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BACKGROUND: Pseudomonas juntendi is a newly identified opportunistic pathogen, of which we have limited understanding. P. juntendi strains are often multidrug resistant, which complicates clinical management of infection. METHODS: A strain of Pseudomonas juntendi (strain L4326) isolated from feces was characterized by MALDI-TOF-MS and Average Nucleotide Identity BLAST. This strain was further subject to whole-genome sequencing and Maximum Likelihood phylogenetic analysis. The strain was phenotypically characterized by antimicrobial susceptibility testing and conjugation assays. RESULTS: We have isolated the novel P. juntendi strain L4236, which was multidrug resistant, but retained sensitivity to amikacin. L4236 harbored a megaplasmid that encoded blaOXA-1 and a novel blaIMP-1 resistance gene variant. P. juntendi strain L4236 was phylogenetically related to P. juntendi strain SAMN30525517. CONCLUSION: A rare P. juntendi strain was isolated from human feces in southern China with a megaplasmid coharboring blaIMP-1-like and blaOXA-1. Antimicrobial selection pressures may have driven acquisition of drug-resistance gene mutations and carriage of the megaplasmid.
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Farmacorresistencia Bacteriana Múltiple , Filogenia , Plásmidos , Pseudomonas , beta-Lactamasas , Pseudomonas/genética , Pseudomonas/aislamiento & purificación , Plásmidos/genética , beta-Lactamasas/genética , Farmacorresistencia Bacteriana Múltiple/genética , China , Humanos , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Secuenciación Completa del Genoma , Heces/microbiología , Cromosomas Bacterianos/genética , Genoma BacterianoRESUMEN
OBJECTIVES: To investigate the clinical and molecular epidemiological characteristics of blaIMP-4-carrying Klebsiella pneumoniae in a tertiary hospital in China. METHODS: Ten carbapenem-resistant K. pneumoniae (CRKP) isolates carrying the blaIMP-4 gene were collected. Molecular characteristics were analysed using whole-genome sequencing. Plasmid conjugation experiments were used to analyse conjugation of the plasmids. We compared and analysed K. pneumoniae-carrying blaIMP-4 genomic datasets obtained from the National Center for Biotechnology Information (NCBI) with the strains in this study. RESULTS: All 10 CRKP isolates carrying blaIMP-4 were collected from 10 adult patients in the respiratory intensive care unit. These strains were only sensitive to polymyxins and tigecycline due to them simultaneously carrying multiple resistance genes, namely blaOKP-A-5, fosA, oqxA, and oqxB. Notably, R29 harboured two carbapenemase genes (blaNDM-1 and blaIMP-4). These strains had similar drug-resistant phenotypes and genes, all belonging to sequence type (ST)196. Additionally, the patients had experienced spatiotemporal intersection during hospitalization, suggesting that these strains underwent clonal transmission, but they belonged to different clonal clusters from the blaIMP-4-positive K. pneumoniae currently published in the NCBI. Among the 10 strains, blaIMP-4 was located on the IncN plasmid, and six strains had successfully transferred the plasmid to the recipient strain EC600 through plasmid conjugation. CONCLUSIONS: The blaIMP-4-positive ST196 CRKP isolate showed clonal distribution in the respiratory intensive care unit, which was mediated by the IncN plasmid. Consequently, there should be increased monitoring of carbapenem-resistant strains in clinical settings to prevent and control its transmission.
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Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Infecciones por Klebsiella , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , Plásmidos , beta-Lactamasas , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Humanos , Plásmidos/genética , beta-Lactamasas/genética , China , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/transmisión , Masculino , Femenino , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Secuenciación Completa del Genoma , Persona de Mediana Edad , Proteínas Bacterianas/genética , Anciano , Adulto , Centros de Atención Terciaria , Epidemiología Molecular , Carbapenémicos/farmacología , Unidades de Cuidados Intensivos , Conjugación GenéticaRESUMEN
BACKGROUND: Klebsiella variicola is considered a newly emerging human pathogen. Clinical isolates of carbapenemase and broad-spectrum ß-lactamase-producing K. variicola remain relatively uncommon. A strain of K. variicola 4253 was isolated from a clinical sample, and was identified to carry the blaIMP-4 and blaSFO-1 genes. This study aims to discern its antibiotic resistance phenotype and genomic characteristics. METHODS: Species identification was conducted using MALDI-TOF/MS. PCR identification confirmed the presence of the blaIMP-4 and blaSFO-1 genes. Antibiotic resistance phenotype and genomic characteristics were detected by antimicrobial susceptibility testing and whole-genome sequencing. Plasmid characterization was carried out through S1-PFGE, conjugation experiments, Southern blot, and comparative genomic analysis. RESULTS: K. variicola 4253 belonged to ST347, and demonstrated resistance to broad-spectrum ß-lactamase drugs and tigecycline while being insensitive to imipenem and meropenem. The blaIMP-4 and blaSFO-1 genes harbored on the plasmid p4253-imp. The replicon type of p4253-imp was identified as IncHI5B, representing a multidrug-resistant plasmid capable of horizontal transfer and mediating the dissemination of drug resistance. The blaIMP-4 gene was located on the In809-like integrative element (Intl1-blaIMP-4-aacA4-catB3), which circulates in Acinetobacter and Enterobacteriaceae. CONCLUSIONS: This study reports the presence of a strain of K. variicola, which is insensitive to tigecycline, carrying a plasmid harboring blaIMP-4 and blaSFO-1. It is highly likely that the strain acquired this plasmid through horizontal transfer. The blaIMP-4 array (Intl1-blaIMP-4-aacA4-catB3) is also mobile in Acinetobacter and Enterobacteriaceae. So it is essential to enhance clinical awareness and conduct epidemiological surveillance on multidrug-resistant K. variicola, conjugative plasmids carrying blaIMP-4, and the In809 integrative element.
