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Cordeiro-Moura JR, Fehlberg LCC, Nodari CS, Matos APD, Alves VDO, Cayô R, Gales AC. Performance of distinct phenotypic methods for carbapenemase detection: The influence of culture media. Diagn Microbiol Infect Dis 2019; 96:114912. [PMID: 31704067 DOI: 10.1016/j.diagmicrobio.2019.114912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/24/2019] [Accepted: 10/07/2019] [Indexed: 10/25/2022]
Abstract
We evaluated the performance of five phenotypic tests [Modified Hodge Test (MHT); combined-disk test (CDT) using phenylboronic acid, EDTA, and cloxacillin; CarbaNP and CarbAcinetoNP; Blue-Carba, Carbapenembac™ and Carbapenembac Metallo™] for carbapenemase detection in Gram-negative bacilli (GNB). A total of 73 carbapenemase producers and 27 non-carbapenemase producers were tested. All GNB were subcultured onto Müeller-Hinton agar (MHA), MacConkey agar (MAC), and sheep blood agar (SBA). High sensitivity (100%) and specificity (100%) was observed for MHA using CarbaNP, Blue-Carba, and Carbapenembac™. The sensitivity and specificity of CarbaNP (98.6%/100%), Blue-Carba (97.1%/91.0%), and Carbapenembac™ (100%/96.5%) were slightly lower for SBA. In contrast, unacceptable sensitivity rates of CarbaNP (71.1%) and Blue-Carba (66.6%), but not Carbapenembac™ (97.3%), were observed for MAC. The colorimetric methods showed high sensitivity and specificity to detect carbapenemase production from isolates grown on MHA or SBA. However, colonies obtained from MAC must not be tested for carbapenemase detection by colorimetric methods.
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Affiliation(s)
- Jhonatha Rodrigo Cordeiro-Moura
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil
| | - Lorena Cristina Corrêa Fehlberg
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil.
| | - Carolina Silva Nodari
- Universidade Federal de São Paulo - UNIFESP, Laboratório de Imunologia e Bacteriologia - LIB, Setor de Biologia Molecular, Microbiologia e Imunologia, Departamento de Ciências Biológicas - DCB, Instituto de Ciências Ambientais, Químicas e Farmacêuticas - ICAQF, Diadema, - SP, Brazil
| | - Adriana Pereira de Matos
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil
| | - Vinicius de Oliveira Alves
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil
| | - Rodrigo Cayô
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil; Universidade Federal de São Paulo - UNIFESP, Laboratório de Imunologia e Bacteriologia - LIB, Setor de Biologia Molecular, Microbiologia e Imunologia, Departamento de Ciências Biológicas - DCB, Instituto de Ciências Ambientais, Químicas e Farmacêuticas - ICAQF, Diadema, - SP, Brazil
| | - Ana Cristina Gales
- Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Division of Infectious Diseases, Departament of Internal Medicine, Escola Paulista de Medicina - EPM, São Paulo, - SP, Brazil
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Comparative Study of CDST & Multiplex PCR to Detect MBL Producing Gram-Negative Bacilli among VAP Patients Admitted in a Public Medical College Hospital of Bangladesh. Pathogens 2019; 8:pathogens8030151. [PMID: 31547453 PMCID: PMC6789483 DOI: 10.3390/pathogens8030151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 11/30/2022] Open
Abstract
Background: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care units (ICU), which accounts for 25% of all ICU infection. Documenting carbapenem-resistant gram-negative bacilli is very important as these strains may often cause outbreaks in the ICU setting and are responsible for the increased mortality and morbidity or limiting therapeutic options. The classical phenotypic method cannot provide an efficient means of diagnosis of the metallo-β-lactamases (MBLs) producer. Polymerase chain reaction (PCR) assays have lessened the importance of the phenotypic approach by detecting metallo-β-lactamase resistance genes such as New Delhi metallo-β-lactamase (NDM), Imipenemase (IMP), Verona integron-encoded metallo-β-lactamase (VIM), Sao Paulo metallo-β-lactamase (SPM), Germany Imipenemase (GIM). Objective: To compare the results of the Combined Disc Synergy Test (CDST) with that of the multiplex PCR to detect MBL-producing gram-negative bacilli. Materials and Method: A total of 105 endotracheal aspirates (ETA) samples were collected from the ICU of a public school in Bangladesh. This cross-sectional study was carried out in the Department of Microbiology, Chittagong for quantitative culture, CDST test, and multiplex PCR for blaIMP, blaVIM, blaNDM genes of MBL producers. Results: Among the 105 clinically suspected VAP cases, the quantitative culture was positive in 95 (90%) and among 95 g-negative bacilli isolated from VAP patients, 46 (48.42%) were imipenem resistant, 30 (65.22%) were MBL producers by CDST, 21 (45.65%) were identified as MBL producers by multiplex PCR. Conclusion: PCR was highly sensitive and specific for the detection of MBL producers.
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Uddin F, McHugh TD, Roulston K, Platt G, Khan TA, Sohail M. Detection of carbapenemases, AmpC and ESBL genes in Acinetobacter isolates from ICUs by DNA microarray. J Microbiol Methods 2018; 155:19-23. [PMID: 30423363 DOI: 10.1016/j.mimet.2018.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/04/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Abstract
The accumulation of multiple inherent and acquired resistance mechanisms in Acinetobacter spp. results in emergence of "pandrug resistant" strains which is one of the major concerns in healthcare sectors worldwide. Surveillance of the carbapenemase/ extended-spectrum β-lactamases (ESBLs) genes in A. baumannii by phenotypic methods is challenging especially in developing countries, like Pakistan. In this context, a novel microarray (CT 103XL Check-MDR) assay was used for simultaneous detection of genes encoding clinically important carbapenemases and ESBLs. The results were compared with the phenotypic methods including MHT, Rapidec Carba NP, EDTA+DDST and Rosco (KPC/MBL). The results of the microarray were also confirmed by PCR. All of the strains of A. baumannii (47) were resistant to imipenem and meropenem. Microarray and PCR results showed presence of OXA-23 in all the isolates of A. baumannii while 36.17% also harbored PER. Rosco kit test showed 100% sensitivity to detect carbapenemases but exhibited low specificity to classify them. Rapidec Carba NP test has 100% sensitivity and specificity to detect the carbapenemases when compared with microarray. Sensitivity and specificity of microarray assay were 100% for bla-genes in comparison to PCR. This reveals that Check-MDR CT103 XL assay is an accurate method for the identification of ESBLs and carbapenemase genes in A. baumannii in comparison to the other methods.
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Affiliation(s)
- Fakhur Uddin
- Department of Microbiology, University of Karachi, Karachi 75270, Pakistan
| | | | - Kerry Roulston
- Centre for Clinical Microbiology, University College London, UK
| | - Gareth Platt
- Centre for Clinical Microbiology, University College London, UK
| | - Taseer Ahmed Khan
- Department of Physiology, University of Karachi, Karachi 75270, Pakistan
| | - Muhammad Sohail
- Department of Microbiology, University of Karachi, Karachi 75270, Pakistan.
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