NRU :: Browsing by Author "Ssekatawa, Kenneth"

Browsing by Author "Ssekatawa, Kenneth"

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Carbapenem Resistance Profiles of Pathogenic Escherichia coli in Uganda
(2020) Ssekatawa, Kenneth; Byarugaba, Denis K.; Nakavuma, Jesca L.; Kato, Charles D.; Ejobi, Francis; Tweyongyere, Robert; Wampande, Eddie M.
Escherichia coli has been implicated as one of the main etiological agents of diarrhea, urinary tract infections, meningitis and septicemia worldwide. The ability to cause diseases is potentiated by presence of virulence factors. The virulence factors influence the capacity of E. coli to infect and colonize different body systems. Thus, pathogenic E. coli are grouped into DEC strains that are mainly clustered in phylogenetic group B1 and A; ExPEC belonging to A, B2 and D. Coexistence of virulence and beta-lactamase encoding genes complicates treatment outcomes. Therefore, this study aimed at presenting the CR profiles among pathogenic E. coli. Methods: This was a retrospective cross-sectional study involving use of archived E. coli clinical isolates collected in 2019 from four Ugandan tertiary hospitals. The isolates were subjected to antibiotics sensitivity assays to determine phenotypic resistance. Four sets of multiplex PCR were performed to detect CR genes, DEC pathotypes virulent genes, ExPEC PAI and the E. coli phylogenetic groups. Results: Antibiotic susceptibility revealed that all the 421 E. coli isolates used were MDR as they exhibited 100% resistance to more than one of the first-line antibiotics. The study registered phenotypic and genotypic CR prevalence of 22.8% and 33.0% respectively. The most predominant gene was blaOXA-48 with genotypic frequency of 33.0%, then blaVIM(21.0%), blaIMP(16.5%), blaKPC(14.8%) and blaNDM(14.8%). Spearman’s correlation revealed that presence of CR genes was highly associated with phenotypic resistance. Furthermore, of 421 MDR E. coli isolates, 19.7% harboured DEC virulent genes, where EPEC recorded significantly higher prevalence (10.8%) followed by S-ETEC(3.1%), STEC(2.9%), EIEC (2.0%) and L-ETEC(2.0%). Genetic analysis characterized 46.1% of the isolates as ExPEC and only PAI IV536(33.0%) and PAI IICFT073(13.1%) were detected. Phylogenetic group B2 was predominantly detected (41.1%), followed by A(30.2%), B1(21.6%), and D(7.1%). Furthermore, 38.6% and 23.1% of the DEC and ExPEC respectively expressed phenotypic resistance. Conclusion: Our results exhibited significant level of CR carriage among the MDR DEC and ExPEC clinical isolates belonging to phylogenetic groups B1 and B2 respectively. Virulence and CR genetic factors are mainly located on mobile elements. Thus, constitutes a great threat to the healthcare system as it promotes horizontal gene transfer.
Corm damage caused by banana weevils Cosmopolites sordidus (Germar) collected from different banana growing regions in Uganda
(Agriculture & Food Security, 2018) Twesigye, Charles K.; Ssekatawa, Kenneth; Kiggundu, Andrew; Tushemereirwe, Wilberforce; Matovu, Enock; Karamura, Eldad
In this study, both healthy tissue culture plantlets and maiden suckers of the Nakitembe cultivar were used to assess the damage level variation caused by banana weevils collected from different banana growing regions. Seventy-nine (79) tissue culture plantlets and fifty (50) suckers were established in buckets in a randomized complete block design for 5 months. Ten adult weevils (5 females and 5 males) were introduced at the base of each plant, and the buckets were covered with a weevil proof mesh. Weevil damage was estimated as a percentage at 60 days after the weevil introduction by estimating the peripheral damage (PD), total cross section corm damage (XT) and above the collar damage (ACD). Results: The results showed high differences in the PD, XI, XO and XT caused by weevils from the different zones. PD and XT ranged from 4.8–50.4 to 4.2–43.8%, respectively, caused by weevils collected from Kabale and Rakai, Kabale and Wakiso, respectively, while XI and XO varied from 0.0–42.9 to 8.3–40.4%, respectively, caused by banana weevils collected from Kabale and Rakai, Kabale and Rakai, respectively. Banana weevils from Rakai caused the highest ACD of 40.4% and no such damage was caused by banana weevils collected from western Uganda. Average ACD in suckers was 19.6% and significantly higher than that in tissue culture plants (8.5%). Conclusions and recommendations: Corm damage assessment suggests the existence of banana weevil biotypes but it is recommended that follow-up studies be carried out to confirm this phenomenon.