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Acinetobacter , Klebsiella , Humanos , Tigeciclina/farmacología , Klebsiella/genética , Plásmidos/genética , beta-Lactamasas/genéticaRESUMEN
INTRODUCTION: Acinetobacter baumannii (A. baumannii) is an opportunistic pathogenic bacterium mainly associated with hospital acquired infections and in immunocompromised individuals who stay in hospitals for a long time. In recent years, it has become increasingly resistant to many different types of antibiotics. The production of the metallo-beta-lactamase (MBL) enzyme is one of the primary causes of this resistance. This study aimed to detect the presence of MBL genes that belong to the verona integrin metallo-ß-lactamase (bla-VIM) and imipenemase (bla-IMP) groups in the isolates of Acinetobacter baumannii from burn patients. METHODOLOGY: One hundred and seventeen (117) isolates of A. baumannii were obtained from patient specimens using traditional methods followed by using the VITEK 2 (BioMérieux, Les Pennes-Mirabeau, France) identification system. Metallo ß-lactamases were detected in the imipenem-resistant strains by using imipenem disks on Muller-Hinton agar. The polymerase chain reaction (PCR) technique was utilized to examine 117 isolates for the detection of MBLs encoding genes such as bla-VIM, and bla-IMP. RESULTS: Imipenem resistance was detected in 78.6% of the patients. The PCR assays of the isolates identified bla-VIM-1, bla-VIM-2, bla-IMP-1 and bla-IMP-2 genes at the rates of 17%, 40.1%, 29.9% and 4.2%, respectively. CONCLUSIONS: The findings suggest that the majority of A. baumannii isolates harbour one or more of the detected genes, signifying that the production of MBLs plays a pivotal role in resistance mechanisms.
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Infecciones por Acinetobacter , Acinetobacter baumannii , Quemaduras , Humanos , Irak , Infecciones por Acinetobacter/microbiología , Reacción en Cadena de la Polimerasa/métodos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Imipenem , beta-Lactamasas/genética , Quemaduras/complicaciones , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: This study aimed to characterize carbapenem-nonsusceptible Acinetobacter (CNSA) isolated from patients with bacteremia from 1997 to 2015. METHODS: A total of 173 CNSA (12.3%) was recovered from 1403 Acinetobacter isolates. The presence of selected ß-lactamase genes in CNSA was determined by PCR amplification. The conjugation test was used to determine the transferability of metallo-ß-lactamase (MBL)-carrying plasmids. Whole genome sequencing in combination with phenotypic assays was carried out to characterize MBL-plasmids. RESULTS: In general, a trend of increasing numbers of CNSA was observed. Among the 173 CNSA, A. baumannii (54.9%) was the most common species, followed by A. nosocomialis (23.1%) and A. soli (12.1%). A total of 49 (28.3%) CNSA were extensively drug-resistant, and all were A. baumannii. The most common class D carbapenemase gene in 173 CNSA was blaOXA-24-like (32.4%), followed by ISAba1-blaOXA-51-like (20.8%), ISAba1-blaOXA-23 (20.2%), and IS1006/IS1008-blaOXA-58 (11.6%). MBL genes, blaVIM-11,blaIMP-1, and blaIMP-19 were detected in 9 (5.2%), 20 (11.6%), and 1 (0.6%) CNSA isolates, respectively. Transfer of MBL genes to AB218 and AN254 recipient cells was successful for 7 and 6 of the 30 MBL-plasmids, respectively. The seven AB218-derived transconjugants carrying MBL-plasmids produced less biofilm but showed higher virulence to larvae than recipient AB218. CONCLUSIONS: Our 19-year longitudinal study revealed a stable increase in CNSA during 2005-2015. blaOXA-24-like, ISAba1-blaOXA-51-like, and ISAba1-blaOXA-23 were the major determinants of Acinetobacter carbapenem resistance. MBL-carrying plasmids contribute not only to the carbapenem resistance but also to A. baumannii virulence.
