Displaying publications 1 - 20 of 84 in total

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  1. Fulltext In vitro screening of five local medicinal plants for antibacterial activity using disc diffusion method
    Zaidan MR, Noor Rain A, Badrul AR, Adlin A, Norazah A, Zakiah I
    Trop Biomed, 2005 Dec;22(2):165-70.
    PMID: 16883283 MyJurnal
    Medicinal plants have many traditional claims including the treatment of ailments of infectious origin. In the evaluation of traditional claims, scientific research is important. The objective of the study was to determine the presence of antibacterial activity in the crude extracts of some of the commonly used medicinal plants in Malaysia, Andrographis paniculata, Vitex negundo, Morinda citrifolia, Piper sarmentosum, and Centella asiatica. In this preliminary investigation, the leaves were used and the crude extracts were subjected to screening against five strains of bacteria species, Methicillin Resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, using standard protocol of Disc Diffusion Method (DDM). The antibacterial activities were assessed by the presence or absence of inhibition zones and MIC values. M. citrifolia, P. sarmentosum and C. asiatica methanol extract and A. paniculata (water extract) have potential antibacterial activities to both gram positive S. aureus and Methicillin Resistant S. aureus (MRSA). None of the five plant extracts tested showed antibacterial activities to gram negative E. coli and K. pneumoniae, except for A. paniculata and P. sarmentosum which showed activity towards P. aeruginosa. A. paniculata being the most potent at MIC of 2 g/disc. This finding forms a basis for further studies on screening of local medicinal plant extracts for antibacteria properties.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  2. Fulltext Preliminary comparative analysis of antibacterial effects of activated and non-activated of expired platelet concentrate by disc diffusion method
    Zabidi MA, Yusoff NM, Kader ZS
    Indian J Pathol Microbiol, 2012 Jan-Mar;55(1):47-51.
    PMID: 22499300 DOI: 10.4103/0377-4929.94855
    Platelets release more than 30 cytokines to provide primary hemostatic function. In addition, platelets are also known to release antimicrobial peptides upon activation by thrombin.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  3. Fulltext Orthopaedic infections: organisms and antibiotic sensitivity
    Yusof MI, Yusof AH
    Med J Malaysia, 2004 Dec;59(5):574-7.
    PMID: 15889557
    Staphylococcus aureus infection remains the commonest organism causing musculoskeletal infection and antibiotic is the mainstay of treatment apart from adequate and appropriate surgical intervention. The exact figure of antibiotic resistance in orthopaedic practice is not known but it is expected to be higher than previously reported as the use of antibiotics is rampant. Its sensitivity to various antibiotics differs from one center to another making local surveillance necessary. From 66 patients with musculoskeletal infections studied in our centre, Staphylococcus aureus was cultured in 50-65% of patients, depending on the sample taken. Fifteen percent of this were methicillin resistant Staphylococcus aureus (MRSA). Staphylococcus aureus was found to be sensitive to cloxacillin in 95% of patients' sample. MRSA remained highly sensitive to vancomycin, clindamycin and fucidic acid.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  4. Stigmasterol: An adjuvant for beta lactam antibiotics against beta-lactamase positive clinical isolates
    Yenn TW, Arslan Khan M, Amiera Syuhada N, Chean Ring L, Ibrahim D, Tan WN
    Steroids, 2017 Dec;128:68-71.
    PMID: 29104098 DOI: 10.1016/j.steroids.2017.10.016
    The emergence of beta lactamase producing bacterial strains eliminated the use of beta lactam antibiotics as chemotherapeutic alternative. Beta lactam antibiotics can be coupled with non-antibiotic adjuvants to combat these multidrug resistant strains. We study the synergistic antibiotic effect of stigmasterol as adjuvant of ampicillin against clinical isolates. Ampicillin was used in this study as a beta lactam antibiotic model. All test bacteria were beta lactamase producing clinical isolates. The combination showed significantly better antibiotic activity on all bacteria tested. The two test substances have synergistic antibiotic activity, and the effect was observed in both Gram positive and Gram negative bacteria. The synergistic antibiotic effect of stigmasterol and ampicillin was evident by the low fractional inhibitory concentration (FIC) index on Checkerboard Assay. The results suggest that the combination of ampicillin and stigmasterol acts additively in the treatment of infections caused by beta-lactamase producing pathogens. In bacterial growth reduction assay, ampicillin and stigmasterol alone exhibited very weak inhibitory effect on the bacterial growth, relative to ethanol control. Comparatively, combination of stigmasterol-ampicillin greatly reduced the colony counts at least by 98.7%. In conclusion, we found synergistic effects of stigmasterol and ampicillin against beta lactamase producing clinical isolates. This finding is important as it shows potential application of stigmasterol as an antibiotic adjuvant.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  5. Intestinal carriage of multidrug-resistant gram-negative bacteria in preterm-infants during hospitalization in neonatal intensive care unit (NICU)
