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Campbell R, Buchbinder NW, Szwetkowski C, Zhu Y, Piedl K, Truong M, Matson JB, Santos WL, Mevers E. Design, Synthesis, and Antifungal Activity of 3-Substituted-2( 5H)-Oxaboroles. ACS Med Chem Lett 2024; 15:349-354. [PMID: 38505851 PMCID: PMC10945556 DOI: 10.1021/acsmedchemlett.3c00463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 03/21/2024] Open
Abstract
Next generation antimicrobial therapeutics are desperately needed as new pathogens with multiple resistance mechanisms continually emerge. Two oxaboroles, tavaborole and crisaborole, were recently approved as topical treatments for onychomycosis and atopic dermatitis, respectively, warranting further studies into this privileged structural class. Herein, we report the antimicrobial properties of 3-substituted-2(5H)-oxaboroles, an unstudied family of medicinally relevant oxaboroles. Our results revealed minimum inhibitory concentrations as low as 6.25 and 5.20 μg/mL against fungal (e.g., Penicillium chrysogenum) and yeast (Saccharomyces cerevisiae) pathogens, respectively. These oxaboroles were nonhemolytic and nontoxic to rat myoblast cells (H9c2). Structure-activity relationship studies suggest that planarity is important for antimicrobial activity, possibly due to the effects of extended conjugation between the oxaborole and benzene rings.
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Affiliation(s)
- Rose Campbell
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | | | - Connor Szwetkowski
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Yumeng Zhu
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Karla Piedl
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Mindy Truong
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - John B. Matson
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Webster L. Santos
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Emily Mevers
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
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Akbar N, Kawish M, Jabri T, Khan NA, Shah MR, Siddiqui R. Enhancing efficacy of existing antibacterials against selected multiple drug resistant bacteria using cinna mic acid-coated magnetic iron oxide and mesoporous silica nanoparticles. Pathog Glob Health 2022; 116:438-454. [PMID: 34937524 PMCID: PMC9518276 DOI: 10.1080/20477724.2021.2014235] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Developing new antibacterial drugs by using traditional ways is insufficient to meet existing challenges; hence, new strategies in the field of antibacterial discovery are necessary. An alternative strategy is to improve the efficacy of currently available antibiotics. Herein, the antibacterial efficacy of drugs (Cefixime, Sulfamethoxazole, and Moxifloxacin) and drug-loaded cinnamic acid-coated magnetic iron oxide and mesoporous silica nanoparticles (NPs) was elucidated versus Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, neuropathogenic Escherichia coli K1 and Serratia marcescens) and Gram-positive bacteria (Methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Streptococcus pneumoniae, and Bacillus cereus). NPs were synthesized by co-precipitation and the Stöber method, and characterized by Fourier transform-infrared spectroscopy, Zetasizer, and Atomic force microscopy. Lactate dehydrogenase (LDH) assays were accomplished to determine drug cytotoxicity against human cells. Spherical NPs in the range of 118-362 nm were successfully synthesized. Antibacterial assays revealed that drugs conjugated with NPs portray enhanced bactericidal efficacies against multiple drug resistant bacteria compared to the drugs alone. Of note, Cefixime-conjugated NPs against Escherichia coli K1 and Methicillin- resistant Staphylococcus aureus, resulted in the complete eradication of all bacterial isolates tested at significantly lower concentrations compared to the antibiotics alone. Likewise, conjugation of Moxifloxacin resulted in the complete elimination of E. coli K1 and MRSA. Of note, nano-formulated drugs presented negligible cytotoxicity against human cells. These results depict potent, and enhanced efficacy of nano-formulated drugs against medically important bacteria and can be used as alternatives to current antibiotics. Future in vivo studies and clinical studies are warranted in prospective years to realize these expectations.
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Affiliation(s)
- Noor Akbar
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, UAE
| | - Muhammad Kawish
- International Centre for Chemical and Biological Sciences, H.e.j. Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Tooba Jabri
- International Centre for Chemical and Biological Sciences, H.e.j. Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah, UAE,CONTACT Naveed Ahmed Khan Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah27272, UAE
| | - Muhammad Raza Shah
- International Centre for Chemical and Biological Sciences, H.e.j. Research Institute of Chemistry, University of Karachi, Karachi, Pakistan
| | - Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, UAE
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Raval YS, Flurin L, Mohamed A, Greenwood-Quaintance KE, Beyenal H, Patel R. in vitro Activity of Hydrogen Peroxide and Hypochlorous Acid Generated by Electroche mical Scaffolds Against Planktonic and Biofilm Bacteria. Antimicrob Agents Chemother 2021; 65:AAC. [PMID: 33649112 DOI: 10.1128/AAC.01966-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) are biocides used for cleaning and debriding chronic wound infections, which often harbor drug resistant bacteria. Here, we evaluated the in vitro activity of H2O2 and HOCl against 27 isolates of eight bacterial species involved in wound infections. Minimum inhibitory concentrations (MICs) and minimum biofilm bactericidal concentrations (MBBCs) were measured. When compared to their respective MICs, MBBCs of isolates exposed to H2O2 were 16- to 1,024-fold higher and those exposed to HOCl were 2- to 4-fold higher. We evaluated selection of resistance after exposure of Staphylococcus aureus and Pseudomonas aeruginosa biofilms to 10 iterations of electrochemically generated HOCl or H2O2 delivered using electrochemical scaffolds (e-scaffolds), observing no decrease in anti-biofilm effects with serial exposure to e-scaffold-generated H2O2 or HOCl. 24-hour exposure to H2O2-generating e-scaffolds consistently decreased colony forming units (CFUs) of S. aureus and P. aeruginosa biofilms by ∼5.0-log10 and ∼4.78-log10 through 10 iterations of exposure, respectively. 4-hour exposure to HOCl-generating e-scaffolds consistently decreased CFUs of S. aureus biofilms by ∼4.9-log10, and 1-hour exposure to HOCl-generating e-scaffolds consistently decreased CFUs of P. aeruginosa biofilms by ∼1.57-log10 These results suggest that HOCl has similar activity against planktonic and biofilm bacteria, whereas the activity of H2O2 is less against biofilm than planktonic bacteria, and that repeat exposure to either biocide, generated electrochemically under the experimental conditions studied, does not lessen antibiofilm effects.