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Acinetobacter baumannii , Sepsis , Humanos , Carbapenémicos/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Estudios Longitudinales , Virulencia/genética , Acinetobacter baumannii/genética , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genética , Proteínas Bacterianas/genética , Plásmidos/genética , Sepsis/tratamiento farmacológicoRESUMEN
In this study, we describe an Enterobacter ludwigii clinical isolate that is resistant to both carbapenems and colistin in South Korea. Antimicrobial susceptibility testing revealed that E. ludwigii CRE2104-31 was non-susceptible to all tested antibiotics except fosfomycin. Whole genome sequencing identified a 323-kbp IncHI2 plasmid, pCRE2104-31a, that was co-harbouring mobile colistin resistance (mcr)-9.1 and blaIMP-1. In comparison with other full plasmids, pCRE2104-31a exhibited the closest similarity to a plasmid from the Klebsiella pneumoniae strain CNR48 from France, with 19.9% query coverage and 99% identity. Notably, we observed five tandem repeats of blaIMP-1 and aac(6')-Il genes, accompanied by multiple attCs within a class I integron on the Tn402-like transposon. The unit of blaIMP-1-attC-aac(6')-Il-attC might have accumulated due to multiple convergent events. In addition to mcr-9.1 and blaIMP-1, various other antibiotic resistance-associated genes were identified in the plasmid, as follows: blaTEM-1B, aph(3')-I, aph(3')-Ia, aac(6')-Il, aac(6')-IIc, aac(6')-IIa, aph(6)-Id, aph(3'')-Ib, aadA2b, aac(6')-Ib3, sul, dfrA19, qnrB2, aac(6')-Ib-cr, ere(A), and qacE. A conjugation assay showed that the mcr-9.1/blaIMP-1-co-bearing plasmid was self-transmissible to E. coli J53. However, colistin and carbapenem resistance could not be transferred to E. coli due to high incompatibility. The convergence of mcr and carbapenemase genes is thought to be host-dependent among Enterobacteriaceae. The emergence of extensively drug-resistant E. ludwigii co-harbouring MCR-9.1 and a multicopy of blaIMP-1 would pose a significant threat within the compatible Enterobacteriaceae.
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Colistina , Enterobacter , Escherichia coli , Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Antibacterianos/farmacología , EnterobacteriaceaeRESUMEN
Carbapenemase-producing Enterobacteriaceae (CPE) are one of the most detrimental species of antibiotic-resistant bacteria globally. Phage therapy has emerged as an effective strategy for the treatment of CPE infections. In western Japan, the rise of Klebsiella pneumoniae strains harboring the pKPI-6 plasmid encoding bla IMP-6 is of increasing concern. To address this challenge, we isolated 29 phages from Japanese sewage, specifically targeting 31 K. pneumoniae strains and one Escherichia coli strain harboring the pKPI-6 plasmid. Electron microscopy analysis revealed that among the 29 isolated phages, 21 (72.4%), 5 (17.2%), and 3 (10.3%) phages belonged to myovirus, siphovirus, and podovirus morphotypes, respectively. Host range analysis showed that 18 Slopekvirus strains within the isolated phages infected 25-26 K. pneumoniae strains, indicating that most of the isolated phages have a broad host range. Notably, K. pneumoniae strain Kp21 was exclusively susceptible to phage øKp_21, whereas Kp22 exhibited susceptibility to over 20 phages. Upon administering a phage cocktail composed of 10 phages, we observed delayed emergence of phage-resistant bacteria in Kp21 but not in Kp22. Intriguingly, phage-resistant Kp21 exhibited heightened sensitivity to other bacteriophages, indicating a "trade-off" for resistance to phage øKp_21. Our proposed phage set has an adequate number of phages to combat the K. pneumoniae strain prevalent in Japan, underscoring the potential of a well-designed phage cocktail in mitigating the occurrence of phage-resistant bacteria. IMPORTANCE The emergence of Klebsiella pneumoniae harboring the bla IMP-6 plasmid poses an escalating threat in Japan. In this study, we found 29 newly isolated bacteriophages that infect K. pneumoniae strains carrying the pKPI-6 plasmid from clinical settings in western Japan. Our phages exhibited a broad host range. We applied a phage cocktail treatment composed of 10 phages against two host strains, Kp21 and Kp22, which displayed varying phage susceptibility patterns. Although the phage cocktail delayed the emergence of phage-resistant Kp21, it was unable to hinder the emergence of phage-resistant Kp22. Moreover, the phage-resistant Kp21 became sensitive to other phages that were originally non-infective to the wild-type Kp21 strains. Our study highlights the potential of a well-tailored phage cocktail in reducing the occurrence of phage-resistant bacteria.