    Yap PS, Ahmad Kamar A, Chong CW, Yap IK, Thong KL, Choo YM, et al.
    Pathog Glob Health, 2016 Sep;110(6):238-246.
    PMID: 27650884
    The prevalence and antibiotic susceptibility of intestinal carriage of Gram-negative bacteria among preterm infants admitted to the neonatal intensive care unit (NICU) in a tertiary teaching hospital in Malaysia were determined. A total of 34 stool specimens were obtained from preterm infants upon admission and once weekly up to two weeks during hospitalization. The presumptive colonies of Escherichia coli and Klebsiella pneumoniae were selected for identification, antibiotic susceptibility testing, and subtyping by using pulsed-field gel electrophoresis (PFGE). Out of 76 Gram-negative isolates, highest resistance was detected for amoxicillin/clavulanate (30.8%, n = 16), ceftriaxone (42.3%, n = 22), ceftazidime (28.8%, n = 15), cefoxitin (28.8%, n = 15), aztreonam (36.5%, n = 19), and polymyxin B (23.1%, n = 12). Three colistin resistant K. pneumoniae have also been detected based on E-test analysis. Thirty-nine isolates of K. pneumoniae and 20 isolates of E. coli were resistant to more than three antimicrobial classes and were categorized as multidrug resistant (MDR). PFGE analysis revealed a higher diversity in pulsotypes for K. pneumoniae (18 pulsotypes) in comparison to E. coli (four pulsotypes). In addition, a total of fifteen pulsotypes was observed from 39 MDR K. pneumoniae. The risk factors for antibiotic resistance were assessed using random forest analysis. Gender was found to be the most important predictor for colistin resistant while length, OFC, and delivery mode were showing greater predictive power in the polymyxin B resistance. This study revealed worrying prevalence rates of intestinal carriage of multidrug-resistant K. pneumoniae and E. coli of hospitalized preterm infants in Malaysia, particularly high resistance to polymyxins.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  6. Biological properties of sodium alkyl methyl ester sulfonate/alkyltrimethylammonium bromide surfactant mixtures
    Wong SP, Lim WH, Cheng SF, Chuah CH
    Colloids Surf B Biointerfaces, 2012 Jan 1;89:48-52.
    PMID: 21937202 DOI: 10.1016/j.colsurfb.2011.08.021
    Quaternary ammonium compounds (QACs) are commonly used as disinfectant in medical care, food industry, detergents and glue industries. This is due to a small concentration of QACs is sufficient to inhibit the growth of various bacteria strains. In this work, the inhibitive power of cationic surfactants, alkyltrimethylammonium bromide (C(n)TAB) in the presence of anionic surfactants, sodium alkyl methyl ester α-sulfonate (C(n)MES) was studied. The growth inhibition test with gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single and mixed surfactants. Results from this work showed that certain mixed surfactants have lower minimum inhibition concentration (MIC) as compared to the single C(n)TAB surfactants. Besides that, it was also found that alkyl chain length and the mixing ratios of the surfactants play a significant role in determining the mixture inhibitive power.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  7. Surveillance of antibiotic resistance in South East Asia
    Williams JD, Moosdeen F, Teoh-Chan CH, Lim VK, Jayanetra P
    Eur J Epidemiol, 1989 Jun;5(2):207-13.
    PMID: 2504618
    Antibiotic resistance in Gram-negative bacteria, particularly Salmonella and Shigella, requires surveillance worldwide. This study describes results of surveys in Hong Kong, Bangkok and Kuala Lumpur. All strains were isolated in hospitals which have large community catchment areas in addition to specialised hospital units. The prevalence of resistant strains was high in all areas. Gram-negative bacteria such as Enterobacter associated with hospital infections were resistant to penicillins and cephalosporins, with gentamicin resistance ranging from about 20% in Kuala Lumpur and Hong Kong, to 35% in Bangkok. Ninety-seven percent of Shigella isolated in Thailand were resistant to ampicillin. About 10% of Salmonella were resistant to chloramphenicol in all three centres.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  8. Growth inhibition of foodborne and nosocomial pathogens by aqueous fraction of bearded Argostemma (Argostemma involucratum Hemsl., Rubiaceae)
    Wiart C, Hannah A, Yusof M, Hamimah H, Sulaiman M
    J Herb Pharmacother, 2005;5(3):97-102.
    PMID: 16520301
