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Cloning of triose phosphate isomerase gene from an antarctic psychrophilic Pseudomonas sp. by degenerate and splinkerette PCR

See Too WC, Few LL

World J Microbiol Biotechnol, 2010 Jul;26(7):1251-9.
PMID: 24026930 DOI: 10.1007/s11274-009-0295-9

Psychrophiles are organisms that thrive in cold environments. One of the strategies for their cold adaptation is the ability to synthesize cold-adapted enzymes. These enzymes usually display higher catalytic efficiency and thermolability at lower temperatures compared to their mesophilic and thermophilic counterparts. In this work, a psychrophilic bacterial isolate codenamed π9 was selected for the cloning of the gene encoding triose phosphate isomerase (TIM), an enzyme in the glycolytic pathway. Based on 16S rRNA gene sequence analysis, this isolate was identified as a species of the genus Pseudomonas under the P. fluorescens group. The cloning of a 816 bp fragment of TIM gene which covers the 756 bp open reading frame was achieved by a combination of degenerate and splinkerette PCRs. The partial sequence of this gene was first PCR amplified by using degenerate primers and the flanking sequences were subsequently amplified by splinkerette PCR technique. Amino acid sequence of the cloned TIM was 97% identical to TIM from Pseudomonas fluorescens and shared 51% identity with the TIM from psychrophilic Vibrio sp. This work demonstrated the use of multiple PCR techniques to clone a gene without prior knowledge of its sequence. The cloning of the TIM gene by PCR was more rapid and cost effective compared to the traditional genomic library construction and screening method. Homology model of the TIM protein in this study was generated based on Escherichia coli TIM crystal structure. The model could serve as a hypothetical TIM structure from a psychrophilic microorganism for further investigation into areas that showed deviations from the known mesophilic TIM structures.

Matched MeSH terms: Escherichia coli
Nitric oxide production by murine spleen cells stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

Sosroseno W, Herminajeng E, Susilowati H, Budiarti S

Anaerobe, 2002 Dec;8(6):333-9.
PMID: 16887678

The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could induce murine spleen cells to produce nitric oxide (NO). Spleen cells derived from Balb/c mice were stimulated with LPS-A. actinomycetemcomitans or LPS from Escherichia coli for 4 days. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B, and cytokines (IFN-gamma and IL-4) on the production of NO were also assessed. The NO production from the carrageenan-treated spleen cells stimulated with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma was determined. The carrageenan-treated mice were transferred with splenic macrophages and the NO production was assessed from the spleen cells stimulated with LPS-A. actinomycetemcomitans or LPS-A. actinomycetemcomitans and IFN-gamma. The results showed that NO production was detectable in the cultures of spleen cells stimulated with LPS-A. actinomycetemcomitans in a dose-dependent fashion, but was lower than in the cells stimulated with LPS from E. coli. The NO production was blocked by NMMA and polymyxin B. IFN-gamma up-regulated but IL-4 suppressed the production of NO by the spleen cells stimulated with LPS-A. actinomycetemcomitans. The carrageenan-treated spleen cells failed to produce NO after stimulation with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma. Adoptive transfer of splenic macrophages to the carrageenan-treated mice could restore the ability of the spleen cells to produce NO. The results of the present study suggest that LPS-A. actinomycetemcomitans under the regulatory control of cytokines induces murine spleen cells to produce NO and that splenic macrophages are the cellular source of the NO production. Therefore, these results may support the view that NO production by LPS-A. actinomycetemcomitans-stimulated macrophages may play a role in the course of periodontal diseases.

Matched MeSH terms: Escherichia coli
Homologs of the Brugia malayi diagnostic antigen BmR1 are present in other filarial parasites but induce different humoral immune responses