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Effective classification and visualization of multiple antimicrobial resistance plasmids can be challenging, and few tools to analyze similarities among plasmids depending on the location of genes are available. We created a new plasmid mapping program called Bird's-eye MApping of plasmids (BeMAp) to map antimicrobial resistance genes across multiple plasmids onto a spreadsheet and visualize their similarities based on gene types, locations, alignments, and organization. We analyzed plasmids containing various antimicrobial resistance genes, together with genes coding for IMP-type metallo-ß-lactamases. Moreover, the mapping of plasmids with antimicrobial resistance genes and Incompatibility (Inc) groups showed that clustered plasmids with a similar organization of antimicrobial resistance genes were not always classified into the same Inc groups, indicating that the program displays multiple plasmids regardless of the Inc group classification. Our results showed that this calculation protocol and mapping strategy could provide a valuable tool for the practical and convenient visualization and comparison of the genomic structure of multiple plasmids in parallel.
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Antibacterianos , Farmacorresistencia Bacteriana , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/genética , Plásmidos/genética , beta-Lactamasas/genética , Genómica , Pruebas de Sensibilidad MicrobianaRESUMEN
INTRODUCTION: The emergence of multidrug-resistant (MDR) E. coli has developed worldwide; therefore, the use of antibiotic combinations may be an effective strategy to target resistant bacteria and fight life-threatening infections. The current study was performed to evaluate the in vitro and in vivo efficacy of amikacin and imipenem alone and in combination against multidrug-resistant E. coli. Methods: The combination treatment was assessed in vitro using a checkerboard technique and time-killing curve and in vivo using a peritonitis mouse model. In resistant isolates, conventional PCR and quantitative real-time PCR techniques were used to detect the resistant genes of Metallo-ß-lactamase gene Imipenemase (bla-IMP) and aminoglycoside 6'-N-acetyltransferase (aac (6')-Ib). Scanning electron microscopy was used to detect the morphological changes in the resistant isolates after treatment with each drug alone and in combination. In vitro and in vivo studies showed a synergistic effect using the tested antibiotic combinations, showing fractional inhibitory concentration indices (FICIs) of ≤0.5. Regarding the in vivo study, combination therapy indicated a bactericidal effect after 24 h. E. coli isolates harboring the resistant genes Metallo-ß-lactamase gene Imipenemase (bla-IMP) and aminoglycoside 6'-N-acetyltransferase (aac (6')-Ib) represented 80% and 66.7%, respectively, which were mainly isolated from wound infections. The lowest effect on Metallo-ß-lactamase gene Imipenemase (bla-IMP) and aminoglycoside 6'-N-acetyltransferase (aac (6')-Ib) gene expression was shown in the presence of 0.25 × MIC of imipenem and 0.5 × MIC of amikacin. The scanning electron microscopy showed cell shrinkage and disruption in the outer membrane of E. coli in the presence of the antibiotic combination. Amikacin and imipenem combination can be expected to be effective in the treatment and control of serious infections caused by multidrug-resistant (MDR) E. coli and the reduction in bacterial resistance emergence.
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BACKGROUND: Polymyxin E (colistin) is a last-resort antibiotic to treat infections caused by carbapenemase-producing Enterobacteriaceae (CPE). However, reports of CPEs resistant to colistin have been increasing, and the mcr genes are emerging as resistance mechanisms. Among them, plasmid-mediate mcr-9 is known to be associated with colistin resistance, whereas reports on chromosomal mcr-9 and its association with colistin resistance in humans are few. CASE PRESENTATION: We identified Enterobacter asburiae harboring mcr-9 and blaIMP-60 in the pleural fluid of a patient with empyema. The long-read sequencing technique revealed that these genes were located on its chromosome. Despite the lack of exposure to colistin, the organism showed microcolonies in the inhibition circle in the E-test and disk diffusion test. Antibiotic susceptibility testing by broth microdilution confirmed its resistance to colistin. CONCLUSION: Our case report showed that mcr-9 can be present not only on plasmids but also on the chromosome in E. asburiae, and that the presence of mcr-9 on its chromosome may influence its susceptibility to colistin.
