scholarly journals Genetic characterization of the K2 serotype capsule of Klebsiella pneumoniae ATCC 43816 and the development of a bioluminescent strain.

Author(s):  
Jacob Scott
2021 ◽  
Author(s):  
RB Gorodnichev ◽  
MA Kornienko ◽  
NS Kuptsov ◽  
MV Malakhova ◽  
DA Bespiatykh ◽  
...  

The Klebsiella pneumoniae bacterium is capable of causing the broad range of human nosocomial infections associated with antibiotic resistance and high mortality. Virulent bacteriophage therapy is one of the promising alternatives to antibiotic treatment of such infections. The study was aimed to isolate virulent bacteriophages effective against the relevant clinical K. pneumoniae strains, and to perform the molecular genetic characterization of these phages. Bacteriophages were isolated from the river water samples using the enrichment method. The whole-genome sequencing was performed on the MiSeq platform (Illumina). Three novel K. pneumoniae bacteriophages belonging to families Autographiviridae (vB_KpnP_NER40, GenBank MZ602146) and Myoviridae (vB_KpnM_VIK251, GenBank MZ602147; vB_KpnM_FRZ284, GenBank MZ602148) have been isolated and characterized. On the collection of 105 K. pneumoniae clinical strains, it has been found that bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251 have a narrow lytic spectrum (22% and 11%), which is limited to strains of the capsular types К2 and К20 respectively. In contrast, bacteriophage vB_KpnM_FRZ284 has a broad lytic spectrum (37%), causing the lysis of strains with different types of capsular polysaccharide. The phages are strictly virulent and have no genes encoding integrases, toxins or pathogenicity factors in their genomes. Genes of depolymerases, encoding the potential receptor binding proteins, have been found in the genomes of the capsular-specific bacteriophages vB_KpnP_NER40 and vB_KpnM_VIK251. The cocktail of three bacteriophages has lysed about 65% of the studied collection of K. рneumoniae strain and is potentially applicable for therapeutic purposes.


2010 ◽  
Vol 4 (10) ◽  
pp. 609-615 ◽  
Author(s):  
Mohammad Mehdi Feizabadi ◽  
Samira Mahamadi-Yeganeh ◽  
Akbar Mirsalehian ◽  
Seyed-Mohammad Mirafshar ◽  
Mohaddeseh Mahboobi ◽  
...  

Introduction: This study was conducted to determine the genetic characterization of extended-spectrum beta-lactamase (ESBL) producing strains of Klebsiella  pneumoniae isolated from Iranian patients in hospitals in Tehran. Methodology: Antibiotic susceptibility of 104 isolates was determined using the disk diffusion test. The Minimum Inhibitory Concentrations (MICs) of imipenem and meropenem were determined for isolates showing reduced susceptibility to carbapenems. The phenotypic confirmatory test (PCT) was used to screen the isolates for ESBL production. PCR was used to detect blaSHV, blaTEM and blaCTX-M and the amplicons from selected clones were sequenced. Isolates producing ESBLs were analyzed by pulsed-field gel electrophoresis (PFGE). Results:  One isolate showed resistance to imipenem (MIC = 16 µg/ml). Resistance to amikacin and ciprofloxacin was 44.2% and 25.0%, respectively. ESBL production was detected in 72.1% (n = 75) of isolates. The prevalence of blaSHV, blaTEM and blaCTX-M genes among the isolates was 55.7% (n = 58), 30.7% (n = 32) and 45.2% (n = 47), respectively. The sequencing revealed the amplicons corresponding to bla (TEM-1, TEM-79, SHV-1, SHV-12, SHV-31, CTX-M-15) genes. While the blaCTX-M-15 is the dominant gene among the Iranian isolates, we detected the blaSHV-31 and blaTEM-79 genes for the first time in the country.  PFGE differentiated the 71 ESBL-producing isolates into 62 different genotypes. Clonal dissemination of ESBLs was found in the neonatal intensive care unit and intensive care unit of one hospital. Conclusion: The findings are evidence of the spread of multi-resistant clones of ESBL producers in Tehran hospitals.


2001 ◽  
Vol 120 (5) ◽  
pp. A166-A166
Author(s):  
S FUJII ◽  
T KUSAKA ◽  
T KAIHARA ◽  
Y UEDA ◽  
T CHIBA ◽  
...  

2009 ◽  
Vol 221 (03) ◽  
Author(s):  
R Vagkopoulou ◽  
C Eckert ◽  
U Ungethüm ◽  
G Körner ◽  
M Stanulla ◽  
...  

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


Author(s):  
Rita Indirli ◽  
Biagio Cangiano ◽  
Eriselda Profka ◽  
Elena Castellano ◽  
Giovanni Goggi ◽  
...  

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