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Zhou S, Peng H, Zhao A, Zhang R, Li T, Yang X, Lin D. Synthesis of bacterial cellulose nanofibers/Ag nanoparticles: Structure, characterization and antibacterial activity. Int J Biol Macromol 2024; 259:129392. [PMID: 38218289 DOI: 10.1016/j.ijbiomac.2024.129392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/26/2023] [Accepted: 01/08/2024] [Indexed: 01/15/2024]
Abstract
The aim of this study was to compare the characterization of bacterial cellulose nanofibers/Ag nanoparticles (BCNs/Ag nanoparticles) obtained by three different pretreatment methods of BCNs (no pretreatment, sodium hydroxide activation pretreatment and TEMPO-mediated oxidation pretreatment), which were recoded as N-BCNs/Ag nanoparticles, A-BCNs/Ag nanoparticles and O-BCNs/Ag nanoparticles, respectively. The results of scanning electron microscopy and transmission electron microscopy showed the prepared Ag nanoparticles by three different pretreatment methods were spherical and dispersed on the surface of BCNs, while the Ag nanoparticles in O-BCNs/Ag nanoparticles displayed the smallest diameter with a value of 20.25 nm and showed the most uniform dispersion on the surface of BCNs. The ICP-MS result showed O-BCNs/Ag nanoparticles had the highest content of Ag nanoparticles with a value of 2.98 wt%, followed by A-BCNs/Ag nanoparticles (1.53 wt%) and N-BCNs/Ag nanoparticles (0.84 wt%). The cytotoxicity assessment showed that the prepared BCNs/Ag nanoparticles were relatively safe. Furthermore, the O-BCNs/Ag nanoparticles had the best antioxidant and antibacterial activities as compared with the other two types of BCNs/Ag nanoparticles, where O-BCNs/Ag nanoparticles destroyed the structure of bacterial cell membranes to lead the leakage of intracellular components. This study showed that O-BCNs/Ag nanoparticles as antibacterial agents have great potential in food packaging.
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Affiliation(s)
- Siyu Zhou
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China
| | - Haonan Peng
- Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Aiqing Zhao
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China
| | - Runguan Zhang
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China
| | - Ting Li
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China
| | - Xingbin Yang
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China
| | - Dehui Lin
- Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, Shaanxi Key Laboratory for Hazard Factors Assessment in Processing and Storage of Agricultural Products, and Xi'an Key Laboratory of Characteristic Fruit Storage and Preservation, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, China.
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Malik AQ, Mir TUG, Kumar D, Mir IA, Rashid A, Ayoub M, Shukla S. A review on the green synthesis of nanoparticles, their biological applications, and photocatalytic efficiency against environmental toxins. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27437-9. [PMID: 37171732 DOI: 10.1007/s11356-023-27437-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 05/01/2023] [Indexed: 05/13/2023]
Abstract
Green synthesis of nanoparticles (NPs) using plant materials and microorganisms has evolved as a sustainable alternative to conventional techniques that rely on toxic chemicals. Recently, green-synthesized eco-friendly NPs have attracted interest for their potential use in various biological applications. Several studies have demonstrated that green-synthesized NPs are beneficial in multiple medicinal applications, including cancer treatment, targeted drug delivery, and wound healing. Additionally, due to their photodegradation activity, green-synthesized NPs are a promising tool in environmental remediation. Photodegradation is a process that uses light and a photocatalyst to turn a pollutant into a harmless product. Green NPs have been found efficient in degrading pollutants such as dyes, herbicides, and heavy metals. The use of microbes and flora in green synthesis technology for nanoparticle synthesis is biologically safe, cost-effective, and eco-friendly. Plants and microbes can now use and accumulate inorganic metallic ions in the environment. Various NPs have been synthesized via the bio-reduction of biological entities or their extracts. There are several biological and environmental uses for biologically synthesized metallic NPs, such as photocatalysis, adsorption, and water purification. Since the last decade, the green synthesis of NPs has gained significant interest in the scientific community. Therefore, there is a need for a review that serves as a one-stop resource that points to relevant and recent studies on the green synthesis of NPs and their biological and photocatalytic efficiency. This review focuses on the green fabrication of NPs utilizing diverse biological systems and their applications in biological and photodegradation processes.
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Affiliation(s)
- Azad Qayoom Malik
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India, 144411.
| | - Tahir Ul Gani Mir
- School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab, India, 144411
| | - Deepak Kumar
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India, 144411
| | - Irtiqa Ashraf Mir
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India, 144411
| | - Adfar Rashid
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India, 144411
| | - Mehnaz Ayoub
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, Punjab, India, 144411
| | - Saurabh Shukla
- School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab, India, 144411
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Bardasheva AV, Fomenko NV, Kalymbetova TV, Babkin IV, Chretien SO, Zhirakovskaya EV, Tikunova NV, Morozova VV. Genetic characterization of clinical <I>Klebsiella</I> isolates circulating in Novosibirsk. Vavilovskii Zhurnal Genet Selektsii 2021; 25:234-245. [PMID: 35083398 PMCID: PMC8698097 DOI: 10.18699/vj21.49-o] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/30/2020] [Accepted: 12/08/2020] [Indexed: 11/19/2022] Open
Abstract
Проанализированы 72 клинических штамма Klebsiella spp., изолированных в Новосибирске из образцов, полученных от людей. Проведена видовая идентификация штаммов по последовательностям генов 16S рРНК
и rpoB. Показано, что в популяции клебсиелл доминировали штаммы Klebsiella pneumoniaе (57 штаммов), остальные
15 штаммов относились к видам K. grimontii, K. aerogenes, K. oxytoca и K. quasipneumoniae. Методом молекулярного
серотипирования с использованием последовательности гена wzi штаммы K. pneumoniae были отнесены к двадцати одному K-cеротипу, при этом большую долю составляли вирулентные серотипы K1 и K2. Выявлено, что штаммы
K. pneumoniae, полученные от госпитализированных пациентов, обладали максимально выраженной резистентностью к различным классам антибиотиков в отличие от остальных видов клебсиелл. Методом ПЦР в реальном времени обнаружено, что в исследованной популяции присутствуют гены семейств blaSHV, blaTEM, blaCTX и ген blaOXA-48 ,
являющиеся генетическими детерминантами резистентности к бета-лактамам. Показано, что присутствие последовательности blaCTX коррелирует с продукцией штаммом бета-лактамаз расширенного спектра, а фенотипическая
устойчивость к карбапенемам обусловлена наличием гена blaOXA-48 . При этом генов карбапенемаз vim, ndm, kpc, imp
обнаружено не было. Cреди исследованных генов устойчивости к аминогликозидам были найдены гены aph(6)-Id и
aadA, однако их наличие не всегда совпадало с фенотипической резистентностью. Устойчивость к фторхинолонам
у большинства штаммов сопровождалась присутствием генов aac(6’)-Ib-cr, oqxA, oqxB, qnrB и qnrS в различных комбинациях, при этом наличие только генов oqxA и/или oqxB не коррелировало с устойчивостью к фторхинолонам.
Таким образом, обнаружение blaCTX и blaOXA-48 может быть использовано для быстрого выявления продукции беталактамаз расширенного спектра и определения резистентности клебсиелл к карбапенемам, а выявление генов
aac(6’)-Ib-cr и/или qnrB/qnrS – для быстрого определения устойчивости к фторхинолонам
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Affiliation(s)
- A. V. Bardasheva
- Institute of Сhemical Biology аnd Fundamental Medicine of Siberian Branch of the Russian Academy of Sciences
| | | | | | - I. V. Babkin
- Institute of Сhemical Biology аnd Fundamental Medicine of Siberian Branch of the Russian Academy of Sciences
| | - S. O. Chretien
- Novosibirsk Research Institute of Traumatology and Orthopedics named after Ya.L. Tsivyan of the Ministry of Health of the Russian Federation
| | - E. V. Zhirakovskaya
- Institute of Сhemical Biology аnd Fundamental Medicine of Siberian Branch of the Russian Academy of Sciences
| | - N. V. Tikunova
- Institute of Сhemical Biology аnd Fundamental Medicine of Siberian Branch of the Russian Academy of Sciences
| | - V. V. Morozova
- Institute of Сhemical Biology аnd Fundamental Medicine of Siberian Branch of the Russian Academy of Sciences
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Weerasinghe J, Li W, Zhou R, Zhou R, Gissibl A, Sonar P, Speight R, Vasilev K, Ostrikov K(K. Bactericidal Silver Nanoparticles by Atmospheric Pressure Solution Plasma Processing. NANOMATERIALS 2020; 10:nano10050874. [PMID: 32369954 PMCID: PMC7279381 DOI: 10.3390/nano10050874] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 01/10/2023]
Abstract
Silver nanoparticles have applications in plasmonics, medicine, catalysis and electronics. We report a simple, cost-effective, facile and reproducible technique to synthesise silver nanoparticles via plasma-induced non-equilibrium liquid chemistry with the absence of a chemical reducing agent. Silver nanoparticles with tuneable sizes from 5.4 to 17.8 nm are synthesised and characterised using Transmission Electron Microscopy (TEM) and other analytic techniques. A mechanism for silver nanoparticle formation is also proposed. The antibacterial activity of the silver nanoparticles was investigated with gram-positive and gram-negative bacteria. The inhibition of both bacteria types was observed. This is a promising alternative method for the instant synthesis of silver nanoparticles, instead of the conventional chemical reduction route, for numerous applications.