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Empiema , Proteínas de Escherichia coli , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Cromosomas , Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Enterobacter , Proteínas de Escherichia coli/genética , Japón , Pruebas de Sensibilidad Microbiana , PlásmidosRESUMEN
OBJECTIVE: To investigate a detailed genomic characterization of the blaIMP-10-carrying plasmid p12NE515 from a Pseudomonas aeruginosa isolate in China. METHODS: Plasmid p12NE515 was subjected to whole-genome sequencing and the complete sequence was compared with related plasmid sequences. Transferability of plasmid, carbapenemase activity and bacterial susceptibility profiles were determined to assess p12NE515-mediated resistance phenotypes. RESULTS: P. aeruginosa 12NE515 was identified as a less common sequence type of ST1976. p12NE515 harboring blaIMP-10 possessed a backbone identical to plasmid p60512-IMP (carrying blaIMP-1), but the accessory resistance regions differed. Only one accessory module, Tn7339, was carried in p12NE515, and this transposon was an insertion sequence-mediated transposition unit generated by the insertion of a novel class 1 integron, In1814, at the downstream end of ISPa17. Here, blaIMP-10 together with aacA7 was located in In1814, being at evolution stage III of Tn402-associated integron due to truncation of the tni module. CONCLUSION: This study is the first to determine the complete sequence of a blaIMP-10-carrying plasmid, and this is also the first report of a blaIMP-10-producing strain in China. The prevalence of the blaIMP-10 gene and the genetic characterization of the blaIMP-10-carrying plasmid should be analyzed to provide deeper insight into the transmission mechanism of antimicrobial resistance genes.
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Pseudomonas aeruginosa , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Pruebas de Sensibilidad Microbiana , Plásmidos/genéticaRESUMEN
BACKGROUND AND OBJECTIVES: Carbapenems have been the choice of antibiotics for the treatment of infections caused by multidrug-resistant bacteria. The main objective of this study was to determine the prevalence of carbapenemase (bla VIM and bla IMP ) producing isolates among Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. MATERIALS AND METHODS: A total of 1,151 clinical samples were collected from the patients visiting Annapurna Neurological Institute and Allied Science and Annapurna Research Centre, Kathmandu, between June 2017 and January 2018. Antibiotic susceptibility testing (AST) was performed on the Enterobacteriaceae, P. aeruginosa and A. baumannii isolates using the Kirby-Bauer disk diffusion method. The modified Hodge test (MHT) was performed on the carbapenem-resistant isolates to confirm carbapenemase production. DNA was extracted and then screened for bla VIM and bla IMP genes by multiplex PCR. RESULTS: Of the total 1,151 clinical samples, 253 (22.0%) showed positive growth. Of them, 226 (89.3%) were identified as Enterobacteriaceae, P. aeruginosa, and A. baumannii. Among the 226 isolates, 106 (46.9%) were multidrug-resistant. Out of the 106, 97 (91.5%) isolates showed resistance to at least one of the carbapenem used. Among the 97 carbapenem-resistant isolates, 67 (69.1%) showed the modified Hodge test (MHT) positive results. bla VIM and bla IMP were detected in 40 and 38 isolates respectively using multiplex PCR assay. CONCLUSION: This study determined a high prevalence of MDR and carbapenem resistance among Enterobacteriaceae, P. aeruginosa, and A. baumannii as detected by the presence of bla VIM and bla IMP genes. This study recommends the use of rapid and advanced diagnostic tools along with conventional phenotypic detection methods in the clinical settings for early detection and management of drug-resistant pathogens to improve treatment strategies.
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BACKGROUND: Productions of metallo-ß-lactamases enzymes are the most common mechanism of antibiotic resistance to all beta-lactam classes (except monobactams) in Acinetobacter baumannii. MBLs are usually associated with gene cassettes of integrons and spread easily among bacteria. The current study was performed to detect the genes encoding MBLs and integron structures in A. baumannii isolates from burn patients. METHODS: This study was performed on 106 non-duplicate A. baumannii isolates from burn patients referred to Shahid Motahari Hospital in Tehran. Antibiotic susceptibility of A. baumannii isolates was performed using disk diffusion and broth microdilution method in accordance with the CLSI guidelines. The presence of class 1 integron and associated gene cassettes as well as MBLs-encoding genes including blaVIM, and blaIMP were investigated using PCR and sequencing techniques. RESULTS: In this cross-sectional study all (100%) of the A. baumannii isolates examined were multidrug resistant. All isolates were sensitive to colistin and simultaneously all were resistant to imipenem. PCR assays showed the presence of blaVIM and blaIMP genes in 102 (96.2%) and 62 (58.5%) isolates of A. baumannii respectively. In addition, 62 (58.5%) of the A. baumannii isolates carried integron class 1, of which 49 (79.0%) were identified with at least one gene cassette. Three types of integron class 1 gene cassettes were identified including: arr2, cmlA5, qacE1 (2300 bp); arr-2, ereC, aadA1, cmlA7, qacE1 (4800 bp); and aac(3)-Ic, cmlA5 (2250 bp). CONCLUSION: A high prevalence of MBLs genes, especially blaVIM, was identified in the studied MDR A. baumannii isolates. In addition, most of the strains carried class 1 integrons. Furthermore, the gene cassettes arrays of integrons including cmlA5 and cmlA7 were detected, for the first time, in A. baumannii strains in Iran.
