Displaying publications 1 - 20 of 126 in total

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  1. 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: Acinetobacter baumannii/isolation & purification
  2. Shu MH, MatRahim N, NorAmdan N, Pang SP, Hashim SH, Phoon WH, et al.
    Sci Rep, 2016;6:22332.
    PMID: 26923424 DOI: 10.1038/srep22332
    Vaccination may be an alternative treatment for infection with multidrug-resistance (MDR) Acinetobacter baumannii. The study reported here evaluated the bactericidal antibody responses following immunization of mice using an inactivated whole-cell vaccine derived from antibiotic-exposed MDR A. baumannii (I-M28-47-114). Mice inoculated with I-M28-47 (non-antibiotic-exposed control) and I-M28-47-114 showed a high IgG antibody response by day 5 post-inoculation. Sera from mice inoculated with I-M28-47-114 collected on day 30 resulted in 80.7 ± 12.0% complement-mediated bacteriolysis in vitro of the test MDR A. baumannii treated with imipenem, which was a higher level of bacteriolysis over sera from mice inoculated with I-M28-47. Macrophage-like U937 cells eliminated 49.3 ± 11.6% of the test MDR A. baumannii treated with imipenem when opsonized with sera from mice inoculated with I-M28-47-114, which was a higher level of elimination than observed for test MDR A. baumannii opsonized with sera from mice inoculated with I-M28-47. These results suggest that vaccination with I-M28-47-114 stimulated antibody responses capable of mounting high bactericidal killing of MDR A. baumannii. Therefore, the inactivated antibiotic-exposed whole-cell vaccine (I-M28-47-114) has potential for development as a candidate vaccine for broad clearance and protection against MDR A. baumannii infections.
    Matched MeSH terms: Acinetobacter baumannii
  3. Mat Rahim N, Lee H, Strych U, AbuBakar S
    Hum Vaccin Immunother, 2021 10 03;17(10):3784-3794.
    PMID: 34106809 DOI: 10.1080/21645515.2021.1927412
    In 2017, the World Health Organization (WHO) named A. baumannii as one of the three antibiotic-resistant bacterial species on its list of global priority pathogens in dire need of novel and effective treatment. With only polymyxin and tigecycline antibiotics left as last-resort treatments, the need for novel alternative approaches to the control of this bacterium becomes imperative. Vaccines against numerous bacteria have had impressive records in reducing the burden of the respective diseases and addressing antimicrobial resistance; as in the case of Haemophilus influenzae type b . A similar approach could be appropriate for A. baumannii. Toward this end, several potentially protective antigens against A. baumannii were identified and evaluated as vaccine antigen candidates. A licensed vaccine for the bacteria, however, is still not in sight. Here we explore and discuss challenges in vaccine development against A. baumannii and the promising approaches for improving the vaccine development process.
    Matched MeSH terms: Acinetobacter baumannii*
  4. Misbah S, Hassan H, Yusof MY, Hanifah YA, AbuBakar S
    Singapore Med J, 2005 Sep;46(9):461-4.
    PMID: 16123830
    This study aims to identify Acinetobacter of clinical isolates from the University of Malaya Medical Centre (UMMC), Kuala Lumpur, to the species level by 16S rDNA sequencing.
    Matched MeSH terms: Acinetobacter baumannii/genetics*; Acinetobacter baumannii/isolation & purification
  5. Basri R, Zueter AR, Mohamed Z, Alam MK, Norsa'adah B, Hasan SA, et al.
    Nagoya J Med Sci, 2015 Feb;77(1-2):59-68.
