Showing posts with label gram-negative bacteria. Show all posts
Showing posts with label gram-negative bacteria. Show all posts

Saturday, 10 May 2025

The Microbial Etiology of Urinary Tract Infections in a Tunisian Orthopedic Institute | Chapter 2 | Medical Science: Recent Advances and Applications Vol. 3

Background: Urinary Tract Infections (UTIs), frequently encountered both in hospitals and community settings, are among the most common reasons for medical consultations in daily practice and constitute a significant driver of antibiotic consumption. The microorganisms most frequently isolated during these infections are Gram-negative bacilli, with Escherichia coli at the top of the list.

Aim: This study aimed to characterise the microbiological profile of Tunisian patients with UTIs and evaluate antibiotic resistance patterns over three years at the Orthopaedic Institute.

Methods: Urine samples collected between January 1, 2019, and December 31, 2021, were analysed. Standard laboratory procedures were employed to identify bacterial strains, and the Microscan Walkway 40 Plus system was used for biochemical assays and antibiotic susceptibility testing. E. coli ATCC 25922, Enterococcus feacalis ATCC 29212, Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC29213 were used as a control strains. Results were interpreted according to EUCAST guidelines.

Results: A total of 1,313 bacterial strains were isolated. The analysis revealed a predominance of Enterobacteriaceae (96.8%), with Escherichia coli (52.2%) and Klebsiella pneumoniae (19.3%) being the most common pathogens. Antibiotic resistance rates in hospital-acquired E. coli strains were as follows (in descending order): amoxicillin (73.05%), trimethoprim/sulfamethoxazole (46.9%), ofloxacin (40.3%), amoxicillin/clavulanic acid (35.05%), and gentamicin (20.5%). Resistance to fosfomycin was low for E. coli (2.6%) in hospitals but higher for K. pneumoniae (≥12.1%). Amikacin resistance remained moderate, affecting ≥20% of E. coli strains and 10% of K. pneumoniae. Nitrofurantoin resistance was minimal in E. coli (1.06%) but significant in K. pneumoniae (21.5%). The production of Extended-Spectrum Beta-Lactamases (ESBLs) was observed in 19.3% of K. pneumoniae and 14.4% of E. coli isolates.

Conclusion: The prevalence of ESBL-producing E. coli and K. pneumoniae in UTIs is on the rise. Continuous surveillance of resistance patterns is essential to guide empirical treatment and mitigate the spread of multidrug-resistant strains. In future, clinico-bacteriological studies with a high level of scientific evidence must be carried out to increase the strength of the recommendations.

 

Author (s) Details

Hajer Kilani
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Faculty of Medicine, LR99ES09 Laboratory of Antibiotic Resistance, University of Tunis El Manar, Tunis, Tunisia.

 

Salma Kaoual
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Department of Biology B, Faculty of Pharmacy, University of Monastir, Monastir, Tunisia.

Fatma Kaabi
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia.

 

Ilhem Boutiba-BenBoubaker
Faculty of Medicine, LR99ES09 Laboratory of Antibiotic Resistance, University of Tunis El Manar, Tunis, Tunisia and Department of Microbiology, Hospital of Charles Nicolle, Tunis, Tunisia.

 

Sophia Bouhalila Besbes
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Department of Biology B, Faculty of Pharmacy, University of Monastir, Monastir, Tunisia.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/msraa/v3/3851

Synthesis, Characterization and Broad-Spectrum Antibacterial Activity of Zinc Oxide Nanoparticles against Gram–Positive and Gram-Negative Bacteria | Chapter 4 | Chemical and Materials Sciences: Research Findings Vol. 3

Zinc oxide nanoparticles (ZnO-NPs) have received significant attention in recent years due to their versatile applications in sunscreen products, cosmetics, pigments, industrial coatings, plastic additives, semiconductors, textiles, and effective antibacterial agents. Due to numerous applications of nanoparticles, research related to preparation and the properties of nanoparticles has become more attention in the past several years. This study deals with the synthesis of zinc oxide nanoparticles and evaluating their antibacterial activity. Zinc oxide nanoparticles were synthesized by a chemical method and characterized by various analytical techniques such as UV-visible spectroscopy, SEM-EDX, XRD, and FTIR. X-ray diffraction and SEM analysis confirmed the formation of well-dispersed zinc oxide nanoparticles with average particle size 22 nm as well as revealed their spherical structure. Using the agar well diffusion technique of the study, chemically synthesized nanoparticles were revealed to have antibacterial activity against the bacterial strains Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. There is a noticeable rise in ZnO nanoparticles' bioactivity because of their tiny size and greater surface area-to-volume ratio. This study demonstrates that ZnO NPs are a potential antibacterial agent that can combat both Gram-positive and Gram-negative bacteria. The antibacterial properties of ZnO nanoparticles make it feasible to be utilized as an antibacterial agent in products like mouthwashes, lotions, and ointments. Nanoparticles can also serve as substrates in medical devices to stop germs from sticking, spreading, and reproducing. Therefore, this work has significant theoretical and practical implications for further in-depth research.

 

Author (s) Details

V. Keerthika
Department of Biology, The Gandhigram Rural Institute (Deemed to be University), Gandhigram – 624 302, Tamil Nadu, India.

 

A. Ananth
Department of Biology, The Gandhigram Rural Institute (Deemed to be University), Gandhigram – 624 302, Tamil Nadu, India.

 

M.R. Rajan
Department of Biology, The Gandhigram Rural Institute (Deemed to be University), Gandhigram – 624 302, Tamil Nadu, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/cmsrf/v3/5299