Molecular diversity of hpd gene in clinical isolates of Haemophilus influenzae

Gene Reports ◽  
2020 ◽  
Vol 18 ◽  
pp. 100556
Author(s):  
Seyed Davar Siadat ◽  
Azad Khaledi ◽  
Fereshteh Shahcheraghi ◽  
Somaye Rashki ◽  
Maryam Arfaatabar
Keyword(s):  
Haemophilus Influenzae ◽  
Molecular Diversity ◽  
Clinical Isolates

scholarly journals Resistance of clinical isolates of Haemophilus influenzae in United Kingdom 1986.

BMJ ◽  
1987 ◽  
Vol 295 (6591) ◽  
pp. 176-179 ◽  
Author(s):  
M Powell ◽  
C Koutsia-Carouzou ◽  
D Voutsinas ◽  
A Seymour ◽  
J D Williams
Keyword(s):  
United Kingdom ◽  
Haemophilus Influenzae ◽  
Clinical Isolates

scholarly journals In Vitro Activities of the Ketolide HMR 3647 against Recent Gram-Positive Clinical Isolates and Haemophilus influenzae

1998 ◽  
Vol 42 (8) ◽  
pp. 2138-2140 ◽  
Author(s):  
Arthur L. Barry ◽  
Peter C. Fuchs ◽  
Steven D. Brown
Keyword(s):  
Haemophilus Influenzae ◽  
Clinical Isolates ◽  
Gram Positive

ABSTRACT The ketolide HMR 3647 (previously RU 66647) was evaluated against 2,563 recent clinical isolates of gram-positive pathogens and 200Haemophilus influenzae isolates. HMR 3647 was active against macrolide-resistant streptococci, including pneumococci, but was not active against macrolide- or lincosamide-resistant staphylococci. Against H. influenzae, the potency of HMR 3647 was similar to that of azithromycin.

scholarly journals National collaborative study of the prevalence of antimicrobial resistance among clinical isolates of Haemophilus influenzae.

1988 ◽  
Vol 32 (2) ◽  
pp. 180-185 ◽  
Author(s):  
G V Doern ◽  
J H Jorgensen ◽  
C Thornsberry ◽  
D A Preston ◽  
T Tubert ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Haemophilus Influenzae ◽  
Collaborative Study ◽  
Clinical Isolates

scholarly journals Genetic and Molecular Characterization of β-Lactamase-Negative Ampicillin-Resistant Haemophilus influenzae with Unusually High Resistance to Ampicillin

2004 ◽  
Vol 48 (5) ◽  
pp. 1630-1639 ◽  
Author(s):  
Frank S. Kaczmarek ◽  
Thomas D. Gootz ◽  
Fadia Dib-Hajj ◽  
Wenchi Shang ◽  
Shawn Hallowell ◽  
...  
Keyword(s):  
North America ◽  
Haemophilus Influenzae ◽  
Efflux Pump ◽  
Geometric Mean ◽  
Resistance Mechanisms ◽  
Clinical Isolates ◽  
Ampicillin Resistance ◽  
Group I ◽  
Acrab Efflux Pump ◽  
High Level

ABSTRACT Previous studies with beta-lactamase-negative, ampicillin-resistant (BLNAR) Haemophilus influenzae from Japan, France, and North America indicate that mutations in ftsI encoding PBP3 confer ampicillin MICs of 1 to 4 μg/ml. Several BLNAR strains with ampicillin MICs of 4 to 16 μg/ml recently isolated from North America were studied. Pulsed-field gel electrophoresis identified 12 unique BLNAR strains; sequencing of their ftsI transpeptidase domains identified 1 group I and 11 group II mutants, as designated previously (K. Ubukata, Y. Shibasaki, K. Yamamoto, N. Chiba, K. Hasegawa, Y. Takeuchi, K. Sunakawa, M. Inoue, and M. Konno, Antimicrob. Agents Chemother. 45:1693-1699, 2001). Geometric mean ampicillin MICs for several clinical isolates were 8 to 10.56 μg/ml. Replacement of the ftsI gene in H. influenzae Rd with the intact ftsI from several clinical isolates resulted in integrants with typical BLNAR geometric mean ampicillin MICs of 1.7 to 2.2 μg/ml. Cloning and purification of His-tagged PBP3 from three clinical BLNAR strains showed significantly reduced Bocillin binding compared to that of PBP3 from strain Rd. Based on these data, changes in PBP3 alone could not account for the high ampicillin MICs observed for these BLNAR isolates. In an effort to determine the presence of additional mechanism(s) of ampicillin resistance, sequencing of the transpeptidase regions of pbp1a, -1b, and -2 was performed. While numerous changes were observed compared to the sequences from Rd, no consistent pattern correlating with high-level ampicillin resistance was apparent. Additional analysis of the resistant BLNAR strains revealed frame shift insertions in acrR for all four high-level, ampicillin-resistant isolates. acrR was intact for all eight low-level ampicillin-resistant and four ampicillin-susceptible strains tested. A knockout of acrB made in one clinical isolate (initial mean ampicillin MIC of 10.3 μg/ml) lowered the ampicillin MIC to 3.67 μg/ml, typical for BLNAR strains. These studies illustrate that BLNAR strains with high ampicillin MICs exist that have combined resistance mechanisms in PBP3 and in the AcrAB efflux pump.

PHENOTYPIC AND MOLECULAR DIVERSITY AMONG ENVIRONMENTAL AND CLINICAL ISOLATES OF ASPERGILLUS FUMIGATUS GROUP

Mycoses ◽  
2002 ◽  
Vol 45 (S2) ◽  
pp. 18-18
Author(s):  
S. Florio ◽  
C. Picone ◽  
G. Damiani ◽  
M. Guglielminetti
Keyword(s):  
Aspergillus Fumigatus ◽  
Molecular Diversity ◽  
Clinical Isolates
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