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Fulltext Clinical and Antibacterial Effects of Tualang Honey on Pseudomonas-induced Keratitis in Rabbit Eyes

Punitan R, Sulaiman SA, Hasan HB, Shatriah I

Cureus, 2019 Mar 27;11(3):e4332.
PMID: 31186997 DOI: 10.7759/cureus.4332

Introduction Pseudomonas aeruginosa is a common cause of microbial keratitis that can cause a significant loss of visual acuity. Antibiotics, including fluoroquinolones and aminoglycosides, are clinically effective against Pseudomonas-induced keratitis, but their effectiveness has been conspicuously reduced as resistant pathogens have become more potent. This study sought to evaluate the clinical and antibacterial effects of tualang honey as an alternative therapeutic agent against Pseudomonas-induced keratitis. Methods We conducted a randomized control trial in which 30 rabbits were injected intrastromally with 1,000 colony-forming units (CFU) of Pseudomonas aeruginosa in the right eye of each rabbit (n = 30). The rabbits were then randomized into three groups of 10 rabbits each. Group A was treated with topical gentamicin 0.3%, group B was treated with topical tualang honey 30%, and group C received both treatments. The specified treatments were administered every two hours from 24 to 48 hours post injection, and subsequently every four hours for six days. Clinical examinations were performed on days one, two, three, five, and seven, and the mean results of slit lamp examinations (SLEs) were documented. On day seven after pseudomonas induction, the rabbits were euthanized and their corneas were harvested to determine the median CFU per cornea. Results There were no statistically significant differences (p > 0.05) in mean SLE scores (p = 0.209) or median CFU values (p = 0.820) between the three groups. Conclusion Topical gentamicin, topical tualang honey, and the combination of the two all showed similar clinical and antimicrobial effects in treating Pseudomonas-induced keratitis in rabbits. These findings should be verified in further studies with larger sample sizes and the addition of a control group.

Matched MeSH terms: Pseudomonas; Pseudomonas aeruginosa
Fulltext The role of hospital environment in transmissions of multidrug-resistant gram-negative organisms

Chia PY, Sengupta S, Kukreja A, S L Ponnampalavanar S, Ng OT, Marimuthu K

Antimicrob Resist Infect Control, 2020 02 11;9(1):29.
PMID: 32046775 DOI: 10.1186/s13756-020-0685-1

Infections by multidrug-resistant (MDR) Gram-negative organisms (GN) are associated with a high mortality rate and present an increasing challenge to the healthcare system worldwide. In recent years, increasing evidence supports the association between the healthcare environment and transmission of MDRGN to patients and healthcare workers. To better understand the role of the environment in transmission and acquisition of MDRGN, we conducted a utilitarian review based on literature published from 2014 until 2019.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects
Fulltext Diagnostic performance of an in-house multiplex PCR assay and the retrospective surveillance of bacterial respiratory pathogens at a teaching hospital, Kelantan, Malaysia

Nik Zuraina NMN, Mohamad S, Hasan H, Goni MD, Suraiya S

Pathog Glob Health, 2023 Feb;117(1):63-75.
PMID: 35331083 DOI: 10.1080/20477724.2022.2028378

Respiratory tract infections (RTIs), including pneumonia and pulmonary tuberculosis, are among the leading causes of death worldwide. The use of accurate diagnostic tests is crucial to initiate proper treatment and therapy to reduce the mortality rates for RTIs. A PCR assay for simultaneous detection of six respiratory bacteria: Haemophilus influenzae, Klebsiella pneumoniae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae, was developed in our lab. The current study aimed to evaluate the performance of this assay along with the retrospective surveillance of respiratory pathogens at a teaching hospital in Kelantan, Malaysia. Leftover sputa (n = 200) from clinical laboratories were collected and undergone DNA template preparation for PCR analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the PCR assay were determined in comparison with the gold standard sputum culture. Overall, the accuracy performance of this assay was 94.67% (95% CI: 90.87% to 97.21%) with sensitivity, specificity, PPV and NPV of 100%, 91.67%, 87.1% and 100%, respectively. Based on the organisms detected from sputa, K. pneumoniae ranked as the top isolate (n = 48), followed by P. aeruginosa (n = 13) and H. influenzae (n = 10). Surveillance among the patients showed that the associations of bacterial positive with gender and means of acquisition were found significant (p values = 0.049 and 0.001, respectively). Besides the promising performance of this ready-to-use molecular-based assay for the rapid detection of selected bacteria pathogens, this study also highlighted significant spread of K. pneumoniae RTIs in the community.