Noordin R, Aziz RA, Ravindran B

Filaria journal, 2004 Dec 31;3(1):10.
PMID: 15627400

BACKGROUND: The recombinant antigen BmR1 has been extensively employed in both ELISA and immunochromatographic rapid dipstick (Brugia Rapid) formats for the specific and sensitive detection of IgG4 antibodies against the lymphatic filarial parasites Brugia malayi and Brugia timori. In sera of individuals infected with Wuchereria bancrofti the IgG4 reactivity to BmR1 is variable, and cross-reactivity of sera from individuals infected with Onchocerca volvulus or Loa loa was observed only in single cases. In order to characterize the homologs of the BmR1 antigen in W. bancrofti (Wb-BmR1), O. volvulus (Ov-BmR1) and L. loa (Ll-BmR1) the cDNA sequences were identified, the protein expressed and the antibody reactivity of patients' sera was studied. METHODS: PCR methodology was used to identify the cDNA sequences from cDNA libraries and/or genomic DNA of W. bancrofti, O. volvulus and L. loa. The clones obtained were sequenced and compared to the cDNA sequence of BmR1. Ov-BmR1 and Ll-BmR1 were expressed in E. coli and tested using an IgG4-ELISA with 262 serum samples from individuals with or without B. malayi, W. bancrofti, O. volvulus and L. loa infections or various other parasitic infections. BmR1, Ov-BmR1 and Ll-BmR1 were also tested for reactivity with the other three IgG subclasses in patients' sera. RESULTS: Wb-BmR1 was found to be identical to BmR1. Ov-BmR1 and Ll-BmR1 were found to be identical to each other and share 99.7% homology with BmR1. The pattern of IgG4 recognition of all serum samples to BmR1, Ov-BmR1 and Ll-BmR1 were identical. This included weak IgG4 reactivities demonstrated by L. loa- and O. volvulus-infected patients tested with Ov-BmR1 and Ll-BmR1 (or BmR1). With respect to reactivity to other IgG subclasses, sera from O. volvulus- and L. loa-infected patients showed positive reactions (when tested with BmR1, Ov-BmR1 or Ll-BmR1 antigens) only with IgG1. No reactivity was observed with IgG2 or with IgG3. Similarly, ELISAs to detect reactivity to other anti-filarial IgG subclasses antibodies showed that sera from individuals infected with B. malayi or W. bancrofti (active infections as well as patients with chronic disease) were positive with BmR1 only for IgG1 and were negative when tested with IgG2 and with IgG3 subclasses. CONCLUSIONS: This study demonstrates that homologs of the BmR1 antigen are present in W. bancrofti, O. volvulus and L. loa and that these antigens are highly conserved. Recognition of this antigen by patients' sera is similar with regard to IgG1, IgG2 and IgG3, but different for IgG4 antibodies. We conclude that the BmR1 antigen is suitable for detection of IgG4 antibodies in brugian filariasis. However, its homologs are not suitable for IgG4-based diagnosis of other filarial infections.

Matched MeSH terms: Escherichia coli
Fulltext Diverse and abundant multi-drug resistant E. coli in Matang mangrove estuaries, Malaysia

Ghaderpour A, Ho WS, Chew LL, Bong CW, Chong VC, Thong KL, et al.

Front Microbiol, 2015;6:977.
PMID: 26483759 DOI: 10.3389/fmicb.2015.00977

E.coli, an important vector distributing antimicrobial resistance in the environment, was found to be multi-drug resistant, abundant, and genetically diverse in the Matang mangrove estuaries, Malaysia. One-third (34%) of the estuarine E. coli was multi-drug resistant. The highest antibiotic resistance prevalence was observed for aminoglycosides (83%) and beta-lactams (37%). Phylogenetic groups A and B1, being the most predominant E. coli, demonstrated the highest antibiotic resistant level and prevalence of integrons (integron I, 21%; integron II, 3%). Detection of phylogenetic group B23 downstream of fishing villages indicates human fecal contamination as a source of E. coli pollution. Enteroaggregative E. coli (1%) were also detected immediately downstream of the fishing village. The results indicated multi-drug resistance among E. coli circulating in Matang estuaries, which could be reflective of anthropogenic activities and aggravated by bacterial and antibiotic discharges from village lack of a sewerage system, aquaculture farms and upstream animal husbandry.

Matched MeSH terms: Escherichia coli
Fulltext Fatal Tenofovir-Associateacd Lactic Acidosis: A Case Report

Hashim H, Sahari NS, Sazlly Lim SM, Hoo FK

Iran Red Crescent Med J, 2015 Oct;17(10):e19546.
PMID: 26568856 DOI: 10.5812/ircmj.19546

INTRODUCTION: The introduction of highly active antiretroviral therapy (HAART), in 1996, has resulted in marked reductions in the rate of illness and death, due to HIV infection. The HAART has transformed HIV infection into a manageable chronic disease. However, although many regimens lower plasma viral load, to below the limit of detection, in most patients, maintaining viral load suppression remains challenging, because of adverse effects and toxicity in the long term, which can lead to non-adherence, virologic failure and drug resistance. Although rare, lactic acidosis often develops fatal complications, as reported in several human immunodeficiency virus infected patients treated with nucleoside reverse transcriptase inhibitors (NRTIs). The purpose of this paper is to report a case of tenofovir induced lactic acidosis and review the literature.
CASE PRESENTATION: A 52-year-old Malay gentleman, with hepatitis C virus and HIV infection was admitted to the intensive care unit for severe lactic acidosis, with concurrent Escherichia coli bacteremia with multiorgan dysfunction. The patient was started on highly active antiretroviral therapy, which included tenofovir, 5 weeks before presentation. Antimicrobial therapy, continuous veno-venous hemofiltration, and other supportive treatments were instituted. However, the patient eventually succumbed to his illness.
CONCLUSIONS: It is essential for clinicians to be able to recognize the signs and symptoms of lactic acidosis in NRTIs treated HIV patients, as an early diagnosis is important to institute treatment.