    PMID: 25797971
    To describe the clinical characteristics and the risk factors associated with mortality in patients with meningitis. This is a retrospective review of patients diagnosed to have meningitis with positive culture of the cerebrospinal fluid (CSF) specimen. All cases aged 19 > years who were admitted to Hospital USM between January 2004 and December 2011 were included in the study. The CSF results database were obtained from the Department of Medical Microbiology and Parasitology, Hospital USM, Kelantan. A checklist was used to record the clinical characteristics. A total of 125 cases met the inclusion criteria. The age of patients ranged between newborn and 19 years old (Mean±SD, 74.5±80.6 months). The majority of them were males (65.6%). Fever was the most common presentation (73.6%) followed by poor oral intake (48.0%), seizure (36.0%) and headache (24.8%). The mortality rate was 31.2%. Coagulase negative staphylococcus was the most frequent pathogens isolated (21.6%), followed by Acinetobacter spp. (17.6%), Staphylococcus aureus (13.6%), Streptococcus spp. (11.2%) and Klebsiella pneumoniae (6.4%). There were significant association of in-hospital death with age (p=0.020) and conscious level (p=0.001). Infectious meningitis is a big health concern, especially among children. We found that coagulase negative staphylococcus, Acinetobacter species, S. aureus, Streptococcus spp and K. pneumoniae were prevalent in our hospital. These microorganisms were hospital associated pathogens. The 31% mortality linked to hospital acquired meningitis specifies the need for focused physician attention especially among younger aged patients.
    Matched MeSH terms: Acinetobacter
  6. Yahya SK, Zakaria ZA, Samin J, Raj AS, Ahmad WA
    Colloids Surf B Biointerfaces, 2012 Jun 1;94:362-8.
    PMID: 22398363 DOI: 10.1016/j.colsurfb.2012.02.016
    The potential use of non-viable biomass of a Gram negative bacterium i.e. Acinetobacter haemolyticus to remove Cr(III) species from aqueous environment was investigated. Highest Cr(III) removal of 198.80 mg g(-1) was obtained at pH 5, biomass dosage of 15 mg cell dry weight, initial Cr(III) of 100 mg L(-1) and 30 min of contact time. The Langmuir and Freundlich models fit the experimental data (R(2)>0.95) while the kinetic data was best described using the pseudo second-order kinetic model (R(2)>0.99). Cr(III) was successfully recovered from the bacterial biomass using either 1M of CH(3)COOH, HNO(3) or H(2)SO(4) with 90% recovery. TEM and FTIR suggested the involvement of amine, carboxyl, hydroxyl and phosphate groups during the biosorption of Cr(III) onto the cell surface of A. haemolyticus. A. haemolyticus was also capable to remove 79.87 mg g(-1) Cr(III) (around 22.75%) from raw leather tanning wastewater. This study demonstrates the potential of using A. haemolyticus as biosorbent to remove Cr(III) from both synthetic and industrial wastewater.
    Matched MeSH terms: Acinetobacter/ultrastructure; Acinetobacter/chemistry*
  7. Zakaria ZA, Zakaria Z, Surif S, Ahmad WA
    J Hazard Mater, 2007 Sep 5;148(1-2):164-71.
    PMID: 17368716
    Acinetobacter haemolyticus, a Gram-negative aerobic locally isolated bacterium, immobilized on wood-husk showed the ability to detoxify Cr(VI) to Cr(III). Wood-husk, a natural cellulose-based support material, packed in an upward-flow column was used as support material for bacterial attachment. Around 97% of the Cr(VI) in wastewater containing 15 mg L(-1) of Cr(VI) was reduced at a flow rate of 8.0 mL min(-1). The wastewater containing Cr(VI) was added with liquid pineapple wastewater as nutrient source for the bacteria. Electron microscopic examinations of the wood-husk after 42 days of column operation showed gradual colonization of the wood-husk by bacterial biofilm. The use of 0.1% (v/v) formaldehyde as a disinfecting agent inhibited growth of bacteria present in the final wastewater discharge. This finding is important in view of the ethical code regarding possible introduction of exogenous bacterial species into the environment.
    Matched MeSH terms: Acinetobacter/cytology; Acinetobacter/metabolism*
  8. Zakaria ZA, Zakaria Z, Surif S, Ahmad WA
    J Hazard Mater, 2007 Jul 19;146(1-2):30-8.