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Devi A, Chiu YT, Hsueh HT, Lin TF. Quantitative PCR based detection system for cyanobacterial geosmin/2-methylisoborneol (2-MIB) events in drinking water sources: Current status and challenges. Water Res 2021; 188:116478. [PMID: 33045635 DOI: 10.1016/j.watres.2020.116478] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/14/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Taste and odor (T&O) are an important issue in drinking water, aquaculture, recreation and a few other associated industries, and cyanobacteria-relevant geosmin and 2-methylisoborneol (2-MIB) are the two most commonly detected T&O compounds worldwide. A rise in the cyanobacterial blooms and associated geosmin/2-MIB episodes due to anthropogenic activities as well as climate change has led to global concerns for drinking water quality. The increasing awareness for the safe drinking, aquaculture or recreational water systems has boost the demand for rapid, robust, on-site early detection and monitoring system for cyanobacterial geosmin/2-MIB events. In past years, research has indicated quantitative PCR (qPCR) as one of the promising tools for detection of geosmin/2-MIB episodes. It offers advantages of detecting the source organism even at very low concentrations, distinction of odor-producing cyanobacterial strains from non-producers and evaluation of odor producing potential of the cyanobacteria at much faster rates compared to conventional techniques.The present review aims at examining the current status of developed qPCR primers and probes in identifying and detecting the cyanobacterial blooms along with geosmin/2-MIB events. Among the more than 100 articles about cyanobacteria associated geosmin/2-MIB in drinking water systems published after 1990, limited reports (approx. 10 each for geosmin and 2-MIB) focused on qPCR detection and its application in the field. Based on the review of literature, a comprehensive open access global cyanobacterial geosmin/2-MIB events database (CyanoGM Explorer) is curated. It acts as a single platform to access updated information related to origin and geographical distribution of geosmin/2-MIB events, cyanobacterial producers, frequency, and techniques associated with the monitoring of the events. Although a total of 132 cyanobacterial strains from 21 genera and 72 cyanobacterial strains from 13 genera have been reported for geosmin and 2-MIB production, respectively, only 58 geosmin and 28 2-MIB synthesis regions have been assembled in the NCBI database. Based on the identity, geosmin sequences were found to be more diverse in the geosmin synthase conserved/primer design region, compared to 2-MIB synthesis region, hindering the design of universal primers/probes. Emerging technologies such as the bioelectronic nose, Surface Enhanced Raman Scattering (SERS), and nanopore sequencing are discussed for future applications in early on-site detection of geosmin/2-MIB and producers. In the end, the paper also highlights various challenges in applying qPCR as a universal system of monitoring and development of response system for geosmin/2-MIB episodes.
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Affiliation(s)
- Apramita Devi
- Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan ROC
| | - Yi-Ting Chiu
- Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan ROC
| | - Hsin-Ta Hsueh
- Sustainable Environment Research Laboratories, National Cheng Kung University, Tainan 70101, Taiwan ROC
| | - Tsair-Fuh Lin
- Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan ROC.
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Li P, Yin YL, Guo T, Sun XY, Ma H, Zhu ML, Zhao FR, Xu P, Chen Y, Wan GR, Jiang F, Peng QS, Liu C, Liu LY, Wang SX. Inhibition of Aberrant MicroRNA-133a Expression in Endothelial Cells by Statin Prevents Endothelial Dysfunction by Targeting GTP Cyclohydrolase 1 in Vivo. Circulation 2016; 134:1752-1765. [PMID: 27765794 PMCID: PMC5120771 DOI: 10.1161/circulationaha.116.017949] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/20/2016] [Indexed: 12/17/2022]
Abstract
Supplemental Digital Content is available in the text. Background: GTP cyclohydrolase 1 (GCH1) deficiency is critical for endothelial nitric oxide synthase uncoupling in endothelial dysfunction. MicroRNAs (miRs) are a class of regulatory RNAs that negatively regulate gene expression. We investigated whether statins prevent endothelial dysfunction via miR-dependent GCH1 upregulation. Methods: Endothelial function was assessed by measuring acetylcholine-induced vasorelaxation in the organ chamber. MiR-133a expression was assessed by quantitative reverse transcription polymerase chain reaction and fluorescence in situ hybridization. Results: We first demonstrated that GCH1 mRNA is a target of miR-133a. In endothelial cells, miR-133a was robustly induced by cytokines/oxidants and inhibited by lovastatin. Furthermore, lovastatin upregulated GCH1 and tetrahydrobiopterin, and recoupled endothelial nitric oxide synthase in stressed endothelial cells. These actions of lovastatin were abolished by enforced miR-133a expression and were mirrored by a miR-133a antagomir. In mice, hyperlipidemia- or hyperglycemia-induced ectopic miR-133a expression in the vascular endothelium, reduced GCH1 protein and tetrahydrobiopterin levels, and impaired endothelial function, which were reversed by lovastatin or miR-133a antagomir. These beneficial effects of lovastatin in mice were abrogated by in vivo miR-133a overexpression or GCH1 knockdown. In rats, multiple cardiovascular risk factors including hyperglycemia, dyslipidemia, and hyperhomocysteinemia resulted in increased miR-133a vascular expression, reduced GCH1 expression, uncoupled endothelial nitric oxide synthase function, and induced endothelial dysfunction, which were prevented by lovastatin. Conclusions: Statin inhibits aberrant miR-133a expression in the vascular endothelium to prevent endothelial dysfunction by targeting GCH1. Therefore, miR-133a represents an important therapeutic target for preventing cardiovascular diseases.
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Affiliation(s)
- Peng Li
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Ya-Ling Yin
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Tao Guo
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Xue-Ying Sun
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Hui Ma
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Mo-Li Zhu
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Fan-Rong Zhao
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Ping Xu
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Yuan Chen
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Guang-Rui Wan
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Fan Jiang
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Qi-Sheng Peng
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Chao Liu
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Li-Ying Liu
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.)
| | - Shuang-Xi Wang
- From School of Pharmacy and School of Basic Medical Sciences, Xinxiang Medical University, China (P.L., Y.-L.Y., M.-L.Z., F.-R.Z., P.X., G.-R.W., S.-X.W.); The Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China (T.G., H.M., Y.C., F.J., S.-X.W.); Department of Pharmacology, School of Pharmacy, Central South University, Changsha, China (X.-Y.S., L.-Y.L.); The Key Laboratory for Zoonosis Research, Institute of Zoonosis, Jilin University, Changchun, China (Q.-S.P.); and Hubei Key Laboratory of Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, China (C.L.).