    The crude methanol extract of Bearded Argostemma (Argostemma involucratum Hemsl., Rubiaceae) showed a good and broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria. The activity was increased on fractionation (hexane, dichloromethane and water), particularly in the aqueous fraction which was more active than the methanol extract and streptomycin (no activity was shown against tested moulds). Both the hexane and dichloromethane fractions were inactive. The objective of this experiment was to investigate the antibacterial activity of hexane, dichloromethane, and aqueous fractions of Argostemma involucratum Hemsl. The aqueous fraction of Bearded Argostemma may be a possible new option for the treatment of bacterial infections.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  9. Antimicrobial activity of tiger's betel (Piper porphyrophyllum N.E. Br., Piperaceae)
    Wiart C, Hannah NA, Yassim M, Hamimah H, Sulaiman M
    Phytother Res, 2004 Sep;18(9):783-4.
    PMID: 15478188
    The ethanol extract of leaves of Piper porphyrophyllum N.E. Br. showed a broad spectrum of antibacterial activity. The activity was increased on fractionation (hexane, dichloromethane and aqueous), particularly in the aqueous fraction. No activity was shown against tested Candida albicans.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  10. Antimicrobial screening of plants used for traditional medicine in the state of Perak, Peninsular Malaysia
    Wiart C, Mogana S, Khalifah S, Mahan M, Ismail S, Buckle M, et al.
    Fitoterapia, 2004 Jan;75(1):68-73.
    PMID: 14693223
    Seventy-two extracts (methanol) obtained from the leaves, barks, and roots of 50 plant species used in the traditional medicine of Perak, Peninsular Malaysia, have been screened for antibacterial and antifungal activities. Peristrophe tinctoria, Polyalthia lateriflora, Knema malayana, Solanum torvum, Celosia argentea, Eclipta prostrata, Ancistrocladus tectorius, Dillenia suffruticosa, Piper stylosum and Rafflesia hasseltii displayed the broadest spectrum of activity.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  11. Fulltext In vitro antibacterial activity of Quercus infectoria gall extracts against multidrug resistant bacteria
    Wan Nor Amilah WA, Masrah M, Hasmah A, Noor Izani NJ
    Trop Biomed, 2014 Dec;31(4):680-8.
    PMID: 25776593 MyJurnal
    Antimicrobial activities of plants have long been evaluated for their promising use as antimicrobial agent and in minimizing the unwanted resistance effects of microorganisms. The study was conducted to evaluate the antibacterial activity of Quercus infectoria gall crude extracts against multidrug resistant (MDR) bacteria in vitro. The screening test was determined by disc diffusion technique using sterile filter paper discs impregnated with 1 mg/ disc (50 mg/ml) aqueous and ethanol extracts of Q. infectoria galls tested on five selected MDR bacterial strains. The minimum inhibitory concentration (MIC) was determined using the twofold serial micro dilution technique at concentration ranging from 5.00 mg/ml to 0.01 mg/ml. The minimum bactericidal concentration (MBC) was determined by sub culturing the microtitre wells showing no turbidity on the agar plate to obtain the MBC value. Both extracts showed substantial inhibitory effects against methicillin resistant coagulase negative Staphylococcus (MRCoNS) and methicillin resistant Staphylococcus aureus (MRSA). A slightly reduced inhibitory zone diameter was observed with MDR Acinetobacter sp. while no inhibitory effect was displayed among the extended spectrum beta lactamases (ESBL) K. pneumoniae and ESBL E. coli isolates. A significant difference in the zone sizes between both extracts was only observed in MRSA (p < 0.05). The MIC values ranged from 0.08 mg/ml to 0.63 mg/ml for aqueous and ethanol extracts against MRSA, MRCoNS and MDR Acinetobacter sp. while their MBC to MIC ratio values were 2 and less. The Q. infectoria gall extracts have shown very promising in vitro antibacterial activities and may be considered as a potentially good source of antimicrobial agent especially against MDR Gram positive bacteria.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  12. Fulltext The Antimicrobial efficacy of Elaeis guineensis: characterization, in vitro and in vivo studies
    Vijayarathna S, Zakaria Z, Chen Y, Latha LY, Kanwar JR, Sasidharan S
    Molecules, 2012 Apr 26;17(5):4860-77.
    PMID: 22538489 DOI: 10.3390/molecules17054860
