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Environmental Health Insights 2022Antimicrobial resistance (AMR) is one of the top 10 public health threats. One approach to tackling the AMR menace could involve expanding the range of AMR surveillance...
BACKGROUND
Antimicrobial resistance (AMR) is one of the top 10 public health threats. One approach to tackling the AMR menace could involve expanding the range of AMR surveillance domains to include hospital wastewater (HWW), a domain that has largely been overlooked by researchers.
AIM
To evaluate the occurrence of multidrug-resistant bacteria in hospital wastewater of the Korle Bu Teaching Hospital (KBTH).
METHODOLOGY
This was a longitudinal study involving 288 HWW samples consecutively collected across 12 weeks from the pool of wastewater emanating from 2 critical care units of KBTH-The Child Health Unit and the Maternity Unit-on Mondays and Thursdays, each week. The samples were cultured for bacteria, which were identified using the Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) technique and subjected to antimicrobial susceptibility testing via the Kirby-Bauer method.
RESULTS
In total, 294 bacteria of 23 different types, all being Gram-negative, were isolated from the 288 samples. The predominant ones were (30.6%, n = 90), (11.2%, n = 33), (10.9%, n = 32), (5.8%, n = 17), and (5.4%, n = 16). The prevalence of multidrug resistance among the isolates was 55.4% (n = 163). Moreover, the prevalence of extended-spectrum beta-lactamase (ESBL) producers was 15.6% (n = 46). accounted for the most ESBL-producing organisms (28.9%, n = 26).
CONCLUSION
The wastewater generated by the Maternity and Child Health Units of KBTH harbored a wide range of multidrug resistant bacteria, with a good proportion of these being ESBL producers, and the predominant one being . The study thus identifies the wastewater of KBTH as an important source of multidrug resistant organisms, and underscores the significance of appropriate treatment of wastewater of the hospital and other clinical, and related settings prior to its discharge.
PubMed: 36311334
DOI: 10.1177/11786302221130613 -
Mussel Inspired Chemistry and Bacteria Derived Polymers for Oral Mucosal Adhesion and Drug Delivery.Frontiers in Bioengineering and... 2021Ulceration of the oral mucosa is common, can arise at any age and as a consequence of the pain lessens enjoyment and quality of life. Current treatment options often...
Ulceration of the oral mucosa is common, can arise at any age and as a consequence of the pain lessens enjoyment and quality of life. Current treatment options often involve the use of topical corticosteroids with poor drug delivery systems and inadequate contact time. In order to achieve local controlled delivery to the lesion with optimal adhesion, we utilized a simple polydopamine chemistry technique inspired by mussels to replicate their adhesive functionality. This was coupled with production of a group of naturally produced polymers, known as polyhydroxyalkanoates (PHA) as the delivery system. Initial work focused on the synthesis of PHA using CH50; once synthesized and extracted from the bacteria, the PHAs were solvent processed into films. Polydopamine coating was subsequently achieved by immersing the solvent cast film in a polymerized dopamine solution. Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy confirmed functionalization of the PHA films via the presence of amine groups. Further characterization of the samples was carried out via surface energy measurements and Scanning Electron Microscopy (SEM) micrographs for surface topography. An adhesion test via reverse compression testing directly assessed adhesive properties and revealed an increase in polydopamine coated samples. To further identify the effect of surface coating, LIVE/DEAD imaging and Alamar Blue metabolic activity evaluated attachment and proliferation of fibroblasts on the biofilm surfaces, with higher cell growth in favor of the coated samples. Finally, biocompatibility was investigated in a rat model where the polydopamine coated PHA showed less inflammatory response over time compared to uncoated samples with sign of neovascularization. In conclusion, this simple mussel inspired polydopamine chemistry introduces a step change in bio-surface functionalization and holds great promise for the treatment of oral conditions.
PubMed: 34026742
DOI: 10.3389/fbioe.2021.663764 -
Microorganisms Nov 2023Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe) levels in surface...
Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe) levels in surface waters in the marine environment, microbes produce a variety of siderophores. In the current study, halophilic bacteria SMI_1, sp., AABM_9, and AMPPS_5 were isolated from marine surface water of Kalinga beach, Bay of Bengal (Visakhapatnam, Andhra Pradesh, India) and were investigated for siderophore production using the Chrome Azurol S (CAS) assay. The effect of various production parameters was also studied. The optimum production of siderophores for SMI_1 was 93.57% siderophore units (SU) (after 48 h of incubation at 30 °C, pH 8, sucrose as carbon source, sodium nitrate as nitrogen source, 0.4% succinic acid), and for AABM_9, it was 87.18 %SU (after 36 h of incubation period at 30 °C, pH 8, in the presence of sucrose, ammonium sulfate, 0.4% succinic acid). The maximum production of siderophores for AMPPS_5 was 91.17 %SU (after 36 h of incubation at 35 °C, pH 8.5, glucose, ammonium sulfate, 0.4% citric acid). The bacterial isolates SMI_1, AABM_9, and AMPPS_5 showed siderophore production at low Fe concentrations of 0.10 µM, 0.01 µM, and 0.01 µM, respectively. The SMI_1 (73.09 %SU) and AMPPS_5 (68.26 %SU) isolates showed siderophore production in the presence of Zn (10 µM), whereas AABM_9 (50.4 %SU) exhibited siderophore production in the presence of Cu (10 µM). Additionally, these bacterial isolates showed better heavy-metal chelation ability and rapid development in seed germination experiments. Based on these results, the isolates of marine-derived bacteria effectively produced the maximum amount of siderophores, which could be employed in a variety of industrial and environmental applications.