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Foongladda S, Banu S, Pholwat S, Gratz J, O-Thong S, Nakkerd N, Chinli R, Ferdous SS, Rahman SMM, Rahman A, Ahmed S, Heysell S, Sariko M, Kibiki G, Houpt E. Comparison of TaqMan(®) Array Card and MYCOTB(TM) with conventional phenotypic susceptibility testing in MDR-TB. Int J Tuberc Lung Dis 2016; 20:1105-12. [PMID: 27393547 PMCID: PMC4937751 DOI: 10.5588/ijtld.15.0896] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/27/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although phenotypic drug susceptibility testing (DST) is endorsed as the standard for second-line drug testing of Mycobacterium tuberculosis, it is slow and laborious. METHODS We evaluated the accuracy of two faster, easier methodologies that provide results for multiple drugs: a genotypic TaqMan(®) Array Card (TAC) and the Sensititre(®) MYCOTB(TM) plate. Both methods were tested at three central laboratories in Bangladesh, Tanzania, and Thailand with 212 multidrug-resistant tuberculosis (MDR-TB) isolates and compared with the laboratories' phenotypic method in use. RESULTS The overall accuracy for ethambutol, streptomycin, amikacin, kanamycin, ofloxacin, and moxifloxacin vs. the phenotypic standard was 87% for TAC (range 70-99) and 88% for the MYCOTB plate (range 76-98). To adjudicate discordances, we re-defined the standard as the consensus of the three methods, against which the TAC and MYCOTB plate yielded 94-95% accuracy, while the phenotypic result yielded 93%. Some isolates with genotypic mutations and high minimum inhibitory concentration (MIC) were phenotypically susceptible, and some isolates without mutations and low MIC were phenotypically resistant, questioning the phenotypic standard. CONCLUSIONS In our view, the TAC, the MYCOTB plate, and the conventional phenotypic method have similar performance for second-line drugs; however, the former methods offer speed, throughput, and quantitative DST information.
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Affiliation(s)
- S Foongladda
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - S Banu
- International Center for Diarrheal Diseases and Research, Dhaka, Bangladesh
| | - S Pholwat
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - J Gratz
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - S O-Thong
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - N Nakkerd
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - R Chinli
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - S S Ferdous
- International Center for Diarrheal Diseases and Research, Dhaka, Bangladesh
| | - S M M Rahman
- International Center for Diarrheal Diseases and Research, Dhaka, Bangladesh
| | - A Rahman
- International Center for Diarrheal Diseases and Research, Dhaka, Bangladesh
| | - S Ahmed
- International Center for Diarrheal Diseases and Research, Dhaka, Bangladesh
| | - S Heysell
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - M Sariko
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - G Kibiki
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - E Houpt
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
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Moreno LZ, Miraglia F, Lilenbaum W, Neto JSF, Freitas JC, Morais ZM, Hartskeerl RA, da Costa BLP, Vasconcellos SA, Moreno AM. Profiling of Leptospira interrogans, L. santarosai, L. meyeri and L. borgpetersenii by SE-AFLP, PFGE and susceptibility testing--a continuous attempt at species and serovar differentiation. Emerg Microbes Infect 2016; 5:e17. [PMID: 26956446 PMCID: PMC4820670 DOI: 10.1038/emi.2016.16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/25/2015] [Accepted: 11/23/2015] [Indexed: 11/08/2022]
Abstract
Leptospirosis is a widespread systemic zoonosis, considered as reemerging in certain developing countries. Although the cross agglutinin absorption test is still considered the standard method for Leptospira identification, it presents several disadvantages. The aim of this study was to characterize Leptospira spp. isolated from various hosts by genotyping and broth microdilution susceptibility testing in an attempt to differentiate Leptospira species, serogroups and serovars. Forty-seven isolates were studied. They were previously serotyped, and species confirmation was performed by 16S rRNA sequencing. Single-enzyme amplified fragment length polymorphism (SE-AFLP) and pulsed-field gel electrophoresis (PFGE) analysis enabled the distinction of L. interrogans from L. santarosai, L. meyeri and L. borgpetersenii in two main clusters. Among L. interrogans, it was possible to differentiate into two new clusters the serogroup Icterohaemorrhagiae from the serogroups Canicola and Pomona. L. santarosai isolates presented higher genetic variation than the other species in both techniques. Interestingly, the minimum inhibitory concentration (MIC) cluster analysis also provided Leptospira serogroup differentiation. Further studies are necessary regarding serovar Bananal isolates, as they presented the highest MIC values for most of the antimicrobials tested. All studied techniques successfully distinguished Leptospira species and serogroups. Despite being library-dependent methods, these approaches are less labor intensive and more economically viable, particularly SE-AFLP, and can be implemented in most reference laboratories worldwide to enable faster Leptospira typing.
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Affiliation(s)
- Luisa Z Moreno
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
| | - Fabiana Miraglia
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
- Veterinary Bacteriology Laboratory, Department of Microbiology and Parasitology, Fluminense Federal University, Hernani Mello, 101 Niterói/RJ 24210 130, Brazil
| | - Walter Lilenbaum
- Veterinary Bacteriology Laboratory, Department of Microbiology and Parasitology, Fluminense Federal University, Hernani Mello, 101 Niterói/RJ 24210 130, Brazil
| | - José SF Neto
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
| | - Julio C Freitas
- Laboratory of Animal Leptospirosis, Londrina State University, Rod Celso Garcia Cid, Londrina/PR 86057 970, Brazil
| | - Zenaide M Morais
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
| | - Rudy A Hartskeerl
- WHO/FAO/OIE and National Leptospirosis Reference Centre, KIT Biomedical Research, Royal Tropical Institute, Amsterdam 391105, Netherlands
| | - Barbara LP da Costa
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
| | - Silvio A Vasconcellos
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
| | - Andrea M Moreno
- Laboratory of Molecular Epidemiology and Antimicrobial Resistance/Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/SP 05508 270, Brazil
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Bhaskar M, Dinoop KP, Mandal J. Characterization of ceftriaxone-resistant Aeromonas spp. isolates from stool samples of both children and adults in Southern India. J Health Popul Nutr 2015; 33:26. [PMID: 26825984 PMCID: PMC5025982 DOI: 10.1186/s41043-015-0036-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/22/2015] [Indexed: 05/05/2023]
Abstract
BACKGROUND Aeromonas species can cause a wide spectrum of illnesses varying from intestinal to extra intestinal and vary in their susceptibility to different antibiotics. The current study was undertaken to characterize the third generation cephalosporin-resistant strains of Aeromonas spp. which were isolated from stool specimens. METHODS Out of a total of 2780 stool samples, 29 Aeromonas spp. were identified, out of which, 9 were resistant to ceftriaxone by the Kirby-Bauer antibiotic testing method. These strains were subjected to minimum inhibitory concentration (MIC) determination by agar dilution for ceftriaxone. Phenotypic and genotypic testing of AmpC beta-lactamase and extended spectrum beta-lactamase (ESBL) were performed. Gene transfer was carried out to demonstrate transmissibility of these genetic elements by conjugation experiments. RESULTS Out of the 29 strains, 9 showed MIC of ≥4 μg/ml. Seven out of 9 showed presence of blaCTX-M, while 2 more strains showed the presence of inducible AmpC beta-lactamase and presence of MOX gene. Gene transfer experiments showed that these elements were transmissible to recipient (Escherichia coli J53 strain) in the presence of ceftriaxone. CONCLUSIONS Dissemination of these resistance determinants like plasmids is pivotal in the spread of these resistance genes into the aquatic environment into organisms like Aeromonas. This may further limit the future use of antibiotics for the treatment of diarrhoeal diseases. Hence, detection and antibiotic susceptibility testing of Aeromonas spp. should be performed when isolated from stool samples.