Matched MeSH terms: Pseudomonas aeruginosa/genetics
Fulltext Rapid determination of kappa-carrageenan using a biosensor from immobilized Pseudomonas carrageenovora cells

Hassan RA, Heng LY, Ahmad A, Tan LL

PLoS One, 2019;14(4):e0214580.
PMID: 30990847 DOI: 10.1371/journal.pone.0214580

A potentiometric whole cell biosensor based on immobilized marine bacterium, Pseudomonas carrageenovora producing κ-carrageenase and glycosulfatase enzymes for specific and direct determination of κ-carrageenan, is described. The bacterial cells were immobilized on the self-plasticized hydrogen ion (H+)-selective acrylic membrane electrode surface to form a catalytic layer. Hydrogen ionophore I was incorporated in the poly(n-butyl acrylate) [poly(nBA)] as a pH ionophore. Catalytic decomposition of κ-carrageenan by the bienzymatic cascade reaction produced neoagarobiose, an inorganic sulfate ion and a proton. The latter was detectable by H+ ion transducer for indirect potentiometric quantification of κ-carrageenan concentration. The use of a disposable screen-printed Ag/AgCl electrode (SPE) provided no cleaning requirement and enabled κ-carrageenan detection to be carried out conveniently without cross contamination in a complex food sample. The SPE-based microbial biosensor response was found to be reproducible with high reproducibility and relative standard deviation (RSD) at 2.6% (n = 3). The whole cell biosensor demonstrated a broad dynamic linear response range to κ-carrageenan from 0.2-100 ppm in 20 mM phosphate buffer saline (PBS) at pH 7.5 with a detection limit at 0.05 ppm and a Nernstian sensitivity of 58.78±0.87 mV/decade (R2 = 0.995). The biosensor showed excellent selectivity towards κ-carrageenan compared to other types of carrageenans tested e.g. ι-carrageenan and λ-carrageenan. No pretreatment to the food sample was necessary when the developed whole cell biosensor was employed for direct assay of κ-carrageenan in dairy product.

Matched MeSH terms: Pseudomonas/metabolism*
A comparison between ice and salt storages on bacteriological quality of Asian seabass (Lates calcarifer)

Rahman MM, Nasrun M, Hossain MY, Aa'zamuddin M

Pak J Biol Sci, 2012 Jun 15;15(12):583-8.
PMID: 24191620

The study compares the bacteriological quality on Asian seabass (Lates calcarifer) between ice and salt storage methods. The main objectives of the study were to identify different bacteria constituents and quantitative bacterial load in Asian seabass when preserved with ice and sea salt. For the purpose of this study, Asian seabass was stored in two different conditions of ice-chilled and salted for 2 days. All fish samples were analyzed by performing bacteriological analysis and the isolated bacteria were identified by using API identification system. In case of the quantity of bacteria in the flesh, Chilling and salting had no significant difference to the quantity of bacteria on fish flesh. As for the skin, salt-preserved fish showed higher quantity of bacteria than ice-preserved fish. Acinetobacter baumannii and Pseudomonas fluorescens had been identified from skin sample of ice-chilled fish. Besides P. fluorescens and A. baumannii other isolates identified include Vibrio and Myxobacteria. All bacteria were cocci-shaped except a few bacilli. In term of bacteria number and morphological characteristics, ice-chilled preserved fish was better than salt preserved fish. Overall, less number of bacteria was observed in both ice-chilled and sea salt preserved fish. The result of this study indicated that the quick preservation is a very important factor to control bacterial load in the preserved fish.

Matched MeSH terms: Pseudomonas fluorescens/isolation & purification
Fulltext Molecular Cloning and Functional Expression of a Δ9- Fatty Acid Desaturase from an Antarctic Pseudomonas sp. A3