    PMID: 17188812
    Possible application of a locally isolated environmental isolate, Acinetobacter haemolyticus to remediate Cr(VI) contamination in water system was demonstrated. Cr(VI) reduction by A. haemolyticus seems to favour the lower concentrations (10-30 mg/L). However, incomplete Cr(VI) reduction occurred at 70-100 mg/L Cr(VI). Initial specific reduction rate increased with Cr(VI) concentrations. Cr(VI) reduction was not affected by 1 or 10 mM sodium azide (metabolic inhibitor), 10 mM of PO(4)3-, SO4(2-), SO(3)2-, NO3- or 30 mg/L of Pb(II), Zn(II), Cd(II) ions. However, heat treatment caused significant dropped in Cr(VI) reduction to less than 20% only. A. haemolyticus cells loses its shape and size after exposure to 10 and 50 mg Cr(VI)/L as revealed from TEM examination. The presence of electron-dense particles in the cytoplasmic region of the bacteria suggested deposition of chromium in the cells.
    Matched MeSH terms: Acinetobacter/drug effects; Acinetobacter/growth & development; Acinetobacter/metabolism*
  9. Cheng-Yee Fish-Low, Chee HY, Ainon Hamzah
    Sains Malaysiana, 2015;44:1625-1633.
    Microbial communities of two oil reservoirs from Malaysia, denoted as Platform Bo and Platform Pe were studied using
    culture-independent approach. Environmental DNA was extracted and the universal amplified ribosomal region (UARR)
    was target amplified for both prokaryotes and eukaryotes. The amplified products were purified and cloned into pTZ57R/T
    vector to construct the 16S/18S rDNA library. Restriction endocucleases HhaI and MspI were used to screen the library.
    From that, 125 and 253 recombinant plasmid representative clones from Platform Bo and Platform Pe, respectively, were
    sent for DNA sequencing. Twenty-six operational taxonomic units (OTUs) consist of 20 genera detected at Platform Bo
    and 17 OTUs consist of 13 genera detected at Platform Pe. Marinobacter and Acinetobacter species co-occurred in both
    platforms whereas the rest are site-specific. Gammaproteobacteria accounted for 86.0% of the microbial community in
    Platform Bo, where OTUs affiliated to Marinobacter, Pseudomonas and Marinobacterium that were the most abundant. The
    major OTUs in the Platform Pe were with affinities to Achromobacter, followed by Stenotrophomonas and Serratia. The
    only archaeal isolates were detected in Platform Pe, which affiliated to Thermocladium. The singletons and doubletons
    accounted for about 50.0% of the OTU abundance in both platforms, which considerably significant despite their rare
    occurrence.
    Matched MeSH terms: Acinetobacter
  10. Chee CS, Tan IK, Alias Z
    ScientificWorldJournal, 2014;2014:750317.
    PMID: 24892084 DOI: 10.1155/2014/750317
    Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively.
    Matched MeSH terms: Acinetobacter calcoaceticus/enzymology*
  11. Rasidin RSM, Suhaili Z, Mohamed AFS, Hod R, Neela V, Amin-Nordin S
    Trop Biomed, 2020 Jun 01;37(2):471-481.
    PMID: 33612816
    Nosocomial infection caused by Acinetobacter baumannii is common among immunocompromised patients. Treatment strategy is limited due to rapid resistance development and lack of novel antibiotic. Colistin has been the last line therapy with good in vitro activity against infections caused by multi-drug resistance A. baumannii. However, pharmacological updates are required to support dosing optimisation. This study aimed to determine the time-kill kinetic and resistance development after antibiotic exposure as well as post-antibiotic effect of colistin at different static concentrations in in vitro A. baumannii system. The static in vitro time-kill and post-antibiotic effect experiments were conducted against two clinical isolates as well as one reference isolate ATCC 19606. Time-kill and postantibiotic effect were studied at colistin concentrations ranging from 0.25MIC to 16.0MIC and 0.5MIC to 4.0MIC, respectively. Post-exposure resistance development was examined in time-kill study. Killing activity and post-antibiotic effect were in a concentration-dependent manner. However, delayed killing activity indicates colistin tolerance. Development of resistance after exposure was not detected except for the ATCC 19606 strain. Dosing suggestion based on the observations include administration of supplemental dose 3 MIU at 12 hours after loading dose, administration of maintenance dose 9 MIU in two divided doses and application of extended interval in renal adjustment dose. However, the information is applicable for non-colistin-heteroresistance A. baumannii with colistin MIC < 1.0 mg/L. As for heteroresistance and strain with colistin MIC > 1.0 mg/L, combination therapy would be the more appropriate treatment strategy.