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Affiliation(s)
- Janith Weerasinghe
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (P.S.); (K.O.)
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia
- Correspondence: ; Tel.: +61-481979488
| | - Wenshao Li
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (W.L.); (A.G.); (R.S.)
| | - Rusen Zhou
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane 4000, Queensland, Australia;
| | - Renwu Zhou
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney 2006, New South Wales, Australia;
| | - Alexander Gissibl
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (W.L.); (A.G.); (R.S.)
| | - Prashant Sonar
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (P.S.); (K.O.)
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia
| | - Robert Speight
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (W.L.); (A.G.); (R.S.)
| | - Krasimir Vasilev
- School of Engineering, University of South Australia, Adelaide 5001, South Australia, Australia;
| | - Kostya (Ken) Ostrikov
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, Queensland, Australia; (P.S.); (K.O.)
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, Queensland, Australia
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Hattori H, Maeda M, Nagatomo Y, Takuma T, Niki Y, Naito Y, Sasaki T, Ishino K. Epidemiology and risk factors for mortality in bloodstream infections: A single-center retrospective study in Japan. Am J Infect Control 2018; 46:e75-e79. [PMID: 30172607 DOI: 10.1016/j.ajic.2018.06.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/26/2018] [Accepted: 06/26/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Few published data are available on the morbidity and mortality of bloodstream infections (BSIs) in Japan. We sought to investigate the epidemiology of BSIs, the involvement of antimicrobial resistance, and the factors that influence patient prognosis. METHODS This single-center study retrospectively evaluated patients who were found to have positive blood cultures at a tertiary teaching hospital between January 2012 and December 2016. RESULTS A total of 2,105 patients with BSIs were included; 1,786 survived and 319 died, and the 30-day mortality rate was 15.2% over the 5-year study period. BSIs caused by yeasts were independently associated with 30-day mortality. The 30-day mortality rate of BSIs caused by extended-spectrum beta lactamase-producing gram-negative bacteria was significantly higher than that of BSIs caused by nonproducing bacteria. DISCUSSION The differences in mortality may be caused by differences in the distribution of pathogens and in the delivery of health care. CONCLUSIONS This study reported epidemiology and antimicrobial resistance data of BSIs in Japan and identified several risk factors associated with 30-day mortality. National surveillance of BSIs is required in Japan for comparison with other countries.
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Affiliation(s)
- Haruka Hattori
- Division of Infection Control Sciences, Department of Clinical Pharmacy, School of Pharmacy, Showa University, Tokyo, Japan; Department of Hospital Pharmaceutics, School of Pharmacy, Showa University, Tokyo, Japan
| | - Masayuki Maeda
- Division of Infection Control Sciences, Department of Clinical Pharmacy, School of Pharmacy, Showa University, Tokyo, Japan.
| | - Yasuhiro Nagatomo
- Division of Clinical Infectious Diseases, Department of Medicine, School of Medicine, Showa University, Tokyo, Japan
| | - Takahiro Takuma
- Division of Clinical Infectious Diseases, Department of Medicine, School of Medicine, Showa University, Tokyo, Japan
| | - Yoshihito Niki
- Division of Clinical Infectious Diseases, Department of Medicine, School of Medicine, Showa University, Tokyo, Japan
| | - Yuika Naito
- Department of Hospital Pharmaceutics, School of Pharmacy, Showa University, Tokyo, Japan
| | - Tadanori Sasaki
- Department of Hospital Pharmaceutics, School of Pharmacy, Showa University, Tokyo, Japan
| | - Keiko Ishino
- Division of Infection Control Sciences, Department of Clinical Pharmacy, School of Pharmacy, Showa University, Tokyo, Japan
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Bhuiya M, Sarkar MKI, Sohag MH, Ali H, Roy CK, Akther L, Sarker AF. Enumerating Antibiotic Susceptibility Patterns of Pseudomonas aeruginosa Isolated from Different Sources in Dhaka City. Open Microbiol J 2018; 12:172-180. [PMID: 29997702 PMCID: PMC5997856 DOI: 10.2174/1874285801812010172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/07/2018] [Accepted: 05/10/2018] [Indexed: 11/22/2022] Open
Abstract
Background: Pseudomonas aeruginosa is a ubiquitous free-living bacterium and is responsible for severe nosocomial infections, life-threatening infections in immune compromised persons. The bacterium, along with its natural resistance, can acquire resistance to many antibiotics by a variety of methods. Method: Therefore, to compare the antibiotic sensitivity pattern of Pseudomonas aeruginosa, a total of seventeen isolates of P. aeruginosa were isolated from different sources; for example environmental sources, frozen food sources, clinical sources and medical waste materials. Isolates were confirmed to be P. aeruginosa by cultural and biochemical properties. Result: The isolates were tested against seventeen commercially available antibiotics to observe the antibiotic susceptibility patterns. Imipenem and meropenem were the most potent antibiotics (100% sensitivity) followed by amikacin and piperacillin with maximum sensitivity. Among others, gentamicin, ciprofloxacin, levofloxacin and aztreonam were found to be fairly active. A good number of isolates were intermediately resistant to ceftriaxone. The rates of resistance to aztreonam, cefotaxime and ceftazidime were 11.76%, 82.35% and 5.88% respectively. Complete resistance was observed against penicillin, ampicillin, cefixime and cefpodoxime. Conclusion: It can be concluded that the clinical isolates including isolate from medical waste, were multi-drug resistant than environmental and food isolates indicating the risk of transmission of resistance to the environmental isolates of P. aeruginosa.
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Affiliation(s)
| | - Mohammad K I Sarkar
- Independent University, Bangladesh (IUB), Bashundhara R/A, Dhaka-1212, Bangladesh
| | | | - Hafij Ali
- Independent University, Bangladesh (IUB), Bashundhara R/A, Dhaka-1212, Bangladesh
| | - Chapol K Roy
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
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Molecular identification of TEM and SHV Genes in Extended Spectrum Beta-lactamase Producing Escherichia coli and Klebsiellae pneumoniae Isolates in a Tertiary Care Hospital, Bangladesh. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2017. [DOI: 10.22207/jpam.11.2.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abiala M, Olayiwola J, Babatunde O, Aiyelaagbe O, Akinyemi S. Evaluation of therapeutic potentials of plant extracts against poultry bacteria threatening public health. Altern Ther Health Med 2016; 16:417. [PMID: 27782860 PMCID: PMC5080767 DOI: 10.1186/s12906-016-1399-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 10/11/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Plant extracts were evaluated on poultry bacteria known to be threatening public health. This is to develop better bio-therapeutic agents from plant origin. METHODS Bacteria were isolated from water, feed, crop, gizzard and faeces of layer chicken. Isolates of interest (Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa and Klebsiella oxytoca) were subjected to antibiotic susceptibility test. Resistant strains were further evaluated against different plant extracts in comparison to Meropenem (control) using agar diffusion method. RESULTS E. coli had the highest occurrence (53 %), followed by P. aeruginosa (25 %) and then S. enteritidis (13 %) while the least was K. oxytoca (9 %). Virtually all the isolates exhibited multi-antibiotic resistance (MAR) with gross resistance to Amoxicillin, Erythromycin and Cefuroxine. P. aeruginosa (75 %), S. enteritidis (75 %) and E. coli (63 %), had the highest MAR. Out of the 11 (100 %) plant extracts evaluated, 7 (64 %) were outstanding and showed varied levels of antibacterial activity. Specifically, methanol extract of Mangifera indica Julie cultivar leaf (MJLM) had the highest antibacterial activity, followed by Euadenia trifoliata stem bark (TB03) and Euadenia eminens leaf (TB05). P. aeruginosa was highly susceptible (81.81 %) to the extracts, followed by S. enteritidis (63.64 %) and then E. coli (27.27 %). CONCLUSIONS MJLM and other extracts have proven to be promising extracts in which to search for bioactive components that can be developed into therapeutic drugs. This may help in the management of antibiotic resistant bacterial isolates from poultry chicken threatening public health.
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Plasmid-Mediated OqxAB Is an Important Mechanism for Nitrofurantoin Resistance in Escherichia coli. Antimicrob Agents Chemother 2015; 60:537-43. [PMID: 26552976 DOI: 10.1128/aac.02156-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/03/2015] [Indexed: 11/20/2022] Open
Abstract
Increasing consumption of nitrofurantoin (NIT) for treatment of acute uncomplicated urinary tract infections (UTI) highlights the need to monitor emerging NIT resistance mechanisms. This study investigated the molecular epidemiology of the multidrug-resistant efflux gene oqxAB and its contribution to nitrofurantoin resistance by using Escherichia coli isolates originating from patients with UTI (n = 205; collected in 2004 to 2013) and food-producing animals (n = 136; collected in 2012 to 2013) in Hong Kong. The oqxAB gene was highly prevalent among NIT-intermediate (11.5% to 45.5%) and -resistant (39.2% to 65.5%) isolates but rare (0% to 1.7%) among NIT-susceptible (NIT-S) isolates. In our isolates, the oqxAB gene was associated with IS26 and was carried by plasmids of diverse replicon types. Multilocus sequence typing revealed that the clones of oqxAB-positive E. coli were diverse. The combination of oqxAB and nfsA mutations was found to be sufficient for high-level NIT resistance. Curing of oqxAB-carrying plasmids from 20 NIT-intermediate/resistant UTI isolates markedly reduced the geometric mean MIC of NIT from 168.9 μg/ml to 34.3 μg/ml. In the plasmid-cured variants, 20% (1/5) of isolates with nfsA mutations were NIT-S, while 80% (12/15) of isolates without nfsA mutations were NIT-S (P = 0.015). The presence of plasmid-based oqxAB increased the mutation prevention concentration of NIT from 128 μg/ml to 256 μg/ml and facilitated the development of clinically important levels of nitrofurantoin resistance. In conclusion, plasmid-mediated oqxAB is an important nitrofurantoin resistance mechanism. There is a great need to monitor the dissemination of this transferable multidrug-resistant efflux pump.