PubMed: 38138017
DOI: 10.3390/microorganisms11122873 -
Ecotoxicology and Environmental Safety Jan 2020Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low...
Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low bioavailability to soil microorganisms affects their rate of biodegradation. This study was performed on samples of soil that were (for over forty years) subjected to contamination with creosote oil, and their metagenome and physicochemical properties were characterized. Moreover, the study was undertaken to evaluate the biodegradation of PAHs by autochthonous consortia as well as by selected bacteria strains isolated from long-term contaminated industrial soil. From among the isolated microorganisms, the most effective in biodegrading the contaminants were the strains Pseudomonas mendocina and Brevundimonas olei. They were able to degrade more than 60% of the total content of PAHs during a 28-day test. The biodegradation of these compounds using AT7 dispersant was enhanced only by Serratia marcescens strain. Moreover, the addition of AT7 improved the effectiveness of fluorene and acenaphthene biodegradation by Serratia marcescens 6-fold. Our results indicated that long-term contact with aromatic compounds induced the bacterial strains to use the PAHs as a source of carbon and energy. We observed that supplementation with surfactants does not increase the efficiency of hydrocarbon biodegradation.
Topics: Biodegradation, Environmental; Caulobacteraceae; Creosote; Environmental Monitoring; Industry; Poland; Polycyclic Aromatic Hydrocarbons; Pseudomonas mendocina; Soil; Soil Microbiology; Soil Pollutants
PubMed: 31678701
DOI: 10.1016/j.ecoenv.2019.109843 -
Journal of Functional Biomaterials Apr 2020A medium chain-length polyhydroxyalkanoate (PHA) was produced by CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was...
A medium chain-length polyhydroxyalkanoate (PHA) was produced by CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was achieved. Chemical analysis confirmed that the polymer produced was a medium chain-length PHA, a copolymer of 3-hydroxyoctanoate and 3-hydroxydecanoate, P(3HO--3HD). Lime oil, an essential oil with known antimicrobial activity, was used as an additive to P(3HO--3HD) to confer antibacterial properties to this biodegradable polymer. The incorporation of lime oil induced a slight decrease in crystallinity of P(3HO-co-3HD) films. The antibacterial properties of lime oil were investigated using ISO 20776 against 6538P and 8739, showing a higher activity against the Gram-positive bacteria. The higher activity of the oil against 6538P defined the higher efficiency of loaded polymer films against this strain. The effect of storage on the antimicrobial properties of the loaded films was investigated. After one-year storage, the content of lime oil in the films decreased, causing a reduction of the antimicrobial activity of the materials produced. However, the films still possessed antibacterial activity against 6538P.
PubMed: 32290046
DOI: 10.3390/jfb11020024 -
Frontiers in Microbiology 2021With the increasing number of drug-resistant bacteria, there is an urgent need for new antimicrobial agents, and antimicrobial peptides (AMPs), which exist in the human...
With the increasing number of drug-resistant bacteria, there is an urgent need for new antimicrobial agents, and antimicrobial peptides (AMPs), which exist in the human non-specific immune system, are one of the most promising candidates. It is an effective optimization strategy to modify antimicrobial peptides (AMPs) according to the distribution of amino acids and hydrophobic characteristics. The addition of bacterial pheromones to the N short peptide can increase the ability to recognize bacteria. In this study, we designed and synthesized AMP1-6 by amino acid substitution of mBjAMP1. Additionally, P-6, S-6, and L-6 were designed and synthesized by adding bacterial pheromones based on 1-6. Functional tests showed that the four AMPs had the ability to kill Gram-negative , , and , and Gram-positive and . Additionally, all four AMPs induced permeabilization and depolarization of bacterial cell membranes and increased intracellular reactive oxygen species (ROS) levels. Importantly, they had little or no mammalian cytotoxicity. At the same time, 1-6 and L-6 protected the stability of intestinal flora in and increased the relative abundance of . In summary, our results indicate that the designed AMPs have broad application prospects as a new type of polypeptide antimicrobial agent.
PubMed: 34733268
DOI: 10.3389/fmicb.2021.773076