Easy and Affordable: A New Method for the Studying of Bacterial Biofilm Formation.

BACKGROUND: Bacterial biofilm formation (BBF) proves itself to be in the spotlight of microbiology research due to the wide variety of infections that it can be associated with, the involvement in food spoilage, industrial biofouling and perhaps sewage treatment. However, BBF remains difficult to study due to the lack of standardization of the existing methods and the expensive equipment needed. We aim to describe a new inexpensive and easy to reproduce protocol for a 3D-printed microfluidic device that can be used to study BBF in a dynamic manner. METHODS: We used the SolidWorks 3D CAD Software (EducationEdition 2019-2020, Dassault Systèmes, Vélizy-Villacoublay, France) to design the device and the Creality3D Ender 5 printer (Shenzhen Creality 3D Technology Co., Ltd., Shenzhen, China) for its manufacture. We cultivated strains of Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. For the biofilm evaluation we used optical coherence tomography (OCT), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and crystal violet staining technique. RESULTS: Based on the analysis, Enterococcus faecalis seems to produce more biofilm in the first hours while Pseudomonas aeruginosa started to take the lead on biofilm production after 24 h. CONCLUSIONS: With an estimated cost around €0.1285 for one microfluidic device, a relatively inexpensive and easy alternative for the study of BBF was developed.

Descriptive Analysis of Circulating Antimicrobial Resistance Genes in Vancomycin-Resistant Enterococcus (VRE) during the COVID-19 Pandemic.

COVID-19 offers ideal premises for bacteria to develop antimicrobial resistance. In this study, we evaluated the presence of several antimicrobial resistance genes (ARG) in vancomycin-resistant Enterococcus (VRE) isolated from rectal swabs from patients at a hospital in Cluj-Napoca, Romania. Rectal swabs were cultivated on CHROMID® VRE (bioMérieux, Marcy-l' Étoile, France) and positive isolates were identified using MALDI-TOF Mass Spectrometry (Bruker Daltonics, Bremen, Germany) and further analyzed using the PCR technique for the presence of the following ARGs: van A, van B, tet(M), tet(L), ermB, msrA, mefA, aac(6')-Im, aph(2)-Ib, ant(4')-Ia, sul1, sul2, sul3, and NDM1. We isolated and identified 68 isolates of Enterococcus faecium and 11 isolates of Enterococcus faecalis. The molecular analysis showed 66 isolates positive for the vanA gene and eight positive for vanB. The most frequent association of ARG in VRE was vanA-tet(M)-ermB. There was no statistically significant difference between Enterococcus faecium and Enterococcus faecalis regarding ARGs. Our work proves that during the COVID-19 pandemic, highly resistant isolates of Enterococcus were present in patients in the intensive care unit; thus, better healthcare policies should be implemented for the management and control of these highly resistant isolates in the future.

Enterococcus raffinosus, Enterococcus durans and Enterococcus avium Isolated from a Tertiary Care Hospital in Romania-Retrospective Study and Brief Review.

(1) Background: This paper aims to provide a description of non-faecalis non-faecium enterococci isolated from a tertiary care hospital in Romania and to briefly review the existing literature regarding the involvement of Enterococcus raffinosus, Enterococcus durans and Enterococcus avium in human infections and their antimicrobial resistance patterns; (2) Methods: We retrospectively analyzed all Enteroccocus species isolated from the "Prof. Dr. O. Fodor" Regional Institute of Gastroenterology and Hepatology from Cluj-Napoca during one year focusing on non-faecalis non-faecium Enterococci. A brief review of the literature was performed using case reports involving Enterococcus raffinosus, Enterococcus durans and Enterococcus avium; (3) Results: Only 58 out of 658 Enteroccocus isolates were non-faecalis non-faecium and met the inclusion criteria. These species were isolated more often (p < 0.05) from the surgical ward from mixed etiology infections with E. coli. In our review, we included 39 case reports involving E. raffinosus, E. durans and E. avium; (4) Conclusions: Isolation of non-faecalis non-faecium enterococci displays an emerging trend with crucial healthcare consequences. Based on the analysis of the case reports, E. avium seems to be involved more often in neurological infections, E. durans in endocarditis, while E. raffinosus displays a more heterogenous distribution.

Influence of Toxoplasma gondii Infection on Male Fertility: A Pilot Study on Immunocompetent Human Volunteers.

BACKGROUND: This study was conducted to investigate the influence of Toxoplasma gondii infection on spermatic and hormonal parameters in a pilot sample of immunocompetent human male subjects. METHODS: This cross sectional, observational pilot study on 60 immunocompetent human male subjects aged between 18 and 60 yr old was conducted between 2012 -2013. Blind evaluation of serological markers of past T. gondii infection (TOX-IgG, TOX-IgM) was performed, along with individual spermiograms and determinations of follicle-stimulating hormone (FSH) and testosterone serum levels. RESULTS: The overall prevalence of past T. gondii infection in the investigated immunocompetent male subjects was 25%. No statistically significant influence of T. gondii infection on sperm characteristics (ejaculate quantity, sperm count, motility, morphology) and serum levels of FSH or testosterone were found. Among possible predictors of a modified spermiogram studied by multiple logistic regression along with the T. gondii infection (age, smoking, alcohol consumption, fertility influencing malformations, infections, trauma or medication), only the presence of varicocele in the medical history of the studied subjects was found to significantly participate in the prediction of a modified spermiogram (P=0.0154). A necessary sample size of 994 subjects was computed in order to achieve a test power of 0.8 (80%) to discriminate an effect size of 8.89% estimated by our pilot study. CONCLUSIONS: Although our investigation did not demonstrate an influence of latent T. gondii infection on spermatic and hormonal parameters of immunocompetent male humans, the absence of such an influence cannot be affirmed, due to the limited sample size of our pilot study.

First isolation and genetic characterization of a Toxoplasma gondii strain from a symptomatic human case of congenital toxoplasmosis in Romania.

Very limited data exists on the genetic diversity of Toxoplasma gondii from Eastern Europe. We present the first Romanian case of symptomatic congenital toxoplasmosis in which the T. gondii strain was isolated after inoculation in mice of a cerebrospinal fluid sample from a living neonate. The T. gondii strain was genotyped with 15 microsatellite markers distributed on 10 of the 14 chromosomes of T. gondii. The strain had a type II genotype.