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Affiliation(s)
| | - K P Dinoop
- Department of Microbiology, JIPMER, Puducherry, India
| | - Jharna Mandal
- Department of Microbiology, JIPMER, Puducherry, India.
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Fomda BA, Khan A, Zahoor D. NDM-1 (New Delhi metallo beta lactamase-1) producing Gram-negative bacilli: emergence & clinical implications. Indian J Med Res 2014; 140:672-8. [PMID: 25579151 PMCID: PMC4311323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
UNLABELLED BACKGOUND & OBJECTIVES: Resistance to carbapenems in Gram-negative bacteria conferred by NDM-1 is a global health problem. We investigated the occurrence of NDM-1 in clinical isolates of Gram-negative bacilli in a tertiary care hospital in Kashmir valley, India. METHODS Gram-negative bacilli from different clinical isolates were included in the study. Antimicrobial susceptibility was performed by Kirby Bauer disk diffusion method and interpreted using Clinical Laboratory Standards Institute (CLSI) guidelines. Isolates resistant to carbapenems were subjected to different phenotypic test such as modified Hodge test (MHT), boronic acid and oxacillin based MHT ( BA-MHT and OXA-MHT), combined disk test and minimum inhibitory concentration (MIC) with imipenem and imipenem -EDTA for determination of class B metallo enzymes. Presence of blaNDM-1 gene was established by PCR and confirmed by sequencing. RESULTS Of the total 1625 Gram-negative isolates received, 100 were resistant to imipenem. Of the 100 isolates, 55 (55%) were positive by modified Hodge test indicating carbapenemase production. Of the 100 isolates tested by MHT, BA-MHT and OXA-MHT, 29 (29%) isolates belonged to Class A and 15 (15%) to Class B, while 56 (56%) isolates were negative. Of the 15 class B metallo beta lactamase producers, nine carried the bla(NDM-1) gene. NDM-1 was found among Escherichia coli (2 isolates), Klebsiella pneumoniae (2 isolates), Citrobacter freundii (3 isolates), Acinetobacter spp (1 isolate), and one isolate of Pseudomonas aeruginosa. Isolates were resistant to all antibiotic tested except polymyxin B and tigecycline. INTERPRETATION & CONCLUSIONS Our study showed the presence of clinical isolates expressing NDM-1 in Srinagar, Jammu & Kashmir, India. These isolates harbour plasmid mediated multiple drug resistant determinants and can disseminate easily across several unrelated genera. To halt their spread, early identification of these isolates is mandatory.
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Affiliation(s)
- Bashir Ahmad Fomda
- Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu & Kashmir, India,Reprint requests: Dr Bashir Ahmad Fomda, Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar 190 011, Jammu & Kashmir, India e-mail:
| | - Asiya Khan
- Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu & Kashmir, India
| | - Danish Zahoor
- Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu & Kashmir, India
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Gaidhani SV, Raskar AV, Poddar S, Gosavi S, Sahu PK, Pardesi KR, Bhide SV, Chopade BA. Time dependent enhanced resistance against antibiotics & metal salts by planktonic & biofilm form of Acinetobacter haemolyticus MMC 8 clinical isolate. Indian J Med Res 2014; 140:665-71. [PMID: 25579150 PMCID: PMC4311322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND & OBJECTIVES Available literature shows paucity of reports describing antibiotic and metal resistance profile of biofilm forming clinical isolates of Acinetobacter haemolyticus. The present study was undertaken to evaluate the antibiotic and metal resistance profile of Indian clinical isolate of A. haemolyticus MMC 8 isolated from human pus sample in planktonic and biofilm form. METHODS Antibiotic susceptibility and minimum inhibitory concentration were determined employing broth and agar dilution techniques. Biofilm formation was evaluated quantitatively by microtiter plate method and variation in complex architecture was determined by scanning electron microscopy. Minimum biofilm inhibiting concentration was checked by Calgary biofilm device. RESULTS Planktonic A. haemolyticus MMC 8 was sensitive to 14 antibiotics, AgNO 3 and HgC1 2 resistant to streptomycin and intermediately resistant to netilmycin and kanamycin. MMC 8 exhibited temporal variation in amount and structure of biofilm. There was 32-4000 and 4-256 fold increase in antibiotic and metal salt concentration, respectively to inhibit biofilm over a period of 72 h as against susceptible planktonic counterparts. Total viable count in the range of 10(5)-10(6) cfu / ml was observed on plating minimum biofilm inhibiting concentration on Muller-Hinton Agar plate without antimicrobial agents. Biofilm forming cells were several folds more resistant to antibiotics and metal salts in comparison to planktonic cells. Presence of unaffected residual cell population indicated presence of persister cells. INTERPRETATION & CONCLUSIONS The results indicate that biofilm formation causes enhanced resistance against antibiotics and metal salts in otherwise susceptible planktonic A. haemolyticus MMC 8.
