Methods for eradication of the biofilms formed by opportunistic pathogens using novel techniques – A review

The inconvenient environmental conditions force microorganisms to colonize either abiotic surfaces or animal and plant tissues and, therefore, form more resistant structures – biofilms. The phenomenon of microbial adherence, opportunistic pathogens in particular, is of a great concern. Colonization of medical devices and biofilm formation on their surface, may lead to severe infections mainly in humans with impaired immune system. Although, current research consider various methods for prevention of microbial biofilms formation, still, once a biofilm is formed, its elimination is almost impossible. This study focuses on the overview of novel methods applied for eradication of mature opportunistic pathogens' biofilms. Among various techniques the following: cold plasma, electric field, ultrasounds, ozonated water treatment, phagotherapy, matrix targeting enzymes, bacteriocins, synthetic chemicals and natural origin compounds used for biofilm matrix disruption were briefly described

Adhesive and hydrophobic properties of Pseudomonas aeruginosa and Pseudomonas cedrina associated with cosmetics

The presence of bacteria in the cosmetic production environment is often connected with non-sterile raw materials, inappropriate production lines disinfection or cross contamination. Among bacteria isolated from the environment, opportunistic pathogens can be also found, posing a risk to patients with lowered immunity. Moreover, their susceptibility to antibiotics and disinfectants is frequently decreased as they develop more complex forms - biofilms. As hydrophobicity and adhesive properties play a vital role in the colonization process the aim of this research was to determine hydrophobic, aggregative and adhesive properties of bacteria isolated from the cosmetics.Bacteria used in the research were isolated from the body balm and the cosmetic preservative (three strains of Pseudomonas aeruginosa and four strains of Pseudomonas cedrina) and identified using 16S rRNA gene sequencing. For those strains and also two reference strains (P. aeruginosa ATCC15442 and P. cedrina DSM17516) an aggregation test, hydrophobicity by two different methods (SAT and MATH) and adhesion to polystyrene by crystal violet binding assay were performed.According to the SAT method more than half of the tested strains were strongly hydrophobic. Using MATH test, it was proved that four strains (P. cedrina DSM17516 and three isolates of P. aeruginosa) were strong hydrophobes, however, the rest of the strains expressed moderate hydrophobicity. Moreover, self-aggregation was also observed and for P. aeruginosa CFII was more than 20%. All of the strains were able to adhere to polystyrene after 30 minutes contact, almost all of them (excluding P. cedrina DSM17516) indicated a moderate adhesion already after four hours of incubation. These results indicate that environmental Pseudomonas strains possess strong hydrophobic and adhesive properties, that may results in a colonization of abiotic surfaces

Early administration of LEvosimendan in Patients witH decompensAted chroNic hearT failure (ELEPHANT) study. Rationale and protocol of the study

Dobutamine and levosimendan are both indicated for inotropic support in acute decompensated heart failure (HF). The study aimed to assess the impact of early administration of levosimendan (first iv therapeutic approach) versus dobutamine (first iv therapeutic approach) on in-hospital treatment expenses and clinical outcomes in patients with decompensated chronic HF. The ELEPHANT study was designed as a phase III, multicentre, randomized 1:1, double-blind, active-controlled trial that will include patients admitted to the hospital due to HF decompensation. Co-primary endpoints were defined as total in-hospital expenses/survivor and duration of hospitalization/survivor. Secondary efficacy endpoints: on the last day of hospitalization: occurrence of treatment side effects, body weight change during hospitalization, BNP change during hospitalization, in-hospital mortality, additional levosimendan administration due to the ineffectiveness of the initial treatment. Patients will be randomized 1:1 to the active group receiving continuous infusion 24 h of levosimendan 0.1 μg/kg/min or to the control group receiving continuous infusion 24 h of dobutamine 3 μg/kg/min. After the enrolment of 20 patients, results analysis will be performed (pilot phase — single centre). Based on this analysis conducted according to the intention-to-treat principle, the final population size will be defined. The multicentre phase of the study will be initiated after the pilot phase

Evaluation of hydrophobicity and quantitative analysis of biofilm formation by Alicyclobacillus sp.

