Infectious complications of transrectal prostate biopsy in patients receiving targeted antibiotic prophylaxis after urethral and rectal swab versus standard prophylaxis: A prospective comparative study.

Background: To evaluate the role of targeted antibiotic prophylaxis (TAP) after rectal and urethral swab cultures compared to empiric antibiotic prophylaxis (EAP) for the prevention of infectious complications after transrectal ultrasound-guided prostate biopsy (TRUS-Bx). Methods: We conducted a prospective comparative study on 141 patients who underwent TRUS-Bx and were allocated in two groups. The first group (n = 71) received EAP with ciprofloxacin and the second (n = 70) received TAP according to rectal and urethral cultures. Post-biopsy infectious complications rates were compared between the two groups. Fluoroquinolone resistance (FQ-R) in the urethral and rectal swabs was recorded. Baseline characteristics were analyzed to assess their relationship with infectious complications and antibiotic resistance. Results: A total of 8 infectious complications were observed, 7 of them in the EAP group (9.85%) and 1 in the TAP group (1.4%). There was a statistically significant difference in febrile UTIs between the two groups (6 vs 0, P = 0.028). FQ-R rate was 4.3% and 12.9% for rectal and urethral samples, respectively. Recent antibiotic exposure was associated with higher post-biopsy infection rates for EAP group and FQ-R rates for TAP group. Conclusion: Combination of rectal and urethral swab cultures for TAP was able to detect FQ-R bacteria carriers and was associated with fewer infectious complications compared to EAP.

Intensity of Humoral Immune Responses, Adverse Reactions, and Post-Vaccination Morbidity after Adenovirus Vector-Based and mRNA Anti-COVID-19 Vaccines.

The aim of the study was to compare mRNA vaccine BNT162b2 with adenovirus vector- based vaccines in terms of presence of adverse reactions, immunogenicity, and protection against COVID-19. A total of 270 individuals were enrolled, of which 135 were vaccinated with adenovirus vector-based vaccines and compared with 135 age- and sex-matched participants who received the BNT162b2 mRNA vaccine. Serum sampling was performed on all participants on days 21, 42, 90, and 180 following the first dose, to evaluate anti-spike IgG and IgA responses. Antibodies were quantified by chemiluminescent microplate and ELISA assays. We demonstrate that both mRNA and adenovirus vector-based vaccines caused mild side-effects and were effective in inducing adequate antibody responses against SARS-CoV-2, although BNT162b2 was superior concerning the intensity of antibody responses and protection against severe COVID-19. Moreover, we identify that IgG and IgA responses depended primarily on both history of previous COVID-19 infection and vaccination platform used, with individuals immunized with a single-dose vaccine having lower antibody titers over time. Lastly, all vaccine platforms had limited side-effects, with the most frequent pain at the injection site. Our results provide useful information regarding antibody responses after vaccination with different vaccine platforms, which can be useful for public health vaccination strategies.

In vitro Inhibition of Biofilm Formation on Silicon Rubber Voice Prosthesis: Α Systematic Review and Meta-Analysis.

INTRODUCTION: Biofilm formation on voice prostheses is the primary reason for their premature implant dysfunction. Multiple strategies have been proposed over the last decades to achieve inhibition of biofilm formation on these devices. The purpose of this study was to assess the results of the available in vitro biofilm inhibition modalities on silicone rubber voice prostheses. METHODS: We conducted a systematic search in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases up to February 29, 2020. A total of 33 in vitro laboratory studies investigating the efficacy of different coating methods against Candida, Staphylococcus, Streptococcus, Lactobacilli, and Rothia biofilm growth on silicone rubber medical devices were included. Subgroup analysis linked to the type of prevention modality was carried out, and quality assessment was performed with the use of the modified CONSORT tool. RESULTS: Data from 33 studies were included in qualitative analysis, of which 12 qualified for quantitative analysis. For yeast biofilm formation assessment, there was a statistically significant difference in favor of the intervention group (standardized mean difference [SMD] = -1.20; 95% confidence interval [CI] [-1.73, -0.66]; p < 0.0001). Subgroup analysis showed that combined methods (active and passive surface modification) are the most effective for biofilm inhibition in yeast (SMD = -2.53; 95% CI [-4.02, -1.03]; p = 0.00001). No statistically significant differences between intervention and control groups were shown for bacterial biofilm inhibition (SMD = -0.09; 95% CI [-0.68, 0.46]; p = 0.65), and the results from the subgroup analysis found no notable differences between the surface modification methods. After analyzing data on polymicrobial biofilms, a statistically significant difference in favor of prevention methods in comparison with the control group was detected (SMD = -2.59; 95% CI [-7.48, 2.31]; p = 0.30). CONCLUSIONS: The meta-analysis on biofilm inhibition demonstrated significant differences in favor of yeast biofilm inhibition compared to bacteria. A stronger inhibition with the application of passive or combined active and passive surface modification techniques was reported.