Matched MeSH terms: Escherichia coli
Fulltext Newly Isolated Paenibacillus tyrfis sp. nov., from Malaysian Tropical Peat Swamp Soil with Broad Spectrum Antimicrobial Activity

Aw YK, Ong KS, Lee LH, Cheow YL, Yule CM, Lee SM

Front Microbiol, 2016;7:219.
PMID: 26973605 DOI: 10.3389/fmicb.2016.00219

Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences for human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystems such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1(T) that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1(T) belonged to the genus Paenibacillus with the highest similarity to Paenibacillus elgii SD17(T) (99.5%). Whole genome comparison between strain MSt1(T) with its closely related species using average nucleotide identity (ANI) revealed that similarity between strain MSt1(T) with P. elgii B69 (93.45%) and Paenibacillus ehimensis A2 (90.42%) was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1(T) with P. elgii B69 (55.4%) and P. ehimensis A2 (43.7%) was below the recommended threshold of 70%. Strain MSt1(T) contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1(T) were anteiso-C15:0 (48.2%) and C16:0 (29.0%) whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids, and one unknown phospholipid. Total DNA G+C content of strain MSt1(T) was 51.5 mol%. The extract from strain MSt1(T) exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 μg/mL), MRSA ATCC 700699 (MIC = 25 μg/mL) and Candida albicans IMR (MIC = 12.5 μg/mL). Partially purified active fraction exerted a strong effect against E. coli ATCC 25922 resulting in cell rupture when viewed with SEM. Based on distinctive taxonomic differences between strain MSt1(T) when compared to its closely related type species, we propose that strain MSt1(T) represents a novel species within the genus of Paenibacillus, for which the name Paenibacillus tyrfis sp. nov. (= DSM 100708(T) = MCCC 1K01247(T)) is proposed.

Matched MeSH terms: Escherichia coli
Fulltext Evaluation of Immunoprotection Conferred by the Subunit Vaccines of GRA2 and GRA5 against Acute Toxoplasmosis in BALB/c Mice

Ching XT, Fong MY, Lau YL

Front Microbiol, 2016;7:609.
PMID: 27199938 DOI: 10.3389/fmicb.2016.00609

Toxoplasmosis is a foodborne disease caused by Toxoplasma gondii, an obligate intracellular parasite. Severe symptoms occur in the immunocompromised patients and pregnant women leading to fatality and abortions respectively. Vaccination development is essential to control the disease. The T. gondii dense granule antigen 2 and 5 (GRA2 and GRA5) have been targeted in this study because these proteins are essential to the development of parasitophorous vacuole (PV), a specialized compartment formed within the infected host cell. PV is resistance to host cell endosomes and lysosomes thereby protecting the invaded parasite. Recombinant dense granular proteins, GRA2 (rGRA2) and GRA5 (rGRA5) were cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of these purified antigens as subunit vaccine candidates against toxoplasmosis were evaluated through subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Results obtained demonstrated that rGRA2 and rGRA5 elicited humoral and cellular-mediated immunity in the mice. High level of IgG antibody was produced with the isotype IgG2a/IgG1 ratio of ≈0.87 (p < 0.001). Significant increase (p < 0.05) in the level of four cytokines (IFN-γ, IL-2, IL-4, and IL-10) was obtained. The antibody and cytokine results suggest that a mix mode of Th1/Th2-immunity was elicited with predominant Th1-immune response inducing partial protection against T. gondii acute infection in BALB/c mice. Our findings indicated that both GRA2 and GRA5 are potential candidates for vaccine development against T. gondii acute infection.

Matched MeSH terms: Escherichia coli
Model-guided metabolic gene knockout of gnd for enhanced succinate production in Escherichia coli from glucose and glycerol substrates

Mienda BS, Shamsir MS, Illias RM

Comput Biol Chem, 2016 Apr;61:130-7.
PMID: 26878126 DOI: 10.1016/j.compbiolchem.2016.01.013

The metabolic role of 6-phosphogluconate dehydrogenase (gnd) under anaerobic conditions with respect to succinate production in Escherichia coli remained largely unspecified. Herein we report what are to our knowledge the first metabolic gene knockout of gnd to have increased succinic acid production using both glucose and glycerol substrates in E. coli. Guided by a genome scale metabolic model, we engineered the E. coli host metabolism to enhance anaerobic production of succinic acid by deleting the gnd gene, considering its location in the boundary of oxidative and non-oxidative pentose phosphate pathway. This strategy induced either the activation of malic enzyme, causing up-regulation of phosphoenolpyruvate carboxylase (ppc) and down regulation of phosphoenolpyruvate carboxykinase (ppck) and/or prevents the decarboxylation of 6 phosphogluconate to increase the pool of glyceraldehyde-3-phosphate (GAP) that is required for the formation of phosphoenolpyruvate (PEP). This approach produced a mutant strain BMS2 with succinic acid production titers of 0.35gl(-1) and 1.40gl(-1) from glucose and glycerol substrates respectively. This work further clearly elucidates and informs other studies that the gnd gene, is a novel deletion target for increasing succinate production in E. coli under anaerobic condition using glucose and glycerol carbon sources. The knowledge gained in this study would help in E. coli and other microbial strains development for increasing succinate production and/or other industrial chemicals.

