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Introduction Pseudomonas and Acinetobacter species are frequently isolated non-fermenting gram negative bacteria in a variety of hospital acquired infections. Metallo-beta-lactamases have become a serious threat in treating infections because of their multiple drug resistance including carbapenems. To determine Objectives the prevalence of MBL production among Pseudomonas and Acinetobacter species and to evaluate the different phenotypic MBL detection methods. A total of 104 isolates of carbapenem resistant Pseudomonas (78) and Materials and methods Acinetobacter (26) from different clinical specimens were tested for MBL production by Modi?ed Hodge Test, Combined Disk Test and Double Disk Synergy Test. Antibiotic susceptibility was performed by Kirby- Bauer Disk Diffusion method. Results Pseudomonas aeruginosa (11.29%) Acinetobacterbaumanii (11.53%) were the predominant MBL producers. MBL production was detected 61.53%, 84.61% and 38.46 % by DDST( Doule disc synergy test), CDT (Combined disc test), and MHT (Modi?ed Hodge test) respectively. Colistin and Polymyxin B are the only option available for treating such infections. MBL Conclusion production among Pseudomonas and Acinetobacter species are increasing due to the continuous use of carbapenems and selective antibiotic pressure. Strict antibiotic policy and infection control practices help prevent the further spread.
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Aims@#The detection of the metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa isolates is crucial for infection control and public health. The present study aimed to investigate the MBL production in carbapenem-resistant P. aeruginosa isolated from various clinical samples in Kastamonu Training and Research Hospital, Turkey. @*Methodology and results@#Seventy-three carbapenem-resistant P. aeruginosa isolates were recovered from different patients between April 2018 and November 2020. Identification of the isolates was performed by conventional methods (culture examination, determination of Gram reaction, and oxidase test) and an automated system (Vitek 2). Antibiotic susceptibility patterns were determined using the Vitek 2 and the results were interpreted based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. The MBL production was phenotypically investigated using the imipenem-EDTA combined disk test. The presence of beta-lactamase IMP (blaIMP), beta-lactamase VIM (blaVIM) and beta-lactamase GIM (blaGIM) genes were determined using PCR to confirm the MBL production. Seventy-one isolates (97%, n=71/73) were resistant to imipenem, sixty-four isolates (88%, n=64/73) to meropenem and sixty-two isolates (85%, n=62/73) to both imipenem and meropenem. Sixty-five isolates (89%, n=65/73) were defined as multidrug-resistant. The MBL production was detected in 57 isolates (78%, n=57/73) phenotypically. However, the blaIMP, blaVIM and blaGIM genes were not detected in all the isolates.@*Conclusion, significance and impact of study@#It was determined that there were no imipenemase (IMP), Verona integron-encoded metallo-beta-lactamase (VIM) and German imipenemase (GIM) type MBLs in carbapenem-resistant P. aeruginosa isolated from Kastamonu Training and Research Hospital. MBL production in carbapenem-resistant P. aeruginosa strains can be investigated phenotypically. However, confirmation of results with molecular tests is especially significant for epidemiological studies.
Subject(s)
beta-Lactamases , Carbapenem-Resistant Enterobacteriaceae , Pseudomonas aeruginosaABSTRACT
RESUMEN La emergencia de enterobacterias productoras de carbapenemasas de tipo Nueva Delhi Metalo beta-lactamasas (NDM), representan, hoy en día, un verdadero problema de salud pública mundial. La presencia de este mecanismo de resistencia limita o anula las opciones terapéuticas para combatir a estas bacterias. En Latinoamérica, las cifras son cada vez más elevadas, pues se reportan en Guatemala, Colombia, Chile, Argentina, entre otros. Perú no ha descrito, hasta la fecha, la presencia de este patrón de resistencia; sin embargo, desde hace varios años se presume de su existencia. Se describen nueve casos de Klebsiella pneumoniae NDM, como agentes infecciosos o colonizantes, en pacientes críticamente enfermos, en su mayoría con patología neuroquirúrgica, del Hospital Nacional Dos de Mayo, en Lima - Perú. Los pacientes de la serie descrita a continuación, representan los primeros reportes de Klebsiella pneumoniae NDM en el Perú.