    Matched MeSH terms: Acinetobacter baumannii/drug effects*
  12. Taherikalani M, Sekawi Z, Azizi-Jalilian F, Keshavarz B, Soroush S, Akbari M, et al.
    J Biol Regul Homeost Agents, 2013 Jul-Sep;27(3):883-9.
    PMID: 24152853
    Antimicrobial susceptibility and ESBLs genes of 42 imipenem resistant A. baumannii carried out by DDST and PCR. The most antimicrobial agents against A. baumannii strains, harboring blaOXA-23-like carbapenemases, were meropenem (33.4 percent), piperacillin-tazobactam (23.9 percent), ceftazidime (14.3 percent) and gatifoxacin (19.1 percent), respectively. All the 42 isolates harbored the blaTEM gene, but the bla SHV and VEB genes were not present among all the isolates. With the exception of seven isolates, all the A. baumannii strains harbor blaTEM showed ESBL positivity in DDST. The result of this study show that resistance against antimicrobial agents, especially carbapenems, has increased and that blaTEM harboring A. baumannii strains can be help the blaOXA-like carbapenemase genes to code for resistance against carbapenem antibiotics.
    Matched MeSH terms: Acinetobacter baumannii/drug effects*; Acinetobacter baumannii/enzymology
  13. Wan Nor Amilah WA, Noor Izani NJ, Ng WK, Ashraful Haq J
    Trop Biomed, 2012 Dec;29(4):588-97.
    PMID: 23202604
    Clinical utilization of carbapenems remains under threat with the emergence of acquired carbapenemase-producing bacteria, particularly metallo-β-lactamases (MBL). Rapid detection of MBL-producing Gram-negative bacilli is essential to prevent their widespread dissemination. However, no standardized detection method is available for routine laboratory use. The purpose of the study was to evaluate a chelating-agent based double disk synergic test and disk potentiation test for MBL-producing strain detection and to determine the isolation rate of MBL-producing Pseudomonas aeruginosa and Acinetobacter from clinical samples in our tertiary teaching hospital. A total of 22 and 66 imipenem-resistant P. aeruginosa and Acinetobacter isolates respectively were tested with ceftazidime (CAZ) disk by modified double disk synergic test and disk potentiation test using ethylenediaminetetraacetic acid (EDTA) and 2-mercaptopropionic acid (as chelating agents) to detect MBL production. The tests were compared with EDTA-phenanthroline-imipenem (EPI) microdilution MIC test as gold standard. MBL positive strains were detected in 17 (77.3%) P. aeruginosa and 2 (3.5%) Acinetobacter isolates. The disk potentiation test with 2-mercaptopropionic acid (2-MPA) dilution of 1:12 provided the most acceptable sensitivities and specificities (88.2% sensitivity and 100% specificity in P. aeruginosa; 100% sensitivity and specificity in Acinetobacter) compared to other screening methods used in this study. This study provided useful information on the local prevalence of MBL-producing P. aeruginosa and Acinetobacter in our hospital. Disc potentiation test with CAZ/2-MPA disc appears to be reliable and convenient MBL detection method in the routine clinical laboratory.