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Al-Bayssari C, Dabboussi F, Hamze M, Rolain JM. Detection of expanded-spectrum β-lactamases in Gram-negative bacteria in the 21st century. Expert Rev Anti Infect Ther 2015; 13:1139-58. [PMID: 26162631 DOI: 10.1586/14787210.2015.1066247] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Emerging β-lactamase-producing-bacteria (ESBL, AmpC and carbapenemases) have become a serious problem in our community due to their startling spread worldwide and their ability to cause infections which are difficult to treat. Diagnosis of these β-lactamases is of clinical and epidemiological interest. Over the past 10 years, several methods have been developed aiming to rapidly detect these emerging enzymes, thus preventing their rapid spread. In this review, we describe the range of screening and detection methods (phenotypic, molecular and other) for detecting these β-lactamases but also whole genome sequencing as a tool for detecting the genes encoding these enzymes.
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Affiliation(s)
- Charbel Al-Bayssari
- Laboratoire Microbiologie Santé et Environnement (LMSE), Centre Azm pour la Recherche en Biotechnologie et ses Applications, Ecole Doctorale de Sciences et de Technologie, Université Libanaise, Tripoli, Liban
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Ho PL, Liu MCJ, Lo WU, Lai ELY, Lau TCK, Law OK, Chow KH. Prevalence and characterization of hybrid blaCTX-M among Escherichia coli isolates from livestock and other animals. Diagn Microbiol Infect Dis 2015; 82:148-53. [PMID: 25861872 DOI: 10.1016/j.diagmicrobio.2015.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/11/2015] [Accepted: 02/17/2015] [Indexed: 11/25/2022]
Abstract
This study investigated 248 extended-spectrum β-lactamase-producing Escherichia coli isolates from 2012 to 2013 for hybrid blaCTX-M genes. blaCTX-M genes were detected in 228 isolates of which 14 isolates were hybrid blaCTX-M positive (6 blaCTX-M-123, 6 blaCTX-M-64, and 2 blaCTX-M-132). The 14 hybrid blaCTX-M-carrying isolates (8 from chickens, 2 each from pigs and cattle, 1 each from dog and rodent) were genetically diverse. All but 2 hybrid blaCTX-M were carried on IncI1 (5 blaCTX-M-123) and IncI2 (6 blaCTX-M-64 and one blaCTX-M-132) plasmids. Our IncI1 and IncI2 plasmids had pHNAH4-1-like and pHN1122-1-like restriction fragment length polymorphism patterns, respectively. Genetic relatedness of the plasmids to pHNAH4-1 and pHN1122-1 were confirmed by complete sequencing of 3 plasmids, pCTXM123_C0996, pCTXM64_C0967, and pCTXM132_P0421. Plasmids closely related to pHNAH4-1 and pHN1122-1 and carrying different blaCTX-M alleles have been reported from multiple geographic areas in China previously. The findings highlighted the wide dissemination of hybrid blaCTX-M variants in different parts of China.
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Affiliation(s)
- Pak-Leung Ho
- Carol Yu Centre for Infection and Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China.
| | - Melissa Chun-Jiao Liu
- Carol Yu Centre for Infection and Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Wai-U Lo
- Carol Yu Centre for Infection and Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Eileen Ling-Yi Lai
- Carol Yu Centre for Infection and Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Terrence Chi-Kong Lau
- Department of Biomedical Sciences, College of Science and Engineering, City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Oi-Kwan Law
- Department of Biomedical Sciences, College of Science and Engineering, City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Kin-Hung Chow
- Carol Yu Centre for Infection and Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
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Nasreen M, Sarker A, Malek MA, Ansaruzzaman M, Rahman M. Prevalence and Resistance Pattern of <i>Pseudomonas aeruginosa</i> Isolated from Surface Water. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/aim.2015.51008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Osawa K, Shigemura K, Shimizu R, Kato A, Kimura M, Katayama Y, Okuya Y, Yutaka S, Nishimoto A, Kishi A, Fujiwara M, Yoshida H, Iijima Y, Fujisawa M, Shirakawa T. Antimicrobial resistance in Salmonella strains clinically isolated in Hyogo, Japan (2009-2012). Jpn J Infect Dis 2014; 67:54-7. [PMID: 24451104 DOI: 10.7883/yoken.67.54] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to examine the in vitro susceptibilities to antimicrobial agents and genetic diversity of 195 clinical strains of Salmonella spp., which were isolated and examined for the extended-spectrum β-lactamase (ESBL) blaCTX-M gene and the presence of gyrA, gyrB, parC, and parE genes mutations in Hyogo, Japan, from 2009 to 2012. Forty-three of the 195 strains were antimicrobial resistant. Two Salmonella enterica subsp. enterica strains, 1 serovar Schwarzengrund, and 1 serovar Enteritidis were identified as ESBL-producing strains possessing blaCTX-M-15 and blaCTX-M-2, respectively. Among 8 nalidixic acid-resistant strains, 7 had mutations in gyrA alone or in gyrA and parC. In conclusion, we identified CTX-M ESBL-producing Salmonella clinical strains with multidrug resistance. Further studies are needed to monitor these serious drug-resistant Salmonella strains in Japan.
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Affiliation(s)
- Kayo Osawa
- Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Science
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Ho PL, Chau PH, Yan MK, Chow KH, Chen JHK, Wong SCY, Cheng VCC. High burden of extended-spectrum β-lactamase-positive Escherichia coli in geriatric patients. J Med Microbiol 2014; 63:878-883. [DOI: 10.1099/jmm.0.068270-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Few studies have described how an expanding elderly population influences the burden of antimicrobial resistance in micro-organisms. This study aimed to investigate trends in age-stratified extended-spectrum β-lactamase (ESBL)-positive Escherichia coli metrics in relation to an ageing population. The antimicrobial resistance database of E. coli from a healthcare region in Hong Kong from 2003 to 2012 was retrospectively reviewed. Future trends in age-stratified ESBL metrics were predicted up to 2022. Susceptibility results of clinical E. coli isolates from patients aged 0–74 years (n = 17 853) and aged ≥75 years (n = 17 047) were analysed. For the period 2003–2012, 23.7 % of the hospital admissions were of patients aged ≥75 years. However, approximately half of the annual ESBL-positive E. coli isolates were recovered from patients aged ≥75 years, being 55.0 % (233/424) in 2003 and 56.0 % (639/1142) in 2012. During this period of time, the annual prevalence and cumulative incidence of ESBL-positive E. coli in patients aged ≥75 years were significantly higher than in patients aged 0–74 years. From 2012–2022, it is predicted that ESBL-positive E. coli prevalence among patients aged 0–74 years and ≥75 years would increase from 25.4 % to 50.2 % and from 30.8 % to 70.0 %, respectively. In 2022, the predicted ESBL-positive E. coli cumulative incidence would be 63.7 per 10 000 admissions and 178.7 per 10 000 admissions among patients aged 0–74 years and ≥75 years, respectively. In conclusion, a rapidly expanding elderly population would substantially add to the burden of ESBL.
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Affiliation(s)
- Pak-Leung Ho
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Pui-Hing Chau
- School of Nursing, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Mei-Kum Yan
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Kin-Hung Chow
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Jonathan H. K. Chen
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Sally C. Y. Wong
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
| | - Vincent C. C. Cheng
- Department of Microbiology and Carol Yu Centre for Infection, University of Hong Kong, Hong Kong Special Administrative Region, PR China
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15
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Takaba K, Shigemura K, Osawa K, Nomi M, Fujisawa M, Arakawa S. Emergence of extended-spectrum β-lactamase-producing Escherichia coli in catheter-associated urinary tract infection in neurogenic bladder patients. Am J Infect Control 2014; 42:e29-31. [PMID: 24581025 DOI: 10.1016/j.ajic.2013.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/21/2013] [Accepted: 11/21/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND Catheter-associated urinary tract infection (CAUTI) is a common clinic problem. The purpose of this study was to investigate recent trends in CAUTI in neurogenic bladder patients focusing on extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. METHODS Isolates from the urine of neurogenic bladder patients with UTI were investigated. Nine strains of ESBL-producing E coli were assayed by molecular strain typing using the Diversilab system for repetitive-sequence-based polymerase chain reaction (rep-PCR). RESULTS E coli accounted for most of the bacteria (74.1% to 81.0%) that produced ESBLs. Rep-PCR data showed that 7 out of 9 ESBL-producing E coli belonged to the same typing group with high similarity (more than 97% similarity) and that this distribution corresponded with antibiotic resistance patterns. CONCLUSION ESBL producing E coli strains isolated from CAUTI patients could be discriminated by rep-PCR typing using the Diversilab system in consistent with antibiotic resistance patterns.