    The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested Elaeis guineensis Jacq (Arecaceae) methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that E. guineensis exhibits excellent antimicrobial activity in vitro and in vivo against the bacterial and fungal strains tested. A marked inhibitory effect of the E. guineensis extracts was observed against C. albicans whereby E. guineensis extract at ½, 1, or 2 times the MIC significantly inhibited C. albicans growth with a noticeable drop in optical density (OD) of the bacterial culture. This finding confirmed the anticandidal activity of the extract on C. albicans. Imaging using scanning (SEM) and transmission (TEM) electron microscopy was done to determine the major alterations in the microstructure of the extract-treated C. albicans. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. In vivo antimicrobial activity was studies in mice that had been inoculated with C. albicans and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  13. Bacterial dynamics associated with algal antibacterial substances during post harvest desiccation process of Sargassum stolonifolium Phang et Yoshida
    Vairappan CS
    Indian J Exp Biol, 2003 Aug;41(8):837-45.
    PMID: 15248481
    Brown algae of genus Sargassum are known to produce relatively higher amount of alginic acid. Optimal extraction of this algalcolloid for local consumption requires in-depth studies on post-harvest treatment of the algal fronds. Present investigation endeavors to establish the dynamics and inter-relationship of moisture content and bacteria found on the surface of the alga and alginic acid content during post-harvest desiccation of Sargassum stolonifolium Phang et Yoshida. Harvested fronds were subjected to desiccation for 31 days and bacterial dynamics were monitored with relation to moisture content and water activity index (a(w)). There was 85% decrease in moisture content, however, a(w) showed a more gradual decrease. Total bacterial count increased during the first week and attained maximal value on day 7. Thereafter, a drastic decrease was seen until day 14, followed by a gradual decline. Six species of bacteria were isolated and identified, i.e. Azomonas punctata, Azomonas sp., Escherichia coli, Micrococcus sp., Proteus vulgaris and Vibrio alginolyticus. Calculated ratios for increase in alginic acid content and decrease in moisture content were almost the same throughout the desiccation process, implying that extracellular alginase-producing bacteria did not use the alginic acid produced by the algae as its carbon source. It became apparent that drastic decrease in bacterial count after day 7 could not be attributed to salinity, moisture content, a(w) or lack of carbon source for the bacteria. The possible exposure of these bacteria to algal cell sap which is formed due to the rupture of algal cells was seen as the most likely reason for the drop in bacterial population. Scanning electron microscope (SEM) micrograph taken on day 10 of desiccation showed the presence of cracks and localities where bacteria were exposed to algal cell sap. In vitro antibacterial tests were carried out to verify the effect of algal extracts. Separation and purification of crude algal extracts via bioassay guided separation methodology revealed the identity of active compounds (i.e. gylcolipids and free fatty acids) involved in this inherently available antibacterial defense mechanism during algal desiccation.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  14. Sesquiterpenes rich essential oil from Garcinia celebica L. and its cytotoxic and antimicrobial activities
    Tan WN, Tan ZH, Zulkifli NI, Nik Mohamed Kamal NNS, Rozman NAS, Tong WY, et al.
    Nat Prod Res, 2020 Dec;34(23):3404-3408.
    PMID: 30773054 DOI: 10.1080/14786419.2019.1569012
    Garcinia celebica L., locally known as "manggis hutan" in Malaysia is widely used in folkloric medicine to treat various diseases. The present study was aimed to examine the chemical composition of the essential oil from the leaves of G. celebica L. (EO-GC) and its cytotoxic and antimicrobial potential. EO-GC obtained by hydrodistillation was analysed using capillary GC and GC-MS. Twenty-two compounds were identified, dominated by α-copaene (61.25%), germacrene D (6.72%) and β-caryophyllene (5.85%). In the in vitro MTT assay, EO-GC exhibited significant anti-proliferative effects towards MCF-7 human breast cancer cells with IC50 value of 45.2 μg/mL. Regarding the antimicrobial activity, it showed better inhibitory effects on Gram-positive bacteria than Gram-negative bacteria and none on the fungi and yeasts tested.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  15. Design, Synthesis, SAR Study, Antimicrobial and Anticancer Evaluation of Novel 2-Mercaptobenzimidazole Azomethine Derivatives
    Tahlan S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA
    Mini Rev Med Chem, 2020;20(15):1559-1571.
    PMID: 30179132 DOI: 10.2174/1389557518666180903151849
    BACKGROUND: Various analogues of benzimidazole are found to be biologically and therapeutically potent against several ailments. Benzimidazole when attached with heterocyclic rings has shown wide range of potential activities. So, from the above provided facts, we altered benzimidazole derivatives so that more potent antagonists could be developed. In the search for a new category of antimicrobial and anticancer agents, novel azomethine of 2-mercaptobenzimidazole derived from 3-(2- (1H-benzo[d]imidazol-2-ylthio)acetamido)benzohydrazide were synthesized.