    Matched MeSH terms: Acinetobacter/enzymology*; Acinetobacter/isolation & purification*; Acinetobacter Infections/microbiology; Acinetobacter Infections/epidemiology
  14. Ariffin H, Navaratnam P, Kee TK, Balan G
    J Trop Pediatr, 2004 Feb;50(1):26-31.
    PMID: 14984166
    The pattern of antibiotic resistance amongst gram-negative bacteria (GNB) in paediatric units, which have heavy empirical usage of broad-spectrum antibiotics, was studied prospectively over a 6-month period. A total of 200 consecutive, non-duplicate gram-negative isolates were obtained from 109 patients admitted to intensive care and oncology units in two hospitals. The commonest isolates were Klebsiella spp (36.5 per cent) and Pseudomonas (20.0 per cent). The isolates showed lower susceptibility rates to the third-generation cephalosporins (47-62 per cent) compared with cefepime (91 per cent), imipenem (90 per cent) and ciprofloxacin (99 per cent). Fifty-four (52.8 per cent) Klebsiella and Escherichia coli isolates were determined to be extended-spectrum beta-lactamase (ESBL) producing strains. Antibiotics found to be effective against ESBL-producers were imipenem and ciprofloxacin. The high resistance rate amongst GNB to third-generation cephalosporins is a likely consequence of heavy empirical usage of this group of antibiotics. The carbapenems and quinolones remain useful agents in the management of patients admitted to these units.
    Matched MeSH terms: Acinetobacter/drug effects; Acinetobacter/isolation & purification
  15. Teerawattanapong N, Kengkla K, Dilokthornsakul P, Saokaew S, Apisarnthanarak A, Chaiyakunapruk N
    Clin Infect Dis, 2017 May 15;64(suppl_2):S51-S60.
    PMID: 28475791 DOI: 10.1093/cid/cix112
    Background: This study evaluated the relative efficacy of strategies for the prevention of multidrug-resistant gram-negative bacteria (MDR-GNB) in adult intensive care units (ICUs).

    Methods: A systematic review and network meta-analysis was performed; searches of the Cochrane Library, PubMed, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) included all randomized controlled trials and observational studies conducted in adult patients hospitalized in ICUs and evaluating standard care (STD), antimicrobial stewardship program (ASP), environmental cleaning (ENV), decolonization methods (DCL), or source control (SCT), simultaneously. The primary outcomes were MDR-GNB acquisition, colonization, and infection; secondary outcome was ICU mortality.

    Results: Of 3805 publications retrieved, 42 met inclusion criteria (5 randomized controlled trials and 37 observational studies), involving 62068 patients (median age, 58.8 years; median APACHE [Acute Physiology and Chronic Health Evaluation] II score, 18.9). The majority of studies reported extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and MDR Acinetobacter baumannii. Compared with STD, a 4-component strategy composed of STD, ASP, ENV, and SCT was the most effective intervention (rate ratio [RR], 0.05 [95% confidence interval {CI}, .01-.38]). When ENV was added to STD+ASP or SCT was added to STD+ENV, there was a significant reduction in the acquisition of MDR A. baumannii (RR, 0.28 [95% CI, .18-.43] and 0.48 [95% CI, .35-.66], respectively). Strategies with ASP as a core component showed a statistically significant reduction the acquisition of ESBL-producing Enterobacteriaceae (RR, 0.28 [95% CI, .11-.69] for STD+ASP+ENV and 0.23 [95% CI, .07-.80] for STD+ASP+DCL).

    Conclusions: A 4-component strategy was the most effective intervention to prevent MDR-GNB acquisition. As some strategies were differential for certain bacteria, our study highlighted the need for further evaluation of the most effective prevention strategies.

    Matched MeSH terms: Acinetobacter baumannii/drug effects
  16. Teerawattanapong N, Panich P, Kulpokin D, Na Ranong S, Kongpakwattana K, Saksinanon A, et al.
    Infect Control Hosp Epidemiol, 2018 05;39(5):525-533.