Garba L, Mohamad Ali MS, Oslan SN, Rahman RN

PLoS One, 2016;11(8):e0160681.
PMID: 27494717 DOI: 10.1371/journal.pone.0160681

Fatty acid desaturase enzymes play an essential role in the synthesis of unsaturated fatty acids. Pseudomonas sp. A3 was found to produce a large amount of palmitoleic and oleic acids after incubation at low temperatures. Using polymerase Chain Reaction (PCR), a novel Δ9- fatty acid desaturase gene was isolated, cloned, and successfully expressed in Escherichia coli. The gene was designated as PA3FAD9 and has an open reading frame of 1,185 bp which codes for 394 amino acids with a predicted molecular weight of 45 kDa. The activity of the gene product was confirmed via GCMS, which showed a functional putative Δ9-fatty acid desaturase capable of increasing the total amount of cellular unsaturated fatty acids of the E. coli cells expressing the gene. The results demonstrate that the cellular palmitoleic acids have increased two-fold upon expression at 15°C using only 0.1 mM IPTG. Therefore, PA3FAD9 from Pseudomonas sp.A3 codes for a Δ9-fatty acid desaturase-like protein which was actively expressed in E. coli.

Matched MeSH terms: Pseudomonas/enzymology*
Sequence analysis and structure prediction of type II Pseudomonas sp. USM 4-55 PHA synthase and an insight into its catalytic mechanism

Wahab HA, Ahmad Khairudin NB, Samian MR, Najimudin N

BMC Struct Biol, 2006;6:23.
PMID: 17076907

Polyhydroxyalkanoates (PHA), are biodegradable polyesters derived from many microorganisms such as the pseudomonads. These polyesters are in great demand especially in the packaging industries, the medical line as well as the paint industries. The enzyme responsible in catalyzing the formation of PHA is PHA synthase. Due to the limited structural information, its functional properties including catalysis are lacking. Therefore, this study seeks to investigate the structural properties as well as its catalytic mechanism by predicting the three-dimensional (3D) model of the Type II Pseudomonas sp. USM 4-55 PHA synthase 1 (PhaC1P.sp USM 4-55).

Matched MeSH terms: Pseudomonas/enzymology*
S5 Lipase: an organic solvent tolerant enzyme

Rahman RN, Baharum SN, Salleh AB, Basri M

J Microbiol, 2006 Dec;44(6):583-90.
PMID: 17205035

In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of production were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions (Mg2+) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, Na+, was found to stimulate the production of S5 lipase.

Matched MeSH terms: Pseudomonas/classification; Pseudomonas/enzymology*; Pseudomonas/genetics; Pseudomonas/growth & development
Pseudomonas aeruginosa eradication therapy and risk of acquiring Aspergillus in young children with cystic fibrosis

Harun SN, Holford NHG, Grimwood K, Wainwright CE, Hennig S, Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) study group

Thorax, 2019 08;74(8):740-748.
PMID: 31203197 DOI: 10.1136/thoraxjnl-2018-211548

BACKGROUND: While Aspergillus detection rates in adults, adolescents and older children with cystic fibrosis (CF) have increased, the risk of acquiring this fungal pathogen in young children is unknown.
AIM: To determine the risk and explanatory factors of acquiring Aspergillus in children with CF by age 5 years.
METHODS: Cross-sectional analysis of clinical, bronchoalveolar lavage and treatment data from the Australasian Cystic Fibrosis Bronchoalveolar Lavage study was used to identify predictive factors for detecting Aspergillus at age 5 years. A parametric repeated time-to-event model quantitatively described the risk and factors associated with acquiring Aspergillus and Pseudomonas aeruginosa from birth until age 5 years.
RESULTS: Cross-sectional analysis found that the number of P. aeruginosa eradication courses increased the odds of detecting Aspergillus at age 5 years (OR 1.61, 95% CI 1.23 to 2.12). The median (IQR) age for the first P. aeruginosa positive culture was 2.38 (1.32-3.79) years and 3.69 (1.68-4.74) years for the first Aspergillus positive culture. The risk of P. aeruginosa and Aspergillus events changes with time after the first year of study entry. It also decreases for P. aeruginosa after completing P. aeruginosa eradication (HR 0.15, 95% CI 0.00 to 0.79), but increases for Aspergillus events (HR 2.75, 95% CI 1.45 to 5.41). The risk of acquiring both types of events increases after having had a previous event.
CONCLUSION: In young children with CF, completing P. aeruginosa eradication therapy and previous Aspergillus events are associated with increased risk of acquiring Aspergillus.

Matched MeSH terms: Pseudomonas aeruginosa*; Pseudomonas Infections/drug therapy*; Pseudomonas Infections/epidemiology*
Cold-adapted organic solvent tolerant alkalophilic family I.3 lipase from an Antarctic Pseudomonas

Ganasen M, Yaacob N, Rahman RN, Leow AT, Basri M, Salleh AB, et al.