ABSTRACT The emergence of Enterobacteria producing carbapenemases of type New Delhi Metalo beta-lactamases (NDM), >represent, today, a real problem of world public health. The presence of this resistance mechanism limits or nullifies the therapeutic options to combat these bacteria. In Latin America, the figures are getting higher, as they are reported in Guatemala, Colombia, Chile, Argentina, among others. Peru has not, to date, described the presence of this resistance pattern; however for several years it has been presumed to exist. Nine cases of Klebsiella pneumoniae NDM are described, as infectious or colonizing agents, in critically ill patients, mostly with neurosurgical pathology, of Hospital Nacional Dos de Mayo in Lima - Peru. The patients in the series described below represent the first reports of Klebsiella pneumoniae NDM in Peru.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Bacterial Proteins/biosynthesis , beta-Lactamases/biosynthesis , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/enzymology , Peru , Microbial Sensitivity Tests , HospitalsABSTRACT
En 2008 se reportó la enzima NDM-1 que genera resistencia a carbapenémicos. Para determinar el perfil de resistencia que presentan las bacterias frente a esta enzima se adelantó una revisión sistemática. La búsqueda de artículos se realizó en diferentes bases de datos y para su selección se consideraron criterios de inclusión y exclusión obteniendo un total de 154 artículos. Se identificaron 617 casos, presentados en trece géneros bacterianos, que codifican para los cuatro mecanismos de resistencia, principalmente a betalactámicos y aminoglucósidos. Cuando se presenta la enzima, la posibilidad que haya genes asociados para la producción de resistencias es alta, generando así que se presenten mecanismos que evitan la acción del antibiótico haciendo difícil implementar un tratamiento efectivo.
In 2008 the NDM-1 enzyme was first reported, the enzyme responsible for the resistance to carbapenems. We conducted a systematic review to determine the resistance profile due to the presence of this enzyme in bacteria. We searched academic articles in principal databases resulting in the selection of 154 articles given our inclusion and exclusion criteria. 617 cases and 13 bacterial genera were reported in our sample. We find 4 resistance mechanisms which are principally resistant to beta-lactams and aminoglycosides. Hence, we have that the presence of the NDM-1 increases the likelihood of having genes that improves the bacteria's resistance dramatically. The presence of the NDM-1 induces mechanisms which impacts the effectiveness of antibiotics and appropriate treatments are difficult to find.
Subject(s)
Humans , Bacteria , beta-Lactamases , Carbapenems , beta-Lactam ResistanceABSTRACT
Carbapenems are mainstay of treating serious multidrug resistant gram-negative biofi lm-based infections. However, recent emergence of metallo-beta-lactamases (ML) producing gram-negative bacilli in different parts of world may be related to gain of virulence factors associated with biofi lm production. Objectives: To explore the association of ML and biofi lm production in various gramnegative bacilli. Materials and Methods: In this study, 110 non-repetitive ceftazidime resistant gram-negative bacilli were evaluated for biofi lm and ML production. Biofi lm forming ability of isolates obtained from various specimens was tested by the tube method. Disks of ceftazidime (30 g) and ceftazidime with ethylenediaminetetraacetic acid (30 g + 750 g, prepared in house) for ML detection were used. Chi-square test was used to study the association between biofi lm and ML production. P value <0.05 was considered signifi cant. Results: 88 (80%) bacilli had shown biofi lm producing ability. The association of biofi lm and ML was signifi cant in cases of non-fermenters as compared to enterobacteriaceae members. Conclusion: The particular combination of virulence factors (biofi lm and ML) in bacteria may be a species specifi c effect which needs to be investigated at molecular level in detail. This may help in designing newer therapies based on interference with biofi lm formation and thus countering clinical episodes of antibiotic resistance.
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Purpose: The emergence and spread of zinc-dependent carbapenem resistance has become a diagnostic challenge for clinical microbiologists. The objective of the present study was to screen zinc-dependent carbapenemase activity in clinical isolates of family Enterobacteriaceae. Materials and Methods: A total of 102 multidrug-resistant organisms (MDROs), non-repeat clinical isolates of family Enterobacteriaceae from two tertiary care centres in Delhi, were screened for carbapenemase production by a modified Hodge test (MHT) and additionally by a re-modified Hodge test, EDTA double disc synergy test, and combined disc test (or disc enhancement test) to determine zinc dependence of carbapenemases harbouring bacteria. Results: Of the total 102 clinical isolates (June through November 2010), 91 were from urine and 11 were from blood specimens. The isolates were obtained from patients visiting the outpatient department (18 isolates), admitted in non-ICU inpatient care units (74 isolates) and patients admitted in ICUs (4 isolates). MHT identified 92 (90.2%) isolates as carbapenemases producers. Among those found negative for MHT (n=10), metallo-beta-lactamases (MBLs) activity was demonstrated through the EDTA disc diffusion synergy test and the combined disc test in 8 and 9 isolates respectively. A total of 63 (61.7%) isolates demonstrated MBL activity despite in vitro sensitivity to Imipenem. Conclusions: The study demonstrated that supplementing the MHT with at least one of the screening methods increases the likelihood of picking up such isolates that may be missed by the MHT. The study also demonstrates the wide-spread presence of MBLs in Enterobacteriaceae members from patients visiting hospitals in east Delhi.