Matched MeSH terms: Escherichia coli
Isolation of Bifidobacteria infantis and its antagonistic activity against ETEC 0157 and Salmonella typhimurium S-285 in weaning foods

Yusof RM, Haque F, Ismail M, Hassan Z

Asia Pac J Clin Nutr, 2000 Jun;9(2):130-5.
PMID: 24394399

Probiotic organism Bifidobacteria was isolated from the faeces of breast-fed infants at Universiti Putra Malaysia. Trypticase phytone peptone yeast extract agar (TPY) was used as a selective media for the isolation. Morphological examination of the isolates indicated that Bifidobacteria was Gram-positive rods in nature, curved with characteristics of V and Y shapes. The organisms were non-catalase producing, non-nitrate reducing, non-motile, had an absence of indole and were unable to liquify gelatin. The ratios of acetic and lactic acids were determined using high performance liquid chromatography (HPLC). Using carbohydrate fermentation profile test API-CH-50 kits, 20 Bifidobacteria strains had been identified: they were the species of Bifidobacteria infantis and two different sub-species, mainly infantis and lacentis. Based on a wide zone of inhibition, three suitable strains of B. infantis, Bifi-11, Bifi-19 and Bifi-20, were tested in weaning foods for antimicrobial activity towards two human pathogens: E. coli-0157 (World Health Organization) and Salmonella typhimurium S-285. The pH, titratable acidity of weaning foods and total colony count for Bifidobacteria, enteropathogenic Escherichia coli and S. typhimurium were recorded at 3-h intervals for 30 h. It was found that after 9 h of incubation of weaning foods, the pH declined to < 3.6 from pH 6.0, whereas titratable acidity increased from 0.026 to 0.08%. It was indicated that Bifidobacteria inhibited E. coli better than did S typhimurium due to low pH. After 24 h of incubation, approximately 98% of E. coli was inhibited by Bifidobacteria. It is suggested that the inhibitory effect of Bifidobacteria strains in weaning foods towards the growth of enteropathogenic E. coli and S. typhimurium was solely due to low pH and the production of volatile acid components by the organism.

Matched MeSH terms: Enteropathogenic Escherichia coli
Fulltext Polycystic kidney disease concurrent with feline parvovirus and bacterial infections in domestic shorthair cat: a case report

Sim Lam PPL, Reduan MFH, Jasni S, Shaari R, Shaharulnizim N, Nordin ML, et al.

Comp Clin Path, 2020 Sep 28.
PMID: 33013278 DOI: 10.1007/s00580-020-03170-4

Feline polycystic kidney disease (PKD) is an inherited disorder caused by the mutation of PKD1 gene that eventually lead to the development of chronic kidney disease. The latter condition causes hypertension and eventually progress into congestive heart failure. Feline parvovirus (FPV) is a highly contagious and often fatal disease infecting cats and other members of Felidae. An 8-month-old female domestic shorthair cat was presented with complaint of wound dehiscence a day after ovarian hysterectomy procedure. The wound at the suture site appeared necrotic, purulent with foul smell. The cat was found to have diarrhoea during the fixation of suture breakdown and, later, was tested positive with parvovirus infection. Complete blood count revealed anaemia, neutrophilia, lymphopenia and thrombocytosis. Biochemistry profiles showed hypoproteinaemia and elevated of urea and creatinine. The cat was hospitalised, and symptomatic treatments were given. During hospitalisation, the cat showed symptoms of polydipsia and polyuria and found dead 2 days later. Post-mortem findings demonstrated the cat had oral ulceration, thoracic effusion, fibrinopleuropneumonia, pericardial effusion, left ventricular hypertrophy and right ventricular dilation, chronic passive liver congestion, mesenteric lymphadenomegaly, intestinal haemorrhage, adrenomegaly and polycystic kidney. Histopathological evaluation revealed fibrinous pleuropneumonia, pulmonary atelectasis, emphysema and oedema, hypertrophic cardiomyopathy, hepatic necrosis, splenic necrosis, intestinal necrosis, renal necrosis and renal polycystic. Staphylococcus aureus and Escherichia coli were isolated from bronchus swab and intestinal segment, respectively. Polymerase chain reaction (PCR) revealed parvovirus infection. The cat was definitely diagnosed with polycystic kidney disease concurrent with parvoviral and secondary bacterial infections.