Int J Biol Macromol, 2016 Nov;92:1266-1276.
PMID: 27506122 DOI: 10.1016/j.ijbiomac.2016.06.095

Lipolytic enzymes with cold adaptation are gaining increasing interest due to their biotechnological prospective. Previously, a cold adapted family I.3 lipase (AMS8 lipase) was isolated from an Antarctic Pseudomonas. AMS8 lipase was largely expressed in insoluble form. The refolded His-tagged recombinant AMS8 lipase was purified with 23.0% total recovery and purification factor of 9.7. The purified AMS8 lipase migrated as a single band with a molecular weight approximately 65kDa via electrophoresis. AMS8 lipase was highly active at 30°C at pH 10. The half-life of AMS8 lipase was reported at 4 and 2h under the incubation of 30 and 40°C, respectively. The lipase was stable over a broad range of pH. It showed enhancement effect in its relative activity under the presence of Li(+), Na(+), K(+), Rb(+) and Cs(+) after 30min treatment. Heavy metal ions such as Cu(2+), Fe(3+) and Zn(2+) inhibited AMS8 activity. This cold adapted alkalophilic AMS lipase was also active in various organic solvent of different polarity. These unique properties of this biological macromolecule will provide considerable potential for many biotechnological applications and organic synthesis at low temperature.

Matched MeSH terms: Pseudomonas/classification; Pseudomonas/enzymology*; Pseudomonas/growth & development; Pseudomonas/chemistry
Fulltext Non-antibiotic quorum sensing inhibitors acting against N-acyl homoserine lactone synthase as druggable target

Chang CY, Krishnan T, Wang H, Chen Y, Yin WF, Chong YM, et al.

Sci Rep, 2014;4:7245.
PMID: 25430794 DOI: 10.1038/srep07245

N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography-mass spectrometry (LCMS). These AHL-producing E. coli served as tools for screening AHL synthase inhibitors. Based on a campaign of screening synthetic molecules and natural products using our approach, three strongest inhibitors namely are salicylic acid, tannic acid and trans-cinnamaldehyde have been identified. LCMS analysis further confirmed tannic acid and trans-cinnemaldehyde efficiently inhibited AHL production by RhlI. We further demonstrated the application of trans-cinnemaldehyde inhibiting Rhl QS system regulated pyocyanin production in P. aeruginosa up to 42.06%. Molecular docking analysis suggested that trans-cinnemaldehyde binds to the LasI and EsaI with known structures mainly interacting with their substrate binding sites. Our data suggested a new class of QS-inhibiting agents from natural products targeting AHL synthase and provided a potential approach for facilitating the discovery of anti-QS signal synthesis as basis of novel anti-infective approach.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/metabolism
Topical piperacillin/tazobactam for recalcitrant pseudomonas aeruginosa keratitis

Chew FL, Soong TK, Shin HC, Samsudin A, Visvaraja S

J Ocul Pharmacol Ther, 2010 Apr;26(2):219-22.
PMID: 20415627 DOI: 10.1089/jop.2009.0077

To report the treatment of therapy-resistant Pseudomonas aeruginosa keratitis with topical piperacillin/tazobactam.

Matched MeSH terms: Pseudomonas Infections/drug therapy*; Pseudomonas Infections/physiopathology
Characterization of hbzE-encoded gentisate 1,2-dioxygenase from Pseudomonas alcaligenes NCIMB 9867

Yeo CC, Tan CL, Gao X, Zhao B, Poh CL

Res. Microbiol., 2007 Sep;158(7):608-16.
PMID: 17720458

Pseudomonas alcaligenes NCIMB 9867 (strain P25X) is known to synthesize two isofunctional gentisate 1,2-dioxygenases (GDO; EC 1.13.11.4) as well as other enzymes involved in the degradation of xylenols and cresols via the gentisate pathway. The hbzE gene encoding what is possibly the strictly inducible gentisate 1,2-dioxygenase II (GDO-II) was cloned, overexpressed and purified as a hexahistidine fusion protein from Escherichia coli. Active recombinant GDO-II had an estimated molecular mass of 150kDa and is likely a tetrameric protein with a subunit mass of approximately 40kDa, similar to the previously characterized gentisate 1,2-dioxygenase I (GDO-I) encoded by xlnE. However, GDO-II was unable to utilize gentisate that is substituted at the carbon-4 position, unlike GDO-I which had broader substrate specificity. GDO-II also possessed different kinetic characteristics when compared to GDO-I. The hbzE-encoded GDO-II shared higher sequence identities (53%) with GDOs from Ralstonia sp. U2 and Polaromonas naphthalenivorans CJ2, compared with only 35% identity with the xlnE-encoded GDO-I. The hbzE gene was found to be part of a cluster of nine genes including the putative regulatory gene designated hbzR, which encodes an LysR-type regulator and is divergently transcribed from the other genes of the hbzHIJKLFED cluster.

