Displaying publications 101 - 120 of 366 in total

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  1. Fulltext In vitro activity of aminoglycosides, ureidopenicillins and cephalosporins against P. aeruginosa isolated in Kuala Lumpur
    Ngeow YS, Puthucheary SD, Lai PS
    Med J Malaysia, 1985 Sep;40(3):196-201.
    PMID: 3939567
    170 clinical isolates of Pseudomonas aeruginosa were tested for in vitro susceptibility to gentamicin, amikacin, tobramycin, netilmicin, kanamycin, streptomycin, cefotaxime, ceftriaxone, cefoperazone, ceftazidime, moxalactam, azlocillin, piperacillin and ticarcillin. Against 93 gentamicin-sensitive strains, the most active antibiotics were in descending order, ceftazidime, tobramycin, gentamicin, amikacin, and the ureidopenicillins. Against 77 gentamicin-resistant strains, only ceftazidime, amikacin and moxalactam had mode minimum inhibitory concentrations within achievable peak serum levels after standard therapeutic dosage. There was no correlation between cephalosporin resistance and aminoglycoside resistance except for cefoperazone, which, together with the ureidopenicillins and ticarcillin, showed marked decrease in activity against gentamicin-resistant strains.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/isolation & purification
  2. Multifaceted interactions between the pseudomonads and insects: mechanisms and prospects
    Teoh MC, Furusawa G, Veera Singham G
    Arch Microbiol, 2021 Jul;203(5):1891-1915.
    PMID: 33634321 DOI: 10.1007/s00203-021-02230-9
    Insects and bacteria are the most widespread groups of organisms found in nearly all habitats on earth, establishing diverse interactions that encompass the entire range of possible symbiotic associations from strict parasitism to obligate mutualism. The complexity of their interactions is instrumental in shaping the roles of insects in the environment, meanwhile ensuring the survival and persistence of the associated bacteria. This review aims to provide detailed insight on the multifaceted symbiosis between one of the most versatile bacterial genera, Pseudomonas (Gammaproteobacteria: Pseudomonadaceae) and a diverse group of insect species. The Pseudomonas engages with varied interactions with insects, being either a pathogen or beneficial endosymbiont, as well as using insects as vectors. In addition, this review also provides updates on existing and potential applications of Pseudomonas and their numerous insecticidal metabolites as biocontrol agents against pest insects for the improvement of integrated pest management strategies. Here, we have summarized several known modes of action and the virulence factors of entomopathogenic Pseudomonas strains essential for their pathogenicity against insects. Meanwhile, the beneficial interactions between pseudomonads and insects are currently limited to a few known insect taxa, despite numerous studies reporting identification of pseudomonads in the guts and haemocoel of various insect species. The vector-symbiont association between pseudomonads and insects can be diverse from strict phoresy to a role switch from commensalism to parasitism following a dose-dependent response. Overall, the pseudomonads appeared to have evolved independently to be either exclusively pathogenic or beneficial towards insects.
    Matched MeSH terms: Pseudomonas/metabolism; Pseudomonas/physiology*
  3. Proteomic profiling of clinical and environmental strains of Pseudomonas aeruginosa
    Liew SM, Puthucheary SD, Rajasekaram G, Chai HC, Chua KH
    Mol Biol Rep, 2021 Mar;48(3):2325-2333.
    PMID: 33728559 DOI: 10.1007/s11033-021-06262-8
    Pseudomonas aeruginosa is a ubiquitous bacterium, which is able to change its physiological characteristics in response to different habitats. Environmental strains are presumably less pathogenic than clinical strains and whether or not the clinical strains originate from the environment or through inter-host transmission remains poorly understood. To minimize the risk of infection, a better understanding of proteomic profiling of P. aeruginosa is necessary for elucidating the correlation between environmental and clinical strains. Based on antimicrobial susceptibility and patterns of virulence, we selected 12 clinical and environmental strains: (i) environmental, (ii) multidrug resistant (MDR) clinical and (iii) susceptible clinical strains. Whole-cell protein was extracted from each strain and subjected to two-dimensional differential gel electrophoresis (2-D DIGE) and liquid chromatography tandem mass spectrometry quadrupole time-of-flight (LC-MS QTOF). All 12 strains were clustered into 3 distinct groups based on their variance in protein expression. A total of 526 matched spots were detected and four differentially expressed protein spots (p < 0.05) were identified and all differential spots were downregulated in MDR strain J3. Upregulation of chitin binding and BON domain proteins was present in the environmental and some MDR strains, whereas the clinical strains exhibited distinct proteomic profiles with increased expression of serine protein kinase and arginine/ornithine transport ATP-binding proteins. Significant difference in expression was observed between susceptible clinical and MDR strains, as well as susceptible clinical and environmental strains. Transition from an environmental saprophyte to a clinical strain could alter its physiological characteristics to further increase its adaptation.