Alicyclobacillus sp. are acidothermophilic bacteria frequently contaminating fruit based products (juices and juice concentrates). These sporulating bacteria are able to survive at elevated temperatures and highly acidic environments which causes difficulties in their removal from industrial environments. Although numerous literature data examine Alicyclobacillus sp. presence in fruit based products and methods of their elimination, there is still a limited knowledge on ability of these bacteria to adhere to abiotic surfaces. Therefore, the objective of this study was to determine Alicyclobacillus sp. cells' hydrophobicity and capability of biofilm formation on a glass surface. The degree of cells hydrophobicity, according to Microbial Adhesion to Hydrocarbon (MATH) and Salt Aggregation Test (SAT), was investigated for eleven environmental isolates from natural Polish habitats, identified as Alicyclobacillus sp., and a Alicyclobacillus acidoterrestris DSM 3922 reference strain. The dynamics of biofilm formation within 3-day incubation on a glass surface was evaluated and quantified by a plate count method both, for cultures with and without agitation. All of the bacterial strains tested expressed ability to colonize a glass surface and four environmental isolates were classified as fast-adherent strains. The mature biofilm structures were predominantly formed after 48 hours of incubation. Dynamic culturing conditions were observed to accelerate the biofilm formation. The majority of strains expressed a moderate hydrophobicity level both, in SAT (41.7%) and MATH-PBS (75.0%), as well as MATH-PUM (91.7%) tests. However, no correlation between hydrophobicity and cell adherence to a glass slide surface was observed

Opportunistic Gram-negative rods' capability of creating biofilm structures on polivynyl chloride and styrene-acronitrile copolymer surfaces

Biofilms are highly organized microbial communities displaying high resistance to disinfectants and other external environmental factors. Medical equipment, such as stents and catheters, can be colonized by a variety of bacteria including opportunistic pathogens circulating in the environment and dangerous to immunocompromised patients. Application of materials resistant to biofilm formation will minimize the risk of patients' infection. Hence, the aim of this research was to determine the biofilm growth of environmental bacteria isolates on polyvinyl chloride and styrene-acronitrile copolymer surfaces. Nine strains (Pseudomonas aeruginosa, Burkholderia cepacia and Serratia liquefacies) isolated from cosmetics, and a reference P. aeruginosa strain ATCC 15442, were tested. The ability and dynamics of biofilm formation on intubation catheters (30°C, up to 24 h) in bacterial growth cultures (107-108 CFU/ml) was investigated, with subsequent sonication and quantification by agar plate count method. The results indicated that all the tested bacteria expressed a strong ability for the polymer surface adhesion, reaching 4.6 to 6.7 log CFU/cm2 after 30 minutes. Moreover, for the majority of strains, the level of 24-hour biofilm production was from 6.67-7.61 log CFU/cm2. This research indicates that the environmental strains circulating between the cosmetics and patients may pose a threat of biofilm formation on medical equipment surfaces, and presumably in the clinical surroundings as well

Opportunistic Gram-negative rods' capability of creating biofilm structures on polivynyl chloride and styrene-acronitrile copolymer surfaces