Matched MeSH terms: Pseudomonas alcaligenes/enzymology*; Pseudomonas alcaligenes/genetics*
Fulltext Actinopyga lecanora hydrolysates as natural antibacterial agents

Ghanbari R, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N

Int J Mol Sci, 2012;13(12):16796-811.
PMID: 23222684 DOI: 10.3390/ijms131216796

Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

Matched MeSH terms: Pseudomonas/drug effects; Pseudomonas/physiology
Fulltext Quorum Sensing Inhibitory Activity of Giganteone A from Myristica cinnamomea King against Escherichia coli Biosensors

Sivasothy Y, Krishnan T, Chan KG, Abdul Wahab SM, Othman MA, Litaudon M, et al.

Molecules, 2016 Mar 21;21(3):391.
PMID: 27102164 DOI: 10.3390/molecules21030391

Malabaricones A-C (1-3) and giganteone A (4) were isolated from the bark of Myristica cinnamomea King. Their structures were elucidated and characterized by means of NMR and MS spectral analyses. These isolates were evaluated for their anti-quorum sensing activity using quorum sensing biosensors, namely Escherichia coli [pSB401] and Escherichia coli [pSB1075], whereby the potential of giganteone A (4) as a suitable anti-quorum sensing agent was demonstrated.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/pathogenicity
Cold-adapted RTX lipase from antarctic Pseudomonas sp. strain AMS8: isolation, molecular modeling and heterologous expression

Ali MS, Ganasen M, Rahman RN, Chor AL, Salleh AB, Basri M

Protein J, 2013 Apr;32(4):317-25.
PMID: 23645400 DOI: 10.1007/s10930-013-9488-z

A new strain of psychrophilic bacteria (designated strain AMS8) from Antarctic soil was screened for extracellular lipolytic activity and further analyzed using molecular approach. Analysis of 16S rDNA showed that strain AMS8 was similar to Pseudomonas sp. A lipase gene named lipAMS8 was successfully isolated from strain AMS8, cloned, sequenced and overexpressed in Escherichia coli. Sequence analysis revealed that lipAMS8 consist of 1,431 bp nucleotides that encoded a polypeptide consisting of 476 amino acids. It lacked an N-terminal signal peptide and contained a glycine- and aspartate-rich nonapeptide sequence at the C-terminus, which are known to be the characteristics of repeats-in-toxin bacterial lipases. Furthermore, the substrate binding site of lipAMS8 was identified as S(207), D(255) and H(313), based on homology modeling and multiple sequence alignment. Crude lipase exhibited maximum activity at 20 °C and retained almost 50 % of its activity at 10 °C. The molecular weight of lipAMS8 was estimated to be 50 kDa via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal expression level was attained using the recombinant plasmid pET32b/BL21(DE3) expressed at 15 °C for 8 h, induced by 0.1 mM isopropyl β-D thiogalactoside (IPTG) at E. coli growth optimal density of 0.5.

Matched MeSH terms: Pseudomonas/enzymology*; Pseudomonas/genetics
Molecular investigation of a gene encoding organic solvent-tolerant alkaline protease from Pseudomonas aeruginosa strain K

Rahman RN, Geok LP, Wong CF, Basri M, Salleh AB

J Basic Microbiol, 2010 Apr;50(2):143-9.
PMID: 20082370 DOI: 10.1002/jobm.200900133

A gene encoding an organic solvent-stable protease was amplified from Pseudomonas aeruginosa strain K by polymerase chain reaction using consensus primers based on multiple sequence alignment of alkaline and metalloprotease genes from Pseudomonas species. The gene, which consisted of 1440 bp nucleotides and deduced 479 amino acid residues, was successfully expressed in pGEX-4T-1 expression system in the presence of 1.0 mM IPTG, after an incubation of 6 h at 37 degrees C. Under these conditions, the recombinant strain K protease was, subsequently, released into the periplasm of E. coli BL21 (DE3) with an optimum proteolytic activity detected at 1.0112 U/ml. To date, this is the first reported expression of alkaline protease (aprA) with such remarkable property in Escherichia coli.