    RESULTS AND DISCUSSION: The synthesized analogues were characterized by FT-IR, 1H/13C-NMR and MS studies as well C, H, N analysis. All synthesized compounds were evaluated for in vitro antibacterial activity against Gram-positive (B. subtilis), Gram-negative (E. coli, P. aeruginosa, K. pneumoniae and S. typhi) strains and in vitro antifungal activity against C. albicans and A. niger strains by serial dilution method, the minimum inhibitory concentration (MIC) described in μM/ml. The in vitro anticancer activity of synthesized compounds was determined against human colorectal carcinoma cell line (HCT- 116) using 5-fluorouracil as standard drug.

    CONCLUSION: In general, most of the synthesized derivatives exhibited significant antimicrobial and anticancer activities. Compounds 8, 10, 15, 16, 17, 20 and 22 showed significant antimicrobial activity towards tested bacterial and fungal strains and compound 26 exhibited significant anticancer activity.

    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  16. 2-Mercaptobenzimidazole Schiff Bases: Design, Synthesis, Antimicrobial Studies and Anticancer Activity on HCT-116 Cell Line
    Tahlan S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA
    Mini Rev Med Chem, 2019;19(13):1080-1092.
    PMID: 30306865 DOI: 10.2174/1389557518666181009151008
    BACKGROUND: Increased rate of mortality due to the development of resistance to currently available antimicrobial and anticancer agents initiated the need to develop new chemical entities for the treatment of microbial infections and cancer.

    OBJECTIVE: The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities of Schiff bases of 2-mercaptobenzimidazole.

    METHODS: The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]- imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively.

    RESULTS: Compounds 8 (MICpa, an = 2.41, 1.20 µM/ml), 10 (MICse, sa = 2.50 µM/ml), 20 (MICec = 2.34 µM/ml) and 25 (MICca = 1.46 µM/ml) showed significant antimicrobial activity against tested bacterial and fungal strains and compounds 20 (IC50 = 8 µg/ml) and 23 (IC50 = 7 µg/ml) exhibited significant anticancer activity.

    CONCLUSION: In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds may be taken as lead molecules for the development of novel antifungal agents.

    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  17. Isolation and identification of antibacterial and cytotoxic compounds from the leaves of Muntingia calabura L
    Sufian AS, Ramasamy K, Ahmat N, Zakaria ZA, Yusof MI
    J Ethnopharmacol, 2013 Mar 7;146(1):198-204.
    PMID: 23276785 DOI: 10.1016/j.jep.2012.12.032
    Muntingia calabura (Elaeocarpaceae) is one of the most common roadside trees in Malaysia. Its leaves, barks, flowers and roots have been used as a folk remedy for the treatment of fever, incipient cold, liver disease, as well as an antiseptic agent in Southeast Asia. The aim of this study is to isolate and identify the antibacterial and cytotoxic compounds from the leaves of Muntingia calabura L.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  18. Fulltext Evaluation of two transformation protocols and screening of positive plasmid introduction into Bacillus cereus EB2, a gram-positive bacterium using qualitative analyses
    Sirajuddin SA, Sundram S
    Braz J Microbiol, 2020 Sep;51(3):919-929.
    PMID: 32078730 DOI: 10.1007/s42770-020-00241-0
    Both Gram-positive and Gram-negative bacteria can take up exogenous DNA when they are in a competent state either naturally or artificially. However, the thick peptidoglycan layer in Gram-positive bacteria's cell wall is considered as a possible barrier to DNA uptake. In the present work, two transformation techniques have been evaluated in assessing the protocol's ability to introduce foreign DNA, pBBRGFP-45 plasmid which harbors kanamycin resistance and green fluorescent protein (GFP) genes into a Gram-positive bacterium, Bacillus cereus EB2. B. cereus EB2 is an endophytic bacterium, isolated from oil palm roots. A Gram-negative