Subject(s)
Bacterial Proteins/metabolism , Bacteriological Techniques/methods , Coenzymes/metabolism , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae/enzymology , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/microbiology , Hospitals , Humans , Immunoassay/methods , India , Zinc/metabolism , beta-Lactamases/metabolismABSTRACT
Purpose: The emergence and spread of zinc-dependent carbapenem resistance has become a diagnostic challenge for clinical microbiologists. The objective of the present study was to screen zinc-dependent carbapenemase activity in clinical isolates of family Enterobacteriaceae. Materials and Methods: A total of 102 multidrug-resistant organisms (MDROs), non-repeat clinical isolates of family Enterobacteriaceae from two tertiary care centres in Delhi, were screened for carbapenemase production by a modified Hodge test (MHT) and additionally by a re-modified Hodge test, EDTA double disc synergy test, and combined disc test (or disc enhancement test) to determine zinc dependence of carbapenemases harbouring bacteria. Results: Of the total 102 clinical isolates (June through November 2010), 91 were from urine and 11 were from blood specimens. The isolates were obtained from patients visiting the outpatient department (18 isolates), admitted in non-ICU inpatient care units (74 isolates) and patients admitted in ICUs (4 isolates). MHT identified 92 (90.2%) isolates as carbapenemases producers. Among those found negative for MHT (n=10), metallo-beta-lactamases (MBLs) activity was demonstrated through the EDTA disc diffusion synergy test and the combined disc test in 8 and 9 isolates respectively. A total of 63 (61.7%) isolates demonstrated MBL activity despite in vitro sensitivity to Imipenem. Conclusions: The study demonstrated that supplementing the MHT with at least one of the screening methods increases the likelihood of picking up such isolates that may be missed by the MHT. The study also demonstrates the wide-spread presence of MBLs in Enterobacteriaceae members from patients visiting hospitals in east Delhi.
Subject(s)
Bacterial Proteins/metabolism , Bacteriological Techniques/methods , Coenzymes/metabolism , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae/enzymology , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/microbiology , Hospitals , Immunoassay/methods , India , Zinc/metabolism , beta-Lactamases/metabolismABSTRACT
Purpose: The newly emerging form of the so-called New Delhi Metallo-beta-lactamases (NDM-1) has been reported recently from patients worldwide and broadly thought as a potential source for the major global health problem. Thus, it is important to study the epidemiology of the so-called NDM-1 harbouring bacteria to prevent its further spread and to place effective control measures. The present study describes the use of the real-time polymerase chain reaction (PCR) assay for the detection of the bla NDM-1 gene using TaqMan probes among clinical isolates. Materials and Methods: Clinical isolates of Escherichia coli (11 strains), Klebsiella pneumoniae (17 strains) and Acinetobacter baumannii (six strains) that were resistant to either of the carbapenems (meropenem or imipenem) were included in the study. The presence of carbapenemases in such strains was confirmed using the modified Hodge test. A real-time PCR assay was optimized for the detection of NDM-1 using a cloned synthetic gene fragment followed by testing of the clinical isolates. The findings were further confirmed using PCR and gene sequencing. Results: TaqMan probe assay displayed a good detection limit with analytical sensitivity of the assay up to 10 copies of bla NDM-1 gene per reaction. The isolates of E. coli and K. pneumoniae revealed narrow range crossing point values (Cp values) between (12-17) cycles (mean Cp value 14), indicating number of bla NDM-1 gene copies of 106-108. The wider range of Cp values (15-34) cycles with a higher mean Cp value (23.6) was observed in A. baumannii with number of bla NDM-1 gene copies of 103-108. Conclusions: The study demonstrates that real-time PCR assay based on TaqMan chemistry is a useful technique for the detection of bla NDM-1 harbouring clinical isolates of E. coli, K. pneumoniae and A. baumannii. The assay has great precision in measuring the number of bla NDM-1 gene copies per specimen of DNA.
