Antibiotic Resistance and Virulence Phenotypes of Recent Bacterial Strains Isolated from Urinary Tract Infections in Elderly Patients with Prostatic Disease.

Acute bacterial prostatitis is one of the frequent complications of urinary tract infection (UTI). From the approximately 10% of men having prostatitis, 7% experience a bacterial prostatitis. The purpose of this study was to investigate the prevalence of uropathogens associated with UTIs in older patients with benign prostatic hyperplasia and to assess their susceptibility to commonly prescribed antibiotics as well as the relationships between microbial virulence and resistance features. Uropathogenic Escherichia coli was found to be the most frequent bacterial strain isolated from patients with benign prostatic hyperplasia, followed by Enterococcus spp., Enterobacter spp., Klebsiella spp., Proteus spp., Pseudomonas aeruginosa, and Serratia marcescens. Increased resistance rates to tetracyclines, quinolones, and sulfonamides were registered. Besides their resistance profiles, the uropathogenic isolates produced various virulence factors with possible implications in the pathogenesis process. The great majority of the uropathogenic isolates revealed a high capacity to adhere to HEp-2 cell monolayer in vitro, mostly exhibiting a localized adherence pattern. Differences in the repertoire of soluble virulence factors that can affect bacterial growth and persistence within the urinary tract were detected. The Gram-negative strains produced pore-forming toxins-such as hemolysins, lecithinases, and lipases-proteases, siderophore-like molecules resulted from the esculin hydrolysis and amylases, while Enterococcus sp. strains were positive only for caseinase and esculin hydrolase. Our study demonstrates that necessity of investigating the etiology and local resistance patterns of uropathogenic organisms, which is crucial for determining appropriate empirical antibiotic treatment in elderly patients with UTI, while establishing correlations between resistance and virulence profiles could provide valuable input about the clinical evolution and recurrence rates of UTI.

Microbial Biofilms in Urinary Tract Infections and Prostatitis: Etiology, Pathogenicity, and Combating strategies.

Urinary tract infections (UTIs) are one of the most important causes of morbidity and health care spending affecting persons of all ages. Bacterial biofilms play an important role in UTIs, responsible for persistent infections leading to recurrences and relapses. UTIs associated with microbial biofilms developed on catheters account for a high percentage of all nosocomial infections and are the most common source of Gram-negative bacteremia in hospitalized patients. The purpose of this mini-review is to present the role of microbial biofilms in the etiology of female UTI and different male prostatitis syndromes, their consequences, as well as the challenges for therapy.

Antagonistic activities of some Bifidobacterium sp. strains isolated from resident infant gastrointestinal microbiota on Gram-negative enteric pathogens.

The gastrointestinal microbiota contributes to the consolidation of the anti-infectious barrier against enteric pathogens. The purpose of this study was to investigate the influence of Bifidobacterium sp. strains, recently isolated from infant gastrointestinal microbiota on the in vitro growth and virulence features expression of enteropathogenic bacterial strains. The antibacterial activity of twelve Bifidobacterium sp. strains isolated from human feces was examined in vitro against a wide range of Gram negative pathogenic strains isolated from 30 infant patients (3 days to 5 years old) with diarrhea. Both potential probiotic strains (Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium catenulatum, Bifidobacterium breve, Bifidobacterium ruminantium) and enteropathogenic strains (EPEC, EIEC, Klebsiella pneumoniae, Salmonella sp., Yersinia enterocolitica, Pseudomonas aeruginosa) were identified by MALDI-TOF and confirmed serologically when needed. The bactericidal activity, growth curve, adherence to the cellular HEp-2 substratum and production of soluble virulence factors have been assessed in the presence of different Bifidobacterium sp. cultures and fractions (whole culture and free-cell supernatants). Among the twelve Bifidobacterium sp. strains, the largest spectrum of antimicrobial activity against 9 of the 18 enteropathogenic strains was revealed for a B. breve strain recently isolated from infant intestinal feces. The whole culture and free-cell supernatant of B. breve culture decreased the multiplication rate, shortened the log phase and the total duration of the growth curve, with an earlier entrance in the decline phase and inhibited the adherence capacity to a cellular substratum and the swimming/swarming motility too. These results indicate the significant probiotic potential of the B. breve strain.

