Isolation and Characterization of Novel Bacteriophages Against Multidrug Resistant Enterobacter Cloacae as Alternatives to Antibiotics
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Date
2022Author
Inyimili, Martin Indongole
Type
ThesisLanguage
enMetadata
Show full item recordAbstract
Enterobacter cloacae is a significant nosocomial pathogen, causing bacteremia and
infections of the lower respiratory tract, urinary tract, and intra-abdominal cavity.
Acquisition of antibiotic resistant genes due to increased pressure on antibiotics use has
resulted in emergence of multidrug-resistant (MDR) Enterobacter species implicated in
hospital acquired infections. Development of antibiotic regimens against MDRs is not at
par with bacteria rates of resistance necessating the need for adoption of alternative
strategies among them the use of bacteriophages (phages). The general objective of this
study was to identify and characterize bacteriophages that can lyse gram-negative MDR
E. cloacae bacteria with potential clinical applications. Three environmental water
samples from each site were obtained from Kenyatta National Hospital (KNH) sewer,
Chiromo River, Mathare River, Kibera slums and Zimmerman and fresh water (Lake
Victoria). Host bacteria were obtained from the KEMRI-CMR repository. Spot test and
plaque assay were used to screen and quantify the isolated bacteriophages. Isolated
bacteriophages were tested for their stability at different temperatures (4, 25, 37, 60 and
90 °C) and pH (2.0, 4.5, 5.5, 7.5, 9.0, 11.5 and 13.0). Host range determination using 28
isolates of E. cloacae bacteria and one Staphylococcus aureus bacteria as a negative
control was done. Whole genome sequencing was done using the Nanopore platform and
results analysed using various bioinformatics tools like PhiSiGns programmes,
GeneMark, REsFINDEr, among others. Nineteen (19) bacteriophages were isolated with
all 19 phages lysing 12/28 (42.9%) E. cloacae bacteria isolates. The phages were stable
at 4, 25 and 37 °C and 4.5, 5.5, 7.5, 9.0, and 11.5 pH. The selected 5 phages had dsDNA
genomes with no genes associated with antibiotic resistance or toxicity. Three phages
belonged to the family Autographiviridea/Studiervirinae while two could not be assigned.
The study identified potentially suitable phage candidates for Enterobacter cloacae
therapy due to their wide host range against endemic clinical isolates and their lack of
genes associated with resistance and toxicity
Publisher
University of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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