Establishment of a transformation protocol for Uganda’s yellow passion fruit using the GUS gene
(African Journal of Biotechnology, 2019) Tuhaise, Samuel; Nakavuma, Jesca L.; Adriko, John; Ssekatawa, Kenneth; Kiggundu, Andrew
Horticulture is one of the fastest growing sectors in Uganda, exporting products worth US$100 million annually. Passion fruit (Passiflora edulis) growing and export is one of the critical contributors to this sector employing over a million farmers. However, a number of biotic and abiotic constraints have initiated widespread enterprise abandonment by farmers. Passiflora improvement efforts by conventional breeding has had limited success calling for research into alternative approaches such as genetic engineering. The study aimed at optimizing existing protocols to develop an efficient and reproducible Agrobacterium mediated transformation system to suit Uganda’s Passiflora cultivars. Agrobacterium tumefaciens strain AGL1 (OD600 of 0.5) harbouring pCAMBIA2301 containing the GUS (uidA) reporter gene was used to infect pre-cultured leaf discs. Leaf discs were then vacuum infiltrated for 1.5 min at 750 mmHg followed by a three day co-cultivation period on MS + acetosyringone (100 μml-1). Putatively transgenic yellow passion fruit shoots were induced on Murashige and Skoog (MS) selection media supplemented with benzylaminopurine (BAP) 8.9 μM, kanamycin (100 mgL-1mgl) and cefotaxime (500 mgL-1). Developed shoots were then transferred to elongation media (MS + 0.44 μM BAP) and later rooted on 5.37 μM naphthaleneacetic acid (NAA). Genetic transformation was monitored using GUS staining. A single independently transformed plant was confirmed by polymerase chain reaction (PCR), translating in a transformation efficiency of 0.456%. A viable in vitro transformation protocol for Uganda’s yellow passion fruit directly from leaf discs was developed using GUS reporter gene. Further investigations are required to improve the reported protocols transformation efficiency.
Green Strategy–Based Synthesis of Silver Nanoparticles for Antibacterial Applications
(Frontiers in Nanotechnology, 2021) Ssekatawa, Kenneth; Byarugaba, Denis K.; Kato, Charles D.; Wampande, Eddie M.; Ejobi, Francis; Nakavuma, Jesca L.; Maaza, Malik; Sackey, Juliet; Nxumalo, Edward; Kirabira, John B.
Antibiotics have been the nucleus of chemotherapy since their discovery and introduction into the healthcare system in the 1940s. They are routinely used to treat bacterial infections and to prevent infections in patients with compromised immune systems and enhancing growth in livestock. However, resistance to last-resort antibiotics used in the treatment of multidrug-resistant infections has been reported worldwide. Therefore, this study aimed to evaluate green synthesized nanomaterials such as silver nanoparticles (AgNPs) as alternatives to antibiotics. UV-vis spectroscopy surface plasmon resonance peaks for AgNPs were obtained between 417 and 475 nm. An X-ray diffraction analysis generated four peaks for both Prunus africana extract (PAE) and Camellia sinensis extract (CSE) biosynthesized AgNPs positioned at 2θ angles of 38.2°, 44.4°, 64.5°, and 77.4° corresponding to crystal planes (111), (200), (220), and (311), respectively. A dynamic light-scattering analysis registered the mean zeta potential of +6.3mV and +0.9 mV for PAE and CSE biosynthesized nanoparticles, respectively. Fourier transform infrared spectroscopy spectra exhibited bands corresponding to different organic functional groups confirming the capping of AgNPs by PAE and CSE phytochemicals. Field emission scanning electron microscopy imaging showed that AgNPs were spherical with average size distribution ranging from 10 to 19 nm. Biosynthesized AgNPs exhibited maximum growth inhibitory zones of 21mm with minimum inhibitory concentration and minimum bactericidal concentration of 125 and 250 μg/ml, respectively, against carbapenem-resistant bacteria
Nanotechnological Solutions For Controlling Transmission And Emergence Of Antimicrobial-Resistant Bacteria, Future Prospects, And Challenges: A Systematic Review
(Journal of Nanoparticle Research, 2020) Ssekatawa, Kenneth; Byarugaba, Dennis K.; Kato, Charles D.; Ejobi, Francis; Tweyongyere, Robert; Lubwama, Michael; Kirabira, John Baptist; Wampande, Eddie M.
