, caps, apron etc. should be encouraged.International Journal of EnvironmentVolume-6, Issue-3, Jun-Aug 2017, page: 15-24

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Involvement of Nitric Oxide in Biofilm Dispersal of Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.00779-06 ◽

2006 ◽

Vol 188 (21) ◽

pp. 7344-7353 ◽

Cited By ~ 482

Author(s):

Nicolas Barraud ◽

Daniel J. Hassett ◽

Sung-Hei Hwang ◽

Scott A. Rice ◽

Staffan Kjelleberg ◽

...

Keyword(s):

Nitric Oxide ◽

Pseudomonas Aeruginosa ◽

Antimicrobial Agents ◽

Nitrosative Stress ◽

Sodium Dodecyl ◽

Anaerobic Respiration ◽

Opportunistic Pathogen ◽

No Donor ◽

Biofilm Dispersal ◽

Novel Strategy

ABSTRACT Bacterial biofilms at times undergo regulated and coordinated dispersal events where sessile biofilm cells convert to free-swimming, planktonic bacteria. In the opportunistic pathogen Pseudomonas aeruginosa, we previously observed that dispersal occurs concurrently with three interrelated processes within mature biofilms: (i) production of oxidative or nitrosative stress-inducing molecules inside biofilm structures, (ii) bacteriophage induction, and (iii) cell lysis. Here we examine whether specific reactive oxygen or nitrogen intermediates play a role in cell dispersal from P. aeruginosa biofilms. We demonstrate the involvement of anaerobic respiration processes in P. aeruginosa biofilm dispersal and show that nitric oxide (NO), used widely as a signaling molecule in biological systems, causes dispersal of P. aeruginosa biofilm bacteria. Dispersal was induced with low, sublethal concentrations (25 to 500 nM) of the NO donor sodium nitroprusside (SNP). Moreover, a P. aeruginosa mutant lacking the only enzyme capable of generating metabolic NO through anaerobic respiration (nitrite reductase, ΔnirS) did not disperse, whereas a NO reductase mutant (ΔnorCB) exhibited greatly enhanced dispersal. Strategies to induce biofilm dispersal are of interest due to their potential to prevent biofilms and biofilm-related infections. We observed that exposure to SNP (500 nM) greatly enhanced the efficacy of antimicrobial compounds (tobramycin, hydrogen peroxide, and sodium dodecyl sulfate) in the removal of established P. aeruginosa biofilms from a glass surface. Combined exposure to both NO and antimicrobial agents may therefore offer a novel strategy to control preestablished, persistent P. aeruginosa biofilms and biofilm-related infections.

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Detection of the Antiseptic Resistance Gene among Pseudomonas aeruginosa Isolates

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.1.7 ◽

2021 ◽

pp. 75-82

Author(s):

اخلاص نعمة

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Susceptibility ◽

Antimicrobial Agents ◽

Opportunistic Pathogen ◽

Susceptibility Test ◽

Diffusion Method ◽

Bacterial Isolates ◽

Disk Diffusion Method ◽

Antibiotic Susceptibility Test ◽

Antibiotics Susceptibility

Pseudomonas aeruginosa is an opportunistic pathogen that causes a number of infections in immunocompromised patients. This organism appears to improve resistance to many antimicrobial agents and a high percentage of clinical isolates of P. aeruginosa exhibit multidrug resistance (MDR) phenotype . The purpose of this study is to screen the antibiotic susceptibility patterns and the prevalence of qacE delta1 gene among bacterial isolates. Accordingly, 145 samples were collected from different clinical sources from patients who admitted to different hospitals in Baghdad city in a period ranged 23/8/2018-1/1/2019. The isolates were diagnosed as P. aeruginosa based on routine bacteriological methods and confirmed by a molecular method using 16SrRNA gene. The antibiotic susceptibility test was performed to all identified isolates by Kirby-Bauer Disk Diffusion method using ten types of antibiotics. The results of antibiotics susceptibility test revealed high levels of resistance toward Piperacillin (72.22%), Trimethoprim (68%), Ceftazidime (68%), Colistin (40.28%), and Levofloxacin (33.33%). And , the minimum inhibitory concentration (MIC) of Cetrimide was tested using different concentrations (2.048 to 0.004µg/100µl) and the results showed that MIC values ranged between 2.048 and 0.016) μg/100μL, and the concentration of 0.256 μg/100μl was more frequent . Finally, the prevalence of qacE delta1 gene among bacterial isolates was detected in percentage 63.88% among bacterial isolates .

