Bacterial biofilm associated with a case of capsular contracture

Capsular contracture is one of the most common complications of implant-based breast augmentation. Despite its prevalence, the etiology of capsular contracture remains controversial although the surface texture of the breast implant, the anatomical position of the prosthesis and the presence of bacterial biofilm could be considered trigger factors. In fact, all medical implants are susceptible to bacterial colonization and biofilm formation. The present study demonstrated the presence of microbial biofilm constituted by cocci in a breast implant obtained from a patient with Baker grade II capsular contracture. This suggests that subclinical infection can be present and involved in low-grade capsular contracture

The adherent/invasive escherichia coli (AIEC) strain LF82 invades and persists in human prostate cell lineRWPE-1 activating a strong inflammatory response

Adherent/invasive Escherichia coli (AIEC) strains have recently been receiving increased attention because they are more prevalent and persistent in the intestine of Crohn's disease (CD) patients than in healthy subjects. Since AIEC strains show a high percentage of similarity to extraintestinal pathogenic E. coli (ExPEC), neonatal meningitis-associated E. coli (NMEC), and uropathogenic E. coli (UPEC) strains, here we compared AIEC strain LF82 with a UPEC isolate (strain EC73) to assess whether LF82 would be able to infect prostate cells as an extraintestinal target. The virulence phenotypes of both strains were determined by using the RWPE-1 prostate cell line. The results obtained indicated that LF82 and EC73 are able to adhere to, invade, and survive within prostate epithelial cells. Invasion was confirmed by immunofluorescence and electron microscopy. Moreover, cytochalasin D and colchicine strongly inhibited bacterial uptake of both strains, indicating the involvement of actin microfilaments and microtubules in host cell invasion. Moreover, both strains belong to phylogenetic group B2 and are strong biofilm producers. In silico analysis reveals that LF82 shares with UPEC strains several virulence factors: namely, type 1 pili, the group II capsule, the vacuolating autotransporter toxin, four iron uptake systems, and the pathogenic island (PAI). Furthermore, compared to EC73, LF82 induces in RWPE-1 cells a marked increase of phosphorylation of mitogen-activated protein kinases (MAPKs) and of NF-κB already by 5 min postinfection, thus inducing a strong inflammatory response. Our in vitro data support the hypothesis that AIEC strains might play a role in prostatitis, and, by exploiting host-cell signaling pathways controlling the innate immune response, likely facilitate bacterial multiplication and dissemination within the male genitourinary trac

Characterization of the ear canal bacterial flora present in hearing Aids (HA) wearing subjects

The use of hearing aids (HA) is considered a predisposing factor for ear microbial infections. We undertook this study to compare the presence and nature of the microbial flora inhabiting of ears of HA and non-HA (nHA) users. Swab samples of the ears of HA and nHA users were collected from the Institute of Otolaryngology, “Cattolica del Sacro Cuore” University “Agostino Gemelli”, Rome, Italy. Swab samples were taken from the ear canal of 57 HA and 33 nHA users. The components of the microbial flora present on each swab sample were identified and characterized at the level of species. A total of 41 different bacterial species were identified. A statistically significant prevalence of polymicrobial communities was found in ears presenting signs of inflammation (2.5 ± 1.7 vs 2.1 ± 1.3; P = 0.02) and in HA users (2.3 ± 1.2 vs 1.7 ± 1.0; P = 0.002). Few putative pathogens were detected. Candida albicans spp. was not isolated in our study. A small number of swab samples presented no microbial growth. Bacterial species isolated from HA users with and without inflammation were assayed for the ability to form a biofilm. Among gram-positive and gram-negative bacteria, S. aureus, CoNS, P. aeruginosa, and K. pneumoniae were found to be strong biofilm producers. S. aureus and P. aeruginosa, isolated only from the ears of HA and nHA users presenting signs of inflammation, were further analyzed for their antibiotic-resistance profile and characterized by the Multilocus Sequence Typing (MLST) assay. The highest rates of antibacterial resistance were in S. aureus to a penicillin (75.5%) and in P. aeruginosa, to amoxicillin-clavulanic acid, cefotaxime, ertapenem, tigecycline and trimethoprim-sulfamethoxazole (100%). Moreover, three S. aureus strains (37.5%) were methicillin-resistant (MRSA). Of the eight S. aureus isolates, we identified six sequence types (ST) indicating that 75% are likely independent clones. For what it concerned P. aeruginosa, six different STs were assigned. Interestingly, two out of the six strains presented newly identified ST values. This study sheds new light on the combined effect of the presence of HA devices and signs of external ear inflammation on the composition of the ear bacterial flora. Our results reinforce the need to practice careful hygiene of HA devices to prevent serious ear canal infections

