Microbial Species Isolated from Infected Wounds and Antimicrobial Resistance Analysis: Data Emerging from a Three-Years Retrospective Study

Abstract

The antimicrobial resistance is a topic of global interest in the treatment of wound infections. The goal of this retrospective study was both the identification of the microorganisms responsible for wound infections and the determination of their drug susceptibility pattern. The study was performed from 2017 to 2019 and included 239 patients. Thirty-four species were isolated by culture methods and identified and analysed for their susceptibility patterns to antimicrobials through the Walk Away automated system. The presence of one species was the most frequent condition (75.3%), whereas a co-infection was detected in 24.7% of samples. The most common species were Gram-negative (57.9%), amongst which the most prevalent were Pseudomonas aeruginosa (40.2%), Escherichia coli (20.7%), Proteus mirabilis (11.2%), and Acinetobacter baumannii/haemolyticus (9.5%). Gram-positive bacteria were observed in 36.6%, Staphylococcus aureus (79.4%) being the most predominant species. At least one resistance to antibiotics was detected in 88.2% of isolates, while a multi-drug-resistance versus no less than 6 antimicrobials was detected in 29.2% of isolates. Although multi-drug resistant species and co-infections were observed, those were less frequently observed at the wound site. These conditions make the microorganisms eradication more difficult. The detection of a polymicrobial infection and multi-drug resistant microorganisms followed by a proper therapeutic treatment would lead to the resolution of the infection, promoting wound healing and the limitation of the spread of antibiotic resistance.

Klebsiella pneumoniae Biofilms and Their Role in Disease Pathogenesis

“…These interactions often lead to an increased resistance against host and antimicrobial agents for all species involved ( Fux et al., 2005 ; Attinger and Wolcott, 2012 ; Kong et al., 2016 ; Wang et al., 2022 ). This occurs either through increased tolerance or adaptive resistance resulting from inter-species synergy or by antibiotic-resistant species in a polymicrobial biofilm protecting other species in the biofilm against antibiotic treatment ( Chatterjee et al., 2014 ; Puca et al., 2021 ). Species in polymicrobial biofilms often show increased virulence ( Pastar et al., 2013 ), an increased ability to degrade and utilize organic compounds in their environment ( Yoshida et al., 2009 ; Elias and Banin, 2012 ), and provide an environment for intra- and interspecies spread of adaptive traits and antimicrobial resistance genes ( Roberts and Kreth, 2014 ).…”

In Vivo Antibacterial Efficacy of Nanopatterns on Titanium Implant Surface: A Systematic Review of the Literature

“…Under ideal conditions, the antibiotics loaded on the surface should release in a controlled path and speed, reach the effective drug concentration, and maintain a long sufficient sterilization time, reducing the risk of bacterial resistance problems caused by antibiotic abuse [ 64 , 65 , 66 ]. Considering that both aerobic and anaerobic organisms can cause bone infections and the high frequency of polymicrobial infections [ 67 , 68 , 69 ], broad-spectrum antibiotics such as rifampicin, gentamicin, vancomycin, etc., are recommended as the loaded agents [ 70 , 71 ]. Under ideal conditions, the antibiotics released by the prepared nanomaterials should reach the effective drug concentration and maintain a long sufficient sterilization time [ 64 , 72 ].…”

Recent Advances in Hydrogel-Mediated Nitric Oxide Delivery Systems Targeted for Wound Healing Applications

“…Bacteria can generate an extracellular matrix in which the diffusion of antibiotics is hindered, which complicates the fight against infections. More than the presence of planktonic bacteria, biofilm formation actually dictates if an acute wound becomes chronic [ 16 ] since biofilms are predominant in at least 60% of chronic wounds [ 55 ]. Biofilms allow gene transfer between bacteria, which could lead to the dissemination of genes associated with antibiotic resistance.…”

“…The most common bacteria detected in infected wounds are Pseudomonas aeruginosa , Staphylococcus aureus , Klebsiella pneumoniae , Enterococcus faecalis , Acinetobacter baumannii [ 55 ], and Escherichia coli [ 59 ]. Often, wounds are polymicrobial, and therefore, single-species biofilms might be inadequate to study the impact of antibacterial agents against typical in vivo infections.…”