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The ability of Pseudomonas aeruginosa to adopt a Small Colony Variant (SCV) phenotype is conserved, and not restricted to clinical isolates

10.1101/2021.02.05.430018 ◽

2021 ◽

Author(s):

Alison Besse ◽

Mylène Trottier ◽

Marie-Christine Groleau ◽

Eric Déziel

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Opportunistic Pathogen ◽

Laboratory Culture ◽

Culture Conditions ◽

Health Concern ◽

Clinical Strain ◽

Adaptation Mechanism ◽

Small Colony Variant ◽

Small Colony

ABSTRACTA subpopulation of Small Colony Variants (SCVs) is a frequently observed feature of Pseudomonas aeruginosa isolated from cystic fibrosis (CF) lungs biofilms. SCVs have almost exclusively been reported from infected hosts, essentially CF individuals or, by extension, from laboratory cultivation of strains originated from infected hosts. We previously reported the identification of P. aeruginosa SCVs emerging from a non-clinical strain and displaying features shared with clinical SCVs. In the present work, we investigated the ability of 22 P. aeruginosa isolates from various environmental origins to, under laboratory culture conditions, spontaneously adopt a SCV-like smaller alternative morphotype distinguishable from the ancestral parent strain. Unexpectedly, we found that all the P. aeruginosa strains tested have the ability to adopt a SCV morphotype, regardless of their origin. Based on the phenotypes already described for SCVs, the SCV-like morphotypes obtained were clustered in two groups displaying various phenotypic profiles, including one characteristic of already described SCVs. We conclude that the ability to switch to a SCV phenotype is a conserved feature in Pseudomonas aeruginosa.IMPORTANCEP. aeruginosa is an opportunistic pathogen that thrives in many environments. It is significant public health concern, notably because it is the most prevalent pathogen found in the lungs of people with cystic fibrosis (CF). In infected hosts, its persistence is believed to be related to the emergence of an alternative small colony variant (SCV) phenotype. By reporting the distribution of P. aeruginosa SCVs in various non-clinical environments, this work contributes to understanding a conserved adaptation mechanism used by P. aeruginosa to rapidly adapt in all environments. Counteraction of this strategy could prevent P. aeruginosa persistent infection in the future.

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Characterization of Pseudomonas aeruginosa Quorum Sensing Inhibitors from the Endophyte Lasiodiplodia venezuelensis and Evaluation of Their Antivirulence Effects by Metabolomics

Microorganisms ◽

10.3390/microorganisms9091807 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1807

Author(s):

Léonie Pellissier ◽

Sara Leoni ◽

Laurence Marcourt ◽

Emerson Ferreira Queiroz ◽

Nicole Lecoultre ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Antimicrobial Agents ◽

Fungal Endophytes ◽

Opportunistic Pathogen ◽

Single Step ◽

Bioactive Natural Products ◽

Quorum Sensing Inhibitors ◽

Wide Range

The opportunistic pathogen Pseudomonas aeruginosa is one of the “critical priority pathogens” due to its multidrug resistance to a wide range of antibiotics. Its ability to invade and damage host tissues is due to the use of quorum sensing (QS) to collectively produce a plethora of virulence factors. Inhibition of QS is an attractive strategy for new antimicrobial agents because it disrupts the initial events of infection without killing the pathogen. Highly diverse microorganisms as endophytes represent an under-explored source of bioactive natural products, offering opportunities for the discovery of novel QS inhibitors (QSI). In the present work, the objective was to explore selective QSIs within a unique collection of fungal endophytes isolated from the tropical palm Astrocaryum sciophilum. The fungi were cultured, extracted, and screened for their antibacterial and specific anti-QS activities against P. aeruginosa. The endophytic strain Lasiodiplodia venezuelensis was prioritized for scaled-up fractionation for its selective activity, leading to the isolation of eight compounds in a single step. Among them, two pyran-derivatives were found to be responsible for the QSI activity, with an effect on some QS-regulated virulence factors. Additional non-targeted metabolomic studies on P. aeruginosa documented their effects on the production of various virulence-related metabolites.

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A Novel Indole Compound That Inhibits Pseudomonas aeruginosa Growth by Targeting MreB Is a Substrate for MexAB-OprM

Journal of Bacteriology ◽

10.1128/jb.00805-07 ◽

2007 ◽

Vol 189 (19) ◽

pp. 6870-6881 ◽

Cited By ~ 25

Author(s):

Gregory T. Robertson ◽

Timothy B. Doyle ◽

Qun Du ◽

Leonard Duncan ◽

Khisimuzi E. Mdluli ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Agents ◽