Molecular Basis of Resistance to First-Line Drugs of Mycobacterium tuberculosis/canettii Strains in Greece.

The aim of this study was to determine the rate and the mutations of genes involved to the first-line antituberculous drugs' resistance of M. tuberculosis/canettii isolated in Central Greece from 2010 to 2019. During the study period, the rate of resistance to isoniazid, rifampicin, ethambutol, and pyrazinamide was 5.4%, 0.4%, 1.1%, and 1.1%, respectively. All phenotypically resistant isolates (14 to isoniazid, 3 to ethambutol, 3 to pyrazinamide, and 1 to rifampicin) and 17 susceptible isolates (control group) were tested for the presence of mutations/alterations/polymorphisms by PCR followed by sequencing analysis. The molecular typing of isolates was based on multispacer sequence typing. Despite the phenotypic resistance, mutations were detected in 13 of 21 isolates (11 isoniazid resistant, 1 rifampicin, and 1 pyrazinamide resistant). Four isoniazid-resistant strains carried the most common mutations S315T and C-15T, whereas the remaining seven isolates carried either less known (E399, A162, W477STOP, S94A, G-48A, C-54T, C-17T, L203, A196, S124, and K367) or novel (D74N, G691S, Ains-85, and D171G); none of the susceptible strains was found to be positive for any novel mutation. The two single rifampicin- and pyrazinamide-resistant strains carried the known mutations S450L (also referred as S531L) and L182W, respectively. The presence of uncommon or novel mutations conferring resistance to isoniazid (INH) creates a diagnostic problem in the routine microbiological laboratory, since commercial methods are focused on the detection of the most common mechanisms of resistance (S315T, C-15T, A-16G, T-8C, and T-8A), therefore, fail to detect such strains. The regional differences in the frequencies of mutations associated with resistance to the first-line drugs provide hints for the development of better molecular-based diagnostic tests.

Microorganisms involved in deep neck infection (DNIs) in Greece: detection, identification and susceptibility to antimicrobials.

BACKGROUND: To determine, from October 2010 to October 2018, the epidemiology of Deep Neck Infections (DNIs), regarding the detection, the identification and the susceptibility to antimicrobials of causative microorganisms, in Thessaly-Central Greece. METHODS: An analysis of data from a prospective database was conducted on 610 consecutive patients with DNIs treated in the Otolaryngology / Head & Neck Surgery Department of University Hospital of Larissa. Demographics, clinical features and microbiological data were analyzed. RESULTS: Among the 610 patients (1,9/1 male to female ratio, mean age: 39,24 ± 17,25) with DNIs, 579 had a single space (94,9%), while the remaining 31 had a multi-space (5,1%) DNI. The most common areas affected were the peritonsillar space (84,6%) followed by the submandibular space (6,5%). Clinical samples were obtained from 462 patients, and were tested by culture and by the application of 16S rRNA PCR. Two hundred fifty-five samples (55,2%) gave positive cultures, in which Streptococcus pyogenes and Staphylococcus aureus were predominant. The application of the 16S rRNA PCR revealed that 183 samples (39,6%) were positive for bacterial DNA; 22 of them, culture negative, were found to be positive for anaerobic (Fusobacterium necrophorum, Actinomyces israellii etc) and for fastidious microorganisms (Brucella mellitensis, Mycobacterium avium). CONCLUSION: DNIs represent a medical and surgical emergency and evidence-guided empirical treatment with intravenous infusion of antibiotics at the time of diagnosis is mandatory, highlighting the importance of epidemiological studies regarding the causative microorganisms. Although, in our study, the predominant pathogens were S. pyogenes and S. aureus, the combination of culture and molecular assay revealed that anaerobic bacteria play also a significant role in the pathogenesis of DNIs. Based on the local epidemiology, we propose as empirical therapy the intravenous use of a beta-lactam /beta-lactamase inhibitor; metronidazole or clindamycin can be added only in specific cases such as in immunocompromised patients.