    PMID: 29580299 DOI: 10.1017/ice.2018.58
    OBJECTIVETo summarize the clinical burden (cumulative incidence, prevalence, case fatality rate and length of stay) and economic burden (healthcare cost) of healthcare-associated infections (HAIs) due to multidrug-resistant organisms (MDROs) among patients in intensive care units (ICUs) in Southeast Asia.DESIGNSystematic review.METHODSWe conducted a comprehensive literature search in PubMed, EMBASE, CINAHL, EconLit, and the Cochrane Library databases from their inception through September 30, 2016. Clinical and economic burdens and study quality were assessed for each included study.RESULTSIn total, 41 studies met our inclusion criteria; together, 22,876 ICU patients from 7 Southeast Asian countries were included. The cumulative incidence of HAI caused by A. baumannii (AB) in Southeast Asia is substantially higher than has been reported in other regions, especially carbapenem-resistant AB (CRAB; 64.91%) and multidrug-resistant AB (MDR-AB) (58.51%). Evidence of a dose-response relationship between different degrees of drug resistance and excess mortality due to AB infections was observed. Adjusted odds ratios were 1.23 (95% confidence interval [CI], 0.51-3.00) for MDR-AB, 1.72 (95% CI, 0.77-3.80) for extensively drug-resistant AB (XDR-AB), and 1.82 (95% CI, 0.55-6.00) for pandrug-resistant AB (PDR-AB). There is, however, a paucity of published data on additional length of stay and costs attributable to MDROs.CONCLUSIONSThis review highlights the challenges in addressing MDROs in Southeast Asia, where HAIs caused by MDR gram-negative bacteria are abundant and have a strong impact on society. With our findings, we hope to draw the attention of clinicians and policy makers to the problem of antibiotic resistance and to issue a call for action in the management of MDROs.Infect Control Hosp Epidemiol 2018;39:525-533.
    Matched MeSH terms: Acinetobacter Infections/drug therapy; Acinetobacter Infections/epidemiology; Acinetobacter baumannii/isolation & purification
  17. Kengkla K, Kongpakwattana K, Saokaew S, Apisarnthanarak A, Chaiyakunapruk N
    J Antimicrob Chemother, 2018 Jan 01;73(1):22-32.
    PMID: 29069421 DOI: 10.1093/jac/dkx368
    Objectives: To comprehensively compare and rank the efficacy and safety of available treatment options for patients with MDR and XDR Acinetobacter baumannii (AB) infection.

    Methods: We searched PubMed, Embase and the Cochrane register of trials systematically for studies that examined treatment options for patients with MDR- and XDR-AB infections until April 2016. Network meta-analysis (NMA) was performed to estimate the risk ratio (RR) and 95% CI from both direct and indirect evidence. Primary outcomes were clinical cure and microbiological cure. Secondary outcomes were all-cause mortality and nephrotoxic and non-nephrotoxic adverse events.

    Results: A total of 29 studies with 2529 patients (median age 60 years; 65% male; median APACHE II score 19.0) were included. Although there were no statistically significant differences between treatment options, triple therapy with colistin, sulbactam and tigecycline had the highest clinical cure rate. Colistin in combination with sulbactam was associated with a significantly higher microbiological cure rate compared with colistin in combination with tigecycline (RR 1.23; 95% CI 1.03-1.47) and colistin monotherapy (RR 1.21; 95% CI 1.06-1.38). No significant differences in all-cause mortality were noted between treatment options. Tigecycline-based therapy also appeared less effective for achieving a microbiological cure and is not appropriate for treating bloodstream MDR- and XDR-AB infections.

    Conclusions: Combination therapy of colistin with sulbactam demonstrates superiority in terms of microbiological cure with a safety profile similar to that of colistin monotherapy. Thus, our findings support the use of this combination as a treatment for MDR- and XDR-AB infections.

    Matched MeSH terms: Acinetobacter Infections/drug therapy*; Acinetobacter Infections/microbiology; Acinetobacter baumannii/drug effects*
  18. Purmal K, Chin S, Pinto J, Yin WF, Chan KG
    Int J Mol Sci, 2010 Sep 16;11(9):3349-56.