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Infecciones por Acinetobacter , Acinetobacter baumannii , Quemaduras , Integrones , beta-Lactamasas , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Antibacterianos/farmacología , Estudios Transversales , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Integrones/genética , Irán , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genéticaRESUMEN
Acquired carbapenemases pose a significant role in the dissemination of antimicrobial-resistant Enterobacteriaceae and in this study we have identified the occurrence of blaIMP-4 in E. coli isolate from a sewage outfall located nearby a secondary health Centre. It was found to co-existed with blaCTX-M-15 located within a self-conjugable plasmid of IncF type. The current study underscores environment as a potential reservoir of carbapenem resistance and the need of the hour is to track and check dissemination of resistance in environment, human and agricultural settings.
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Escherichia coli , Aguas del Alcantarillado , beta-Lactamasas , Antibacterianos/farmacología , Proteínas Bacterianas , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Humanos , Aguas del Alcantarillado/microbiología , Agua , beta-Lactamasas/genéticaRESUMEN
OBJECTIVES: The spread of carbapenemase-producing Enterobacterales (CPE) with colistin resistance is a critical public health issue. We genetically characterized the clinical isolate Enterobacter roggenkampii OIPH-N260, which harboured carbapenemase genes blaIMP-1 and blaGES-5 with multiple resistance genes, including mcr-9 and blaCTX-M-9. METHODS: This isolate was characterized by whole-genome sequencing, comparative analysis of resistance plasmids, susceptibility tests, bacterial conjugation, S1-nuclease digested pulsed-field-gel electrophoresis, and Southern blot hybridization. RESULTS: The OIPH-N260 isolate exhibited resistance to most ß-lactams and colistin. It co-harboured two resistance plasmids, the blaIMP-1- and blaGES-5-encoding IncP6 plasmid pN260-3 and mcr-9- and blaCTX-M-9-encoding IncHI2 plasmid pN260-1. The comparative analysis of pN260-3 indicated that a unique blaIMP-1-surrounding region was inserted into the blaGES-5-encoding plasmid with the mobile element IS26, which plays an important role in the spread of resistance genes. pN260-1 did not possess the mcr-9 expression regulative gene qseBC. Both plasmids were transferable into other bacterial species via conjugation. CONCLUSIONS: This is the first study to report not only a blaIMP-1 and blaGES-5 co-encoding plasmid, but also the co-harbouring of another plasmid carrying mcr-9 and blaCTX-M-9 in Enterobacter cloacae complex. The development of advanced resistance via IS26-mediated insertion and the co-harbouring of resistance plasmids highlights the need to monitor for resistance genes in CPE.
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Antibacterianos , Enterobacter , Antibacterianos/farmacología , Genómica , Japón , Pruebas de Sensibilidad Microbiana , Plásmidos/genéticaRESUMEN
BACKGROUND: The increasing number of carbapenemase-producing Enterobacteriaceae (CPE) has become a global problem. Most carbapenemases detected in Japan are imipenemase, which is an imipenem-degrading enzyme with low ability; thus, CPE could have been overlooked. Therefore, this study aimed to detect and analyze CPE, without overlooking CPE showing the low minimum inhibitory concentration phenotype. METHODS: CPE screening was conducted on 531 ceftazidime-resistant Enterobacteriaceae isolated from Kitasato University Hospital during 2006-2015. We confirmed the presence of the carbapenemase genes (blaIMP, blaVIM, blaKPC, blaNDM, and blaOXA-48) by multiplex polymerase chain reaction. The detected CPE strains were analyzed by antimicrobial susceptibility testing, multilocus sequence typing, conjugal experiments, replicon typing, and plasmid profiling by restriction enzyme treatment. RESULTS: The CPE detection rate in Kitasato University Hospital within the past 10 years was 0.0003% (nine CPE strains). These nine CPE strains were identified to harbor 8 blaIMP-1 or 1 blaNDM-5. The CPE strains consisted of five species including Klebsiella pneumoniae and Citrobacter freundii. Six of eight blaIMP-1 were coded by IncHI2 plasmid, and the other two were coded by IncA/C plasmid. Plasmid profiling revealed that K. pneumoniae and C. freundii isolated from the same patient harbored the same plasmid. CONCLUSION: The CPE detection rate in this study was significantly lower than those previously reported in Japan. In one case, IncA/C plasmid transmission through different bacterial species within the body was speculated. Although the number of CPE detected was low, these results indicated that the resistance plasmid could spread to other bacterial species.