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Affiliation(s)
| | | | | | - Shriya Gosavi
- Department of Microbiology, University of Pune, Pune, India
| | | | | | | | - Balu Ananada Chopade
- Institute of Bioinformatics & Biotechnology, University of Pune, Pune, India,Reprint requests: Prof. B.A. Chopade, Department of Microbiology, University of Pune, Pune 411 007, Maharashtra, India e-mail:
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Praharaj I, Sujatha S, Parija SC. Phenotypic & genotypic characterization of vancomycin resistant Enterococcus isolates from clinical specimens. Indian J Med Res 2013; 138:549-56. [PMID: 24434263 PMCID: PMC3868069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND & OBJECTIVES Enterococci have emerged as important nosocomial pathogens and emergence of resistance to many of the antimicrobials used for Gram-positive organisms has made the management of infections due to Enterococcus species difficult. Resistance to glycopeptide antibiotics, especially vancomycin is of special concern. This study was undertaken to perform a phenotypic and genotypic characterization of vancomycin resistant Enterococcus (VRE) isolates obtained from clinical samples in a tertiary care hospital in southern India. METHODS Susceptibility testing was performed for Enterococcus isolates collected over a period of one year (November 2008-October 2009). Minimum inhibitory concentrations (MIC) of vancomycin and teicoplanin were determined for the isolates by the agar dilution method. Genotypic characterization of VRE isolates was done by performing multiplex polymerase chain reaction (PCR) for detecting the various vancomycin resistance genes. RESULTS Of the 367 isolates of Enterococcus species isolated, 32 were found to be resistant to vancomycin after MIC testing. VanA was the commonest phenotype of vancomycin resistance and the commonest genotype was vanA. Among the other important findings of the study was the presence of heterogeneity in isolates of VRE with the vanA gene cluster with regards to resistance to teicoplanin and the coexistence of vanA and vanC1 gene clusters in an isolate of E. gallinarum which conferred high level glycopeptide resistance to the isolate. INTERPRETATION & CONCLUSIONS Enterococcus species have emerged as important nosocomial pathogens in our patients with a capacity to cause a variety of infections. The vancomycin resistance among Enterococcus isolates was 8.7 per cent in our study which was high compared to other Indian studies. VanA was the commonest phenotype of glycopeptide resistance and vanA was the commonest vancomycin resistance gene. The study also demonstrates phenotypic as well as genotypic heterogeneity among isolates of VRE from clinical specimens.
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Affiliation(s)
- Ira Praharaj
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India,Reprint requests: Dr Ira Praharaj, Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry 605 006, India e-mail:
| | - S. Sujatha
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
| | - Subhash Chandra Parija
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India
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Nasser NE, Abbas AT, Hamed SL. Bacterial contamination in intensive care unit at Al-Imam Al-Hussein Hospital in Thi-qar province in Iraq. Glob J Health Sci 2012; 5:143-9. [PMID: 23283046 PMCID: PMC4776990 DOI: 10.5539/gjhs.v5n1p143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 11/11/2012] [Indexed: 12/04/2022] Open
Abstract
Cross- infection from patient to patient or from hospital personnel to patients represents constant hazards. It is one of the most important causes of morbidity and mortality especially in Intensive Care Unit all over the world. To identify the types and the source of bacterial contamination in ICU and to study the sensitivity of bacterial isolates to commonly used antibiotics in hospitals this study had been conducted in Al-Imam Al-Hussein hospital in Thi-qar province for the period from the 1st of September to the end of December 2011. A total of 320 swabs and samples were collected from 17 different sites of Intensive Care Unit environment and inoculated on a normal cultural media, then incubated at 37°C for 24 hour. The obtained growth revealed different bacterial colonies which had been tested for their morphological and biochemical characteristics. Sixty eight of pure isolates were obtained including 24 (35.29%) Gram positive bacterial isolates, and 44(64.71%) of Gram negative bacterial isolates, the highest rates (19.11%) of bacterial contamination had been found on the walls and the floor. Sensitivity tests for all isolates were done using 25 types of commonly used antibiotics in Iraq, among Gram negative bacteria and gram positive bacteria the genus Enterobacter spp and Staphylococcus spp respectively, showed the highest resistance to most of the tested antibiotics, MIC tests for 5 types of antibiotics being applied for the most resistant and the most sensitive isolates had identified that all isolates have a low rate of MIC against Ciprofloxacine. Bacillus spp and Enterobacter spp were the most prevalent bacterial contaminants of Intensive Care Unit environment .such contamination could be managed mostly by strict application of sterilization measures.
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Rocha PMDM, Rodilla JM, Díez D, Elder H, Guala MS, Silva LA, Pombo EB. Synergistic antibacterial activity of the essential oil of aguaribay (Schinus molle L.). Molecules 2012; 17:12023-36. [PMID: 23085653 PMCID: PMC6268320 DOI: 10.3390/molecules171012023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 08/17/2012] [Accepted: 09/21/2012] [Indexed: 11/20/2022] Open
Abstract
Schinus molle L. (aguaribay, aroeira-falsa, "molle", family Anacardiaceae), a native of South America, produces an active antibacterial essential oil extracted from the leaves and fruits. This work reports a complete study of its chemical composition and determines the antibacterial activity of Schinus molle L. essential oil and its main components. The results showed that the crude extract essential oil has a potent antibacterial effect on Staphylococcus aureus ATCC 25923, a strong/moderate effect on Escherichia coli ATCC 25922 and moderate/weak one on Pseudomonas aeruginosa ATCC 27853.