Matched MeSH terms: Pseudomonas aeruginosa/enzymology*; Pseudomonas aeruginosa/genetics*
Production and recovery of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from biodiesel liquid waste (BLW)

Martla M, Umsakul K, Sudesh K

J Basic Microbiol, 2018 Nov;58(11):977-986.
PMID: 30095175 DOI: 10.1002/jobm.201800279

Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But, at industrial level, the successful commercialization of PHAs is limited by the high production cost due to the expensive carbon source and recovery processes. Pseudomonas mendocina PSU cultured for 72 h in mineral salts medium (MSM) containing 2% (v/v) biodiesel liquid waste (BLW) produced 79.7 wt% poly(3-hydroxybutyrate) (PHB) at 72 h. In addition, this strain produced 43.6 wt% poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 8.6 HV mol% at 60 h when added with 0.3% sodium propionate. The synthesized intracellular PHA granules were recovered and purified by the recently reported biological method using mealworms. The weight average molecular weight (Mw ) and number average molecular weight (Mn ) of the biologically extracted PHA were higher than that from the chloroform extraction with comparable melting temperature (Tm ) and high purity. This study has successfully established a low-cost process to synthesize PHAs from BLW and subsequently confirmed the ability of mealworms to extract PHAs from various kinds of bacterial cells.

Matched MeSH terms: Pseudomonas mendocina/growth & development; Pseudomonas mendocina/metabolism*
Cloning and characterization of poly(3-hydroxybutyrate) biosynthesis genes from Pseudomonas sp. USM 4-55

Tan Y, Neo PC, Najimudin N, Sudesh K, Muhammad TS, Othman AS, et al.

J Basic Microbiol, 2010 Apr;50(2):179-89.
PMID: 20082371 DOI: 10.1002/jobm.200900138

Pseudomonas sp. USM 4-55 is a locally isolated bacterium that possesses the ability to produce polyhydroxyalkanoates (PHA) consisting of both poly(3-hydroxybutyrate) [P(3HB)] homopolymer and medium-chain length (mcl) monomers (6 to 14 carbon atoms) when sugars or fatty acids are utilized as the sole carbon source. In this study, the P(3HB) biosynthesis operon carrying the phbC(Ps) P(3HB) synthase was successfully cloned and sequenced using a homologous probe. Three open reading frames encoding NADPH-dependent acetoacetyl-coenzyme A reductase (PhbB(Ps)), beta-ketothiolase (PhbA(Ps)) and P(3HB) synthase (PhbC(Ps)) were found in the phb operon. The genetic organization of phb operon showed a putative promoter region, followed by phbB(Ps)-phbA(Ps)-phbC(Ps). phbR(Ps)which encoded a putative transcriptional activator was located in the opposite orientation, upstream of phbBAC(Ps). Heterologous expression of pGEM''ABex harboring phbC(Ps) in Escherichia coli JM109 resulted in P(3HB) accumulation of up to 40% of dry cell weight (DCW).

Matched MeSH terms: Pseudomonas/genetics*; Pseudomonas/metabolism*
Isolations of enteric pathogens from synanthropic flies trapped in downtown Kuala Lumpur

Sulaiman S, Othman MZ, Aziz AH

J Vector Ecol, 2000 Jun;25(1):90-3.
PMID: 10925800

Four species of synanthropic flies were trapped in downtown Kuala Lumpur: Chrysomya megacephala, Chrysomya rufifacies, Musca domestica, and Musca sorbens. Burkholderia pseudomallei, the organism causing melioidosis, was the dominant bacteria isolated from Chrysomya megacephala. Klebsiella oxytoca, commonly associated with nosocomial infections, was commonly isolated from Chrysomya megacephala, Musca domestica, and Musca sorbens. Aeromonas hydrophila, the bacteria causing gastroenteritis, was predominantly isolated from Chrysomya megacephala and also from Musca domestica and Musca sorbens. A total of 18 bacterial species was isolated from the synanthropic flies trapped. Burkholderia pseudomallei had been reported for the first time.

Matched MeSH terms: Pseudomonas/classification; Pseudomonas/isolation & purification

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