Implementation of the Rapid Polymyxin™ NP test directly to positive blood cultures bottles.

The present study assessed the performance of Rapid Polymyxin™ NP test to detect colistin resistance directly from 132 blood cultures found positive for Enterobacterales by FilmArray. Additionally, colistin MICs of isolated microorganisms were determined by the commercial broth microdilution method ComASP™ Colistin, used as the gold standard comparator. The Rapid Polymyxin™ NP test correctly detected all colistin-resistant isolates. However, the test has misidentified as resistant 4 colistin-susceptible isolates (1 Escherichia coli and 3 Klebsiella pneumoniae). Molecular characterization of colistin-resistant isolates showed that K. pneumoniae, which belonged to ST15 and ST147, carried alterations in the mgrB. Moreover, the first Greek mcr-1-positive colistin-resistant E. coli was detected. The rapidity (2-3 h) of the results, combined with its excellent negative predictive value (100%), allows implementation of the test for routine testing of blood cultures mainly in the clinical settings that are endemic for carbapenem-resistant bacteria, avoiding misuse of colistin and preventing the spread of colistin-resistant bacteria.

Predisposing factors for bacterial mastitis in ewes.

Objective of this review paper is the appraisal of predisposing factors for bacterial mastitis in ewes. Factors that predispose ewes to mastitis can be classified into non-animal-related factors (environmental and climatological factors, housing, nutrition, milking practices) and animal-related factors (anatomic, genetic, litter size-ethological factors, number and stage of lactation period, health problems). There are clear management-environment-animal interactions in mastitis development in ewes, which underline its multifactorial nature. Research and studies regarding risk factors are important, in order to develop strategies for their elimination, control or correction. Control measures for bacterial mastitis, which attempt to eliminate predisposing factors for infection, can thus be developed and implemented.

Antimicrobial Agent Susceptibility and Typing of Staphylococcal Isolates from Subclinical Mastitis in Ewes.

Objective was to study susceptibility to antimicrobial agents of 142 staphylococcal isolates from subclinical mastitis in ewes. In total, 41.5% of these were resistant and 5.6% multidrug resistant. More coagulase-negative staphylococci (47.0%) were resistant than Staphylococcus aureus (18.5%) isolates. Resistance was greater to penicillin (22.5%), tetracycline, or ampicillin (18.3%). More biofilm-forming (20.6%) isolates were resistant to tetracycline than nonbiofilm-forming (0.0%) ones. Presence of tetK was associated with presence of icaA in the same strains. Further, 76.6% of resistant isolates versus 57.7% of susceptible ones were recovered immediately postpartum and 23.4% of resistant isolates versus 9.9% of susceptible ones were recovered in farms that practiced routine administration of antimicrobial agents at the end of a lactation period. Most S. aureus (59.3%) were classified in ST133 and most Staphylococcus epidermidis were classified in ST100, ST142, or ST152 (19.0% each). There was no association of sequence types with resistance. Whole genome sequencing showed that, in a Staphylococcus lentus strain, the ermB gene was part of transposon Tn917 integrated into the chromosome; also, a small plasmid was observed in an ermC-carrying Staphylococcus hominis strain and, finally, in an S. aureus and an S. epidermidis strains, small tetK-carrying plasmids (pSau-2716Lar, pSau-3893Lar) of 4.439 kb were found.