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Affiliation(s)
- Pedro M. de Mendonça Rocha
- Departamento de Química, Unidade I&D Materiais Têxteis e do Papel, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
| | - Jesus M. Rodilla
- Departamento de Química, Unidade I&D Materiais Têxteis e do Papel, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
| | - David Díez
- Departamento de Química Orgánica, Universidad de Salamanca, Plaza de los Caídos 1-5, 37008 Salamanca, Spain
| | - Heriberto Elder
- Departamento de Ingeniería Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, CP 3000, Santa Fe, Argentina
| | - Maria Silvia Guala
- Departamento de Ingeniería Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, CP 3000, Santa Fe, Argentina
| | - Lúcia A. Silva
- Departamento de Química, Unidade I&D Materiais Têxteis e do Papel, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
| | - Eunice Baltazar Pombo
- Departamento de Química, Unidade I&D Materiais Têxteis e do Papel, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
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De S. Retrospective analysis of lung function abnormalities of Bhopal gas tragedy affected population. Indian J Med Res 2012; 135:193-200. [PMID: 22446861 PMCID: PMC3336850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND & OBJECTIVES A large numbers of subjects were exposed to the aerosol of methyl isocyanate (MIC) during Bhopal gas disaster and lung was one of the most commonly affected organs. The aim of the present study was to analyze retrospectively the lung function abnormalities among the surviving MIC exposed population (gas victims) and to compare it with the non-MIC exposed (non gas exposed) population. METHODS The spirometry data of both gas victims and non gas exposed population who attended the Bhopal Memorial Hospital & Research Centre for evaluation of their respiratory complaints from August 2001 to December 2009, were retrospectively evaluated and compared. RESULTS A total 4782 gas victims and 1190 non gas exposed individuals performed spirometry during the study period. Among the gas victims, obstructive pattern was the commonest (50.8%) spirometric abnormality followed by restrictive pattern (13.3%). The increased relative risk of developing restrictive abnormality among gas victims was observed in 20-29 yr age group only (adjusted relative risk: 2.94, P<0.001). Male gas victims were more affected by severe airflow obstruction than females and the overall increased relative risk (1.33 to 1.45, P<0.001) of developing obstructive pattern among gas victims was observed. INTERPRETATION & CONCLUSIONS The present study showed that the relative risk for pulmonary function abnormalities in gas victims was significantly more among those who were young at the time of disaster. Increased smoking habit among gas victims might have played an additive effect on predominance of obstructive pattern in spirometry.
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Affiliation(s)
- Sajal De
- Department of Pulmonary Medicine, Bhopal Memorial Hospital & Research Centre, Bhopal, India,Reprint requests: Dr Sajal De, Qr No-8, Type III, Vivekananda Block, MGIMS Campus, Sevagram 442 102, India e-mail:
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Shakibaie MR, Adeli S, Salehi MH. Antibiotic resistance patterns and extended-spectrum β-lactamase production among Acinetobacter spp. isolated from an intensive care Unit of a hospital in Kerman, Iran. Antimicrob Resist Infect Control 2012; 1:1. [PMID: 22958725 PMCID: PMC3415115 DOI: 10.1186/2047-2994-1-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 01/26/2012] [Indexed: 02/08/2023] Open
Abstract
UNLABELLED BACKGROUND The global increase in multidrug resistance of Acinetobacter spp. has created widespread problems in the treatment of patients in intensive care units (ICUs) of hospitals. To assess the sensitivity of Acinetobacter isolates to antibiotics routinely used in ICUs, we investigated antibiotic resistance patterns and extended-spectrum β-lactamase (ESBL) production among Acinetobacter spp. isolated from the ICU of a university hospital in Kerman, Iran. METHODS Fifteen isolates of Acinetobacter spp. were recovered from one hundred clinical specimens collected from the ICU of Afzalipoor Hospital in Kerman, Iran, from October 2010 to June 2011. Preliminary antibiotic sensitivity testing was carried out using the disk-diffusion breakpoint assay, and MICs of different antibiotics were determined using the E-test. ESBL production was detected by a double-disk synergy test and confirmed by a phenotypic confirmatory test. Substrate hydrolysis in the presence and absence of the following inhibitors was carried out using the rapid fixed-time method: para-chloromercuribenzoate (p-CMB), clavulanic acid, sulbactam, and NaCl. RESULTS Overall, 73.3% of the isolates were resistant to imipenem (MIC range 240-128 µg/mL) and 66% to ciprofloxacin (MIC range 240-64 ± 0.08 µg/mL). All of the isolates were fully resistant (MIC 240 µg/mL) to piperacillin, while 93.3%, 53.3%, and 93.3% were resistant to piperacillin + tazobactam (MIC 240 µg/mL), amikacin (MIC range 128-16 µg/mL), and cefepime (MIC range 240-60 µg/mL), respectively. The isolates were also resistant to chloramphenicol and tetracycline: MICs of these two agents were ≥ 240 µg/mL. The test for ESBL production was positive for only three isolates (nos. 1, 10, and 15). The rate of substrate hydrolysis was highest in the presence of p-CMB (80.2 ± 0.02) and lowest in the presence of NaCl (2.1 ± 0.01) (P ≤ 0.05). CONCLUSIONS Many isolates of Acinetobacter spp. are resistant to almost all antibiotics routinely used in the ICU of our hospital, including imipenem, ciprofloxacin, and piperacillin + tazobactam. Three isolates were ESBL producers. The other isolates exhibited high resistance to β-lactams, but they did not produce any ESBL enzymes.
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Affiliation(s)
| | - Saied Adeli
- Department of Microbiology, Kerman University of Medical Sciences, Kerman, Iran
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Singh M, Jadaun G, Ramdas, Srivastava K, Chauhan V, Mishra R, Gupta K, Nair S, Chauhan D, Sharma V, Venkatesan K, Katoch V. Effect of efflux pump inhibitors on drug susceptibility of ofloxacin resistant Mycobacterium tuberculosis isolates. Indian J Med Res 2011; 133:535-40. [PMID: 21623040 PMCID: PMC3121286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND & OBJECTIVES In drug resistant, especially multi-drug resistant (MDR) tuberculosis, fluoroquinolones (FQs) are used as second line drugs. However, the incidence of FQ-resistant Mycobacterium tuberculosis is rapidly increasing which may be due to extensive use of FQs in the treatment of various other diseases. The most important known mechanism i.e., gyrA mutation in FQ resistance is not observed in a significant proportion of FQ resistant M. tuberculosis isolates suggesting that the resistance may be because of other mechanisms such as an active drug efflux pump. In this study we evaluated the role of the efflux pumps in quinolone resistance by using various inhibitors such as carbonyl cyanide m-chlorophenyl hydrazone (CCCP), 2,4-dinitrophenol (DNP) and verapamil, in clinical isolates of M. tuberculosis. METHODS A total of 55 M. tuberculosis clinical isolates [45 ofloxacin (OFL) resistant and 10 ofloxacin sensitive] were tested by Resazurin microtitre assay (REMA) to observe the changes in ofloxacin minimum inhibitory concentration (MIC) levels in presence of efflux inhibitors as compared to control (without efflux inhibitor). RESULTS The MIC levels of OFL showed 2-8 folds reduction in presence of CCCP (16/45; 35.5%), verapamil (24/45; 53.3%) and DNP (21/45; 46.6%) while in case of isolates identified as OFL sensitive these did not show any effect on ofloxacin MICs. In 11 of 45 (24.5%) isolates change in MIC levels was observed with all the three inhibitors. Overall 30 (66.6%) isolates had reduction in OFL MIC after treatment with these inhibitors. A total of eight isolates were sequenced for gyrA gene, of which, seven (87.5%) showed known mutations. Of the eight sequenced isolates, seven (87.5%) showed 2 to 8 fold change in MIC in presence of efflux inhibitors. INTERPRETATION & CONCLUSIONS Our findings suggest the involvement of active efflux pumps of both Major Facilitator Super Family (MFS) family (inhibited by CCCP and DNP) and ATP Binding Cassette (ABC) transporters (inhibited by verapamil) in the development of OFL resistance in M. tuberculosis isolates. Epidemiological significance of these findings needs to be determined in prospective studies with appropriate number of samples/isolates.