bacterium, Pseudomonas aeruginosa EB35 was used as a control sample for both transformation protocols. The cells were made competent using respective chemical treatment to Gram-positive and Gram-negative bacteria, and kanamycin concentration in the selective medium was also optimized. Preliminary findings using qualitative analysis of colony polymerase chain reaction (PCR)-GFP indicated that the putative positive transformants for B. cereus EB2 were acquired using the second transformation protocol. The positive transformants were then verified using molecular techniques such as observation of putative colonies on specific media under UV light, plasmid extraction, and validation analyses, followed by fluorescence microscopy. Conversely, both transformation protocols were relatively effective for introduction of plasmid DNA into P. aeruginosa EB35. Therefore, this finding demonstrated the potential of chemically prepared competent cells and the crucial step of heat-shock in foreign DNA transformation process of Gram-positive bacterium namely B. cereus was required for successful transformation.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  19. Sulfur and nitrogen containing plasma polymers reduces bacterial attachment and growth
    Siow KS, Abdul Rahman AS, Ng PY, Majlis BY
    Mater Sci Eng C Mater Biol Appl, 2020 Feb;107:110225.
    PMID: 31761201 DOI: 10.1016/j.msec.2019.110225
    Role of sulfur (S) and nitrogen (N) groups in promoting cell adhesion or commonly known as biocompatibility, is well established, but their role in reducing bacterial attachment and growth is less explored or not well-understood. Natural sulfur-based compounds, i.e. sulfide, sulfoxide and sulfinic groups, have shown to inhibit bacterial adhesion and biofilm formation. Hence, we mimicked these surfaces by plasma polymerizing thiophene (ppT) and air-plasma treating this ppT to achieve coatings with S of similar oxidation states as natural compounds (ppT-air). In addition, the effects of these N and S groups from ppT-air were also compared with the biocompatible amine-amide from n-heptylamine plasma polymer. Crystal violet assay and live and dead fluorescence staining of E. coli and S. aureus showed that all the N and S coated surfaces generated, including ppHA, ppT and ppT-air, produced similarly potent, growth reduction of both bacteria by approximately 65% at 72 h compared to untreated glass control. The ability of osteogenic differentiation in Wharton's jelly mesenchymal stem cells (WJ-MSCs) were also used to test the cell biocompatibility of these surfaces. Alkaline phosphatase assay and scanning electron microscopy imaging of these WJ-MSCs growths indicated that ppHA, and ppT-air were cell-friendly surfaces, with ppHA showing the highest osteogenic activity. In summary, the N and S containing surfaces could reduce bacteria growth while promoting mammalian cell growth, thus serve as potential candidate surfaces to be explored further for biomaterial applications.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects
  20. Antibiotics' susceptibility patterns of bacterial isolates causing lower respiratory tract infections in ICU patients at referral hospitals in Namibia
    Simeon P, Godman B, Kalemeera F
    Hosp Pract (1995), 2021 Dec;49(5):356-363.
    PMID: 34436942 DOI: 10.1080/21548331.2021.1973825
    BACKGROUND: Lower respiratory tract infections (LRTIs) are a particular public health concern especially among sub-Saharan African countries. This is especially the case in Namibia, where LRTIs are currently the third leading cause of death, 300 deaths in children under 5 years of age. To reduce the burden of LRTIs on health systems and ensure appropriate patient management, it is critical to know the most prevalent pathogens leading to LRTIs and their susceptibility patterns in the local setting. Consequently, the objective of this study was to formulate cumulative antibiograms for Intensive Care Units (ICUs) of referral hospitals in Namibia to guide future antibiotic use.