    Matched MeSH terms: Pseudomonas aeruginosa/genetics; Pseudomonas aeruginosa/metabolism*
  4. Rhamnolipid produced by Pseudomonas aeruginosa USM-AR2 facilitates crude oil distillation
    Asshifa Md Noh N, Al-Ashraf Abdullah A, Nasir Mohamad Ibrahim M, Ramli Mohd Yahya A
    J Gen Appl Microbiol, 2012;58(2):153-61.
    PMID: 22688247
    A biosurfactant-producing and hydrocarbon-utilizing bacterium, Pseudomonas aeruginosa USM-AR2, was used to assist conventional distillation. Batch cultivation in a bioreactor gave a biomass of 9.4 g L(-1) and rhamnolipid concentration of 2.4 g L(-1) achieved after 72 h. Biosurfactant activity (rhamnolipid) was detected by the orcinol assay, emulsification index and drop collapse test. Pretreatment of crude oil TK-1 and AG-2 with a culture of P. aeruginosa USM-AR2 that contains rhamnolipid was proven to facilitate the distillation process by reducing the duration without reducing the quality of petroleum distillate. It showed a potential in reducing the duration of the distillation process, with at least 2- to 3-fold decreases in distillation time. This is supported by GC-MS analysis of the distillate where there was no difference between compounds detected in distillate obtained from treated or untreated crude oil. Calorimetric tests showed the calorie value of the distillate remained the same with or without treatment. These two factors confirmed that the quality of the distillate was not compromised and the incubation process by the microbial culture did not over-degrade the oil. The rhamnolipid produced by this culture was the main factor that enhanced the distillation performance, which is related to the emulsification of hydrocarbon chains in the crude oil. This biotreatment may play an important role to improve the existing conventional refinery and distillation process. Reducing the distillation times by pretreating the crude oil with a natural biosynthetic product translates to energy and cost savings in producing petroleum products.
    Matched MeSH terms: Pseudomonas aeruginosa/growth & development; Pseudomonas aeruginosa/metabolism*
  5. Fulltext Cloning and Characterisation of (R)-3-hydroxyacyl-acyl Carrier Protein-coenzyme A Transferase Gene (phaG) from Pseudomonas sp. USM 4-55
    Arsad H, Sudesh K, Nazalan N, Muhammad TS, Wahab H, Razip Samian M
    Trop Life Sci Res, 2009 Dec;20(2):1-14.
    PMID: 24575175 MyJurnal
    The (R)-3-hydroxyacyl-ACP-CoA transferase catalyses the conversion of (R)-3-hydroxyacyl-ACP to (R)-3-hydroxyacyl-CoA derivatives, which serves as the ultimate precursor for polyhydroxyalkanoate (PHA) polymerisation from unrelated substrates in pseudomonads. PhaG was found to be responsible for channelling precursors for polyhydroxyalkanoate (PHA) synthase from a de novo fatty acid biosynthesis pathway when cultured on carbohydrates, such as glucose or gluconate. The phaG gene was cloned from Pseudomonas sp. USM 4-55 using a homologous probe. The gene was located in a 3660 bp Sal I fragment (GenBank accession number EU305558). The open reading frame (ORF) was 885 bp long and encoded a 295 amino acid protein. The predicted molecular weight was 33251 Da, and it showed a 62% identity to the PhaG of Pseudomonas aeruginosa. The function of the cloned phaG of Pseudomonas sp. USM 4-55 was confirmed by complementation studies. Plasmid pBCS39, which harboured the 3660 bp Sal I fragment, was found to complement the PhaG-mutant heterologous host cell, Pseudomonas putida PhaGN-21. P. putida PhaGN-21, which harboured pBCS39, accumulated PHA that accounted for up to 18% of its cellular dry weight (CDW). P. putida PhaGN-21, which harboured the vector alone (PBBR1MCS-2), accumulated only 0.6% CDW of PHA.