Septic shock due to Candida famata (Debaryomyces hansenii) candidemia in an ICU immunocompetent trauma-patient.

Sepsis related to Candida famata (C. famata) fungemia is extremely rare in immunocompetent patients. Moreover, septic shock has not been reported due to this yeast. A previously healthy young multi-trauma male, presented septic shock from C. famata, after he had been admitted in the Intensive Care Unit (ICU) due to haemorrhagic shock. Risk factors for candidemia in ICU patients are the presence of a central venous catheter (CVC), Total Parenteral Nutrition (TPN), use of broad-spectrum antimicrobials, immunosuppression and the length of ICU stay. The presence of CVCs, prior use of antibiotics, prolonged hospitalization, disruption of skin flora and immunocompromised states have been identified as predisposing risk factors for C. famata fungemia. It is worth noting that the present case concerns a non-immunocompromised patient, but long ICU stay and brain injury may indicate a state of immunoparalysis. Identification of the yeast was performed by partial amplification and sequencing of the 26S ribosomal DNA gene [hypervariable region D1/D2; partial sequencing of the act1 gene confirmed the identity of the strain as Debaryomyces hansenii (GenBank submission ID: 1688297)] The patient quickly recovered from sepsis after initiation of amphotericin B and was discharged on the 60th day.

MLSB-Resistant Staphylococcus aureus in Central Greece: Rate of Resistance and Molecular Characterization.

The aim of the present study was to determine the rate and mechanisms of resistance to macrolides, lincosamides, and streptogramin B (MLSB) antibiotics of Staphylococcus aureus collected in Central Greece. Of the 2,893 S. aureus collected during 2012-2017, 1,161 isolates (40.2%) exhibited resistance to at least one of the MLSB agents. The rate of erythromycin resistance was statistically significantly higher in methicillin-resistant S. aureus (MRSA) (58.6%) than in methicillin-sensitive S. aureus (MSSA) isolates (20.7%) (p = 0.002). Two hundred seventy-five representative MLSB-resistant S. aureus, including 81 MSSA and 194 MRSA isolates, were further studied. Thirty-eight MSSA isolates carried ermC, 26 MSSA were positive for ermA, whereas 17 isolates carried msrA gene. Among MRSA, the ermA gene was identified in the majority of the isolates (n = 153). Thirty-seven MRSA isolates carried ermC; three isolates carried msrA, whereas the remaining MRSA was positive for two genes (ermA and ermC). Phylogenetic analysis showed that ST225, which belongs to CC5, was the most prevalent, accounting for 137 MRSA isolates. Higher genetic diversity was found in the group of MSSA isolates, which comprised of 13 sequence types. Whole-genome sequencing data showed that all ermA-positive S. aureus, with the exception of one ST398 isolate, harbored the ermA-carrying Tn554 transposon integrated into their chromosomes. Furthermore, Illumina sequencing followed by polymerase chain reaction screening identified that ermC, which was identified in a polyclonal population of MSSA and MRSA isolates, was carried by small plasmids, like pNE131. These findings highlighted the important role of high-risk clones and of mobile elements carrying resistance genes in the successful dissemination of MLSB-resistant staphylococci.

Colistin versus Colistin Combined with Ampicillin-Sulbactam for Multiresistant Acinetobacter baumannii Ventilator-associated Pneumonia Treatment: An Open-label Prospective Study.

