The Role of Bacterial Colonization of the Suture Thread in Early Identification and Targeted Antibiotic Treatment of Surgical Site Infections: A Prospective Cohort Study.

Background: The aim of the present study is to investigate the role of the colonization of suture thread to identify patients at risk of developing a surgical site infection (SSI) after clean surgical procedures. Methods: Patients who underwent elective clean surgery procedures at the Surgery Unit of the AOU-University of Campania Luigi Vanvitelli in a 21-month period were prospectively enrolled. For each patient, a synthetic absorbable thread in Lactomer 9-1 was inserted into the surgical site at the end of surgery and microbiologically evaluated after 48 h. Antibiotic prophylaxis was chosen according to international guidelines. Results: A total of 238 patients were enrolled; 208 (87.4%) of them were subjected to clean procedures without the placement of prosthesis, and 30 (12.6%) with prosthesis. Of the 238 patients, 117 (49.2%) underwent an antimicrobial prophylaxis. Overall, 79 (33.2%) patients showed a bacterial colonization of the thread: among the 208 without the implantation of prosthesis, 19 (21.8%) of the 87 with antibiotic prophylaxis and in 58 (47.9%) of the 121 without it; among the 30 patients with the implantation of prosthesis, only two patients showed a colonized thread. The patients with antibiotic prophylaxis developed a colonization of the thread less frequently than those without it (17.9% vs. 47.9%, p < 0.001). SSI was observed in six (2.5%) patients, all of them showing a colonized thread (7.6% vs. 0%, p < 0.001). The bacteria identified in colonized threads were the same as those found in SSIs. Conclusions: Our study presents a new method that is able to precociously assess patients who have undergone clean procedures who may develop SSI, and identify the microorganism involved.

Prevalence and Antimicrobial Susceptibility Patterns of Bacterial Pathogens in Urinary Tract Infections in University Hospital of Campania "Luigi Vanvitelli" between 2017 and 2018.

Urinary tract infections (UTIs) are the most common and expensive health problem globally. The treatment of UTIs is difficult owing to the onset of antibiotic-resistant bacterial strains. The aim of this study was to define the incidence of infections, identify the bacteria responsible, and identify the antimicrobial resistance profile. Patients of all ages and both sexes were included in the study, all admitted to University Hospital of Campania "Luigi Vanvitelli", between January 2017 and December 2018. Bacterial identification and antibiotic susceptibility testing were performed using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Phoenix BD. Among the 1745 studied patients, 541 (31%) and 1204 (69%) were positive and negative for bacterial growth, respectively. Of 541 positive patients, 325 (60%) were females, while 216 (39.9%) were males. The largest number of positive subjects was recorded in the elderly (>61 years). Among the pathogenic strains, 425 (78.5%) were Gram-negative, 107 (19.7%) were Gram-positive, and 9 (1.7%) were Candida species. The most isolated Gram-negative strain is Escherichia coli (E. coli) (53.5%). The most frequent Gram-positive strain was Enterococcus faecalis (E. faecalis) (12.9%). Gram-negative bacteria were highly resistant to ampicillin, whereas Gram-positive bacteria were highly resistant to erythromycin.

Use of MALDI-TOF MS to Discriminate between Biofilm-Producer and Non-Producer Strains of Staphylococcus epidermidis.

For the management of Staphylococci coagulase-negative infection, often related to biofilm formation, rapid and accurate identification is necessary in choosing a correct antibiotic therapy. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is becoming increasingly important for bacterial identification over traditional methods. Our aim was to validate the use of MALDI to discriminate Staphylococcus epidermidis biofilm-producing strains. Clinical strains coming from suture wires were identified and their protein profiles were compared to that obtained from two ATCC reference strains (biofilm producer and non-producer). MALDI identified the eighteen isolates as S. epidermidis, combining sixteen profiles with the biofilm producer and two with the non-producer, confirming the results of crystal violet assay. Our data highlight that MALDI can be considered a good tool to discriminate between biofilm-producer and non-producer strains of S. epidermidis, thus helping to establish an effective antibiotic therapy.