Globally, a high prevalence of multi-drug-resistant (MDR) bacteria, mostly methicillin-resistant Staphylococcus aureus and carbapenem-resistant Enterobacteriaceae, has been reported. Infections caused by such bacteria are expensive and hard to treat due to reduced efficient treatment alternatives. Centered on the current rate of antibiotics production and approvals, it is anticipated that by 2050 up to 10 million people could die annually due to MDR pathogens. To this effect, alternative strategies such as the use of nanotechnology to formulate nanobactericidal agents are being explored. This systematic review addresses the recent approaches, future prospects, and challenges of nanotechnological solutions for controlling transmission and emergence of antibiotic resistance. A comprehensive literature search of PubMed and BioMed Central databases from June 2018 to January 2019 was performed. The search keywords used were “use of nanotechnology to control antibiotic resistance” to extract articles published only in English encompassing all research papers regardless of the year of publication. PubMed and BioMed Central databases literature exploration generated 166 articles of which 49 full-text research articles met the inclusion guidelines. Of the included articles, 44.9%, 30.6%, and 24.5% reported the use of inorganic, hybrid, and organic nanoparticles, respectively, as bactericidal agents or carriers/enhancers of bactericidal agents. Owing to the ever-increasing prevalence of antimicrobial resistance to old and newly synthesized drugs, alternative approaches such as nanotechnology are highly commendable. This is supported by in vitro, ex vivo, and in vivo studies assessed in this review as they reported high bactericide efficacies of organic, inorganic, and hybrid nanoparticles.
Physiochemical properties and antibacterial activity of silver nanoparticles green synthesized by Camellia sinensis and Prunus africana extracts
(2021) Ssekatawa, Kenneth; Byarugaba, Denis; Kato, Charles; Nakavuma, Jesca; Wampande, Eddie; Ejobi, Francis; Maaza, Malik; Sackey, Juliet; Kirabira, John; Nxumalo, Edward
Antibiotics have been the nucleus of chemotherapy since their discovery and introduction into the healthcare system in the 1940s. They are used routinely not only to treat bacterial infections but also to prevent infections in patients with compromised immune systems and enhancing growth in livestock. However, resistance to last-resort antibiotics used in the treatment of MDR infections has been reported worldwide. Therefore, the aim of this study was to evaluate green synthesized nanomaterials such as AgNPs as alternatives to antibiotics. UV Vis Spectroscopy surface plasmon resonance peaks for AgNPs were obtained between 417 to 475nm. XRD analysis generated 4 peaks for both PAE and CSE biosynthesized AgNPs positioned at 2θ angles of 38.2˚, 44.4˚, 64.5˚, and 77.4˚ corresponding to crystal planes (111), (200), (220) and (311) respectively. DLS registered mean zeta potential of + 6.3mV and + 0.9mV for PAE and CSE biosynthesized nanoparticles respectively. FTIR spectra exhibited bands corresponding to different organic functional groups confirming capping of AgNPs by PAE and CSE phytochemicals. FESEM imaging showed that AgNPs were spherical with average size distribution ranging from 10 to 19nm. Biosynthesized AgNPs exhibited maximum growth inhibitory zones of 21mm with MIC and MBC of 125μg/ml and 250μg/ml respectively against carbapenem resistant bacteria.
Prevalence of pathogenic Klebsiella pneumoniae based on PCR capsular typing harbouring carbapenemases encoding genes in Uganda tertiary hospitals
(Antimicrobial Resistance & Infection Control, 2021) Ssekatawa, Kenneth; Byarugaba, Denis K.; Nakavuma, Jesca L.; Kato, Charles D.; Ejobi, Francis; Tweyongyere, Robert; Wampande, Eddie M.
Background: Klebsiella pneumoniae is an opportunistic pathogen that has been implicated as one of commonest cause of hospital and community acquired infections. The K. pneumoniae infections have considerably contributed to morbidity and mortality in patients with protracted ailments. The capacity of K. pneumoniae to cause diseases depends on the presence of an array virulence factors. Coexistence and expression of virulence factors and genetic determinants of antibiotic resistance complicates treatment outcomes. Thus, emergence of pathogenic MDR K. pneumoniae poses a great threat to the healthcare system. However, the carriage of antibiotic resistance among pathogenic K. pneumoniae is yet to be investigated in Uganda. We sought to investigate the carbapenem resistance profiles and pathogenic potential based on capsular serotypes of K. pneumoniae clinical isolates. Methods: This was a cross sectional study involving use of archived Klebsiella pneumoniae isolates collected between January and December, 2019 at four tertiary hospitals in Uganda. All isolates were subject to antimicrobial susceptibility assays to determine phenotypic antibiotic resistance, pentaplex PCR to detect carbapenemases encoding genes and heptaplex PCR to identify capsular serotypes K1, K2, K3, K5, K20, K54 and K57. Results: The study found an overall phenotypic carbapenem resistance of 23.3% (53/227) and significantly higher genotypic resistance prevalence of 43.1% (98/227). Over all, the most prevalent gene was blaOXA-48-like (36.4%), followed by blaIMP-type (19.4%), blaVIM-type (17.1%), blaKPC-type (14.0%) and blaNDM-type (13.2%). blaVIM-type and blaOXA-48-like conferred phenotypic resistance in all isolates and 38.3% of isolates that harbored them respectively. Capsular multiplex PCR revealed that 46.7% (106/227) isolates were pathogenic and the predominantly prevalent pathotype was K5 (18.5%) followed by K20 (15.1%), K3 (7.1%), K2 (3.1%) and K1 (2.2%). Of the 106 capsular serotypes, 37 expressed phenotypic resistance; thus, 37 of the 53 carbapenem resistant K. pneumoniae were pathogenic. Conclusion: The high prevalence of virulent and antibiotic resistant K. pneumoniae among clinical isolates obtained from the four tertiary hospital as revealed by this study pose a great threat to healthcare. Our findings underline the epidemiological and public health risks and implications of this pathogen.