    Matched MeSH terms: Pseudomonas; Pseudomonas aeruginosa; Pseudomonas putida
  6. First characterization of bla(VIM-11) cassette-containing integron in metallo-beta-lactamase producing Pseudomonas aeruginosa in Malaysia
    Khosravi Y, Tay ST, Vadivelu J
    Eur Rev Med Pharmacol Sci, 2010 Nov;14(11):999-1000.
    PMID: 21284350
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/genetics*
  7. Fulltext Biosynthesis of Phenolic Compounds of Medicago truncatula After Inoculation with Selected PGPR Strains
    Kisiel A, Miller T, Łobodzińska A, Rybak K
    Int J Mol Sci, 2024 Nov 26;25(23).
    PMID: 39684404 DOI: 10.3390/ijms252312684
    The phenylpropanoid biosynthesis pathway is involved in the response of plants to stress factors, including microorganisms. This paper presents how free-living strains of rhizobacteria Pseudomonas brassicacearum KK5, P. corrugata KK7, Paenibacillus borealis KK4, and the symbiotic strain Sinorhizobium meliloti KK13 affect the expression of genes encoding phenylalanine ammonia-lyase (PAL), the activity of this enzyme, and the production of phenolic compounds in Medicago truncatula. Seedlings were inoculated with rhizobacteria, then at T0, T24, T72, and T168 after inoculation, the leaves and roots were analyzed for gene expression, enzyme activity, and the content of phenolic compounds. All bacteria affected PAL gene expression, in particular, MtPAL2, MtPAL3, and MtPAL4. Pseudomonas strains had the greatest impact on gene expression. The inoculation affected PAL activity causing it to increase or decrease. The most stimulating effect on enzyme activity was observed 168 h after inoculation. A varied effect was also observed in the case of the content of phenolic compounds. The greatest changes were observed 24 h after inoculation, especially with the KK7 strain. The influence of the studied rhizobacteria on the biosynthesis of phenolic compounds at the molecular level (expression of MtPAL genes) and biochemical level (PAL activity and content of phenolic compounds) was confirmed. The MtPAL3 gene underwent the most significant changes after inoculation and can be used as a marker to assess the interaction between M. truncatula and rhizobacteria. The Pseudomonas strains had the greatest influence on the biosynthesis pathway of phenolic compounds.
    Matched MeSH terms: Pseudomonas/genetics; Pseudomonas/metabolism
  8. Fulltext Polyhydroxyalkanoate production by antarctic soil bacteria isolated from Casey Station and Signy Island
    Goh YS, Tan IK
    Microbiol Res, 2012 Apr 20;167(4):211-9.
    PMID: 21945102 DOI: 10.1016/j.micres.2011.08.002
    Polyhydroxyalkanoate (PHA) is a family of biopolymers produced by some bacteria and is accumulated intracellularly as carbon and energy storage material. Fifteen PHA-producing bacterial strains were identified from bacteria isolated from Antarctic soils collected around Casey Station (66°17'S, 110°32'E) and Signy Island (60°45'S, 45°36'W). Screening for PHA production was carried out by incubating the isolates in PHA production medium supplemented with 0.5% (w/v) sodium octanoate or glucose. 16S rRNA gene sequence analysis revealed that the isolated PHA-producing strains were mainly Pseudomonas spp. and a few were Janthinobacterium spp. All the isolated Pseudomonas strains were able to produce medium-chain-length (mcl) PHA using fatty acids as carbon source, while some could also produce mcl-PHA by using glucose. The Janthinobacterium strains could only utilize glucose to produce polyhydroxybutyrate (PHB). A Pseudomonas isolate, UMAB-40, accumulated PHA up to 48% cell dry mass when utilizing fatty acids as carbon source. This high accumulation occurred at between 5°C and 20°C, then decreased with increasing temperatures. Highly unsaturated mcl-PHA was produced by UMAB-40 from glucose. Such characteristics may be associated with the ability of UMAB-40 to survive in the cold.
    Matched MeSH terms: Pseudomonas/classification; Pseudomonas/genetics; Pseudomonas/isolation & purification*; Pseudomonas/metabolism*
  9. In vitro antimicrobial activity against Pseudomonas aeruginosa and acute oral toxicity of marine algae Gracilaria changii
    Sasidharan S, Darah I, Noordin MK
    N Biotechnol, 2010 Sep 30;27(4):390-6.