BACKGROUND: Retrospective studies have reported good clinical success rates using colistin as monotherapy to treat Acinetobacter baumannii ventilator-associated pneumonia (VAP), comparable to that obtained with colistin combined with other antibiotics. However, inadequate penetration into the pulmonary parenchyma for colistin has been shown in animal models. AIM: The aim of the study was to study prospectively the outcome, measured as clinical response and survival, of intravenously administered colistin versus colistin combined with high-dose ampicillin-sulbactam in Intensive Care Unit (ICU) patients with multiresistant A. baumannii VAP. METHODS AND SUBJECTS: This prospective, open-label, randomized study included consecutive patients who developed microbiologically documented VAP due to A. baumannii with carbapenem-resistant strains but susceptible to colistin and ampicillin-sulbactam. Seventy-four patients were screened, but finally, 39 participants were enrolled and finished the study Patients received colistin (Group A - 19 patients) or colistin and ampicillin/sulbactam (Group B - 20 patients). The clinical response of VAP was assessed on day 4th to 5th of treatment (early response). If therapy was considered unsuccessful after this period, ampicillin/sulbactam was added in Group A or changed therapy in B. RESULTS: Early cure rates in Group A and B were 15.8% and 70%, respectively (P = 0.001). Multiple regression analysis revealed that combination treatment (odds ratio [OR]: 43.6, 95% confidence interval [CI]: 3.594-530.9) and Sequential Organ Failure Assessment score <8 (OR: 0.022, 95% CI: 0.001-0.43) were independently associated with favorable clinical response. APACHE II score ≤15 (OR: 0.049, 95% CI: 0.003-0.0942) and an early favorable response to treatment (OR: 244.4, 95% CI: 2.151-27850.9) were associated with survival and discharge from ICU. CONCLUSION: Combination therapy with colistin and a high dose of ampicillin/sulbactam was associated with a more favorable clinical response to VAP due to carbapenem-resistant A. baumannii than colistin monotherapy.

First Description in Greece of mphC-Positive Staphylococci Causing Subclinical Mastitis in Ewes.

The aim of the present study was to describe the first mphC-positive staphylococci, including two Staphylococcus lentus (Sle-087lar and Sle-091lar) and one Staphylococcus xylosus (Sxy-228lar), isolated from samples of animal origin, in Greece. Isolates Sle-087lar and Sxy-228lar were resistant to erythromycin, whereas Sle-091lar was resistant to erythromycin and lincomycin. All three isolates were susceptible to the remaining antibiotics. PCR screening showed that isolate Sle-091lar carried also ermB. For Sxy-228lar, whole-genome sequencing (WGS) and de novo assembly obtained an mphC-positive contig of 57.3-kb exhibiting high similarity with the genome of mphC-negative S. xylosus S170. However, mphC of Sxy-228lar was 91% similar to that found in plasmid pJW2311 from S. xylosus JW2311. Additionally, WGS data showed that Sle-087lar and Sle-091lar harbored mphC-carrying sequences being highly similar to the recently announced genome of the mphC-carrying S. lentus isolate 050AP from Tanzania. However, differences were observed in the mphC environment, suggesting the independent acquisition of the gene by each isolate. Sle-091lar also harbored transposon Tn917, which carries ermB resistance gene, integrated into S. lentus chromosome. These findings indicated that acquisition of resistance genes can lead to the emergence of multiresistant staphylococci, causing animal infections with economic burden.

Brucella Melitensis As Causative Agent for Neck Abscess in an Endemic Area.

BACKGROUND: Brucellosis, a zoonotic disease, is very common in the Mediterranean basin and a major concern in livestock areas. We present a rare case of a Brucella-caused abscess in the neck of a stock-breeder in an endemic Greek area. CASE REPORT: A 39-year-old male, living in the rural area of Thessaly, presented with a mass in the left area of his neck. Clinical examination and imaging tests revealed an abscess in the left sternocleidomastoid muscle. Sampling of the abscess by fine-needle aspiration yielded inflammatory fluid (17x103 cells/µL). Molecular sequencing (16S rRNA polymerase chain reaction) performed directly in the clinical sample identified the presence of Brucella melitensis within 24 hours after material sampling. The microorganism was isolated in agar media four days later. The Rose-Bengal test was negative, while the Brucellacapt test showed titer 1/320. Given the results obtained with these molecular techniques, the patient was offered treatment with streptomycin (1 g for 3 weeks) and oral doxycycline (100 mg twice daily for 6 weeks), concurrently. CONCLUSION: In areas endemic for brucellosis, the investigation of a patient with a neck abscess should include Brucella spp. among possible causative agents.

Isolation and identification of nontuberculous mycobacteria from hospitalized patients and drinking water samples--examination of their correlation by chemometrics.

