Characterization of the Antibacterial Activity of an SiO2 Nanoparticular Coating to Prevent Bacterial Contamination in Blood Products

Technological innovations and quality control processes within blood supply organizations have significantly improved blood safety for both donors and recipients. Nevertheless, the risk of transfusion-transmitted infection remains non-negligible. Applying a nanoparticular, antibacterial coating at the surface of medical devices is a promising strategy to prevent the spread of infections. In this study, we characterized the antibacterial activity of an SiO2 nanoparticular coating (i.e., the “Medical Antibacterial and Antiadhesive Coating” [MAAC]) applied on relevant polymeric materials (PM) used in the biomedical field. Electron microscopy revealed a smoother surface for the MAAC-treated PM compared to the reference, suggesting antiadhesive properties. The antibacterial activity was tested against selected Gram-positive and Gram-negative bacteria in accordance with ISO 22196. Bacterial growth was significantly reduced for the MAAC-treated PVC, plasticized PVC, polyurethane and silicone (90–99.999%) in which antibacterial activity of ≥1 log reduction was reached for all bacterial strains tested. Cytotoxicity was evaluated following ISO 10993-5 guidelines and L929 cell viability was calculated at ≥90% in the presence of MAAC. This study demonstrates that the MAAC could prevent bacterial contamination as demonstrated by the ISO 22196 tests, while further work needs to be done to improve the coating processability and effectiveness of more complex matrices.

Microbial Contamination of Photographic and Cinematographic Materials in Archival Funds in the Czech Republic

In this study we investigated the microbial contamination of 126 samples of photographic and cinematographic materials from 10 archival funds in the Czech Republic. Microorganisms were isolated from the light-sensitive layer by swabbing it with a polyurethane sponge. Microbial isolates were identified by MALDI-TOF MS (bacteria) or by phenotype testing and microscopy (fungi). Bacterial contamination was more abundant and more diverse than fungal contamination, and both were significantly associated with archives. The most frequently isolated fungal genera were Cladosporium, Eurotium, Penicillium, Aspergillus and Alternaria. The most frequently isolated bacteria were Gram-positive genera such as Staphylococcus, Micrococcus, Kocuria, Streptococcus and Bacillus. This bacterial and fungal diversity suggests that air is the main vehicle of contamination. We also analysed the impact of the type of material used for the carrier (paper, baryta paper, cellulose acetate and nitrate or glass) or the light-sensitive layer (albumen, gelatine, collodion and other) on the level and diversity of microbial contamination. Carriers such as polyester and cellulose nitrate may have a negative impact on bacterial contamination, while paper and baryta paper may have a partially positive impact on both fungal and bacterial contamination.

Evaluation of bacterial contamination of blood components in a tertiary care centre

not available Bangladesh Journal of Medical Science Vol. 21(1) 2022 Page : 213-215

Successful Disinfection of a New Healthcare Facility Contaminated with Pseudomonas aeruginosa

Contamination of water use points in health establishments is a frequent and concerning problem. Maintenance and disinfection of water systems can be inefficient. Sterilizing filters are commonly used at selected taps. We report diagnostic and corrective approaches that have succeeded in making a contaminated health facility sustainably compatible with its activity without restriction in taps use. The zones contaminated with pseudomonas as well as those, along the water networks, at risk of biofilm development were identified. Corrective measures on the network and various types of decontamination were carried out. At the end of this work, the bacterial load in the water significantly decreased and 219 out of 223 controls were negative for P. aeruginosa over 3 years of follow-up. Four positive results were linked to three taps not used for care which were satisfactorily treated locally. Errors at the design and setup phases of health facilities may result in resistant bacterial contamination. P. aeruginosa contamination of newly built healthcare facilities is an underreported problem. Guidelines on design, disinfection, and monitoring procedures of water networks of healthcare facilities should be adapted consequently and would certainly improve the offered care limiting patients’ risk and avoid many unwanted financial situations for the providers.

