Faculty Opinions recommendation of Virulent clones of Klebsiella pneumoniae: identification and evolutionary scenario based on genomic and phenotypic characterization.

2014 ◽  
Author(s):  
Virginia L Miller
Keyword(s):  
Klebsiella Pneumoniae ◽  
Phenotypic Characterization ◽  
Evolutionary Scenario

scholarly journals Virulent Clones of Klebsiella pneumoniae: Identification and Evolutionary Scenario Based on Genomic and Phenotypic Characterization

PLoS ONE ◽  
2009 ◽  
Vol 4 (3) ◽  
pp. e4982 ◽  
Author(s):  
Sylvain Brisse ◽  
Cindy Fevre ◽  
Virginie Passet ◽  
Sylvie Issenhuth-Jeanjean ◽  
Régis Tournebize ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Phenotypic Characterization ◽  
Evolutionary Scenario

Emergence of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae in vivo

2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Galleria Mellonella ◽  
Phenotypic Characterization ◽  
Infection Model ◽  
Development Of Resistance ◽  
Time Kill

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.

scholarly journals Molecular and phenotypic characterization of clinical isolates belonging to a KPC-2-producing strain of ST15 Klebsiella pneumoniae from a Vietnamese pediatric hospital

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Björn Berglund ◽  
Ngoc Thi Bich Hoang ◽  
Maria Tärnberg ◽  
Ngai Kien Le ◽  
Maud Nilsson ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Phenotypic Characterization ◽  
Polymorphism Analysis ◽  
Pediatric Hospital ◽  
Carbapenem Resistant ◽  
Global Epidemiology

Abstract Background Carbapenem-resistant Klebsiella pneumoniae are becoming increasingly common in hospital settings worldwide and are a source of increased morbidity, mortality and health care costs. The global epidemiology of carbapenem-resistant K. pneumoniae is characterized by different strains distributed geographically, with the strain ST258 being predominant in Europe and USA, and ST11 being most common in East Asia. ST15 is a less frequently occurring strain but has nevertheless been reported worldwide as a source of hospital outbreaks of carbapenem-resistant K. pneumoniae. Methods In this study, whole-genome sequencing and antimicrobial susceptibility testing was used to characterize 57 clinical isolates of carbapenem-resistant K. pneumoniae belonging to a strain of ST15, which were collected at a Vietnamese pediatric hospital from February throughout September 2015. Results Aside from the carbapenem resistance gene blaKPC-2, which was carried by all isolates, prevalence of resistance genes to other antibiotics including aminoglycosides, macrolides, quinolones, fosfomycin and trimethoprim, was also high. All isolates were multidrug-resistant. Susceptibility was highest to ceftazidime/avibactam (96%), gentamicin (91%) and tigecycline (82%). Notably, the colistin resistance rate was very high (42%). Single-nucleotide polymorphism analysis indicated that most isolates belonged to a single clone. Conclusions The diverse variety of antibiotic resistance genes and the high antibiotic resistance rates to last-resort antibiotics such as carbapenems and colistin, is indicative of a highly adaptable strain. This emphasizes the importance of implementation of infection controls measures, continued monitoring of antibiotic resistance and prudent use of antibiotics to prevent further selection of resistant strains and the emergence of pan-resistant clones.

scholarly journals Phenotypic Characterization of Bacteria Isolated from the Recreational Sites of Two Rivers in Orashi Region, Rivers State, Nigeria

2021 ◽  
pp. 16-23
Author(s):  
T. Sampson ◽  
L. K. Giami ◽  
J. A. Okedike
Keyword(s):  
Klebsiella Pneumoniae ◽  
Statistical Difference ◽  
Water Bodies ◽  
Monthly Interval ◽  
Phenotypic Characterization ◽  
Recreational Water ◽  
Bacterial Counts ◽  
Recreational Activities ◽  
Microbiological Methods ◽  
Rivers State

Recreational water bodies are water bodies used for recreational activities such as swimming, surfing, water skiing, water diving and sailing. They include rivers, lakes, beaches, spas and swimming pools. This work was therefore aimed at determining the bacteriological profile of recreational water bodies in Orashi region of Rivers State, Nigeria. Surface water samples were collected from two different sites (Orashi River, Mbiama and Sombreiro River, Ahoada) using standard microbiological methods. Upstream, midstream and downstream samples were collected for a period of three months at monthly interval. Standard plate counts were used for total heterotrophic and coliform bacterial counts using standard microbiological media. The total heterotrophic bacterial count ranged from 4.1X104 to 9.5X104 for Orashi River and 3.0X103 to 4.0X103 for Sombreiro River. A significant statistical difference (p < 0.05) however, existed between total heterotrophic bacterial counts of the samples collected from Orashi River, while no statistical difference (p > 0.05) was observed in the total heterotrophic bacterial counts of samples from Sombreiro River. In the comparative analysis of the samples from the two water bodies, no statistical difference (p > 0.05) was recorded in the total coliform count in Orashi and Sombreiro Rivers. The phenotypic characterization identified the isolates to include Staphylococcus spp., Klebsiella spp., Pseudomonas spp., Bacillus spp., Enterococcus spp. and Micrococcus spp., with Klebsiella pneumoniae as the most occurring (26.1%). Klebsiella pneumoniae and Staphylococcus aureus are known for their pathogenic potentials, hence their presence in these recreational sites are of public health importance. Provision of standard recreational facilities in localities will however reduce the dependency on river sites for recreational activities, and as well prevent recreational associated illnesses.