Nontuberculous mycobacteria (NTM) have been found to be widely dispersed in the environment and are being considered potentially pathogenic for humans and animals, while reports of their human to human transmission are absent. Water and aerosols are potential transmission modes of NTM to humans. Hospitalized patients with NTM infections were studied together with drinking water samples from their respective residence areas during 2003-2013. Cluster analysis and factor analysis were used to analyze the data matrix. A total of 367 hospitalized patients living in 30 localities in the Prefecture of Larissa were tested positive for NTM. The most frequently isolated NTM species of the 383 NTM isolates from the clinical specimens were Mycobacterium fortuitum (n = 118, 30.8 %), M. gordonae (n = 87, 22.7 %), M. peregrinum (n = 46, 12.0 %), M. chelonae (n = 11, 2.9 %), M. avium (n = 8, 2.1 %), and M. intracellulare (n = 7, 1.8 %), while 88 (23.0 %) of these isolates were not identified. It is noted that in 8 patients, M. tuberculosis was isolated simultaneously with one NTM, in 15 patients, together with two types of NTM, while in 1 patient, it was found at the same time as three different NTM. In addition, 3360 drinking water samples were collected from 30 localities and analyzed during 2010 to 2013; they were found 11.2 % NTM positive. Cluster analysis and factor analysis results confirm that NTM strains are correlated to each other in both isolated samples from patients and drinking water, while the strength of their correlation varied from weak to moderate (e.g., factor loadings ranged from 0.69 to 0.74 when all data are considered). These results provide indications that drinking water could be linked with NTM cases in humans.

Confronting carbapenemase-producing Klebsiella pneumoniae.

The ongoing spread of carbapenemase-producing (CP) multidrug-resistant enterobacteria, primarily Klebsiella pneumoniae, has undoubtedly caused a public health crisis of unprecedented dimensions. The scientific community has been struggling with these highly problematic nosocomial pathogens for more than a decade. Faced with the current situation, one cannot help but wish we could have done better, earlier. However, significant steps have been and are currently being made towards a better understanding of transmission routes of CP microorganisms and in designing strategies that could effectively curb this devastating epidemic. Most importantly, the systematic evaluation of accumulating experimental and clinical data has paved the way to a more rational management of CP-infected patients. In addition, systematic efforts of the industry have led to the development of novel antibacterial agents that are active against CP strains and expected to be introduced to clinical practice in the immediate future.

Interactions of oximino-substituted boronic acids and ß-lactams with the CMY-2-derived extended-spectrum cephalosporinases CMY-30 and CMY-42.

CMY-30 and CMY-42 are extended-spectrum (ES) derivatives of CMY-2. ES characteristics are due to substitutions of Gly (CMY-30) and Ser (CMY-42) for Val211 in the Ω-loop. To characterize the effects of 211 substitutions, we studied the interactions of CMY-2, -30, and -42 with boronic acid transition state inhibitors (BATSIs) resembling ceftazidime and cefotaxime, assessed thermal stability of the enzymes in their free forms and in complexes with BATSIs and oximino-ß-lactams, and simulated, using molecular dynamics (MD), the CMY-42 apoenzyme and the CMY-42 complexes with ceftazidime and the ceftazidime-like BATSI. Inhibition constants showed that affinities between CMY-30 and CMY-42 and the R1 groups of BATSIs were lower than those of CMY-2. ES variants also exhibited decreased thermal stability either as apoenzymes or in covalent complexes with oximino compounds. MD simulations further supported destabilization of the ES variants. Val211Ser increased thermal factors of the Ω-loop backbone atoms, as previously observed for CMY-30. The similar effects of the two substitutions seemed to be due to a less-constrained Tyr221 likely inducing concerted movement of elements at the edges of the active site (Ω-loop-Q120 loop-R2 loop/H10 helix). This inner-protein movement, along with the wider R1 binding cleft, enabled intense vibrations of the covalently bound ceftazidime and ceftazidime-like BATSIs. Increased flexibility of the ES enzymes may assist the productive adaptation of the active site to the various geometries of the oximino substrates during the reaction (higher frequency of near-attack conformations).