Boar Semen Contamination: Identification of Gram-Negative Bacteria and Antimicrobial Resistance Profile

Bacterial contamination of boar semen occurs with some frequency in artificial insemination centers and may have a negative effect on the quality of the semen as well as on the sows’ reproductive capacity. Normally, the source of bacterial contamination in pig seminal doses is the own boar. However, distilled water or laboratory equipment used to elaborate the seminal doses can be an important source of bacterial contamination. This study focused on the identification of gram-negative bacteria in boar semen, and impact on the quality of ejaculates obtained from boar, as well as on the establishment of antimicrobial resistance patterns of isolated gram-negative bacteria. Semen samples were collected from 96 boars, ranging in age from 12–36 month, from three artificial insemination centers from the North-West of Romania. Bacterial species were identified by two methods: matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and API 20 E (BioMerieux, France). The main bacteria isolated from the doses diluted semen were gram-negative bacteria (47.91%), with a majority of the contaminant bacteria belonging to the family Enterobacteriaceae: Seratia marcescens 19.56%, Proteus mirabilis 15.21% and Escherichia coli 10.86% and to the family Pseudomonaceae: Ralstonia picketii 17.39%, Burkholderia cepacia 10.86%, Pseudomonas aeruginosa 8.69%, and Pseudomonas fluorescens 4.34%, respectively. More than half of these isolates (56.52%) were resistant to gentamycin and 58.69% were resistant to penicillin. These antibiotics are very frequently added in sperm diluent in the centers for the processing of sperm from boars in Romania. Regular monitoring for bacterial contamination is an important aspect of a control program.

Study of Microbial Contamination of Some Commercial Contact Lens Solutions

Sixty samples of commercially available contact lens solutions were collected from students at the Pharmacy College/Baghdad University. The types of lenses used varied from medical to cosmetic. They were cultured to diagnose any microbial contamination within the solutions. Both used and unused solutions were subject for culturing. Thirty six (60%) used samples showed bacterial growth, fungal growth was absent. Pseudomonas aeruginosa accounts for the highest number of isolates (25%) followed by E. coli (21%), Staphylococcus epidermidis (6.6%), Pseudomonas fluorescence (5%) and Proteus mirabilis (1.6%) respectively. Only one (1) unused (sealed) sample showed growth of P. fluorescence. These bacterial contamination likely came from bad personal hygiene and improper or misuse of the solutions where these bacteria especially P. aeruginosa are frequently found in various environments from skin to solid materials and surfaces and are known to thrive in harsh environments. No relation was found between eye associated diseases and solution contamination among contact lens users. Special care should be paid in maintaining aseptic solutions and proper handling to avoid transmitting harmful bacteria to the eye where it may lead to serious eye infections

Occurrence of Vibrio parahaemolyticus and Staphylococcus aureus in seafood

The objective of this study was to establish the occurrence of Vibrio parahaemolyticus and Staphylococcus aureus in several species of sea fish and mussels (Mytilus galloprovincialis). The study included a total of 33 samples of frozen sea fish and 64 samples of fresh wild and farmed mussels purchased from the stores. V. parahaemolyticus was isolated and confirmed via PCR in 2 (6%) fish samples (Atlantic cod and Alaska pollock) and 20 (31%) mussel samples. S. aureus was also isolated and confirmed via PCR in 2 (6%) fish samples (Argentine hake and Atlantic cod). Significant differences were found in the total bacterial contamination between wild mussels (6.54 log cfu/g) and farmed mussels (6.69 log cfu/g). Total V. parahaemolyticus count did not show significant differences either between wild (4.45 log cfu/g) and farmed mussels (4.99 log cfu/g). In wild mussels the S. aureus count was found to be 4.50 log cfu/g, while in farmed mussels it was 3.14 log cfu/g. The occurrence of V. parahaemolyticus and S. aureus in fish and mussels presents a risk to the consumer’s health.