    PMID: 20170762 DOI: 10.1016/j.nbt.2010.02.002
    Methanol extract of the Gracilaria changii has been screened for antimicrobial activity against Pseudomonas aeruginosa. Antimicrobial activities were carried out using disc diffusion assay and broth dilution method against P. aeruginosa. The methanol extract of G. changii showed a good antimicrobial activity against P. aeruginosa with MIC (Minimum Inhibitory Concentration) value of 6.25mg/ml. Exposure of P. aeruginosa cells to 6.25mg/ml of methanol extract of G. changii resulted in complete inhibition of the bacterial cells. The main abnormalities noted via SEM and TEM studies were the alterations in morphology and cytology of the bacterial cells. The main reason for this deterioration was discussed. The effect of the methanol extract on the growth profile for the bacteria was also done and confirmed the bactericidal effect of the G. changii methanol extract on P. aeruginosa by changing the normal growth profile of P. aeruginosa. In an acute toxicity study using mice, the median lethal dose (LD(50)) of the extract was greater than 2000 mg/kg, and we found no pathological changes in macroscopic examination by necropsy of mice treated with extract. We conclude that G. changii might be safely used as an antimicrobial agent.
    Matched MeSH terms: Pseudomonas aeruginosa/cytology; Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/growth & development; Pseudomonas aeruginosa/ultrastructure
  10. Fulltext Pseudomonas laryngeal perichondritis: unexpected diagnosis
    Zainal Abidin SS, Kew TY, Azman M, Mat Baki M
    BMJ Case Rep, 2020 Dec 22;13(12).
    PMID: 33370978 DOI: 10.1136/bcr-2020-237129
    A 57-year-old male chronic smoker with underlying diabetes mellitus presented with dysphonia associated with cough, dysphagia and reduced effort tolerance of 3 months' duration. Videoendoscope finding revealed bilateral polypoidal and erythematous true and false vocal fold with small glottic airway. The patient was initially treated as having tuberculous laryngitis and started on antituberculous drug. However, no improvement was observed. CT of the neck showed erosion of thyroid cartilage, which points to laryngeal carcinoma as a differential diagnosis. However, the erosion was more diffuse and appeared systemic in origin. The diagnosis of laryngeal perichondritis was made when the histopathological examination revealed features of inflammation, and the tracheal aspirate isolated Pseudomonas aeruginosa The patient made a good recovery following treatment with oral ciprofloxacin.
    Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification*; Pseudomonas Infections/complications; Pseudomonas Infections/diagnosis*; Pseudomonas Infections/drug therapy; Pseudomonas Infections/microbiology
  11. Assessment of polymerase chain reaction in the detection of pseudomonas aeruginosa in contact lens-induced severe infectious keratitis
    Subrayan V, Peyman M, Lek Yap S, Mohamed Ali NA, Devi S
    Eye Contact Lens, 2010 Jul;36(4):201-3.
    PMID: 20531205 DOI: 10.1097/ICL.0b013e3181e3efa3
    PURPOSE: The aim of this study is to evaluate the role of real-time polymerase chain reaction (PCR) and conventional bacterial culture methods in the detection of Pseudomonas aeruginosa in contact lens-induced severe, partially treated corneal ulcers referred to a tertiary center.
    METHODS: The study duration was 6 months. All patients with contact lens-related corneal ulcer, requiring admission during the study period were recruited. Samples from corneal scrapings were simultaneously sent at the time of admission for PCR and culture testing. An in-house real-time PCR was developed to detect the P. aeruginosa lasA gene. The results of PCR and culture were compared using McNemar's chi2 test.
    RESULTS: Ten patients were recruited. The mean age was 33 years (20-45 years). All the patients had contact lens-related keratitis (>4 mm) of which eight (80%) were found positive for P. aeruginosa by PCR or culture. There was no significant difference between PCR and culture in detecting P. aeruginosa (P<0.05).
    CONCLUSIONS: PCR is, at least, as good as conventional cultures in detecting P. aeruginosa. It is a rapid assay as compared with culture, and early detection enables prompt treatment thus reducing the destructive effect of the organism on the cornea.
    Matched MeSH terms: Pseudomonas aeruginosa/genetics*; Pseudomonas aeruginosa/isolation & purification; Pseudomonas Infections/diagnosis*; Pseudomonas Infections/drug therapy; Pseudomonas Infections/microbiology
  12. Sweetening Inhaled Antibiotic Treatment for Eradication of Chronic Respiratory Biofilm Infection
    Loo CY, Lee WH, Lauretani G, Scalia S, Cipolla D, Traini D, et al.