Phytochemical study of Helichrysum italicum (Roth) G. Don: Spectroscopic elucidation of unusual amino-phlorogucinols and antimicrobial assessment of secondary metabolites from medium-polar extract.

Three unusual amino-phloroglucinols, named helichrytalicines A-C, along with seventeen known compounds including acetophenones, tremetrone derivatives, low-molecular weight phenols, flavonol glucosides, have been isolated from the medium-polar extract of Helichrysum italicum (Roth) G. Don, a medicinal plant typical of the Mediterranean vegetation. The structures of the compounds have been elucidated based on extensive 2D-NMR spectroscopic analyses, including COSY, TOCSY, HSQC, CIGAR-HMBC, H2BC and HSQC-TOCSY, along with Q-TOF HRMS2 analysis. Stereostructure of the new compounds has been elucidated by Mosher's method and NOESY experiment. Antimicrobial properties against Staphylococcus epidermidis of selected compounds have been evaluated.

Large Porous Particles for Sustained Release of a Decoy Oligonucelotide and Poly(ethylenimine): Potential for Combined Therapy of Chronic Pseudomonas aeruginosa Lung Infections.

We have recently demonstrated that the specific inhibition of nuclear factor-κB by a decoy oligonucleotide (dec-ODN) delivered through inhalable large porous particles (LPP) made of poly(lactic-co-glycolic acid) (PLGA) may be highly beneficial for long-term treatment of lung inflammation. Nevertheless, besides chronic inflammation, multifunctional systems aimed to control also infection are required in chronic lung diseases, such as cystic fibrosis (CF). In this work, we tested the hypothesis that engineering PLGA-based LPP with branched poly(ethylenimine) (PEI) may improve LPP properties for pulmonary delivery of dec-ODN, with particular regard to the treatment of Pseudomonas aeruginosa lung infections. After getting insight into the role of PEI on the technological properties of PLGA-based LPP for delivery of dec-ODN, the putative synergistic effect of PEI free or PEI released from LPP on in vitro antimicrobial activity of tobramycin (Tb) and aztreonam (AZT) against P. aeruginosa was elucidated. Meanwhile, cytotoxicity studies on A549 cells were carried out. Results clearly demonstrate that the dry powders have promising aerosolization properties and afford a prolonged in vitro release of both dec-ODN and PEI. The encapsulation of PEI into LPP results in a 2-fold reduction of the minimum inhibitory concentration of AZT, while reducing the cytotoxic effect of PEI. Of note, the developed ODN/PLGA/PEI LPP persisted at lung at least for 14 days after intratracheal administration in rats where they can provide sustained and combined release of dec-ODN and PEI. dec-ODN will likely act as an anti-inflammatory drug, while PEI may enhance the therapeutic activity of inhaled antibiotics, which are commonly employed for the treatment of concomitant lung infections.

Bacterial inactivation/sterilization by argon plasma treatment on contaminated titanium implant surfaces: In vitro study

