Biofilms and antibiotic susceptibility of multidrug-resistant bacteria from wild animals

Abstract

BackgroundThe “One Health” concept recognizes that human health and animal health are interdependent and bound to the health of the ecosystem in which they (co)exist. This interconnection favors the transmission of bacteria and other infectious agents as well as the flow of genetic elements containing antibiotic resistance genes. This problem is worsened when pathogenic bacteria have the ability to establish as biofilms. Therefore, it is important to understand the characteristics and behaviour of microorganisms in both planktonic and biofilms states from the most diverse environmental niches to mitigate the emergence and dissemination of resistance.MethodsThe purpose of this work was to assess the antibiotic susceptibility of four bacteria (Acinetobacter spp., Klebsiella pneumoniae, Pseudomonas fluorescens and Shewanella putrefaciens) isolated from wild animals and their ability to form biofilms. The effect of two antibiotics, imipenem (IPM) and ciprofloxacin (CIP), on biofilm removal was also assessed. Screening of resistance genetic determinants was performed by PCR. Biofilm tests were performed by a modified microtiter plate method. Bacterial surface hydrophobicity was determined by sessile drop contact angles.ResultsThe susceptibility profile classified the bacteria as multidrug-resistant. Three genes coding for β-lactamases were detected in K. pneumoniae (TEM, SHV, OXA-aer) and one in P. fluorescens (OXA-aer). K. pneumoniae was the microorganism that carried more β-lactamase genes and it was the most proficient biofilm producer, while P. fluorescens demonstrated the highest adhesion ability. Antibiotics at their MIC, 5 × MIC and 10 × MIC were ineffective in total biofilm removal. The highest biomass reductions were found with IPM (54% at 10 × MIC) against K. pneumoniae biofilms and with CIP (40% at 10 × MIC) against P. fluorescens biofilms.DiscussionThe results highlight wildlife as important host reservoirs and vectors for the spread of multidrug-resistant bacteria and genetic determinants of resistance. The ability of these bacteria to form biofilms should increase their persistence.

ZnO/CdS Nanocomposite: An Anti-Microbial and Anti-Biofilm Agent

“…EPS behaves as diffusion barrier and does not allow an entry of antibiotics inside the biofilm, thereby protecting cells residing inside the biofilm. The consequences of the restricted entry of antibiotics inside biofilm allow cells to grow and proliferate by drawing nutrients from biofilm, eventually emerging as multidrug resistant pathogens [3]. In the medical science, a recent survey shows that up to 60% of all human infections are owing to the biofilm.…”

Peer Review #1 of "Biofilm released cells can easily be obtained in a fed-batch system using ica+ but not with ica- isolates (v0.1)"

“…S. epidermidis infections are more likely to happen upon invasive procedures involving indwelling medical devices, in which the physiological barriers are compromised, since this bacterium is a ubiquitous inhabitant of the skin and mucosae in humans (Ziebuhr et al, 2006) and has a strong ability to form biofilms on the surface of medical devices (Cerca et al, 2005;Laverty et al, 2013). Bacteria within biofilms are undoubtedly more resistant to antibiotics (Albano et al, 2019;Cerca et al, 2005a;Dias et al, 2018) and to the host immune defense (Cerca et al, 2006;Gray et al, 1984;Yao et al, 2005), contributing to the persistence and recurrence of infections (Mah, 2012;Schommer et al, 2011;Singh and Ray, 2014). For all these reasons, biofilms have been a major research target and extensive studies allowed to characterize the biofilm lifecycle and divide it into three main stages: attachment, maturation and disassembly (as reviewed in (Boles and Horswill, 2011;Otto, 2013)).…”

Biofilm released cells can easily be obtained in a fed-batch system using ica+ but not with ica- isolates

“…S. epidermidis infections are more likely to happen upon invasive procedures involving indwelling medical devices, in which the physiological barriers are compromised, since this bacterium is a ubiquitous inhabitant of the skin and mucosae in humans ( Ziebuhr et al, 2006 ) and has a strong ability to form biofilms on the surface of medical devices ( Cerca et al, 2005c ; Laverty, Gorman & Gilmore, 2013 ). Bacteria within biofilms are undoubtedly more resistant to antibiotics ( Albano et al, 2019 ; Cerca et al, 2005a ; Dias et al, 2018 ) and to the host immune defense ( Cerca et al, 2006 ; Gray et al, 1984 ; Yao, Sturdevant & Otto, 2005 ), contributing to the persistence and recurrence of infections ( Mah, 2012 ; Schommer et al, 2011 ; Singh & Ray, 2014 ). For all these reasons, biofilms have been a major research target and extensive studies allowed to characterize the biofilm lifecycle and divide it into three main stages: attachment, maturation and disassembly (as reviewed in Boles & Horswill, 2011 ; Otto, 2013 ).…”