Opportunistic Pathogen ◽

Binding Pocket ◽

Cross Resistance ◽

Dependent Manner ◽

Intrinsic Resistance ◽

Outer Membrane Channel

ABSTRACT Drug efflux systems contribute to the intrinsic resistance of Pseudomonas aeruginosa to many antibiotics and biocides and hamper research focused on the discovery and development of new antimicrobial agents targeted against this important opportunistic pathogen. Using a P. aeruginosa PAO1 derivative bearing deletions of opmH, encoding an outer membrane channel for efflux substrates, and four efflux pumps belonging to the resistance nodulation/cell division class including mexAB-oprM, we identified a small-molecule indole-class compound (CBR-4830) that is inhibitory to growth of this efflux-compromised strain. Genetic studies established MexAB-OprM as the principal pump for CBR-4830 and revealed MreB, a prokaryotic actin homolog, as the proximal cellular target of CBR-4830. Additional studies establish MreB as an essential protein in P. aeruginosa, and efflux-compromised strains treated with CBR-4830 transition to coccoid shape, consistent with MreB inhibition or depletion. Resistance genetics further suggest that CBR-4830 interacts with the putative ATP-binding pocket in MreB and demonstrate significant cross-resistance with A22, a structurally unrelated compound that has been shown to promote rapid dispersion of MreB filaments in vivo. Interestingly, however, ATP-dependent polymerization of purified recombinant P. aeruginosa MreB is blocked in vitro in a dose-dependent manner by CBR-4830 but not by A22. Neither compound exhibits significant inhibitory activity against mutant forms of MreB protein that bear mutations identified in CBR-4830-resistant strains. Finally, employing the strains and reagents prepared and characterized during the course of these studies, we have begun to investigate the ability of analogues of CBR-4830 to inhibit the growth of both efflux-proficient and efflux-compromised P. aeruginosa through specific inhibition of MreB function.

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Adaptive Resistance to the “Last Hope” Antibiotics Polymyxin B and Colistin in Pseudomonas aeruginosa Is Mediated by the Novel Two-Component Regulatory System ParR-ParS

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00242-10 ◽

2010 ◽

Vol 54 (8) ◽

pp. 3372-3382 ◽

Cited By ~ 181

Author(s):

Lucía Fernández ◽

W. James Gooderham ◽

Manjeet Bains ◽

Joseph B. McPhee ◽

Irith Wiegand ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Lipid A ◽

Antimicrobial Agents ◽

Regulatory System ◽

Opportunistic Pathogen ◽

Polymyxin B ◽

Adaptive Resistance ◽

Two Component ◽

Induce Resistance ◽

Two Component Systems

ABSTRACT As multidrug resistance increases alarmingly, polymyxin B and colistin are increasingly being used in the clinic to treat serious Pseudomonas aeruginosa infections. In this opportunistic pathogen, subinhibitory levels of polymyxins and certain antimicrobial peptides induce resistance toward higher, otherwise lethal, levels of these antimicrobial agents. It is known that the modification of lipid A of lipopolysaccharide (LPS) is a key component of this adaptive peptide resistance, but to date, the regulatory mechanism underlying peptide regulation in P. aeruginosa has remained elusive. The PhoP-PhoQ and PmrA-PmrB two-component systems, which control this modification under low-Mg2+ conditions, do not appear to play a major role in peptide-mediated adaptive resistance, unlike in Salmonella where PhoQ is a peptide sensor. Here we describe the identification and characterization of a novel P. aeruginosa two-component regulator affecting p olymyxin- a daptive r esistance, ParR-ParS (PA1799-PA1798). This system was required for activation of the arnBCADTEF LPS modification operon in the presence of subinhibitory concentrations of polymyxin, colistin, or the bovine peptide indolicidin, leading to increased resistance to various polycationic antibiotics, including aminoglycosides. This study highlights the complexity of the regulatory network controlling resistance to cationic antibiotics and host peptides in P. aeruginosa, which has major relevance in the development and deployment of cationic antimicrobials.

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Pseudomonas aeruginosa in bottled drinking water in Sri Lanka: a potential health hazard

Water Science & Technology Water Supply ◽

10.2166/ws.2014.057 ◽

2014 ◽

Vol 14 (6) ◽

pp. 1045-1050

Author(s):

A. T. Herath ◽

C. L. Abayasekara ◽

Rohana Chandrajith ◽

N. K. B. Adikaram

Keyword(s):

Pseudomonas Aeruginosa ◽

Drinking Water ◽

Sri Lanka ◽

Dna Sequencing ◽

Membrane Filtration ◽

Health Hazard ◽

Opportunistic Pathogen ◽

Bottled Water ◽

Potential Health ◽

Bottled Drinking Water

Pseudomonas aeruginosa, a food- and water-borne opportunistic pathogen, constitutes a health risk mostly to immunocompromised patients, and also affects the taste, odour and turbidity of potable water. In order to detect P. aeruginosa in bottled water in Sri Lanka, 36 bottled water brands were collected randomly from retail and supermarkets island wide. P. aeruginosa was detected by the membrane filtration technique, using cetrimide agar supplemented with nalidixic acid. The isolates were subjected to confirmatory tests, viz: ISO 16266:2006 methods and growth at 4 and 42°C, and API 20NE followed by DNA sequencing. Presumptive isolates of P. aeruginosa were observed on cetrimide agar in 50% of brands. Among these isolates, ISO procedures confirmed 58% as P. aeruginosa. Thirty-nine randomly selected isolates were identified as P. aeruginosa by the API 20NE, three of which were further confirmed by DNA sequencing. The presence of P. aeruginosa in bottled water raises health concerns since P. aeruginosa is an indicator of inferior water quality. Therefore, strict regulations and regular monitoring of bottling plants are recommended in order to supply safe and acceptable bottled drinking water to the Sri Lankan market.

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