Biofilms are highly organized microbial communities displaying high resistance to disinfectants and other external environmental factors. Medical equipment, such as stents and catheters, can be colonized by a variety of bacteria including opportunistic pathogens circulating in the environment and dangerous to immunocompromised patients. Application of materials resistant to biofilm formation will minimize the risk of patients' infection. Hence, the aim of this research was to determine the biofilm growth of environmental bacteria isolates on polyvinyl chloride and styrene-acronitrile copolymer surfaces. Nine strains (Pseudomonas aeruginosa, Burkholderia cepacia and Serratia liquefacies) isolated from cosmetics, and a reference P. aeruginosa strain ATCC 15442, were tested. The ability and dynamics of biofilm formation on intubation catheters (30°C, up to 24 h) in bacterial growth cultures (107-108 CFU/ml) was investigated, with subsequent sonication and quantification by agar plate count method. The results indicated that all the tested bacteria expressed a strong ability for the polymer surface adhesion, reaching 4.6 to 6.7 log CFU/cm2 after 30 minutes. Moreover, for the majority of strains, the level of 24-hour biofilm production was from 6.67-7.61 log CFU/cm2. This research indicates that the environmental strains circulating between the cosmetics and patients may pose a threat of biofilm formation on medical equipment surfaces, and presumably in the clinical surroundings as well

Predictive performance and clinical application of COV50, a urinary proteomic biomarker in early COVID-19 infection : a prospective multicentre cohort study

Background: The SARS-CoV-2 pandemic is a worldwide challenge. The CRIT-CoV-U pilot study generated a urinary proteomic biomarker consisting of 50 peptides (COV50), which predicted death and disease progression from SARS-CoV-2. After the interim analysis presented for the German Government, here, we aimed to analyse the full dataset to consolidate the findings and propose potential clinical applications of this biomarker. Methods: CRIT-CoV-U was a prospective multicentre cohort study. In eight European countries (Austria, France, Germany, Greece, North Macedonia, Poland, Spain, and Sweden), 1012 adults with PCR-confirmed COVID-19 were followed up for death and progression along the 8-point WHO scale. Capillary electrophoresis coupled with mass spectrometry was used for urinary proteomic profiling. Statistical methods included logistic regression and receiver operating characteristic curve analysis with a comparison of the area under curve (AUC) between nested models. Hospitalisation costs were derived from the care facility corresponding with the Markov chain probability of reaching WHO scores ranging from 3 to 8 and flat-rate hospitalisation costs adjusted for the gross per capita domestic product of each country. Findings: From June 30 to Nov 19, 2020, 228 participants were recruited, and from April 30, 2020, to April 14, 2021, 784 participants were recruited, resulting in a total of 1012 participants. The entry WHO scores were 1–3 in 445 (44%) participants, 4–5 in 529 (52%) participants, and 6 in 38 (4%) participants; and of all participants, 119 died and 271 had disease progression. The odds ratio (OR) associated with COV50 in all 1012 participants for death was 2·44 (95% CI 2·05–2·92) unadjusted and 1·67 (1·34–2·07) when adjusted for sex, age, BMI, comorbidities, and baseline WHO score; and for disease progression, the OR was 1·79 (1·60–2·01) when unadjusted and 1·63 (1·41–1·91) when adjusted (p<0·0001 for all). The predictive accuracy of the optimised COV50 thresholds was 74·4% (71·6–77·1%) for mortality (threshold 0·47) and 67·4% (64·4–70·3%) for disease progression (threshold 0·04). When adjusted for covariables and the baseline WHO score, these thresholds improved AUCs from 0·835 to 0·853 (p=0·033) for death and from 0·697 to 0·730 (p=0·0008) for progression. Of 196 participants who received ambulatory care, 194 (99%) did not reach the 0·04 threshold. The cost reductions associated with 1 day less hospitalisation per 1000 participants were million Euro (M€) 0·887 (5–95% percentile interval 0·730–1·039) in participants at a low risk (COV50 <0·04) and M€2·098 (1·839-2·365) in participants at a high risk (COV50 ≥0·04). Interpretation: The urinary proteomic COV50 marker might be predictive of adverse COVID-19 outcomes. Even in people with mild-to-moderate PCR-confirmed infections (WHO scores 1–4), the 0·04 COV50 threshold justifies earlier drug treatment, thereby potentially reducing the number of days in hospital and associated costs. Funding: German Federal Ministry of Health