Matched MeSH terms: Escherichia coli
Fulltext Biosynthesized Silver Nanoparticles by Aqueous Stem Extract of Entada spiralis and Screening of Their Biomedical Activity

Wan Mat Khalir WKA, Shameli K, Jazayeri SD, Othman NA, Che Jusoh NW, Hassan NM

Front Chem, 2020;8:620.
PMID: 32974269 DOI: 10.3389/fchem.2020.00620

Silver nanoparticles (Ag-NPs) have been established as antibacterial nanoparticles and have been innovatively developed to overcome the occurrence of antibiotic resistance in the environment. In this study, an environmentally friendly and easy method of the biosynthesis of Ag-NPs plants, mediated by aqueous extract stem extract of Entada spiralis (E. spiralis), was successfully developed. The E. spiralis/Ag-NPs samples were characterized using spectroscopy and the microscopic technique of UV-visible (UV-vis), X-ray Diffraction (XRD), Field Emission Transmission Electron Microscope (FETEM), zeta potential, and Fourier Transform Infrared (FTIR) analyses. Surface Plasmon Resonance (SPR) absorption at 400-450 nm in the UV-vis spectra established the formation of E. spiralis/Ag-NPs. The crystalline structure of E. spiralis/Ag-NPs was displayed in the XRD analysis. The small size, around 18.49 ± 4.23 nm, and spherical shape of Ag-NPs with good distribution was observed in the FETEM image. The best physicochemical parameters on Ag-NPs biosynthesis using E. spiralis extract occurred at a moderate temperature (~52.0°C), 0.100 M of silver nitrate, 2.50 g of E. spiralis dosage and 600 min of stirring reaction time. The antibacterial activity was tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Proteus vulgaris using an antibacterial disk diffusion assay. Based on the results, it is evident that E. spiralis/Ag-NPs are susceptible to all the bacteria and has promising potential to be applied in both the industry and medical fields.

Matched MeSH terms: Escherichia coli
Fulltext Microbiome of tracheoesophageal prosthesis: who are they?

Syatirah Abdullah, Janet Quinn, Mohamed EL-Badawey, Nicholas Jakubovics

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):44-44.
MyJurnal

Introduction: Laryngectomy patients undergo voice rehabilitation that requires implantation of trachea-oesophagal speech valves (TESV). Usually, laryngeal cancer patients require insertion of these devices post-operatively to im-prove their quality of life. Implantation of TESV dates back to 1979 by pioneering work of Blom and Singer. There are cases of aspiration of TESV wearer reported, and obstruction of the TESV causes leakage through the valve and is suggested as a main reason for replacement of the device. The dysfunctional failure may be caused by microbial colonization on the valve or physical malfunction and requires immediate replacement is desirable. The aim of this study is to identify the microbial community members of selected TESVs using both culture-independent techniques (Next-generation sequencing) to analyse the microbiota, including unculturable species, and routine microbiology techniques (culture-dependent method) and to obtain representative isolates that can form the basis for experiments to enable increased understanding of the community. Methods: Biofilms were harvested from 16 explanted speech valves from patients visiting the ENT clinic in Freeman Hospital, Newcastle, UK. Routine microbiology techniques (culture-dependent method) including ChromeID® plates and Matrix-Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectrometry were used for identification of TESV microbiome. Sequencing of the samples was performed at MR DNA (www.mrdnalab.com, USA) on a MiSeq following the manufacturer’s guidelines in order to determine the bacteria and candida composition in the biofilm community. Results: The most frequently isolated fungal species was C. albicans, which was cultured from 11 out of 16 TESVs (79%), followed by five TESVs with C. tropicalis (36%), three TESVs had C. glabrata (21%) and only one TESV contained S. cerevisiae (7%). Interestingly no biofilm communities contained more than two fungal species and 2 TESVs (12%) possessed only bacterial species. There were only 16 species of bacteria cultured and identified by MALDI-TOF MS. This was far lower than the 91 species that were detected by NGS. Species from the genus Lactobacillus were found in 10 of 16 TESVs (63%), the highest frequency of any bacterial genus isolated from TESVs followed by S. aureus found in eight TESVs of 16. S. epidermidis was identified in two TESVs (13%), Streptococcus spp., K. oxytoca and O. anthropi were both identified in five different TESVs, while the gut bacterium E. faecium was found in four TESVs. Only one TESV contained E. coli. Conclusion: TESV biofilm composition was dominated by Candida spp. and occasionally contained other types of eukaryote such as Saccharomycetes. It was not uncommon for more than one Candida species to be present. The biofilms also harboured a mixture of bacteria, with lactic acid producers (Lactobacillus sp. and Streptococcus sp.) normally accompanying Candida sp. in the biofilm.

Matched MeSH terms: Escherichia coli
Fulltext Antibacterial activities of green silver nanoparticles-Strobilanthes crispus (AgNP-SC) against clinically important bacteria