    Pharm Res, 2018 Feb 07;35(3):50.
    PMID: 29417313 DOI: 10.1007/s11095-018-2350-4
    PURPOSE: The failure of chronic therapy with antibiotics to clear persistent respiratory infection is the key morbidity and mortality factor for patients with chronic lung diseases, primarily due to the presence of biofilm in the lungs. It is hypothesised that carbon sources, such as mannitol, could stimulate the metabolic activity of persister cells within biofilms and restore their susceptibility to antibiotics. The aims of the current study are to: (1) establish a representative in vitro model of Pseudomonas aeruginosa biofilm lung infection, and (2) investigate the effects of nebulised mannitol on antibiotic efficacy, focusing on ciprofloxacin, in the eradication of biofilm.

    METHOD: Air interface biofilm was cultured onto Snapwell inserts incorporated into a modified pharmacopeia deposition apparatus, the Anderson Cascade Impactor (ACI). Three different formulations including mannitol only, ciprofloxacin only and combined ciprofloxacin and mannitol were nebulised onto the P. aeruginosa biofilm using the modified ACI. Antibacterial effectiveness was evaluated using colony-forming units counts, biofilm penetration and scanning electron microscopy.

    RESULTS: Nebulised mannitol promotes the dispersion of bacteria from the biofilm and demonstrated a synergistic enhancement of the antibacterial efficacy of ciprofloxacin compared to delivery of antibiotic alone.

    CONCLUSIONS: The combination of ciprofloxacin and mannitol may provide an important new strategy to improve antibiotic therapy for the treatment of chronic lung infections. Furthermore, the development of a representative lung model of bacterial biofilm could potentially be used as a platform for future new antimicrobial pre-clinical screening.

    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/physiology; Pseudomonas Infections/drug therapy*; Pseudomonas Infections/microbiology
  13. New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia
    Kor SB, Choo QC, Chew CH
    J Med Microbiol, 2013 Mar;62(Pt 3):412-420.
    PMID: 23180481 DOI: 10.1099/jmm.0.053645-0
    This study investigated 147 multidrug-resistant Enterobacteriaceae and Pseudomonas aeruginosa isolates from hospitalized patients in Malaysia. Class 1 integrons were the most dominant class identified (45.6%). Three isolates were shown to contain class 2 integrons (2.0%), whilst one isolate harboured both class 1 and 2 integrons. No class 3 integrons were detected in this study. In addition, the sul1 gene was amplified in 35% of isolates and was significantly associated with the presence of integrase genes in an integron structure. RFLP and DNA sequencing analyses revealed the presence of 19 different cassette arrays among the detected integrons. The most common gene cassettes were those encoding resistance towards aminoglycosides (aad) and trimethoprim (dfr). As far as is known, this study is the first to identify integron-carrying cassette arrays such as aadA2-linF, aacC3-cmlA5 and aacA4-catB8-aadA1 in the Malaysian population. Patients' age was demonstrated as a significant risk factor for the acquisition of integrons (P=0.028). Epidemiological typing using PFGE also demonstrated a clonal relationship among isolates carrying identical gene cassettes in Klebsiella pneumoniae and P. aeruginosa but not in Escherichia coli isolates.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/genetics; Pseudomonas Infections/microbiology*; Pseudomonas Infections/epidemiology
  14. Fulltext Association of some Campylobacter jejuni with Pseudomonas aeruginosa biofilms increases attachment under conditions mimicking those in the environment
    Teh AHT, Lee SM, Dykes GA
    PLoS One, 2019;14(4):e0215275.
    PMID: 30970009 DOI: 10.1371/journal.pone.0215275
    Campylobacter jejuni is a microaerophilic bacterial species which is a major food-borne pathogen worldwide. Attachment and biofilm formation have been suggested to contribute to the survival of this fastidious bacteria in the environment. In this study the attachment of three C. jejuni strains (C. jejuni strains 2868 and 2871 isolated from poultry and ATCC 33291) to different abiotic surfaces (stainless steel, glass and polystyrene) alone or with Pseudomonas aeruginosa biofilms on them, in air at 25°C and under static or flow conditions, were investigated using a modified Robbins Device. Bacteria were enumerated and scanning electron microscopy was carried out. The results indicated that both C. jejuni strains isolated from poultry attached better to Pseudomonas aeruginosa biofilms on abiotic surfaces than to the surfaces alone under the different conditions tested. This suggests that biofilms of other bacterial species may passively protect C. jejuni against shear forces and potentially oxygen stress which then contribute to their persistence in environments which are detrimental to them. By contrast the C. jejuni ATCC 33291 strain did not attach differentially to P. aeruginosa biofilms, suggesting that different C. jejuni strains may have alternative strategies for persistence in the environment. This study supports the hypothesis that C. jejuni do not form biofilms per se under conditions they encounter in the environment but simply attach to surfaces or biofilms of other species.