Influence of salinity upon the phenotypic expression of antibiotic resistance in nonhalophilic and halophilic vibrios.

The purpose of the present work is to demonstrate the influence of different NaCI concentrations included in the Mueller Hinton medium, upon the antibiotic susceptibility of 10 non-halophilic and 28 halophilic Vibrio strains. The highest number of resistance aspects were recorded at 1% NaCl concentration for V. cholerae O1/non O1 strains and at 3% for V. parahaemolyticus, V. algynolyticus, V. vulnificus, V. fisheri, V. anguillarum and V. metschnikovii.

Antimicrobial activity of some new of 2-(4-ethyl-phenoximethyl) benzoic acid thioureides against planktonic cells.

The aim of the present study was to evaluate the antimicrobial activity of new 2-(4-ethyl-phenoxymethyl) benzoic acid thioureides. The synthesis of the new compounds was done in three steps starting with the synthesis of 2-(4-ethyl-phenoxymethyl) benzoic acid. In the second stage, the 2-(4-ethyl-phenoxymethyl)-benzoyl chloride was prepared and the new thioureides were synthesized in the third step by the reaction of 2-(4-ethyl-phenoxymethyl) benzoyl isothiocyanate with various primary aromatic amines. The original compounds were screened for their in vitro antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) as well as to fungal strains (Candida albicans, Aspergillus niger), using both reference and clinical, multidrug resistant strains. The qualitative screening of the susceptibility spectra of various microbial strains versus these compounds was performed by three adaptated diffusion methods: (1) impregnation of the filter paper disks with the respective substance solutions, (2) distribution of the tested solutions into agar wells and (3) spotting of the respective solutions on the solid medium previously inoculated with the microbial suspensions. The quantitative assay of the antimicrobial activity was performed by broth microdilution method in 96-well microplates in order to establish the minimal inhibitory concentration (MIC). The tested compounds exhibited specific antimicrobial activity with MICs ranging from 3.9 microg/mL to 250 microg/mL.

[Trends of antimicrobial resistance in microbial strains isolated from invasive infections in Romania. Experience of participation in EARSS (European Antimicrobial Resistance Surveillance System), 2002-2008]. / Tendintele rezistentei la antibiotice a izolatelor din infectii invazive în România. Experienta participarii în Sistemul European de Supraveghere a Rezistentei la Antibiotice (EARSS) în perioada 2002-2008.

EARSS (European Antimicrobial Resistance Surveillance System) is the biggest antimicrobial resistance surveillance project in the world financed from public finds, aiming to provide validated and comparable official data on antimicrobial resistance of invasive microbial strains (isolated from blood and CSF), belonging to 6 indicator bacterial species, i.e.: S. aureus, E. coli, E. faecium/faecalis, Str. pneumoniae, Ps. aeruginosa, K. pneumoniae. Romania reported data to EARSS since 2002 so far. Though the number of participating laboratories increased progressively from 12 to 35, the number of hospitals which reported for EARSS. as the number of strains included in the data base remained steady and relatively low. This issue is related to the particular position of Romania in the European context, in respect of the very low number of blood cultures performed in hospitals. Our paper is presenting the trends of antimicrobial resistance in the indicator strains in the 2002-2008 interval. During the 2002-2008 interval, Romania reported to EARSS a total number of 1276 bacterial strains, distributed by species as follows: 513 S aureus, 369 E. coli, 128 Streptococcus pneumoniae, 127 Enterococcus spp.. 71 Klebsiella pneumoniae, 68 Pseudomonas aeruginosa. Klebsiella pneumoniae and Pseudomonas aeruginosa were reported, according to the EARSS protocol, only for the 2005-2008 interval. It is difficult to describe trends, specially in Enterococcus, Streptococcus pneumonaie and the 2 species collected only since 2005, because of the low number of isolates, but there are several results that are supporting us to claim that antimicrobial resistance in invasive isolates is a real problem in Romanian hospitals, like in other Central, Southern and South Eastern European countries: more than 25% of S. aureus strains resistant to methicilline, with more than 50% in some years, high aminoglycozides resistance in more than 70-80% of Enterococcus faecium invasive strains, more than 80% of strains resistant to 3rd generation cephalosporines etc.