BACKGROUND: Surface treatment by argon plasma is widely used as the last step of the manufacturing process of titanium implant fixtures before their sterilization by gamma rays. The possibility of using such a technology in the daily clinical practice is particularly fascinating. The aim of the present study was to assess the effects of the argon plasma treatment on different titanium implant surfaces previously exposed in vitro to bacterial contamination. MATERIAL AND METHODS: Sterile c.p. titanium implant discs with turned (T, Sa: 0.8ìm), sandblasted/acid-etched (SAE, Sa: 1.3ìm) and titanium plasma sprayed (TPS, Sa: 3.0ìm) surface were used in this study. A strain of Aggregatibacter actinomycetemcomitans ATCC3718 was grown at 37°C under anaerobic conditions for 24 h and then transferred on six discs for each of the three surface types. After 24 hours, a half of the contaminated discs (control group) were directly used to evaluate the colony forming units (CFUs). The other half of the contaminated discs (test group) were treated in an argon plasma chamber for 12 minutes at room temperature prior to be analyzed for CFU counting. All assays were performed using triplicate samples of each material in 3 different experiments. RESULTS: When the CFU counting was carried out on control discs, a total of 1.50x106 plus - minus1.4x105 , 1.55x106 plus - minus7.07x104 and 3.15x106 plus - minus2.12x105 CFU was respectively assessed for T, SAE and TPS discs, without statistically significant differences among the three surfaces. On the contrary, any trace of bacterial contamination was assessed for titanium discs treated in the argon plasma chamber prior to be analyzed, irrespectively to the implant surface tested. CONCLUSIONS: Within the limit of this study, reported data suggested that the argon plasma technology could be efficiently used to decontaminate/sterilize previously infected titanium implant surfaces

Bacterial inactivation/sterilization by argon plasma treatment on contaminated titanium implant surfaces: In vitro study.

BACKGROUND: Surface treatment by argon plasma is widely used as the last step of the manufacturing process of titanium implant fixtures before their sterilization by gamma rays. The possibility of using such a technology in the daily clinical practice is particularly fascinating. The aim of the present study was to assess the effects of the argon plasma treatment on different titanium implant surfaces previously exposed in vitro to bacterial contamination. MATERIAL AND METHODS: Sterile c.p. titanium implant discs with turned (T, Sa: 0.8µm), sandblasted/acid-etched (SAE, Sa: 1.3µm) and titanium plasma sprayed (TPS, Sa: 3.0µm) surface were used in this study. A strain of Aggregatibacter actinomycetemcomitans ATCC3718 was grown at 37°C under anaerobic conditions for 24 h and then transferred on six discs for each of the three surface types. After 24 hours, a half of the contaminated discs (control group) were directly used to evaluate the colony forming units (CFUs). The other half of the contaminated discs (test group) were treated in an argon plasma chamber for 12 minutes at room temperature prior to be analyzed for CFU counting. All assays were performed using triplicate samples of each material in 3 different experiments. RESULTS: When the CFU counting was carried out on control discs, a total of 1.50x106±1.4x105, 1.55x106±7.07x104 and 3.15x106±2.12x105 CFU was respectively assessed for T, SAE and TPS discs, without statistically significant differences among the three surfaces. On the contrary, any trace of bacterial contamination was assessed for titanium discs treated in the argon plasma chamber prior to be analyzed, irrespectively to the implant surface tested. CONCLUSIONS: Within the limit of this study, reported data suggested that the argon plasma technology could be efficiently used to decontaminate/sterilize previously infected titanium implant surfaces.

In vitro growth versus inhibition of growth of Malassezia pachydermatis in the presence of the antibacterial drug gentamicin.

Malassezia pachydermatis is part of the normal cutaneous microbiota of most warm-blooded vertebrates and is associated with otitis externa and seborrhoeic dermatitis in dogs and cats. In this study, we evaluated the growth capacity of nine M. pachydermatis strains on Sabouraud medium in the presence of a high concentration of gentamicin. Strains of M. pachydermatis cultured on Sabouraud medium in the presence of 50 and 100 µg gentamicin ml(-1) displayed different growth patterns such as growth or lack of growth. We hypothesized that this difference in growth of M. pachydermatis strains was correlated with the different genotypes of the strains. Random amplification of polymorphic DNA (RAPD) was applied for genetic typing of M. pachydermatis isolates, derived from the external ears of house pet cats suffering from otitis externa. The M. pachydermatis strains were cultured on commercial or home-made Sabouraud medium supplemented or not with gentamicin. RAPD analysis demonstrated a genetic heterogeneity between each strain. In particular, five out of nine strains tested were able to form colonies in the presence of gentamicin. However, a correlation between M. pachydermatis genotype and growth capacity in the presence of gentamicin was not widely demonstrated.