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Affiliation(s)
- Mradula Singh
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - G.P.S. Jadaun
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Ramdas
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - K. Srivastava
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Vipin Chauhan
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Ritu Mishra
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Kavita Gupta
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Surya Nair
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - D.S. Chauhan
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - V.D. Sharma
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - K. Venkatesan
- Department of Biochemistry, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - V.M. Katoch
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India,Reprint requests: Dr V.M. Katoch, Secretary (Department of Health Research) & Director-General, Indian Council of Medical Research, V. Ramalingaswami Bhawan, Ansari Nagar, New Delhi 110 029, India e-mail:
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Penduka D, Okoh OO, Okoh AI. In-vitro antagonistic characteristics of crude aqueous and methanolic extracts of Garcinia kola (Heckel) seeds against some Vibrio bacteria. Molecules 2011; 16:2754-65. [PMID: 21441874 PMCID: PMC6260614 DOI: 10.3390/molecules16042754] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 03/18/2011] [Accepted: 03/22/2011] [Indexed: 10/25/2022] Open
Abstract
The methanolic and aqueous extracts of Garcinia kola seeds were screened for their anti-Vibrio activities against 50 Vibrio isolates obtained from wastewater final effluents in the Eastern Cape Province, South Africa. The crude extracts at 10 mg/mL exhibited appreciable inhibitory activities against most of the test Vibrio isolates, with zones of inhibition ranging from 10-19 mm for methanol extract and 8-15 mm for the aqueous extracts. The minimum inhibitory concentrations (MIC) of the methanol extract varied from 0.313 to 2.5 mg/mL while that for the aqueous extract was 10 mg/mL for all the susceptible Vibrio isolates. Rate of kill assay of the methanolic extracts against three selected Vibrio species showed bacteriostatic activities against all of them achieving 58% and 60% (Vibrio vulnificus AL042); 68% and 69% (Vibrio parahaemolyticus AL049); and 70% and 78% (Vibrio fluvialis AL040) killing of the test bacteria at 3× and 4 ×MIC values, respectively, after 2 h exposure time. We conclude that Garcinia kola seeds hold promise as a potential source of therapeutic compounds of relevance in Vibrio infections management.
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Affiliation(s)
- Dambudzo Penduka
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa; E-Mail:
| | - Omobola O. Okoh
- Department of Chemistry, University of Fort Hare, Alice, South Africa; E-Mail:
| | - Anthony I. Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa; E-Mail:
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Rajeh MAB, Zuraini Z, Sasidharan S, Latha LY, Amutha S. Assessment of Euphorbia hirta L. leaf, flower, stem and root extracts for their antibacterial and antifungal activity and brine shrimp lethality. Molecules 2010; 15:6008-18. [PMID: 20877206 PMCID: PMC6257735 DOI: 10.3390/molecules15096008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Revised: 08/07/2010] [Accepted: 08/20/2010] [Indexed: 11/16/2022] Open
Abstract
The antimicrobial activities of the methanolic extracts of Euphorbia hirta L leaves, flowers, stems and roots were evaluated against some medically important bacteria and yeast using the agar disc diffusion method. Four Gram positive (Staphylococcus aureus, Micrococcus sp., Bacillus subtilis and Bacillus thuringensis), four Gram negative (Escherichia coli, Klebsiella pneumonia, Salmonella typhi and P. mirabilis) and one yeast (Candida albicans) species were screened. Inhibition zones ranged between 16-29 mm. Leaves extract inhibited the growth of all tested microorganisms with large zones of inhibition, followed by that of flowers, which also inhibited all the bacteria except C. albicans. The most susceptible microbes to all extracts were S. aureus and Micrococcus sp. Root extract displayed larger inhibition zones against Gram positive bacteria than Gram negative bacteria and had larger inhibition zones compared to stem extract. The lowest MIC values were obtained with E. coli and C. albicans (3.12 mg/mL), followed by S. aureus (12.50 mg/mL) and P. mirabilis (50.00 mg/mL). All the other bacteria had MIC values of 100.00 mg/mL. Scanning Electron Microscopic (SEM) studies revealed that the cells exposed to leaf extract displayed a rough surface with multiple blends and invaginations which increased with increasing time of treatment, and cells exposed to leaf extract for 36 h showed the most damage, with abundant surface cracks which may be related to final cell collapse and loss of function. Time-kill assay of C. albicans indicated a primarily fungicidal effect at 1- and 2-fold MIC. E. hirta extracts had LC(50) values of 0.71, 0.66, 0.41 and 0.03 mg/mL for stems, leaves, roots and flowers, respectively against Artemia salina. Hence, these plants can be used to discover new bioactive natural products that may serve as leads in the development of new pharmaceuticals.
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Affiliation(s)
- Mohammad Abu Basma Rajeh
- School of Distance Education, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: (Z.Z)
| | - Zakaria Zuraini
- School of Distance Education, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: (Z.Z)
| | - Sreenivasan Sasidharan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: (S.S)
| | - Lachimanan Yoga Latha
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: (S.S)
| | - Santhanam Amutha
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: (S.S)
- School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India
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Abstract
Natural killer group 2, member D (NKG2D) is an activating receptor present on the surface of natural killer (NK) cells, some NKT cells, CD8(+) cytotoxic T cells, gammadelta T cells, and under certain conditions CD4(+) T cells. Present in both humans and mice, this highly conserved receptor binds to a surprisingly diverse family of ligands that are distant relatives of major histocompatibility complex class I molecules. There is increasing evidence that ligand expression can result in both immune activation (tumor clearance, viral immunity, autoimmunity, and transplantation) and immune silencing (tumor evasion). In this review, we describe this family of NKG2D ligands and the various mechanisms that control their expression in stressed and normal cells. We also discuss the host response to both membrane-bound and secreted NKG2D ligands and summarize the models proposed to explain the consequences of this differential expression.