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Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Hospitales/tendencias , Resistencia betalactámica/genética , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Ceftazidima/farmacología , Ceftazidima/uso terapéutico , Citrobacter freundii/efectos de los fármacos , Citrobacter freundii/genética , Citrobacter freundii/aislamiento & purificación , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/microbiología , Transferencia de Gen Horizontal , Genes Bacterianos/genética , Hospitales/estadística & datos numéricos , Humanos , Imipenem/farmacología , Imipenem/uso terapéutico , Japón/epidemiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Plásmidos/genética , Plásmidos/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Prevalencia , beta-Lactamasas/genética , beta-Lactamasas/aislamiento & purificaciónRESUMEN
OBJECTIVES: The aim of this study was to investigate the characteristics and complete genome sequence of an IMP-8, CTX-M-14, CTX-M-3 and QnrS1 co-producing multidrug-resistant Enterobacter asburiae isolate (EN3600) from a patient with wound infection. METHODS: Species identification was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Carbapenemase genes were identified by PCR and Sanger sequencing. The complete genome sequence of E. asburiae EN3600 was obtained using a PacBio RS II platform. Genome annotation was done by Rapid Annotation using Subsystem Technology (RAST) server. Acquired antimicrobial resistance genes (ARGs) and plasmid replicons were detected using ResFinder 2.1 and PlasmidFinder 1.3, respectively. RESULTS: The genome of E. asburiae EN3600 consists of a 4.8-Mbp chromosome and five plasmids. The annotated genome contains various ARGs conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones, fosfomycin, macrolides, phenicols, rifampicin and sulfonamides. In addition, plasmids of incompatibility (Inc) groups IncHI2A, IncFIB(pECLA), IncFIB(pQil) and IncP1 were identified. The genes blaIMP-8, blaCTX-M-14 and blaCTX-M-3 were located on different plasmids. The blaIMP-8 gene was carried by an 86-kb IncFIB(pQil) plasmid. The blaCTX-M-3 and qnrS1 genes were co-harboured by an IncP1 plasmid. In addition, blaCTX-M-14 was associated with blaTEM-1B, blaOXA-1, catB3 and sul1 genes in a 116-kb non-typeable plasmid. CONCLUSION: To our knowledge, this is the first complete genome sequence of an E. asburiae isolate co-producing IMP-8, CTX-M-14, CTX-M-3 and QnrS1. This genome may facilitate the understanding of the resistome, pathogenesis and genomic features of Enterobacter cloacae complex (ECC) and will provide valuable information for accurate identification of ECC.
Asunto(s)
Enterobacter/genética , Secuenciación Completa del Genoma , Infección de Heridas/microbiología , beta-Lactamasas/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Enterobacter/efectos de los fármacos , Enterobacter/enzimología , Humanos , Pruebas de Sensibilidad Microbiana , Análisis de Secuencia de ADNRESUMEN
BACKGROUND AND STUDY AIMS: Colonized patients with carbapenamase producing Enterobacteriaceae (CPE) are vulnerable to invasive infections from their endogenous flora. We aimed to assess faecal colonization with (CPE) among children admitted to Cairo University paediatric intensive care units (ICUs). The phenotypic and genotypic characterizations of carbapenemase-producing Enterobacteriaceae were also studied. PATIENTS AND METHODS: A total of 413 Enterobacteriaceae isolates have been isolated from cultured rectal swabs of 100 children. All swabs were inoculated on ChromID™ CARBA agar to screen for carbapenem resistant Enterobacteriaceae (CRE). Disk diffusion method, Modified Hodge test (MHT) and further genotypic detection of carbapenemases genes (blaOXA-48, blaKPC and blaNDM-1, blaVIM and blaIMP) by multiplex PCR were done. RESULTS: Out of 413 Enterobacteriaceae isolates; 100 isolates were defined as CRE. BlaOXA-48 was detected in (33%); Escherichia coli (nâ¯=â¯11), Klebsiella oxytoca (nâ¯=â¯3) and Klebsiella pneumoniae (nâ¯=â¯19), while (27%) carried blaNDM-1Escherichia coli (nâ¯=â¯7), and Klebsiella pneumoniae (nâ¯=â¯20). CONCLUSION: Prevalence of carbapenem resistant Enterobacteriaceae was 24%, various genes of carbapenemases were detected in 80% of carbapenem resistant Enterobacteriaceae with dominance of blaOXA-48. Understanding the colonization status of our patients with strict infection control measures can reduce the risk of horizontal gene transfer of carbapenemases.