    METHODS: A retrospective analytical cross-sectional study was conducted over 2 years. The cumulative antibiograms were constructed in accordance with current guidelines.

    RESULTS: A total of 976 first isolate cultures were obtained from ICUs of the different referral hospitals. K. pneumoniae (8.8%, 8.1%) was a predominant pathogen in Windhoek Central hospital ICU in 2017 and 2018. In Oshakati intermediate hospital ICU, Enterobacter sp. (22.2%) and P. aeruginosa (37.5%) were the common pathogens in 2017 and 2018, respectively. A. baumannii isolates were >90% susceptibility to colistin, carbapenems, and tigecycline in 2017. In 2017, K. pneumoniae isolates were more susceptible to carbapenems (94% and 93.8% among isolates), amikacin (89.3%), and tigecycline (88.7%). In 2018, K. pneumoniae isolates were 100% susceptible amikacin, colistin, and carbapenems. S. maltophilia isolates were more than 80% susceptible to all the tested antibiotics. S. aureus isolates were 100% susceptible to linezolid, rifampicin, teicoplanin, and vancomycin in 2017 and in 2018. Its susceptibility to these antibiotics did not change.

    CONCLUSION: The susceptibility patterns of the common isolated gram-negative pathogens were highly variable. Meropenem in combination with gentamicin is now the recommended antibiotic combination for empiric therapy for patients with LRTIs in Windhoek Central Hospital ICU.

    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
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