scholarly journals Diversity of mucoid to non-mucoid switch among carbapenemase-producing Klebsiella pneumoniae

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Adriana Chiarelli ◽  
Nicolas Cabanel ◽  
Isabelle Rosinski-Chupin ◽  
Pengdbamba Dieudonné Zongo ◽  
Thierry Naas ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Phenotypic Variation ◽  
Point Mutations ◽  
Carbapenem Resistance ◽  
Selective Advantage ◽  
Clinical Isolates ◽  
Phenotypic Characterization ◽  
Colony Development ◽  
Genome Comparison

Abstract Background Klebsiella pneumoniae is a leading cause of intractable hospital-acquired multidrug-resistant infections and carbapenemase-producing K. pneumoniae (CPKp) are particularly feared. Most of the clinical isolates produce capsule as a major virulence factor. Recombination events at the capsule locus are frequent and responsible for capsule diversity within Klebsiella spp. Capsule diversity may also occur within clonal bacterial populations generating differences in colony aspect. However, little is known about this phenomenon of phenotypic variation in CPKp and its consequences. Results Here, we explored the genetic causes of in vitro switching from capsulated, mucoid to non-mucoid, non-capsulated phenotype in eight clinical CPKp isolates. We compared capsulated, mucoid colony variants with one of their non-capsulated, non-mucoid isogenic variant. The two colony variants were distinguished by their appearance on solid medium. Whole genome comparison was used to infer mutations causing phenotypic differences. The frequency of phenotypic switch was strain-dependent and increased along with colony development on plate. We observed, for 72 non-capsulated variants that the loss of the mucoid phenotype correlates with capsule deficiency and diverse genetic events, including transposition of insertion sequences or point mutations, affecting genes belonging to the capsule operon. Reduced or loss of capsular production was associated with various in vitro phenotypic changes, affecting susceptibility to carbapenem but not to colistin, in vitro biofilm formation and autoaggregation. Conclusions The different impact of the phenotypic variation among the eight isolates in terms of capsule content, biofilm production and carbapenem susceptibility suggested heterogeneous selective advantage for capsular loss according to the strain and the mutation. Based on our results, we believe that attention should be paid in the phenotypic characterization of CPKp clinical isolates, particularly of traits related to virulence and carbapenem resistance.

scholarly journals Phenotypic Characterization of Extended Spectrum Beta-lactamase, Class C Cephalosporinase and Carbapenemase-Producing Klebsiella Species Isolated from Patients Consulted at Four Yaounde-Based Hospitals.

2021 ◽  
Author(s):  
Emilia Enjema Lyonga Mbamyah ◽  
Mangum Patience Kumcho ◽  
Michel Toukam ◽  
Dieudonné Sedena ◽  
Florence Anjabie Enyeji ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Opportunistic Infections ◽  
Acquired Resistance ◽  
Multidrug Resistant ◽  
Phenotypic Characterization ◽  
Beta Lactamase ◽  
Klebsiella Species ◽  
Extended Spectrum Beta Lactamase ◽  
Extended Spectrum ◽  
Class C

Abstract Background: Klebsiella spp. are bacteria of medical importance for their role in opportunistic infections. These infections are often difficult to treat because of acquired resistance to one or several families of antimicrobials. The present study aimed at detecting Extended Spectrum Beta-lactamase (ESBL), Class C cephalosporinase (AmpC) and carbapenemase resistant phenotypes of Klebsiella spp. isolated from patients consulted at four Yaounde-based hospitals. Results: The frequency of the species isolated was Klebsiella pneumoniae (69%), K. oxytoca (14%), K. ozaenae (12%) and K. rhinoscleromatis (5%). Isolates were most resistant to penicillins (90%), sulphonamides (84%), cepaholosporins (80%), and least resistant to carbapenems (10.2%). Three isolates namely: two K. oxytoca and one K. pneumoniae were resistant to all twenty-eight (28) antibiotics tested. Klebsiella pneumoniae was the species with the most multidrug resistant isolates (59.4%). Most isolates (83.6%) expressed at least one resistance phenotype, while 63.6% of the isolates expressed all three phenotypes. Many of the isolates were ESBL producers (71.6%), while fewer isolates were carbapenemase (26.7%) and AmpC (6.6%) producers. Three carbapenemases (Klebsiella pneumoniae carbapenemase-KPC, Metallo-Beta Lactamase-MBL and OXA-48) were detected from 26.7% of the isolates and the combination KPC and MBL were the most detected phenotypes (12.9%). Conclusion: These results reveal that resistance of Klebsiella spp. to cephalosporins is high and this may be exacerbated as a result of the co-expression of AmpC and carbapenemases. About a quarter of the isolates had acquired carbapenemases that confer resistance to all beta-lactamases and carbapenems which constitute last line drugs. The resistance burden is further strengthened in isolates that acquired more than one carbapenemase aggravating associated patient morbidity and mortality. Therefore, it is necessary to continue monitoring antimicrobial resistance of local strains for better informed decisions on empirical treatment guide and better patient care.

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