Subject(s)
Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Anti-Bacterial Agents/metabolism , Bacteriological Techniques/methods , Carbapenems/metabolism , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli/isolation & purification , Genes, Bacterial , Humans , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Real-Time Polymerase Chain Reaction/methods , beta-Lactam Resistance , beta-Lactamases/genetics , beta-Lactamases/metabolismABSTRACT
En el presente estudio, que tuvo por objeto analizar los mecanismos involucrados en la resistencia a carbapenemes, se incluyeron 129 aislamientos de Pseudomonas aeruginosa recuperados durante el año 2006 en el Hospital "Eva Perón" de la Provincia de Buenos Aires. La caracterización fenotípica y genotípica de la resistencia permitió reconocer la presencia de metalo-beta-lactamasas (MBL) en el 14% de esos aislamientos. En todos ellos se identificó la presencia de la enzima IMP-13; sin embargo, algunos aislamientos resultaron sensibles a carbapenemes de acuerdo con los puntos de corte establecidos por el CLSI e incluso con las sugerencias de la Subcomisión de Antimicrobianos de SADEBAC, AAM. El ensayo de detección fenotípica de MBL de sinergia con doble disco resultó útil en este estudio. Sólo aquellos aislamientos productores de IMP-13 que a su vez presentaron alteraciones en las proteínas de membrana externa resultaron completamente resistentes a imipenem. Los aislamientos productores de MBL correspondieron a varios tipos clonales, lo cual sugiere no sólo la diseminación de una cepa resistente, sino también la diseminación horizontal de este mecanismo de resistencia entre clones diferentes.
From 129 P. aeruginosa isolated at a health care centre located in Buenos Aires (Hospital "Eva Perón"), 14% produced IMP-13. Although 18 isolates were metallo-beta-lactamases (MBL) producers, only those isolates that displayed altered outer membrane protein profiles correlated with the resistant category according to CLSI or even Subcomisión de Antimicrobianos, SADEBAC, AAM. Phenotypic screening of metallo-beta-lactamases proved to be appropriate for detecting MBL producing isolates. IMP-13 producing isolates corresponded to at least five different clonal types, which not only suggests the dissemination of the resistant strain but also of the resistant marker.
Subject(s)
beta-Lactam Resistance , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Imipenem/pharmacology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/isolation & purification , Argentina/epidemiology , Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins/analysis , Bacterial Proteins/genetics , Ceftazidime/pharmacology , Cross Infection/epidemiology , Genotype , Microbial Sensitivity Tests , Phenotype , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/genetics , Sequence Analysis, DNA , beta-Lactamases/analysis , beta-Lactamases/geneticsABSTRACT
Se estudiaron 91 aislamientos de Pseudomonas aeruginosa resistentes a carbapenemes con el objetivo de conocer la prevalencia de metalo-β-lactamasas y evaluar la habilidad del ensayo de inhibición empleando discos de EDTA (1 µmol) en su detección. Se determinó la presencia de carbapenemasas en 10 (11%) de los aislamientos recuperados. La sensibilidad a aztreonam en los aislamientos resistentes a ambos carbapenemes resultó un buen predictor de la presencia de estas enzimas. Dichas carbapenemasas correspondieron a la enzima VIM-2 en tres de ellos y a VIM-11 en otros siete. En todos los casos los genes codificantes de estas enzimas se encontraron localizados en integrones de clase 1 seguidos corriente abajo de genes codificantes de enzimas acetilantes de antibióticos aminoglucosídicos. El ensayo de detección fenotípica de metalo-β-lactamasas empleando discos de EDTA mostró un 100% de especificidad y sensibilidad en la detección de estas enzimas en la población de Pseudomonas aeruginosa analizadas.
The present study was conducted to estimate the prevalence of metallo-β-lactamases in 91 consecutive carbapenem resistant Pseudomonas aeruginosa isolates, recovered from inpatients at Hospital de Clínicas in Buenos Aires. Both, phenotypic and genotypic methods detected the presence of carbapenemases in 10 (11%) isolates, corresponding to VIM-11 in 7/10 and VIM-2 in the others. Codifying genes were all included in class 1 integrons, upstream genes coding for aminoglycoside modifying enzymes. One hundred percent sensitivity and specificity was achieved by the metallo-β-lactamases phenotypic screening method using EDTA (1 µmol) disks in the Pseudomonas aeruginosa isolates included in this study. Sensitivity to aztreonam in carbapenem resistant isolates was suspicious of the presence of these enzymes.