Clinical and molecular evaluation of pseudomonas aeruginosa nosocomial infections among adult patients at the university teaching hospital in Lusaka province and Ndola teaching hospital in Copperbelt province of Zambia.
Date
2024
Authors
Ntanda, Patrice Mukomena
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Pseudomonas is a type of bacteria commonly found in the environment, like soil and water. Of the many types of Pseudomonas, the one that most often causes infections in humans is called Pseudomonas aeruginosa, accounting for about 10% of hospital-acquired infections. Pseudomonas aeruginosa is one of the most commonly isolated nosocomial pathogen, often found in numerous reservoirs in hospital settings, such as disinfectants and medical devices. It has limited susceptibility to antibiotics, leading to increased morbidity and mortality. Despite the previous research reports on Pseudomonas aeruginosa in Zambia, there is a paucity of data on clinical Pseudomonas aeruginosa population diversity and molecular characterization of clinical isolates in correlation with clinical outcomes. Further, data on the genetic determinants of Pseudomonas aeruginosa and antimicrobial resistance (AMR) is scarce. Therefore, this study aimed to evaluate hospital-acquired Pseudomonas aeruginosa infections in selected hospitals of Lusaka and Copperbelt provinces in Zambia. The study assessed the
clinical and molecular characteristics of Pseudomonas aeruginosa and determined predictors of hospital-acquired infections with multidrug-resistant Pseudomonas aeruginosa in patients at various study sites. The study also evaluated antimicrobial resistance patterns in patients infected with Pseudomonas aeruginosa at different study sites. Frequencies were estimated, and the association between the outcome variable (positive culture) and categorical predictor
variables was analyzed using the Chi-square test and logistic regression. Further, the study described phenotypic characteristics, assessed the genetic diversity of clinical isolates of Pseudomonas aeruginosa, and assessed the clinical relationship between Pseudomonas aeruginosa phenotypes and genotypes with antimicrobial resistance and treatment outcomes. A year-long hospital-based cross-sectional study was conducted from April 2020 to April 2021 at two large tertiary-level hospitals in Zambia. Hospitalized and out-patients with previous hospital contact were screened for nosocomial infections, followed by the collection of specimens (skin swabs, urine, or sputum) for bacteriological culture and Polymerase Chain Reaction (PCR) amplification of 16S rRNA gene fragments. Nosocomial infections were defined according to the World Health Organization case definitions. Clinical assessment and follow-up of patients till discharge, 30 days, or death were conducted to establish the clinical outcomes. The Kirby-Bauer's disk diffusion method was used to evaluate antibiotic resistance patterns. The resistance genes, bla IMP, bLaOXA 51, and other resistance genes were detected using PCR. Eight hundred and forty-one clinical specimens were collected and analyzed, 640 from the University Teaching Hospital in Lusaka district and 201 from the Ndola Teaching Hospital in Ndola district. Of the 841 participants, 116 (13.7%) were diagnosed with Pseudomonas aeruginosa nosocomial infections. Among these, 96 participants were males (71.2%), and 20 were females (28.8%). The study participants ranged from 15 to 98 years, with a mean age of 51 (SD ± 18). Catheter-associated urinary tract infections (57%) were the most common, followed by those from pressure sores (38.7%). Antibiotic sensitivity of Pseudomonas aeruginosa was best with amikacin and worse with cefepime. We observed a high prevalence of multidrug resistance (73.6 %). The Antimicrobial resistance (AMR) was associated with
carbapenem-hydrolyzing b-lactamase gene blaOXA-51, literacy level, and ward attendance. Conclusions: This study showed that multidrug-resistant Pseudomonas aeruginosa is highly prevalent in the hospital settings at the University Teaching Hospital in Lusaka province and at the Ndola Teaching Hospital in Ndola in the Copperbelt province of Zambia. This calls for establishing and implementing antimicrobial stewardship programs, using antimicrobial
sensitivity to treat infection, and strengthening the AMR surveillance system and awareness at the two hospitals.
Description
Thesis of Doctor of Philosophy in Infectious Diseases.