Asunto(s)
Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Portador Sano/microbiología , Proteínas Bacterianas/metabolismo , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Pruebas Antimicrobianas de Difusión por Disco , Egipto , Escherichia coli/enzimología , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Heces/microbiología , Microbioma Gastrointestinal , Genotipo , Humanos , Unidades de Cuidado Intensivo Pediátrico , Klebsiella oxytoca/enzimología , Klebsiella oxytoca/genética , Klebsiella oxytoca/aislamiento & purificación , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Fenotipo , Recto/microbiología , beta-Lactamasas/genética , beta-Lactamasas/metabolismoRESUMEN
Acinetobacter spp. are opportunistic pathogens being A. baumannii the most frequently identified in nosocomial settings. A. ursingii was mainly described as causing bacteremia and outbreaks in neonatal intensive care units. Ten A. ursingii isolates were recovered from rectal swab screening for carbapenemase-producing bacteria between June 2013 and December 2015 from a children hospital in Argentina. All ten isolates were metallo-ß-lactamase-producing, nine were positive for blaIMP-1 and one for blaNDM-1. IMP-positive isolates were also positive for blaOXA-58 gene. All isolates were susceptible to ciprofloxacin, colistin and minocycline, and nine were susceptible to ampicillin-sulbactam and gentamicin. Two A. ursingii displayed high level of resistance to aztreonam associated with blaCTX-M-15 in one isolate, and blaVEB-1 in the other. Eight SmaI-PFGE patterns were recognized. We evaluated the usefulness of Acinetobacter MLST-Pasteur scheme, to analyse A. ursingii isolates, however the rpoB gene was not amplified. A new set of primers were designed for specific amplification and sequencing, allowing the analysis of rpoB gene for this species. New alleles and the sequence types 748, 749, 750, 751, 993, 1186, 1187, and 1189 were included at the Acinetobacter MLST-Pasteur database. Those isolates showing related PFGE patterns were assigned to the same ST. To the best of our knowledge, this is the first report of MBL-producing A. ursingii in Argentina. The inclusion of A. ursingii species to the Acinetobacter MLST-Pasteur scheme allows deeper molecular characterization and a better understanding about the epidemiology of this germen.
Asunto(s)
Infecciones por Acinetobacter/epidemiología , Infecciones por Acinetobacter/microbiología , Acinetobacter/genética , Infección Hospitalaria , beta-Lactamasas/genética , Acinetobacter/clasificación , Acinetobacter/efectos de los fármacos , Infecciones por Acinetobacter/tratamiento farmacológico , Antibacterianos/farmacología , Argentina/epidemiología , Niño , Electroforesis en Gel de Campo Pulsado , Hospitales Pediátricos , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Filogenia , Resistencia betalactámicaRESUMEN
OBJECTIVES: A carbapenem-resistant Providencia rettgeri (PR1) isolate was recovered from a wound infection in Missouri, USA. This isolate possessed an EDTA-inhibitable carbapenemase that was unidentified using the Xpert CARBA-R assay. Our objective was to elucidate the molecular determinant of carbapenem resistance in this isolate. We then sought to test the transmissibility of blaIMP-27 loci in clinical P. rettgeri and Proteus mirabilis isolates. METHODS: In October 2016 the novel ambler Class B carbapenemase blaIMP-27, was reported in two different Proteus mirabilis (PM185 and PM187) isolates. Broth mating assays for transfer of carbapenemase activity were performed for the three clinical isolates with recipient sodium azide-resistant Escherichia coli J53. Antibiotic susceptibility testing and phenotypic carbapenemase activity testing were performed on the clinical isolates, J53 and transconjugants using the Kirby-Bauer disc diffusion method according to CLSI guidelines. Plasmid DNA from PM187, PR1 and their transconjugants were used as input for Nextera Illumina sequencing libraries and sequenced on a NextSeq platform. RESULTS: PR1 was resistant to both imipenem and meropenem. PM187 and PR1 could transfer resistance to E. coli through plasmid conjugation (pPM187 and pPR1). pPM187 had a virB/virD4 type IV secretion system whereas pPR1 had a traB/traD type IV secretion system. CONCLUSION: Two of three blaIMP-27-bearing clinical isolates tested could conjugate resistance into E. coli. The resulting transconjugants became positive for phenotypic carbapenemase production but did not pass clinical resistance breakpoints. blaIMP-27 can be transmitted on different plasmid replicon types that rely on distinct classes of type IV secretion system for horizontal transfer.