Rohazila Mohamad Hanafiah, Siti Nor Asma Musa, Siti Aisyah Abd Ghafar

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):40-40.
MyJurnal

Introduction: Silver nanoparticles has been proven to be an effective agent for antimicrobial efficacy against bacte-ria, viruses and other eukaryotic microorganisms. Green synthesis is one of the methods that has been developed to synthesize silver nanoparticles in environmentally-friendly conditions. It uses plant extracts as reducing and capping agents. Besides act as reducing and capping agents, bioactives such as phenolic compounds may bind to silver nanoparticles and enhance its medicinal properties. Strobilanthes crispus is a Malaysian native plant. Previous stud-ies had shown that S. crispus contains polyphenols, catechins, alkaloids, caffeine, tannins and vitamins. Therefore, the aim of this study is to determine antibacterial activities of silver nanoparticles-Strobilanthes crispus (AgNP-SC) against clinically important pathogens such as Escherichia coli, Pseudomonas aeruginosa and Streptococcus mutans. Methods: The disc diffusion assay (DDA) was performed to investigate the inhibition zone of AgNps-Sc towards E. coli, P. aeruginosa and S. mutans. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) was used to determine bactericidal/bacteriostatic profile of AgNP- SC against E. coli, P. aeruginosa and S. mu-tans. Results: AgNP-SC (40mg/mL) shows the greatest inhibition properties (12.67±0.6mm) against S. mutans when compared to Strobilanthes crispus leaves extract (6.0±0.001mm) and blank silver nanoparticles (6.0±0.001mm). MIC values for AgNP-SC against S. mutans and E. coli were at 0.625 mg/mL and 1.25 mg/mL, respectively. Whereas the MIC value of AgNP- SC against P. aeruginosa was at 2.5 mg/mL. MBC values of AgNP-SC against E. coli, P. aerugino-sa and S. mutans were at 1.25, 2.5 mg/mL respectively. Results are concentration-dependent, with higher concentra-tion demonstrating better inhibition property. Conclusion: It can be concluded that AgNP-SC possesses bactericidal properties against S. mutans, E. coli and P. aeruginosa.

Matched MeSH terms: Escherichia coli
Fabrication of biopolymer polyhydroxyalkanoate/chitosan and 2D molybdenum disulfide-doped scaffolds for antibacterial and biomedical applications

Mukheem A, Shahabuddin S, Akbar N, Anwar A, Sarih NM, Sudesh K, et al.

Appl Microbiol Biotechnol, 2020 Apr;104(7):3121-3131.
PMID: 32060693 DOI: 10.1007/s00253-020-10416-2

Antibiotic resistance in pathogenic bacteria is a major health challenge, as Infectious Diseases Society of America (IDSA) has recognized that the past simply drugs susceptible pathogens are now the most dangerous pathogens due to their nonstop growing resistance towards conventional antibiotics. Therefore, due to the emergence of multi-drug resistance, the bacterial infections have become a serious global problem. Acute infections feasibly develop into chronic infections because of many factors; one of them is the failure of effectiveness of antibiotics against superbugs. Modern research of two-dimensional nanoparticles and biopolymers are of great interest to attain the intricate bactericidal activity. In this study, we fabricated an antibacterial nanocomposite consisting of representative two-dimensional molybdenum disulfide (2D MoS2) nanoparticles. Polyhydroxyalkanoate (PHA) and chitosan (Ch) are used to encapsulate MoS2 nanoparticles into their matrix. This study reports the in vitro antibacterial activity and host cytotoxicity of novel PHA-Ch/MoS2 nanocomposites. PHA-Ch/MoS2 nanocomposites were subjected to time-dependent antibacterial assays at various doses to examine their antibacterial activity against multi-drug-resistant Escherichia coli K1 (Malaysian Type Culture Collection 710859) and methicillin-resistant Staphylococcus aureus (MRSA) (Malaysian Type Culture Collection 381123). Furthermore, the cytotoxicity of nanocomposites was examined against spontaneously immortalized human keratinocyte (HaCaT) cell lines. The results indicated significant antibacterial activity (p value

Matched MeSH terms: Escherichia coli
Fulltext Decoding Antioxidant and Antibacterial Potentials of Malaysian Green Seaweeds: Caulerpa racemosa and Caulerpa lentillifera

Yap WF, Tay V, Tan SH, Yow YY, Chew J

Antibiotics (Basel), 2019 Sep 17;8(3).
PMID: 31533237 DOI: 10.3390/antibiotics8030152

Seaweeds are gaining a considerable amount of attention for their antioxidant and antibacterial properties. Caulerpa racemosa and Caulerpa lentillifera, also known as 'sea grapes', are green seaweeds commonly found in different parts of the world, but the antioxidant and antibacterial potentials of Malaysian C. racemosa and C. lentillifera have not been thoroughly explored. In this study, crude extracts of the seaweeds were prepared using chloroform, methanol, and water. Total phenolic content (TPC) and total flavonoid content (TFC) were measured, followed by in vitro antioxidant activity determination using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Antibacterial activities of these extracts were tested against Methicillin-resistant Staphylococcus aureus (MRSA) and neuropathogenic Escherichia coli K1. Liquid chromatography-mass spectrometry (LCMS) analysis was then used to determine the possible compounds present in the extract with the most potent antioxidant and antibacterial activity. Results showed that C. racemosa chloroform extract had the highest TPC (13.41 ± 0.86 mg GAE/g), antioxidant effect (EC50 at 0.65 ± 0.03 mg/mL), and the strongest antibacterial effect (97.7 ± 0.30%) against MRSA. LCMS analysis proposed that the chloroform extracts of C. racemosa are mainly polyunsaturated and monounsaturated fatty acids, terpenes, and alkaloids. In conclusion, C. racemosa can be a great source of novel antioxidant and antibacterial agents, but isolation and purification of the bioactive compounds are needed to study their mechanism of action.