    PMID: 20957099 DOI: 10.3390/ijms11093349
    This study aimed to test the sterility of new unused orthodontic buccal tubes received from manufacturers. Four different types of buccal tubes were used straight from the manufactures package without any additional sterilizing step. Of these buccal tubes tested, three genera of bacteria, implicated as opportunistic pathogens, namely Micrococcus luteus, Staphylococcus haemolyticus and Acinetobacter calcoaceticus were recovered from these buccal tubes. Our data showing microbial contamination on buccal tubes highlights the need of sterilization before clinical use. We also suggest that manufacturers should list the sterility state of orthodontic buccal tubes on their packaging or instructions stating the need for sterilization.
    Matched MeSH terms: Acinetobacter calcoaceticus/isolation & purification
  19. How KY, Hong KW, Sam CK, Koh CL, Yin WF, Chan KG
    Front Microbiol, 2015;6:240.
    PMID: 25926817 DOI: 10.3389/fmicb.2015.00240
    Myriad proteobacteria use N-acyl homoserine lactone (AHL) molecules as quorum sensing (QS) signals to regulate different physiological functions, including virulence, antibiotic production, and biofilm formation. Many of these proteobacteria possess LuxI/LuxR system as the QS mechanism. Recently, we reported the 3.89 Mb genome of Acinetobacter sp. strain GG2. In this work, the genome of this long chain AHL-producing bacterium was unravelled which led to the molecular characterization of luxI homologue, designated as aciI. This 552 bp gene was cloned and overexpressed in Escherichia coli BL21(DE3). The purified protein was ∼20.5 kDa and is highly similar to several autoinducer proteins of LuxI family among Acinetobacter species. To verify the AHL synthesis activity of this protein, high-resolution liquid chromatography-mass spectrometry analysis revealed the production of 3-oxo-dodecanoyl-homoserine lactone and 3-hydroxy-dodecanoyl-homoserine lactone from induced E. coli harboring the recombinant AciI. Our data show for the first time, the cloning and characterization of the luxI homologue from Acinetobacter sp. strain GG2, and confirmation of its AHLs production. These data are of great significance as the annotated genome of strain GG2 has provided a valuable insight in the study of autoinducer molecules and its roles in QS mechanism of the bacterium.
    Matched MeSH terms: Acinetobacter
  20. Ng CK, How KY, Tee KK, Chan KG
    Genes (Basel), 2019 04 08;10(4).
    PMID: 30965610 DOI: 10.3390/genes10040282
    Quorum sensing (QS) is a cell-to-cell communication system that uses autoinducers as signaling molecules to enable inter-species and intra-species interactions in response to external stimuli according to the population density. QS allows bacteria such as Acinetobacter baumannii to react rapidly in response to environmental changes and hence, increase the chances of survival. A. baumannii is one of the causative agents in hospital-acquired infections and the number of cases has increased remarkably in the past decade. In this study, A. baumannii strain 863, a multidrug-resistant pathogen, was found to exhibit QS activity by producing N-acyl homoserine lactone. We identified the autoinducer synthase gene, which we named abaI, by performing whole genome sequencing analysis of A. baumannii strain 863. Using high resolution tandem triple quadrupole mass spectrometry, we reported that abaI of A. baumannii strain 863 produced 3-hydroxy-dodecanoyl-homoserine lactone. A gene deletion mutant was constructed, which confirmed the functionality of abaI. A growth defect was observed in the QS-deficient mutant strain. Transcriptome profiling was performed to determine the possible genes regulated by QS. Four groups of genes that showed differential expression were discovered, namely those involved in carbon source metabolism, energy production, stress response and the translation process.
    Matched MeSH terms: Acinetobacter Infections/genetics*; Acinetobacter Infections/microbiology; Acinetobacter Infections/pathology; Acinetobacter baumannii/genetics*; Acinetobacter baumannii/pathogenicity
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