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A simple multiplex PCR for assessing prevalence of extended-spectrum β-lactamases producing Klebsiella pneumoniae in Intensive Care Units of a referral hospital in Shiraz, Iran. ASIAN PAC J TROP MED 2014; 6:703-8. [PMID: 23827147 DOI: 10.1016/s1995-7645(13)60122-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/15/2013] [Accepted: 09/20/2013] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE To identify three common genes (blaTEM, blaSHV and blaCTX-M) responsible for ESBL production in Klebsiella pneumoniae (K. pneumoniae)isolated from Intensive Care Units of Namazi Hospital, Shiraz, Iran. METHODS A total of 60 non-repetitive nosocomial isolates from 60 patients were selected during 2009-2010. The phenotypic identification of ESBL production was confirmed by Double Disk Synergy Test (DDST) according to CLSI guidelines. The ESBL's genotype was then analyzed by multiplex PCR of blaTEM, blaSHV and blaCTX-M genes and DNA sequencing. RESULTS The primary susceptibility tests of K. pneumoniae showed that among 10 examined antibiotics, the most resistant and susceptible antibiotics identified in this study were ampicillin and imipenem, respectively. The phenotypic determination of ESBL by DDST showed that 60% (n=36) of isolates produced ESBL. Multiplex PCR of genes among K. pneumoniae isolates showed that 39% (n=18) of them have TEM, 39% (n=18) of them have both CTX-M and TEM and 13% (n=8) of them have TEM, SHV, CTX-M. CONCLUSIONS Our findings reveal the high prevalence (60%) of ESBL producing K. pneumoniae from ICU patients along with a new pattern of blaTEMdistribution differ from other countries.
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A simple assay to screen antimicrobial compounds potentiating the activity of current antibiotics. BIOMED RESEARCH INTERNATIONAL 2013; 2013:927323. [PMID: 23865073 PMCID: PMC3705824 DOI: 10.1155/2013/927323] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 11/27/2022]
Abstract
Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotics.
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Acanthamoeba castellanii of the T4 genotype is a potential environmental host for Enterobacter aerogenes and Aeromonas hydrophila. Parasit Vectors 2013; 6:169. [PMID: 23742105 PMCID: PMC3682894 DOI: 10.1186/1756-3305-6-169] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 05/27/2013] [Indexed: 11/15/2022] Open
Abstract
Background Acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including Legionella pneumophila, Pseudomonas aeruginosa, Vibrio cholerae, Helicobacter pylori, Listeria monocytogenes, Mycobacterium spp., and Escherichia coli. In this capacity, Acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts. Methods Here, we used a keratitis isolate of A. castellanii of the T4 genotype and studied its interactions with two bacterial genera which have not been tested before, Enterobacter aerogenes, and Aeromonas hydrophila, as well as E. coli. Assays were performed to determine bacterial association with and invasion of A. castellanii. Additionally, bacterial survival intracellular of A. castellanii trophozoites as well as cysts was determined. Results All three bacterial isolates tested, associated, invaded, and survived inside A. castellanii trophozoites as well as A. castellanii cysts. However, E. aerogenes and E. coli exhibited significantly reduced association with and invasion of A. castellanii as compared with A. hydrophila (P < 0.01 using paired T-test, one tail distribution). In the long term survival assays, all three bacterial isolates tested remained viable inside A. castellanii trophozoites, while amoeba remained intact; however A. hydrophila exhibited higher survival inside amoebae (14.54 ± 3.3 bacteria:amoeba ratio) compared with E. aerogenes (3.96 ± 0.7 bacteria:amoeba ratio) and E. coli (5.85 ± 1.1 bacteria:amoeba ratio). A. hydrophila, E. coli, and E. aerogenes remained viable during the encystment process and exhibited higher levels of recovery from mature cysts (14.13 ± 0.89 A. hydrophila:amoeba ratio, 10.13 ± 1.17 E. aerogenes:amoeba ratio, and 11.95 ± 0.7 E. coli:amoeba ratio). Conclusions A. hydrophila and E. aerogenes also joined the ranks of other bacteria that could benefit from A. castellanii. Because cysts can be airborne, these findings suggest that Acanthamoeba is a potential vector in the transmission of A. hydrophila and E. aerogenes to susceptible hosts.
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Kinali-Demirci S, Demirci S, Kurt M. Synthesis, structure characterization and antimicrobial evaluation of 4-(substituted phenylazo)-3,5-diacetamido-1H-pyrazoles. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 106:12-18. [PMID: 23353762 DOI: 10.1016/j.saa.2012.12.074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/17/2012] [Accepted: 12/22/2012] [Indexed: 06/01/2023]
Abstract
The present article deals with the synthesis, spectral characterization and antimicrobial activity of phenylazo dyes. All of the synthesized phenylazo dyes were characterized using ATR-FTIR, FT-Raman, (1)H NMR, (13)C NMR, elemental analysis and mass spectroscopic techniques. Solvent effects on the UV-Vis absorption spectra of these phenylazo dyes were studied. Acid and base effects on the visible absorption maxima of the phenylazo dyes were also reported. The structural and spectroscopic analysis of the molecules were carried out using Density Functional Theory (DFT) employing the standard 6-31G(d) basis set, and the optimized geometries and calculated vibrational frequencies were evaluated via comparison with experimental values. The antimicrobial activity of 4-(substituted phenylazo)-3,5-diacetamido-1H-pyrazoles was reported against bacteria, including B. cereus (RSKK 863), S. aureus (ATCC 259231), M. luteus (NRRL B-4375), E. coli (ATCC 11230) and the yeast C. albicans (ATCC 10239).
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Affiliation(s)
- Selin Kinali-Demirci
- Department of Chemistry, Faculty of Science, Gazi University, 06500 Ankara, Turkey
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20
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Harwalkar A, Sataraddi J, Gupta S, Yoganand R, Rao A, Srinivasa H. The detection of ESBL-producing Escherichia coli in patients with symptomatic urinary tract infections using different diffusion methods in a rural setting. J Infect Public Health 2013; 6:108-14. [PMID: 23537823 DOI: 10.1016/j.jiph.2012.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 10/09/2012] [Accepted: 10/12/2012] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES This study aimed to determine the prevalence of extended spectrum of beta lactamases (ESBLs), to compare different phenotypic methods for ESBL confirmation and to evaluate the antibiotic resistance patterns among ESBL-producing urinary Escherichia coli. METHODS Urinary E. coli isolates that were resistant to at least one of the three indicator cephalosporins (cefotaxime, cefpodoxime and ceftazidime) were tested for ESBL production using the double disc synergy test (DDST), the inhibitory potentiated disc diffusion (IPDD) test and the quantitative E-strip method. RESULT Of the 163 E. coli strains isolated, 80 (49%) were resistant to at least one of the three cephalosporins, and 38 (47.5%) tested positive for ESBLs by the IPDD test and the E-strip test. However, only15 (18.7%) strains tested positive by the DDST. Among the third-generation cephalosporins, cefpodoxime (46.1%) was the best screening indicator, followed by ceftazidime (43%) and cefotaxime (39.9%). Most of the ESBL producers (97.3%) were resistant to three or more drugs, compared with 51.2% of non-ESBL producers. CONCLUSION Compared with the DDST, the IPDD and E-strip tests appear to be preferable methods for detecting ESBLs, with better sensitivity (100%) and specificilty (97.6%) and positive predictive values (97.3%). ESBL producers showed significantly (p<0.05) higher resistance to tobramycin, co-amoxyclav and amikacin than did non-ESBL producers.
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Affiliation(s)
- Anandkumar Harwalkar
- Department of Microbiology, Navodaya Medical College, Raichur, Karnataka, India.
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Ho PL, Chan J, Lo WU, Law PY, Li Z, Lai EL, Chow KH. Dissemination of plasmid-mediated fosfomycin resistance fosA3 among multidrug-resistant Escherichia coli from livestock and other animals. J Appl Microbiol 2012; 114:695-702. [PMID: 23216653 DOI: 10.1111/jam.12099] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 11/27/2022]
Abstract
AIMS To investigate plasmid-mediated fosfomycin resistance related to fosA3 in Escherichia coli isolates collected from different animals in Hong Kong, China, 2008-2010. METHODS AND RESULTS In total, 2106 faecal specimens from 210 cattle, 214 pigs, 460 chickens, 398 stray cats, 368 stray dogs and 456 wild rodents were cultured. The faecal colonization rates of fosfomycin-resistant E. coli were as follows: 11.2% in pigs, 8.6% in cattle, 7.3% in chickens, 2.4% in dogs, 0.8% in cats and 1.5% in rodents. The cultures yielded 1693 isolates of which 831 were extended-spectrum β-lactamases (ESBL) producers. Fosfomycin-resistant isolates were more likely than fosfomycin-susceptible isolates to be producers of ESBL and to have resistance to chloramphenicol, ciprofloxacin, cotrimoxazole, gentamicin and tetracycline. Of the 101 fosfomycin-resistant isolates, 97 (96.0%) isolates were fosA3 positive and 94 (93.1%) were bla(CTX) (-M) positive. PCR mapping showed that the fosA3-containing regions were flanked by IS26, both upstream and downstream in 81 (83.5%) isolates, and by an upstream bla(CTX-M-14) -containing transposon-like structure (ΔISEcp1-bla(CTX-M-14) -ΔIS903 or ISEcp1-IS10 -bla(CTX-M-14) -ΔIS903) and a downstream IS26 in 14 (14.4%) isolates. For the remaining two isolates, fosA3 was flanked by a downstream IS26 but the upstream part cannot be defined. In a random subset of 18 isolates, fosA3 was carried on transferable plasmids with sizes of 50-200 kb and the following replicons: F2:A-B- (n = 3), F16:A1:B- (n = 2), F24:A-B- (n = 1), N (n = 1), B/O (n = 1) and untypeable (n = 3). SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates the emergence of fosA3-mediated fosfomycin resistance among multidrug-resistant E. coli isolates from various animals. IS26 transposon-like structures might be the main vehicles for dissemination of fosA3.