16S metagenomics reveals dysbiosis of nasal core microbiota in children with chronic nasal inflammation: role of adenoid hypertrophy and allergic rhinitis

Allergic rhinitis (AR) and adenoid hypertrophy (AH) are, in children, the main cause of partial or complete upper airway obstruction and reduction in airflow. However, limited data exist about the impact of the increased resistance to airflow, on the nasal microbial composition of children with AR end AH. Allergic rhinitis (AR) as well as adenoid hypertrophy (AH), represent extremely common pathologies in this population. Their known inflammatory obstruction is amplified when both pathologies coexist. In our study, the microbiota of anterior nares of 75 pediatric subjects with AR, AH or both conditions, was explored by 16S rRNA-based metagenomic approach. Our data show for the first time, that in children, the inflammatory state is associated to similar changes in the microbiota composition of AR and AH subjects respect to the healthy condition. Together with such alterations, we observed a reduced variability in the between-subject biodiversity on the other hand, these same alterations resulted amplified by the nasal obstruction that could constitute a secondary risk factor for dysbiosis. Significant differences in the relative abundance of specific microbial groups were found between diseased phenotypes and the controls. Most of these taxa belonged to a stable and quantitatively dominating component of the nasal microbiota and showed marked potentials in discriminating the controls from diseased subjects. A pauperization of the nasal microbial network was observed in diseased status in respect to the number of involved taxa and connectivity. Finally, while stable co-occurrence relationships were observed within both control- and diseases-associated microbial groups, only negative correlations were present between them, suggesting that microbial subgroups potentially act as maintainer of the eubiosis state in the nasal ecosystem. In the nasal ecosysteminflammation-associated shifts seem to impact the more intimate component of the microbiota rather than representing the mere loss of microbial diversity. The discriminatory potential showed by differentially abundant taxa provide a starting point for future research with the potential to improve patient outcomes. Overall, our results underline the association of AH and AR with the impairment of the microbial interplay leading to unbalanced ecosystems

Acinetobacter baumannii Virulence Traits: A Comparative Study of a Novel Sequence Type with Other Italian Endemic International Clones

Carbapenem-resistant Acinetobacter baumannii (CRAb) have emerged in recent decades as major causes of nosocomial infections. Resistance is mainly due to overexpression of intrinsic and/or acquired carbapenemases, especially oxacillinases (OXA). In Italy, although the sequence type (ST) 2 and the ST78 are the most frequently detected, we recently reported ST632, a single locus variant of ST2. Therefore, this study was aimed at unraveling common bacterial surface virulence factors involved in pathogenesis and antibiotic resistance in representative CRAb of these ST genotypes. Outer membrane protein (OMP) composition together with motility, biofilm formation, in vitro adherence to, invasion of, and survival within pneumocytes were analyzed. Differently from the carbapenem-susceptible reference strain ATCC 17978, either overexpressed OXA-51 or both OXA-23 and OXA-51 co-purified with OMPs in CRAb. This tight association ensures their maximal concentration on the inner surface of the outer membrane to provide the best protection against carbapenems. These findings led us to propose for the first time a common behavior of OXA enzymes in CRAb. Despite the presence of both OmpA and phosphorylcholine-porinD and the ability of all the strains to adhere to cells, invasion, and survival within pneumocytes was shown only by ST2 and ST78 isolates, sharing the highest number of identified OMPs. Conversely, notwithstanding genetic and OMPs similarities with ST2, ST632 was unable to invade and survive within epithelial cells. Overall, our study shows that different STs share a specific OMP composition, also shaped by overexpressed OXA, that is needed for invasiveness and survival of CRAb

Proprietà invasive in cellule prostatiche e profilo di virulenza di Escherichia coli isolati da infezione del tratto urinario in pazienti comunitari

E. coli è altamente adattato alla colonizzazione del tratto urinario: la presenza di numerose adesine, siderofori, tossine, rivestimenti polisaccaridici e altri fattori di virulenza possono favorire l’adesione al tessuto mucoso dell’ospite permettendo l’elusione della difesa immune e l’invasione dei tessuti. E. coli urinari sono in grado di invader e persistere nel citoplasma di cellule epiteliali prostatiche. Ceppi di E. coli isolati da pazienti comunitari con infezioni urinarie sono stati caratterizzati per capacità adesiva e invasiva in cellule prostatiche RWPE-1