Matched MeSH terms: Escherichia coli
Feline hemotropic mycoplasmosis concurrent with bacterial cystitis in a domestic shorthair cat

Hemasri S, Okene IA, Goni MD

J Adv Vet Anim Res, 2018 Dec;5(4):490-495.
PMID: 31453163 DOI: 10.5455/javar.2018.e304

Objective: The main aim of this case report is to present a case of feline hemotropic mycoplasmosis that occurred concurrently with bacterial cystitis following the bite.
Material and methods: A 3-year-old intact male domestic shorthair cat weighing 3.7 kg was referred to the Universiti Malaysia Kelantan Veterinary Clinic with clinical signs of hematuria and dysuria. History revealed that it was managed outdoor, fed with kibbles and wet food, but with no vaccination and deworming. Upon physical examination, the cat had a dull appearance, pale mucous membrane, normal respiratory rate, hypothermia, and bradycardia. Upon the examination of the urogenital system, there were urine burns at the anal region, necrotized penile tip, and presence of bite wound observed at the perineal region. Turgid and enlarged urinary bladder was identified upon palpation.
Results: Diagnostic investigation revealed the hemotropic mycoplasmosis via microscopy, while urine culture was positive for Escherichia coli infection. The cat was successfully treated symptomatically.
Conclusion: However, the prognosis of this cat was guarded given that the anemia was unresolved at the point of discharge.

Matched MeSH terms: Escherichia coli Infections
Phage N15 protelomerase resolves its tos recognition site into hairpin telomeres within mammalian cells

Liew PS, Chen Q, Ng AWR, Chew YC, Ravin NV, Sim EUH, et al.

Anal Biochem, 2019 10 15;583:113361.
PMID: 31306622 DOI: 10.1016/j.ab.2019.113361

Phage N15 protelomerase (TelN) cleaves double-stranded circular DNA containing a telomerase-occupancy-site (tos) and rejoins the resulting linear-ends to form closed-hairpin-telomeres in Escherichia coli (E. coli). Continued TelN expression is essential to support resolution of the linear structure. In mammalian cells, no enzyme with TelN-like activities has been found. In this work, we show that phage TelN, expressed transiently and stably in human and mouse cells, recapitulates its native activities in these exogenous environments. We found TelN to accurately resolve tos-DNA in vitro and in vivo within human and mouse cells into linear DNA-containing terminal telomeres that are resistant to RecBCD degradation, a hallmark of protelomerase processing. In stable cells, TelN activity was detectable for at least 60 days, which suggests the possibility of limited silencing of its expression. Correspondingly, linear plasmid containing a 100 kb human β-globin gene expressed for at least 120 h in non-β-globin-expressing mouse cells with TelN presence. Our results demonstrate TelN is able to cut and heal DNA as hairpin-telomeres within mammalian cells, providing a tool for creating novel structures by DNA resolution in these hosts. The TelN protelomerase may be useful for exploring novel technologies for genome interrogation and chromosome engineering.

Matched MeSH terms: Escherichia coli
Fulltext Identification of Risk Factors Associated with Resistant Escherichia coli Isolates from Poultry Farms in the East Coast of Peninsular Malaysia: A Cross Sectional Study

Elmi SA, Simons D, Elton L, Haider N, Abdel Hamid MM, Shuaib YA, et al.

Antibiotics (Basel), 2021 Jan 26;10(2).
PMID: 33530462 DOI: 10.3390/antibiotics10020117

Antimicrobial resistance is of concern to global health security worldwide. We aimed to identify the prevalence, resistance patterns, and risk factors associated with Escherichia coli (E. coli) resistance from poultry farms in Kelantan, Terengganu, and Pahang states of east coast peninsular Malaysia. Between 8 February 2019 and 23 February 2020, a total of 371 samples (cloacal swabs = 259; faecal = 84; Sewage = 14, Tap water = 14) were collected. Characteristics of the sampled farms including management type, biosecurity, and history of disease were obtained using semi-structured questionnaire. Presumptive E. coli isolates were identified based on colony morphology with subsequent biochemical and PCR confirmation. Susceptibility of isolates was tested against a panel of 12 antimicrobials and interpreted alongside risk factor data obtained from the surveys. We isolated 717 E. coli samples from poultry and environmental samples. Our findings revealed that cloacal (17.8%, 46/259), faecal (22.6%, 19/84), sewage (14.3%, 2/14) and tap water (7.1%, 1/14) were significantly (p < 0.003) resistant to at least three classes of antimicrobials. Resistance to tetracycline class were predominantly observed in faecal samples (69%, 58/84), followed by cloacal (64.1%, 166/259), sewage (35.7%, 5/14), and tap water (7.1%, 1/84), respectively. Sewage water (OR = 7.22, 95% CI = 0.95-151.21) had significant association with antimicrobial resistance (AMR) acquisition. Multivariate regression analysis identified that the risk factors including sewage samples (OR = 7.43, 95% CI = 0.96-156.87) and farm size are leading drivers of E. coli antimicrobial resistance in the participating states of east coast peninsular Malaysia. We observed that the resistance patterns of E. coli isolates against 12 panel antimicrobials are generally similar in all selected states of east coast peninsular Malaysia. The highest prevalence of resistance was recorded in tetracycline (91.2%), oxytetracycline (89.1%), sulfamethoxazole/trimethoprim (73.1%), doxycycline (63%), and sulfamethoxazole (63%). A close association between different risk factors and the high prevalence of antimicrobial-resistant E. coli strains reflects increased exposure to resistant bacteria and suggests a concern over rising misuse of veterinary antimicrobials that may contribute to the future threat of emergence of multidrug-resistant pathogen isolates. Public health interventions to limit antimicrobial resistance need to be tailored to local poultry farm practices that affect bacterial transmission.