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Affiliation(s)
- P L Ho
- Department of Microbiology, University of Hong Kong, Pokfulam, Hong Kong, China.
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Abstract
Antibacterial strategies to eradicate superbugs from hospitals/nursing homes have had limited success, suggesting the need for employing innovative preventative measures and better understanding of the prevalence of microbial pathogens in close proximity of susceptible populations. A total of 120 environmental samples were collected from the Aga Khan University hospital. Amoebae were identified using morphological characteristics as well as PCR using genus-specific primers, while bacteria were identified using standard biochemical testing. Out of 120 samples tested, 52 (43.3 %) samples were positive for Acanthamoeba, while all 120 (100 %) samples were positive for bacteria. Following bacterial identification, samples showed mixed bacterial populations. Out of 120 samples, 76 (63.3 %) samples were positive for Bacillus spp., 64 (53.3 %) samples were positive for Corynebacterium spp., 32 (26.6 %) samples were positive for Staphylococcus spp., and 9 (7.5 %) samples were positive for Micrococcus spp. The antibiotic susceptibility showed that all bacterial isolates recovered were multiple drug-resistant. The current findings suggest that Acanthamoeba and bacteria coexist in a clinical environment. Given that Acanthamoeba can harbor bacteria, anti-amoebic approaches may represent a strategy in eradicating "superbugs" from the clinical setting in addition to the current measures.
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Ho PL, Chan J, Lo WU, Law PY, Chow KH. Plasmid-mediated fosfomycin resistance in Escherichia coli isolated from pig. Vet Microbiol 2012; 162:964-967. [PMID: 23078751 DOI: 10.1016/j.vetmic.2012.09.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/21/2012] [Accepted: 09/22/2012] [Indexed: 10/27/2022]
Abstract
Previous studies have reported plasmid-mediated fosA3 among Escherichia coli originating from human and companion animals. In this study, the plasmid, designated pHK23a originating from a multidrug-resistant E. coli isolate recovered from a slaughter pig in December 2008 in Hong Kong, China was sequenced. In conjugation, the plasmid readily transferred to E. coli J53 at high frequencies. It belongs to the narrow host range IncFII incompatibility group and is 73,607 bp in length. Sequence alignment showed that pHK23a has a 59.1 kb backbone which shares high homology with the prototype R100 plasmid and a 14.5 kb variable region. The variable region includes three genes mediating antimicrobial resistance (fosA3, Δbla(TEM-1), bla(CTX-M-3)), ten mobile genetic elements (four copies of IS26, insA, ΔinsB, ΔTn2, IS1, ΔISEcp1, Δintl1), the tir transfer inhibition protein, the pemI/pemK addiction system and eight ORFs of unknown functions (orf1, orf2, Δorf3, orf20, orf23, orf24, ycdA and ycdB). The three resistance genes were organized in a novel IS26-composite transposon-like structure. In conclusion, this is the first report of fosA3 containing plasmid in an isolate of pig origin. Since IncFII plasmids spread efficiently in Enterobacteriaceae, the detection of fosA3 with bla(CTX-M) is worrisome and might become a public health concern.
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Affiliation(s)
- P L Ho
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China; Carol Yu Center for Infection, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China.
| | - Jane Chan
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - W U Lo
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - Pierra Y Law
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - K H Chow
- Department of Microbiology, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
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Ho PL, Chow KH, Lai EL, Lo WU, Yeung MK, Chan J, Chan PY, Yuen KY. Extensive dissemination of CTX-M-producing Escherichia coli with multidrug resistance to 'critically important' antibiotics among food animals in Hong Kong, 2008-10. J Antimicrob Chemother 2011; 66:765-8. [DOI: 10.1093/jac/dkq539] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tonkić M, Mohar B, Šiško-Kraljević K, Meško-Meglič K, Goić-Barišić I, Novak A, Kovačić A, Punda-Polić V. High prevalence and molecular characterization of extended-spectrum β-lactamase-producing Proteus mirabilis strains in southern Croatia. J Med Microbiol 2010; 59:1185-1190. [DOI: 10.1099/jmm.0.016964-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to determine the prevalence and antibiotic resistance rates of extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis strains isolated from inpatients at the Split University Hospital (southern Croatia) during a survey performed between 2005 and 2008. A total of 2152 consecutive isolates of P. mirabilis were isolated. The prevalence was 0.5 % in 2005 and increased significantly to 20.9 % by 2008. Strains were most frequently isolated from urine (36.5 %) and bronchial aspirates and wound swabs (11.3 %). ESBL-producing P. mirabilis isolates showed very high resistance rates to the majority of non-β-lactam antibiotics and were susceptible to a β-lactam/β-lactamase inhibitor and carbapenems. The isolates were genotyped and their ESBLs were molecularly characterized. Strains originating from the intensive care unit and the surgery and neurosurgery wards were clonally related. All P. mirabilis isolates produced the TEM-52 type of ESBL. To the best of our knowledge, our work detailed here and summarized in an earlier communication is the first report of such isolates from southern Croatia. Increased monitoring and screening for ESBL production in this species at our hospital is mandatory.
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Affiliation(s)
- Marija Tonkić
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
- Department of Clinical Microbiology, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia
| | - Bojana Mohar
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
| | - Katarina Šiško-Kraljević
- Public Health Institute of Split–Dalmatia County, Vukovarska 46, Split, Croatia
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
| | - Karmen Meško-Meglič
- Institute of Microbiology and Immunology, Medical Faculty, University of Ljubljana, Zaloška 4, 1105 Ljubljana, Slovenia
| | - Ivana Goić-Barišić
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
- Department of Clinical Microbiology, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia
| | - Anita Novak
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
- Department of Clinical Microbiology, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia
| | - Ana Kovačić
- Public Health Institute of Split–Dalmatia County, Vukovarska 46, Split, Croatia
| | - Volga Punda-Polić
- Department of Medical Microbiology, School of Medicine, University of Split, Šoltanska 2, Split, Croatia
- Department of Clinical Microbiology, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia
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Abstract
Extended-spectrum β-lactamases (ESBLs) are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. β-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBL-producing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens.
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Affiliation(s)
- Deepti Rawat
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| | - Deepthi Nair
- Department of Microbiology, Vardhaman Mahavir Medical College & Safdarjang Hospital, New Delhi, India
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Ho PL, Yip KS, Chow KH, Lo JYC, Que TL, Yuen KY. Antimicrobial resistance among uropathogens that cause acute uncomplicated cystitis in women in Hong Kong: a prospective multicenter study in 2006 to 2008. Diagn Microbiol Infect Dis 2009; 66:87-93. [PMID: 19446980 DOI: 10.1016/j.diagmicrobio.2009.03.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/18/2009] [Accepted: 03/27/2009] [Indexed: 01/18/2023]
Abstract
A prospective multicenter study was conducted to assess the epidemiology of antimicrobial resistance among uropathogens causing uncomplicated cystitis. Adult women with clinical diagnosis of uncomplicated cystitis were enrolled from 54 participating centers distributed all over Hong Kong during 2006 to 2008. A positive urine culture was found in 59.5% (352/592) patients. The patients had mean age of 44.9 years, and most (89.2%) were otherwise healthy. The most prevalent causative organism was Escherichia coli (77%), followed by other Enterobacteriaceae (14.2%), staphylococci (5.1%), and other Gram-positive bacteria (3.7%). The resistance rates of E. coli to co-trimoxazole and ciprofloxacin were 29.5% and 12.9%, respectively, and 14 isolates (5.2%) were confirmed as extended-spectrum beta-lactamase (ESBL) producers. Of the ESBL producers, molecular studies showed CTX-M-14, CTX-M-24, or CTX-M-9. Nitrofurantoin and fosfomycin were active against >90% of the isolates, regardless of resistance phenotypes for other drugs. Pulsed-field gel electrophoresis of representative isolates showed that the antibiotic-resistant strains were genetically diverse. Patients with history of recent antibiotic use were significantly more likely to have infection by E. coli with co-trimoxazole resistance (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.4-5.7; P = 0.003) and ciprofloxacin resistance (OR, 2.5; 95% CI, 1.1-5.8; P = 0.03). Knowledge of the resistance data and risk factors could inform better use of antibiotics for empiric therapy for acute uncomplicated cystitis.
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Affiliation(s)
- Pak-leung Ho
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China.