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Affiliation(s)
- Marine Champsaur
- Department of Microbiology and Immunology, The Biomedical Sciences Graduate Program and The Cancer Research Institute, University of California San Francisco, San Francisco, CA 94143, USA
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Opintan JA, Newman MJ. Distribution of serogroups and serotypes of multiple drug resistant Shigella isolates. Ghana Med J 2007; 41:8-29. [PMID: 17622331 PMCID: PMC1890532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
SUMMARY BACKGROUND The distribution of Shigella serotypes is of epidemiological importance and antimicrobial therapy for shigellosis can prevent potential complications of shigellosis. Studies done fifty years ago in Ghana indicated the predominance of Shigella flexneri. OBJECTIVES To describe the distribution of Shigella serogroups and serotypes and their antibiogram profiles. STUDY DESIGN A prospective descriptive study. SETTING The Microbiology Department of the Korle Bu Teaching Hospital. METHODS Consecutive stool specimens from patients with diarrhoea submitted between February 2004 and June 2005 were cultured for Shigella and the isolates typed with commercial anti-sera. The susceptibilities of the isolates were also tested against eleven antimicrobial agents by the disc diffusion method. Minimum inhibitory concentrations (MIC) of isolates to ciprofloxacin were also determined by the E-test. RESULTS Five hundred and ninety four diarrhoea stool specimens yielded 24 Shigella isolates with the following serogroup distribution: S. flexneri 70.8%, S. dysenteriae 16.7%, S. sonnei 8.3% and S. boydii 4.2%. Approximately 96% of the isolates were multi-drug resistant but all twenty four were susceptible to nalidixic acid and the fluoroquinolones (ofloxacin and ciprofloxacin). The MICs of twenty one of the isolates to ciprofloxacin were </= 0.064 microg ml(-1). CONCLUSIONS The predominance of S. flexneri was confirmed and Shigella isolates from Accra are susceptible to nalidixic acid and the fluoroquinolones. Surveillance of antimicrobial resistance particularly to monitor the emergence of Shigella strains resistant to nalidixic acid and the fluoroquiolones is important.
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Estevez AY, Roberts RK, Strange K. Identification of store-independent and store-operated Ca2+ conductances in Caenorhabditis elegans intestinal epithelial cells. J Gen Physiol 2003; 122:207-23. [PMID: 12860924 PMCID: PMC2229548 DOI: 10.1085/jgp.200308804] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nematode Caenorhabditis elegans offers significant experimental advantages for defining the genetic basis of diverse biological processes. Genetic and physiological analyses have demonstrated that inositol-1,4,5-trisphosphate (IP3)-dependent Ca2+ oscillations in intestinal epithelial cells play a central role in regulating the nematode defecation cycle, an ultradian rhythm with a periodicity of 45-50 s. Patch clamp studies combined with behavioral assays and forward and reverse genetic screening would provide a powerful approach for defining the molecular details of oscillatory Ca2+ signaling. However, electrophysiological characterization of the intestinal epithelium has not been possible because of its relative inaccessibility. We developed primary intestinal epithelial cell cultures that circumvent this problem. Intestinal cells express two highly Ca2+-selective, voltage-independent conductances. One conductance, IORCa, is constitutively active, exhibits strong outward rectification, is 60-70-fold more selective for Ca2+ than Na+, is inhibited by intracellular Mg2+ with a K1/2 of 692 microM, and is insensitive to Ca2+ store depletion. Inhibition of IORCa with high intracellular Mg2+ concentrations revealed the presence of a small amplitude conductance that was activated by passive depletion of intracellular Ca2+ stores. Active depletion of Ca2+ stores with IP3 or ionomycin increased the rate of current activation approximately 8- and approximately 22-fold compared with passive store depletion. The store-operated conductance, ISOC, exhibits strong inward rectification, and the channel is highly selective for Ca2+ over monovalent cations with a divalent cation selectivity sequence of Ca2+ > Ba2+ approximately Sr2+. Reversal potentials for ISOC could not be detected accurately between 0 and +80 mV, suggesting that PCa/PNa of the channel may exceed 1,000:1. Lanthanum, SKF 96365, and 2-APB inhibit both IORCa and ISOC reversibly. Our studies provide the first detailed electrophysiological characterization of voltage-independent Ca2+ conductances in C. elegans and form the foundation for ongoing genetic and molecular studies aimed at identifying the genes that encode the intestinal cell channels, for defining mechanisms of channel regulation and for defining their roles in oscillatory Ca2+ signaling.
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Affiliation(s)
- Ana Y Estevez
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Dunn C, Chalupny NJ, Sutherland CL, Dosch S, Sivakumar PV, Johnson DC, Cosman D. Human cytomegalovirus glycoprotein UL16 causes intracellular sequestration of NKG2D ligands, protecting against natural killer cell cytotoxicity. J Exp Med 2003; 197:1427-39. [PMID: 12782710 PMCID: PMC2193902 DOI: 10.1084/jem.20022059] [Citation(s) in RCA: 223] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The activating receptor, NKG2D, is expressed on a variety of immune effector cells and recognizes divergent families of major histocompatibility complex (MHC) class I-related ligands, including the MIC and ULBP proteins. Infection, stress, or transformation can induce NKG2D ligand expression, resulting in effector cell activation and killing of the ligand-expressing target cell. The human cytomegalovirus (HCMV) membrane glycoprotein, UL16, binds to three of the five known ligands for human NKG2D. UL16 is retained in the endoplasmic reticulum and cis-Golgi apparatus of cells and causes MICB to be similarly retained and stabilized within cells. Coexpression of UL16 markedly reduces cell surface levels of MICB, ULBP1, and ULBP2, and decreases susceptibility to natural killer cell-mediated cytotoxicity. Domain swapping experiments demonstrate that the transmembrane and cytoplasmic domains of UL16 are important for intracellular retention of UL16, whereas the ectodomain of UL16 participates in down-regulation of NKG2D ligands. The intracellular sequestration of NKG2D ligands by UL16 represents a novel HCMV immune evasion mechanism to add to the well-documented viral strategies directed against antigen presentation by classical MHC molecules.
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Affiliation(s)
- Claire Dunn
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR 97239, USA
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