    Matched MeSH terms: Pseudomonas aeruginosa/physiology*; Pseudomonas aeruginosa/ultrastructure
  15. Fulltext New Recombinant Cold-Adapted and Organic Solvent Tolerant Lipase from Psychrophilic Pseudomonas sp. LSK25, Isolated from Signy Island Antarctica
    Salwoom L, Raja Abd Rahman RNZ, Salleh AB, Mohd Shariff F, Convey P, Mohamad Ali MS
    Int J Mol Sci, 2019 Mar 13;20(6).
    PMID: 30871178 DOI: 10.3390/ijms20061264
    In recent years, studies on psychrophilic lipases have become an emerging area of research in the field of enzymology. The study described here focuses on the cold-adapted organic solvent tolerant lipase strain Pseudomonas sp. LSK25 isolated from Signy Station, South Orkney Islands, maritime Antarctic. Strain LSK25 lipase was successfully cloned, sequenced, and over-expressed in an Escherichia coli system. Sequence analysis revealed that the lipase gene of Pseudomonas sp. LSK25 consists of 1432 bp, lacks an N-terminal signal peptide and encodes a mature protein consisting of 476 amino acids. The recombinant LSK25 lipase was purified by single-step purification using Ni-Sepharose affinity chromatography and had a molecular mass of approximately 65 kDa. The final recovery and purification fold were 44% and 1.3, respectively. The LSK25 lipase was optimally active at 30 °C and at pH 6. Stable lipolytic activity was reported between temperatures of 5⁻30 °C and at pH 6⁻8. A significant enhancement of lipolytic activity was observed in the presence of Ca2+ ions, the organic lipids of rice bran oil and coconut oil, a synthetic C12 ester and a wide range of water immiscible organic solvents. Overall, lipase strain LSK25 is a potentially desirable candidate for biotechnological application, due to its stability at low temperatures, across a range of pH and in organic solvents.
    Matched MeSH terms: Pseudomonas/genetics; Pseudomonas/metabolism*
  16. Betacyanin-inhibited biofilm formation of co-culture of Staphylococcus aureus and Pseudomonas aeruginosa on different polymer surfaces
    Yong YY, Ong MWK, Dykes G, Choo WS
    FEMS Microbiol Lett, 2021 01 26;368(1).
    PMID: 33338235 DOI: 10.1093/femsle/fnaa214
    Staphylococcus aureus and Pseudomonas aeruginosa are bacteria that cause biofilm-associated infections. The aim of this study was to determine the activity of combined betacyanin fractions from Amaranthus dubius (red spinach) and Hylocereus polyrhizus (red pitahaya) against biofilms formed by co-culture of S. aureus and P. aeruginosa on different polymer surfaces. Various formulations containing different concentrations of the betacyanin fractions were investigated for biofilm-inhibiting activity on polystyrene surfaces using crystal violet assay and scanning electron microscopy. A combination of each betacyanin fraction (0.625 mg mL-1) reduced biofilm formation of five S. aureus strains and four P. aeruginosa strains from optical density values of 1.24-3.84 and 1.25-3.52 to 0.81-2.63 and 0.80-1.71, respectively. These combined fractions also significantly inhibited dual-species biofilms by 2.30 and reduced 1.0-1.3 log CFU cm-2 bacterial attachment on polymer surfaces such as polyvinyl chloride, polyethylene, polypropylene and silicone rubber. This study demonstrated an increase in biofilm-inhibiting activity against biofilms formed by two species using combined fractions than that by using single fractions. Betacyanins found in different plants could collectively be used to potentially decrease the risk of biofilm-associated infections caused by these bacteria on hydrophobic polymers.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/physiology
  17. Fulltext Use of gallium-67 in the assessment of response to antibiotic therapy in malignant otitis externa--a case report
    Paramsothy M, Khanijow V, Ong TO
    Singapore Med J, 1997 Aug;38(8):347-9.