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Ho PL, Wong RCW, Yip KS, Loke SL, Leung MST, Mak GC, Chow FKH, Tsang KWT, Que TL. Antimicrobial resistance in Escherichia coli outpatient urinary isolates from women: emerging multidrug resistance phenotypes. Diagn Microbiol Infect Dis 2007; 59:439-45. [PMID: 17888610 DOI: 10.1016/j.diagmicrobio.2007.06.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2007] [Revised: 06/14/2007] [Accepted: 06/20/2007] [Indexed: 10/22/2022]
Abstract
This study evaluated the antimicrobial resistance profile of outpatient urinary Escherichia coli isolated from women obtained throughout Hong Kong during 2004-2005. Of 1067 single patient isolates analyzed, 60.1% were resistant to ampicillin, 34% were resistant to co-trimoxazole, and 22.1% were resistant to ciprofloxacin. Thirty-four (6.6%) of 519 isolates in 2004 and 55 (10%) of 548 isolates in 2005 were extended-spectrum beta-lactamase (ESBL) producers with a CTX-M phenotype. Rates of non-beta-lactam resistance and ESBL production were strongly influenced by patient age. The age-stratified rates for dual co-trimoxazole and ciprofloxacin resistance and for ESBL production were 10.9% and 7.6% in women aged 18-35 years, 13% and 6.9% in women aged 36-50 years, 20.4% and 8.8% in women aged 51-64 years, and 23.7% and 11.8% in women aged > or =65 years, respectively. Nitrofurantoin and fosfomycin remain active against >90% of the isolates, irrespective of the resistance phenotypes for other drugs. Our results documented the emergence of problematic resistance phenotypes among community urinary E. coli and highlight the need to explore strategies for their containment.
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Affiliation(s)
- Pak-Leung Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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Bedenic B, Vranes J, Mihaljevic L, Tonkic M, Sviben M, Plecko V, Kalenic S. Sensitivity and specificity of various beta-lactam antibiotics and phenotypical methods for detection of TEM, SHV and CTX-M extended-spectrum beta-lactamases. J Chemother 2007; 19:127-39. [PMID: 17434820 DOI: 10.1179/joc.2007.19.2.127] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The aim of this study was to compare the sensitivity and specificity of six different beta-lactam antibiotics using five phenotypical tests for detection of extended spectrum beta-lactamases (ESBLs) based on synergism of beta-lactam antibiotics and clavulanate. Experiments were performed on a set of 80 Klebsiella pneumoniae strains and 105 Escherichia coli strains with previously characterized ESBLs (SHV, TEM and CTX-M). ESBLs were detected by five different phenotypical methods: MIC (minimum inhibitory concentration) determination of beta-lactam antibiotics with and without clavulanate, double-disk synergy test (DDST), inhibitor-potentiated disk-diffusion test (IPDDT), CLSI-Clinical and Laboratory Standard Institution (former NCCLS) combined-disk-test, and modified MAST-disk-diffusion test (MAST-DD-test). Seven antibiotics were tested as indicators of ESBL production: ceftazidime, cefotaxime, ceftriaxone, aztreonam, ceftibuten, cefpodoxime and cefepime. Ceftazidime and aztreonam were the best indicators for SHV-5, SHV-12 and TEM beta-lactamases whereas cefotaxime and ceftriaxone were the most sensitive in detection of SHV-2 and CTX-M beta-lactamases in DDST, IPDDT and CLSI test. MIC determination of beta-lactam antibiotics with and without clavulanate was the most sensitive method. DDST was the least sensitive test. Double-disk synergy test, which is the most frequently used test for detection of ESBLs in routine laboratories, was the least sensitive independently of the indicator antibiotic. Since MIC determination is a very laborious and time consuming method, we would recommend the NCCLS combined disk test or IPDD test for detection of ESBLs in routine laboratories with 5 mm zone augmentation breakpoint.
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Affiliation(s)
- B Bedenic
- Department of Microbiology, School of Medicine, University of Zagreb, Zagreb, Croatia.
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Ho PL, Poon WWN, Loke SL, Leung MST, Chow KH, Wong RCW, Yip KS, Lai EL, Tsang KWT. Community emergence of CTX-M type extended-spectrum β-lactamases among urinary Escherichia coli from women. J Antimicrob Chemother 2007; 60:140-4. [PMID: 17496058 DOI: 10.1093/jac/dkm144] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To conduct a territory-wide study of extended-spectrum beta-lactamases (ESBLs) among community isolates of urinary Escherichia coli from women in Hong Kong. METHODS Up to 50 consecutive single-patient E. coli isolates, collected from 13 laboratories in 2004, were studied. The ESBLs were characterized by PCR sequencing using specific primers. The epidemiological relationship of the isolates was studied by PFGE and phylogenetic group PCRs. RESULTS Forty-two ESBL producers were found among 600 consecutive isolates tested. The ESBL prevalence was 7.3% (15/205) for women aged 18-35 years, 5% (11/219) for women aged 36-50 years, 6.3% (4/63) for women aged 51-64 years and 10.6% (12/113) for women aged >or=65 years (P=0.3). The ESBL-producing isolates were often multidrug-resistant and CTX-M-14 was found in 37 isolates, CTX-M-15 in 3 isolates and CTX-M-3 in 2 isolates. PFGE revealed no significant clusters among the ESBL producers. Overall, CTX-M-14 producers were significantly more likely to belong to group D than non-ESBL producers [18/37 (48.6%) versus 13/57 (22.8%), P=0.009]. However, 7 of 13 (53.8%) CTX-M-14 producers from women aged 18-35 years represented phylogenetic group B2, compared with 7 of 24 (29.2%) for women of all other ages (P=0.1). CONCLUSIONS The study documented the community emergence of CTX-M as the predominant ESBL type among urinary isolates from women. The spread of CTX-M enzymes among isolates from young women is concerning and deserves close monitoring.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
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Spanu T, Sanguinetti M, Tumbarello M, D'Inzeo T, Fiori B, Posteraro B, Santangelo R, Cauda R, Fadda G. Evaluation of the new VITEK 2 extended-spectrum beta-lactamase (ESBL) test for rapid detection of ESBL production in Enterobacteriaceae isolates. J Clin Microbiol 2006; 44:3257-62. [PMID: 16954257 PMCID: PMC1594689 DOI: 10.1128/jcm.00433-06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Extended-spectrum beta-lactamases (ESBLs) are a large, rapidly evolving group of enzymes that confer resistance to oxyimino cephalosporins and monobactams and are inhibited by clavulanate. Rapid reliable detection of ESBL production is a prerequisite for successful infection management and for monitoring resistance trends and implementation of intervention strategies. We evaluated the performance of the new VITEK 2 ESBL test system (bioMérieux, Inc, Hazelwood, Mo.) in the identification of ESBL-producing Enterobacteriaceae isolates. We examined a total of 1,129 clinically relevant Enterobacteriaceae isolates (including 218 that had been previously characterized). The ESBL classification furnished by the VITEK 2 ESBL test system was concordant with that of the comparison method (molecular identification of beta-lactamase genes) for 1,121 (99.3%) of the 1,129 isolates evaluated. ESBL production was correctly detected in 306 of the 312 ESBL-producing organisms (sensitivity, 98.1%; positive predictive value, 99.3%). False-positive results emerged for 2 of the 817 ESBL-negative isolates (specificity, 99.7%; negative predictive value, 99.3%). VITEK 2 ESBL testing took 6 to 13 h (median, 7.5 h; mean +/- SD, 8.2 +/- 2.39 h). This automated short-incubation system appears to be a rapid and reliable tool for routine identification of ESBL-producing isolates of Enterobacteriaceae.
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Affiliation(s)
- Teresa Spanu
- Institute of Microbiology, Caholic University of the Sacred Heart, Rome, Italy.
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Duan RS, Sit THC, Wong SSY, Wong RCW, Chow KH, Mak GC, Yam WC, Ng LT, Yuen KY, Ho PL. Escherichia coli Producing CTX-M β-Lactamases in Food Animals in Hong Kong. Microb Drug Resist 2006; 12:145-8. [PMID: 16922633 DOI: 10.1089/mdr.2006.12.145] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A study was conducted to evaluate the occurrence of extended-spectrum beta-lactamases (ESBLs)-producing Escherichia coli from fecal samples of healthy food animals in Hong Kong. Rectal or cloacal swabs were obtained from cattle, pigs, chicken, ducks, geese, and pigeons in slaughterhouses or wholesale markets over a 5- month period in 2002. Antibiotic-containing medium was used for selective isolation of potentially ESBL-producing E. coli. Of 734 samples analyzed, six (2%) from pigs, three (3.1%) from cattle, and one (3%) from pigeons had E. coli strains with the ESBL phenotype. The ESBL content for the 10 isolates include CTXM- 3 (n = 4), CTX-M-13 (n = 3), CTX-M-14 (n = 2), and CTX-M-24 (n = 1). In five isolates, the bla (CTX-M) gene was encoded on transferable plasmids (60 or 90 kb), and the gene was found to transfer to E. coli (J53 or JP995) with frequencies of 10(7) to 10(3) per donor cells. The ten isolates had five distinct pulsotypes with some clonal spread. However, the isolates from the different kinds of animals were not clonally related. These findings imply that bacteria of animal origins may serve as reservoirs of some ESBL genes.