Matched MeSH terms: Escherichia coli
Fulltext Phenotypic Antimicrobial Susceptibility of Escherichia coli from Raw Meats, Ready-to-Eat Meats, and Their Related Samples in One Health Context

Adzitey F, Huda N, Shariff AHM

Microorganisms, 2021 Feb 05;9(2).
PMID: 33562804 DOI: 10.3390/microorganisms9020326

Meat is an important food source that can provide a significant amount of protein for human development. The occurrence of bacteria that are resistant to antimicrobials in meat poses a public health risk. This study evaluated the occurrence and antimicrobial resistance of E. coli (Escherichia coli) isolated from raw meats, ready-to-eat (RTE) meats and their related samples in Ghana. E. coli was isolated using the USA-FDA Bacteriological Analytical Manual and phenotypic antimicrobial susceptibility test was performed by the disk diffusion method. Of the 200 examined meats and their related samples, 38% were positive for E. coli. Notably, E. coli was highest in raw beef (80%) and lowest in RTE pork (0%). The 45 E. coli isolates were resistant ≥ 50% to amoxicillin, trimethoprim and tetracycline. They were susceptible to azithromycin (87.1%), chloramphenicol (81.3%), imipenem (74.8%), gentamicin (72.0%) and ciprofloxacin (69.5%). A relatively high intermediate resistance of 33.0% was observed for ceftriaxone. E. coli from raw meats, RTE meats, hands of meat sellers and working tools showed some differences and similarities in their phenotypic antimicrobial resistance patterns. Half (51.1%) of the E. coli isolates exhibited multidrug resistance. The E. coli isolates showed twenty-two different resistant patterns, with a multiple antibiotic resistance index of 0.0 to 0.7. The resistant pattern amoxicillin (A, n = 6 isolates) and amoxicillin-trimethoprim (A-TM, n = 6 isolates) were the most common. This study documents that raw meats, RTE meats and their related samples in Ghana are potential sources of antimicrobial-resistant E. coli and pose a risk for the transfer of resistant bacteria to the food chain, environment and humans.

Matched MeSH terms: Escherichia coli
Fulltext In Vitro Efficacy of Flomoxef against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Associated with Urinary Tract Infections in Malaysia

Ngoi ST, Teh CSJ, Chong CW, Abdul Jabar K, Tan SC, Yu LH, et al.

Antibiotics (Basel), 2021 Feb 11;10(2).
PMID: 33670224 DOI: 10.3390/antibiotics10020181

The increasing prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has greatly affected the clinical efficacy of β-lactam antibiotics in the management of urinary tract infections (UTIs). The limited treatment options have resulted in the increased use of carbapenem. However, flomoxef could be a potential carbapenem-sparing strategy for UTIs caused by ESBL-producers. Here, we compared the in vitro susceptibility of UTI-associated ESBL-producers to flomoxef and established β-lactam antibiotics. Fifty Escherichia coli and Klebsiella pneumoniae strains isolated from urine samples were subjected to broth microdilution assay, and the presence of ESBL genes was detected by polymerase chain reactions. High rates of resistance to amoxicillin-clavulanate (76-80%), ticarcillin-clavulanate (58-76%), and piperacillin-tazobactam (48-50%) were observed, indicated by high minimum inhibitory concentration (MIC) values (32 µg/mL to 128 µg/mL) for both species. The ESBL genes blaCTX-M and blaTEM were detected in both E. coli (58% and 54%, respectively) and K. pneumoniae (88% and 74%, respectively), whereas blaSHV was found only in K. pneumoniae (94%). Carbapenems remained as the most effective antibiotics against ESBL-producing E. coli and K. pneumoniae associated with UTIs, followed by flomoxef and cephamycins. In conclusion, flomoxef may be a potential alternative to carbapenem for UTIs caused by ESBL-producers in Malaysia.

Matched MeSH terms: Escherichia coli

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