    PMID: 9364890
    Malignant Otitis Externa (MOE) can cause considerable morbidity and mortality in affected individuals. The outlook is now much improved with the use of ciprofloxacin, but it is important to ascertain that the infection has been completely eradicated before stopping treatment, as undertreatment may lead to a recurrence which is usually more resistant than the initial infection. Gallium-67 Single Photon Emmision Computerised Tomography (SPECT) is a sensitive and cost effective tool in monitoring the disease activity of MOE, and should be used in the assessment of the response to antibiotic therapy.
    Matched MeSH terms: Pseudomonas Infections/drug therapy*; Pseudomonas Infections/radionuclide imaging*
  18. Carbapenem-resistant Pseudomonas aeruginosa in malaysia producing IMP-7 beta-lactamase
    Ho SE, Subramaniam G, Palasubramaniam S, Navaratnam P
    Antimicrob Agents Chemother, 2002 Oct;46(10):3286-7.
    PMID: 12234862
    We have isolated and identified a carbapenem-resistant Pseudomonas aeruginosa strain from Malaysia that produces an IMP-7 metallo-beta-lactamase. This isolate showed high-level resistance to meropenem and imipenem, the MICs of which were 256 and 128 micro g/ml, respectively. Isoelectric focusing analyses revealed pI values of >9.0, 8.2, and 7.8, which indicated the possible presence of IMP and OXA. DNA sequencing confirmed the identity of the IMP-7 determinant.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/enzymology*
  19. Heterologous Expression of PA8FAD9 and Functional Characterization of a Δ9-Fatty Acid Desaturase from a Cold-Tolerant Pseudomonas sp. A8
    Garba L, Ali MS, Oslan SN, Rahman RN
    Mol Biotechnol, 2016 Nov;58(11):718-728.
    PMID: 27629791
    Fatty acid desaturase enzymes are capable of inserting double bonds between carbon atoms of saturated fatty acyl-chains to produce unsaturated fatty acids. A gene coding for a putative Δ9-fatty acid desaturase-like protein was isolated from a cold-tolerant Pseudomonas sp. A8, cloned and heterologously expressed in Escherichia coli. The gene named as PA8FAD9 has an open reading frame of 1185 bp and codes for 394 amino acids with a predicted molecular weight of 45 kDa. The enzyme showed high Δ9-fatty acid desaturase-like protein activity and increased overall levels of cellular unsaturated fatty acids in the recombinant E. coli cells upon expression at different temperatures. The results showed that the ratio of palmitoleic to palmitic acid in the recombinant E. coli cells increased by more than twice the amount observed in the control cells at 20 °C using 0.4 mM IPTG. GCMS analysis confirmed the ability of this enzyme to convert exogenous stearic acid to oleic acid incorporated into the recombinant E. coli membrane phospholipids. It may be concluded that the PA8FAD9 gene from Pseudomonas sp. A8 codes for a putative Δ9-fatty acid desaturase protein actively expressed in E. coli under the influence of temperature and an inducer.
    Matched MeSH terms: Pseudomonas/enzymology*; Pseudomonas/genetics
  20. The patterns and transmissibility of antibiotic resistance among clinical strains of Pseudomonas aeruginosa
    Palillo ES, Salleh MA
    Microbiol. Immunol., 1992;36(11):1195-200.
    PMID: 1491621
    Four hundred and ninety-eight predominantly pyocin-type 10 clinical strains of Pseudomonas aeruginosa were analyzed for resistance to carbenicillin, cefoperazone, cefotaxime, ceftazidime, gentamicin, amikacin and netilmicin. Based on NCCLS-recommended MIC breakpoints, 245 strains were found to be resistant, of which 41.6% were resistant to carbenicillin, 38% to gentamicin, 37.8% to netilmicin, 26.3% to cefoperazone, 17.9% to cefotaxime, 0.6% to amikacin and none to ceftazidime. Quadruple resistance to carbenicillin, cefoperazone, gentamicin and netilmicin was the most frequent pattern observed. Resistance to older antibiotics (kanamycin, streptomycin and tetracycline) and to mercuric chloride were also common. Conjugation experiments suggested that self-transmissible and non-transmissible plasmids occurred in at least 66 strains.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/genetics
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