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Affiliation(s)
- R S Duan
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, University of Hong Kong, Hong Kong Special Administrative Region, China
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Abstract
Extended-spectrum beta-lactamases (ESBLs) are a rapidly evolving group of beta-lactamases which share the ability to hydrolyze third-generation cephalosporins and aztreonam yet are inhibited by clavulanic acid. Typically, they derive from genes for TEM-1, TEM-2, or SHV-1 by mutations that alter the amino acid configuration around the active site of these beta-lactamases. This extends the spectrum of beta-lactam antibiotics susceptible to hydrolysis by these enzymes. An increasing number of ESBLs not of TEM or SHV lineage have recently been described. The presence of ESBLs carries tremendous clinical significance. The ESBLs are frequently plasmid encoded. Plasmids responsible for ESBL production frequently carry genes encoding resistance to other drug classes (for example, aminoglycosides). Therefore, antibiotic options in the treatment of ESBL-producing organisms are extremely limited. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBL-producing organisms may appear susceptible to some extended-spectrum cephalosporins. However, treatment with such antibiotics has been associated with high failure rates. There is substantial debate as to the optimal method to prevent this occurrence. It has been proposed that cephalosporin breakpoints for the Enterobacteriaceae should be altered so that the need for ESBL detection would be obviated. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in klebsiellae and Escherichia coli. In common to all ESBL detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic resistance mechanisms in the face of the introduction of new antimicrobial agents.
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Affiliation(s)
- David L Paterson
- Infectious Disease Division, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
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Ho PL, Ho AYM, Chow KH, Wong RCW, Duan RS, Ho WL, Mak GC, Tsang KW, Yam WC, Yuen KY. Occurrence and molecular analysis of extended-spectrum β-lactamase-producing Proteus mirabilis in Hong Kong, 1999–2002. J Antimicrob Chemother 2005; 55:840-5. [PMID: 15857942 DOI: 10.1093/jac/dki135] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES A study was conducted to evaluate the occurrence and characterization of extended-spectrum beta-lactamases (ESBLs) among blood isolates of Proteus mirabilis collected over a 4 year period in Hong Kong. METHODS Production of ESBLs among 99 consecutive and non-duplicate isolates was evaluated by the double-disc synergy test. The ESBLs were characterized by isoelectric focusing and PCR sequencing using specific primers. The epidemiological relationship of the isolates was studied by the Dienes test and PFGE. RESULTS ESBLs were identified in 13 isolates, from none in 1999-2000 and up to 18.5% (5/27) in 2001 and 25.8% (8/31) in 2002. The ESBL-producing isolates were more resistant to ceftriaxone than to ceftazidime, and were more likely than non-ESBL-producers to have resistance to ciprofloxacin (76.9% versus 14%) and gentamicin (38.5% versus 9.3%). The ESBL content included CTX-M-13 (n=8), CTX-M-14 (n=3), SHV-5 (n=2), TEM-11 (n=1), and an unidentified ESBL with a pI of 7.5. The Dienes test revealed that the genetic background in the 99 isolates was highly heterogeneous, with 54 distinct types among 92 isolates and seven were non-typeable. Among the 13 ESBL-producing isolates, five different backgrounds, including one cluster (Dienes-pulsotype A) with nine isolates, were identified by both Dienes test and PFGE, thus suggesting both clonal and multi-clonal spread of the CTX-M enzymes. CONCLUSIONS Our findings indicate the emergence of CTX-M enzymes among P. mirabilis in Hong Kong. More ESBL screening of this species is required to improve their recognition.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region, China.
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Ho PL, Shek RHL, Chow KH, Duan RS, Mak GC, Lai EL, Yam WC, Tsang KW, Lai WM. Detection and characterization of extended-spectrum β-lactamases among bloodstream isolates of Enterobacter spp. in Hong Kong, 2000–2002. J Antimicrob Chemother 2005; 55:326-32. [PMID: 15681579 DOI: 10.1093/jac/dki010] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES A total of 139 consecutive and non-duplicate bloodstream isolates of Enterobacter spp. collected from inpatients in Hong Kong during 2000-2002 were studied for production of extended-spectrum beta-lactamases (ESBLs). METHODS All isolates were evaluated by the modified double-disc synergy test (m-DDST), the combined disc method (CDM) and the three-dimensional (3D) test. The m-DDST and CDM were modified by the use of cefepime discs. beta-Lactamases were characterized by isoelectric focusing and PCR sequencing using specific primers. RESULTS ESBLs were identified in nine isolates (overall 6.5%), including seven of 39 (17.9%) Enterobacter hormaechei, one of 27 (3.7%) Enterobacter aerogenes and the only Enterobacter intermedius strain. The E. intermedius strain was positive only in the 3D test but not in the other two tests. The other eight strains were positive in all three tests. No ESBL was detected in the other species, including non-hormaechei members of the Enterobacter cloacae complex (n=61), Enterobacter agglomerans (n=7), Enterobacter gergoviae (n=4) and Enterobacter sakazakii (n=1). The ESBL content included five different CTX-M enzymes (CTX-M-9, CTX-M-13, CTX-M-14, CTX-M-24 and a novel CTX-M-2-like beta-lactamase), SHV-12 (n=2) and unidentifiable ESBLs with a pI of 7.7 or 7.9 in two strains. The seven ESBL-producing E. hormaechei were genotyped by pulsed-field gel electrophoresis and were found to be unrelated to each other. In three of the CTX-M-producing strains, ISEcp1-like elements, including promoters for the beta-lactamase gene, were found. CONCLUSIONS Our data underscore the diversity of CTX-M enzymes among Enterobacter spp. in Hong Kong.
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Affiliation(s)
- P L Ho
- Division of Infectious Diseases, Department of Microbiology and Centre of Infection, United Christian Hospital, University of Hong Kong, Hong Kong SAR, China.
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Oh EJ, Lee S, Park YJ, Park JJ, Park K, Kim SI, Kang MW, Kim BK. Prevalence of metallo-beta-lactamase among Pseudomonas aeruginosa and Acinetobacter baumannii in a Korean university hospital and comparison of screening methods for detecting metallo-beta-lactamase. J Microbiol Methods 2003; 54:411-8. [PMID: 12842488 DOI: 10.1016/s0167-7012(03)00090-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To identify the metallo-beta-lactamases (MBLs) prevalent in Korea, a total of 130 clinical isolates of Pseudomonas aeruginosa and Acinetobacter baumannii (99 P. aeruginosa and 31 A. baumannii) with a reduced susceptibility to imipenem (IPM) and/or ceftazidime (CAZ) was subjected to PCR analyses with primers specific to bla(IMP-1), bla(VIM-1), and bla(VIM-2). In addition, inhibitor-potentiated disk diffusion methods (IPD) using two kinds of substrate-inhibitor combinations (ceftazidime-2-mercaptopropionic acid (2MPA) and imipenem-EDTA) were investigated. Thirty-three isolates (29 P. aeruginosa and 4 A. baumannii) carried bla(VIM-2) and two P. aeruginosa isolates harbored bla(IMP-1). The enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) pattern revealed that many of the VIM-2-producing P. aeruginosa isolates were clonally related, whereas the A. baumannii isolates were diverse. The inhibitor-potentiated disk diffusion test using imipenem-EDTA was highly sensitive and specific for detecting the VIM-2 producer. These results suggest that VIM-2 is an important MBL in P. aeruginosa and A. baumannii in the Korean hospital of this study and that the IMP-1-producing P. aeruginosa has also emerged. Screening for MBLs and strict infection control for these isolates will contribute to prevent further spread of resistance.
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Affiliation(s)
- Eun-Jee Oh
- Department of Clinical Pathology, College of Medicine, The Catholic University of Korea, Kangnam St. Mary's Hospital, 505 Banpo-dong, Seocho-ku, Seoul 137-040, South Korea
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Ho PL. Carriage of methicillin-resistant Staphylococcus aureus, ceftazidime-resistant Gram-negative bacilli, and vancomycin-resistant enterococci before and after intensive care unit admission. Crit Care Med 2003; 31:1175-82. [PMID: 12682490 DOI: 10.1097/01.ccm.0000059437.01924.97] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To measure patients' risk for acquiring antibiotic-resistant microorganisms associated with intensive care unit admission. DESIGN Prospective, observational study. SETTING Ten public hospitals including one university medical center. PATIENTS Consecutive patients admitted to ten intensive care units. INTERVENTIONS Serial patient surveillance cultures were screened for vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus (MRSA), ceftazidime-resistant Gram-negative bacilli (CR-GNB), Acute Physiology and Chronic Health Evaluation II score, and antibiotic and medical device exposures. MEASUREMENTS AND MAIN RESULTS A total of 1,697 patient admissions in ten intensive care units were enrolled. The overall carriage rate of antibiotic-resistant bacteria at intensive care unit entry was 12.1% for MRSA, 14% for CR-GNB and 4.7% for both. At discharge from the intensive care unit, new carriage of MRSA, CR-GNB, and both was found in 11.1%, 14.2%, and 2.4% of the patients, respectively. The acquisition rates in the individual units correlated highly and positively with proportion of patients with carriage at intensive care unit entry for both MRSA (n = 10, Pearson's r =.89, p < 0.001) and CR-GNB (n = 10, Pearson's r =.92, p < 0.001). By logistic regression, severity of illness (odds ratio, 1.4), length of stay (odds ratio, 1.7), use of penicillins (odds ratio, 1.9), and number of antibiotics (odds ratio, 1.2) and medical devices (odds ratio, 1.2) were independently associated with intensive care unit acquisition of MRSA. In comparison, variables independently associated with intensive care unit acquisition of CR-GNB were Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.5), number of antibiotics (odds ratio, 1.1), and artificial airway (odds ratio, 1.5). CONCLUSIONS These data suggest that hospitalization in the intensive care unit introduces significant risk to patients in terms of transmission of MRSA and/or CR-GNB. This risk seems to be influenced strongly by the proportion of patients with colonization at intensive care unit admission and is associated with severity of illness, length of stay, and exposures to antibiotics and medical devices.