A review of phage mediated antibacterial applications
(Alexandria Journal of Medicine, 2021) Ssekatawa, Kenneth; Byarugaba, Denis K.; Kato, Charles D.; Wampande, Eddie M.; Ejobi, Francis; Tweyongyere, Robert; Nakavuma, Jesca L.
For over a decade, resistance to newly synthesized antibiotics has been observed worldwide. The challenge of antibiotic resistance has led to several pharmaceutical companies to abandon the synthesis of new drugs in fear of bacteria developing resistance in a short period hence limiting initial investment return. To this effect, alternative approaches such as the use of bacteriophages to treat bacterial infections are being explored. This review explores the recent advances in phage-mediated antibacterial applications and their limitations. Methods: We conducted a comprehensive literature search of PubMed, Lib Hub and Google Scholar databases from January 2019 to November 2019. The search key words used were the application of bacteriophages to inhibit bacterial growth and human phage therapy to extract full-text research articles and proceedings from International Conferences published only in English. Results: The search generated 709 articles of which 95 full-text research articles fulfilled the inclusion guidelines. Transmission Electron Microscopy morphological characterization conducted in 23 studies registered Myoviruses, Siphoviruses, Podoviruses, and Cytoviruses phage families while molecular characterization revealed that some phages were not safe to use as they harbored undesirable genes. All in vivo phage therapy studies in humans and model animals against multidrug-resistant (MDR) bacterial infection provided 100% protection. Ex vivo and in vitro phage therapy experiments exhibited overwhelming results as they registered high efficacies of up to 100% against MDR clinical isolates. Phage-mediated bio-preservation of foods and beverages and bio-sanitization of surfaces were highly successful with bacterial growth suppression of up to 100%. Phage endolysins revealed efficacies statistically comparable to those of phages and restored normal ethanol production by completely eradicating lactic acid bacteria in ethanol fermenters. Furthermore, the average multiplicity of infection was highest in ex vivo phage therapy (557,291.8) followed by in vivo (155,612.4) and in vitro (434.5).
Variation among banana weevil Cosmopolites sordidus (Germar) populations in Uganda as revealed by AFLP markers and corm damage differences
(Agriculture & Food Security, 2018) Twesigye, Charles K.; Ssekatawa, Kenneth; Kiggundu, Andrew; Tushemereirwe, Wilberforce; Matovu, Enock
The banana weevil Cosmopolites sordidus (Germar) is a major production constraint of bananas and plantains (Musa spp.) in the world. Differences in damage levels and pesticide response across regions led to the postulation that there might be considerable variation between banana weevil populations (biotypes) with varying levels of virulence. One of the most sustainable options for banana weevil control is the use of host plant resistance. While new resistant varieties are being developed through both conventional crossbreeding and biotechnology, there is a need to assess the genetic variation of banana weevil populations from eastern, central, southern, southwestern and midwest regions of Uganda to determine whether there are biotypes with different virulence levels. This would help guide new control strategies to target all the possible biotypes. The amplified fragment length polymorphism (AFLP) technique was used to analyze population genetic diversity using four primer combinations (EcoRI/MSeI). Results: Analysis of molecular variance results presented no evidence to support significant genetic variability among the banana weevil populations from eastern, central, southern, southwestern and midwest regions. Practically, all the genetic variation was found to reside within populations (97% for sites and 98% for regions), with only approximately 3% and 2% residing among populations of sites and regions, respectively. Conclusions and recommendations: AFLP markers clustered the banana weevils into two distinct populations consequently supporting the hypothesis of possible presence of banana weevil biotypes in Uganda. However, attempts should be made to make follow-up studies on the seemingly unique population of eastern Uganda using more robust molecular techniques to establish whether the eastern Uganda population constitutes a different biotype.

Browsing by Author "Ssekatawa, Kenneth"

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