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Affiliation(s)
- Pak-Leung Ho
- Centre of Infection and Department of Microbiology, Faculty of Medicine, University of Hong Kong, People's Republic of China
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Sanders CC, Ehrhardt AF, Moland ES, Thomson KS, Zimmer B, Roe DE. BetalasEN: microdilution panel for identifying beta-lactamases present in isolates of Enterobacteriaceae. J Clin Microbiol 2002; 40:123-7. [PMID: 11773104 PMCID: PMC120116 DOI: 10.1128/jcm.40.1.123-127.2002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A dried investigational use-only microdilution panel named betalasEN (a short named derived from the panel's purpose, to identify beta-lactamases in Enterobacteriaceae) containing 10 beta-lactam drugs with and without beta-lactamase inhibitors was developed to identify beta-lactamases among clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri, Citrobacter freundii group, Enterobacter spp., and Serratia marcescens. The MICs obtained with a collection of 383 organisms containing well-characterized beta-lactamases were used to develop numeric codes and logic pathways for computerized analysis of results. The resultant logic pathways and betalasEN panel were then used to test and identify beta-lactamases among 885 isolates of Enterobacteriaceae recovered in cultures obtained at six different hospital laboratories across the United States. beta-Lactamases present in 801 (90.5%) of the 885 isolates were identified by betalasEN by using the existing logic pathways and codes or after minor modifications were made to the existing codes. The 84 strains that gave codes that betalasEN could not identify were collected, reidentified, and retested by using betalasEN. Three strains had been misidentified, 54 strains gave different codes upon repeat testing that could be identified by betalasEN, and 27 strains repeated new codes. The beta-lactamases in these strains were identified, and the new codes were added to the betalasEN logic pathways. These results indicate that betalasEN can identify clinically important beta-lactamases among most isolates of Enterobacteriaceae. The results also show that good quality control and attention to proper performance of the tests are essential to the correct performance of betalasEN.
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Affiliation(s)
- Christine C Sanders
- Center for Research in Anti-Infectives and Biotechnology, Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
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Bradford PA. Extended-spectrum beta-lactamases in the 21st century: characterization, epidemiology, and detection of this important resistance threat. Clin Microbiol Rev 2001; 14:933-51, table of contents. [PMID: 11585791 PMCID: PMC89009 DOI: 10.1128/cmr.14.4.933-951.2001] [Citation(s) in RCA: 1567] [Impact Index Per Article: 68.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Beta-lactamases continue to be the leading cause of resistance to beta-lactam antibiotics among gram-negative bacteria. In recent years there has been an increased incidence and prevalence of extended-spectrum beta-lactamases (ESBLs), enzymes that hydrolyze and cause resistance to oxyimino-cephalosporins and aztreonam. The majority of ESBLs are derived from the widespread broad-spectrum beta-lactamases TEM-1 and SHV-1. There are also new families of ESBLs, including the CTX-M and OXA-type enzymes as well as novel, unrelated beta-lactamases. Several different methods for the detection of ESBLs in clinical isolates have been suggested. While each of the tests has merit, none of the tests is able to detect all of the ESBLs encountered. ESBLs have become widespread throughout the world and are now found in a significant percentage of Escherichia coli and Klebsiella pneumoniae strains in certain countries. They have also been found in other Enterobacteriaceae strains and Pseudomonas aeruginosa. Strains expressing these beta-lactamases will present a host of therapeutic challenges as we head into the 21st century.
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Affiliation(s)
- P A Bradford
- Wyeth-Ayerst Research, Pearl River, New York 10965, USA.
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Shen D, Winokur P, Jones RN. Characterization of extended spectrum beta-lactamase-producing Klebsiella pneumoniae from Beijing, China. Int J Antimicrob Agents 2001; 18:185-8. [PMID: 11516943 DOI: 10.1016/s0924-8579(01)00351-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Fourteen clinical isolates of Klebsiella pneumoniae with extended-spectrum beta-lactamases (ESBLs) were detected by the double disk synergy test and the Etest ESBL strip. Co-resistances included high MICs for aminoglycosides, fluoroquinolones, tetracyclines, and trimethoprim/sulphamethoxazole. Co-resistance was not observed in five of the 14 strains. These isolates were all genetically distinct as determined by the automated ribotyping method. Isoelectric focusing documented the presence of multiple beta-lactamases (one to four per isolate) with pIs ranging from 5.4 to 8.4. The majority of isolates contained beta-lactamases with pI values of 7.6 and 8.4 consistent with SHV-type ESBLs and an Amp C enzyme, respectively. Emerging ESBL strains in K. pneumoniae compromise the use of agents such as cefotaxime, ceftriaxone, ceftazidime in China; leading to the expansion of quality infection control practices and formulary management programmes to minimize clonal expansion.
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Affiliation(s)
- D Shen
- Department of Microbiology 301 Hospital 28, FuXing Road, Beijing 100853, People's Republic of China.
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Bedenic B, Randegger C, Boras A, Haechler H. Comparison of five different methods for detection of SHV extended-spectrum beta-lactamases. J Chemother 2001; 13:24-33. [PMID: 11233796 DOI: 10.1179/joc.2001.13.1.24] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Five different methods for detection of different types of SHV extended-spectrum beta-lactamases (ESBL) were compared: minimum inhibitory concentration (MIC) determination of beta-lactam with and without clavulanic acid, double-disk synergy test (DDST), inhibitor potentiated disk diffusion test (IPDDT), three-dimensional test (TDT) and PCR/Nhe I test. MIC determination of beta-lactam with and without clavulanic acid was the most sensitive method regardless of the type of beta-lactamase. However the specificity of this method was a little above 90%. IPDDT turned out to be a very sensitive method too but it lacks specificity because 26.9% of ceftazidime sensitive strains (putative ESBL negative), gave a positive result. It is important to put all four disks on the plate because ceftazidime and aztreonam were more sensitive indicators for SHV-5 and SHV-12 beta-lactamase producers while cefotaxime and ceftriaxone were more reliable in detecting SHV-2 beta-lactamase producers. The DDST detected all SHV-5 and SHV-12 beta-lactamase producers and 95.2% of SHV-2, so it was less sensitive than MIC determination but was highly specific, since there were no false negative results observed. The sensitivity of DDST can be improved by using all four disks and placing them at the smaller distance from the central disk (2.5 cm). The TDT was the least sensitive method, particularly for SHV-5 and SHV-12 beta-lactamase producers. The PCR/Nhe I test for detection of ESBL blaSHV genes is a highly sensitive and specific method but it is rather laborious and thus not very practical for use in routine clinical laboratories. Nevertheless it has potential to serve as the gold standard in epidemiological investigations on ESBLs. According to the results of this investigation MIC determination of beta-lactam with and without clavulanic acid, even if only one antibiotic is used and the PCR/Nhe I tests are the most reliable methods for detection of SHV ESBLs.
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Affiliation(s)
- B Bedenic
- Department of Microbiology, School of Public Health A. Stampar, Medical School, University of Zagreb, Croatia
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Ho PL, Tsang DN, Que TL, Ho M, Yuen KY. Comparison of screening methods for detection of extended-spectrum beta-lactamases and their prevalence among Escherichia coli and Klebsiella species in Hong Kong. APMIS 2000; 108:237-40. [PMID: 10752694 DOI: 10.1034/j.1600-0463.2000.d01-50.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Three tests, the disk diffusion test, the double-disc synergy test and the inhibitor-potentiated disc diffusion test, were compared for their abilities to detect production of extended-spectrum beta-lactamases (ESBL) in 702 Escherichia coli and 472 Klebsiella spp. strains from four hospitals. Eleven percent E. coli and 13% Klebsiella spp. were found to produce ESBL. As an indicator of ESBL activity, the sensitivities of the five extended-spectrum beta-lactams were as follows: cefotaxime (100%), cefpodoxime (99.3%), ceftriaxone (98.6%), aztreonam (93%) and ceftazidime (57.7%) when interpreted using the National Committee for Clinical Laboratory Standards criteria. Their positive predictive values ranged from 67.8-83.8%. Both the inhibitor-potentiated disc diffusion test and the double-disc synergy test (at three inter-disc widths of 20, 25 and 30 mm) were capable of identifying all the ESBL-producers. However, at a single inter-disc width of 30 mm, the double-disc synergy test has limited sensitivity (83.8%). As a second test for confirming ESBL activity in strains with reduced susceptibility to beta-lactams, the inhibitor-potentiated disc diffusion test is therefore a simple and reliable option.
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Affiliation(s)
- P L Ho
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam, China.
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