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Seyyed Askhan Senobar Tahaei,1 Anette Stájer,2 Ibrahim Barrak,2 Eszter Ostorházi,3 Dóra Szabó,3 Márió Gajdács1,3 1Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Szeged, 6720, Hungary; 2Department of Periodontology, Faculty of Dentistry, University of Szeged, Szeged, 6720, Hungary; 3Institute of Medical Microbiology, Faculty of Medicine, Semmelweis University, Budapest, 1089, HungaryCorrespondence: Márió Gajdács Tel +36 62-341-330Email gajdacs.mario@szte.huIntroduction: Staphylococcus aureus (S. aureus) is an important causative pathogen in human infections. The production of biofilms by bacteria is an important factor, leading to treatment failures. There has been significant interest in assessing the possible relationship between the multidrug-resistant (MDR) status and the biofilm-producer phenotype in bacteria. The aim of our present study was to assess the biofilm-production rates in clinical methicillin-susceptible S. aureus [MSSA] and methicillin-resistant S. aureus [MRSA] isolates from Hungarian hospitals and the correlation between resistance characteristics and their biofilm-forming capacity.Methods: A total of three hundred (n=300) S. aureus isolates (corresponding to MSSA and MRSA isolates in equal measure) were included in this study. Identification of the isolates was carried out using the VITEK 2 ID/AST system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method and E-tests, confirmation of MRSA status was carried out using PBP2a agglutination assay. Biofilm-production was assessed using the crystal violet (CV) tube-adherence method and the Congo red agar (CRA) plate method.Results: There were significant differences among MSSA and MRSA isolates regarding susceptibility-levels to commonly used antibiotics (in case of erythromycin, clindamycin and ciprofloxacin: p< 0.001, gentamicin: p=0.023, sulfamethoxazole/trimethoprim: p=0.027, rifampin: p=0.037). In the CV tube adherence-assay, 37% (n=56) of MSSA and 39% (n=58) of MRSA isolates were positive for biofilm-production, while during the use of CRA plates, 41% (n=61) of MSSA and 44% (n=66) of MRSA were positive; no associations were found between methicillin-resistance and biofilm-production. On the other hand, erythromycin, clindamycin and rifampin resistance was associated with biofilm-positivity (p=0.004, p< 0.001 and p< 0.001, respectively). Biofilm-positive isolates were most common from catheter-associated infections.Discussion: Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of implant-associated and chronic S. aureus infections.Keywords: Staphylococcus aureus, MSSA, MRSA, biofilm, antibiotic resistance, crystal violet, Congo red agar, phenotypic assay

The microbiota isolated from the urine of bladder carcinoma patients exhibits significantly increased compositional abundance of some bacterial genera compared to the urine of healthy patients. Our aim was to compare the microbiota composition of cancerous tissues and urine samples collected from the same set of patients in order to improve the accuracy of diagnostic measures. Tissue samples were collected from patients during cancer tissue removal by transurethral resection. In parallel, urine samples were obtained by transurethral resectoscopy from the same patients. The V3–V4 region of the bacterial 16S rRNA gene was sequenced and analyzed using the Kraken pipeline. In the case of four patients, duplicate microbiota analysis from distant parts of the cancerous tissues was highly reproducible, and independent of the site of tissue collection of any given patient. Akkermansia, Bacteroides, Clostridium sensu stricto, Enterobacter and Klebsiella, as “five suspect genera”, were over-represented in tissue samples compared to the urine. To our knowledge, this is the first study comparing urinary and bladder mucosa-associated microbiota profiles in bladder cancer patients. More accurate characterization of changes in microbiota composition during bladder cancer progression could provide new opportunities in the development of appropriate screening or monitoring methods.

Absztrakt: Bevezetés: 2020. március végén a SARS-CoV-2-vírusfertőzöttség (COVID–19-betegség) diagnosztizálására megjelentek Magyarországon a vírussal szembeni specifikus antitestek jelenlétét kimutató gyorstesztek. Célkitűzés: Munkánkban két gyorsteszt, az Anhui és a Clungene teszt diagnosztikai teljesítményét értékeltük a fertőzés kimutatásában arany standardnak számító ’real-time’ (valós idejű) PCR (a továbbiakban: PCR) vizsgálati eredmények alapján. Módszer: 2020. március 16. és április 14. között intézetünk 20 120, COVID–19-fertőzéssel kapcsolatos rekordot küldött be az országos adatszolgáltató rendszeren keresztül. Ebben 4140 személynél csak IgM és IgG jelenlétét kimutató gyorstesztvizsgálat történt; 3210 személynél csak PCR-teszt, 1654 személynél pedig PCR- és gyorstesztvizsgálat (Anhui: 625, Clungene: 1029) végzésére maximum 3 nap eltéréssel is sor került. PCR-pozitívnak azt a személyt tekintettük, akinél bármikor PCR-pozitivitás fordult elő, illetve antitestpozitívnak azt, akinél IgM- és/vagy IgG-pozitivitást észleltünk. (Megjegyzés: a Clungene tesztet Lungene néven is forgalmazzák.) Eredmények: A 4864, PCR-rel vizsgált személy közül 308 volt PCR-pozitív (a PCR-pozitivitás prevalenciája 6,3% volt). A PCR alapján az Anhui gyorsteszt szenzitivitása 33,3%, specificitása 72,85%; a Clungene gyorsteszt szenzitivitása 35,48%, specificitása 85,02% volt. 6%-os PCR-pozitivitási prevalencia esetén a pozitív és a negatív prediktív érték az Anhui gyorsteszt esetében 7,28%, illetve 94,48%, míg a Clungene gyorsteszt esetében 13,13%, illetve 95,38% volt. Következtetés: Az aktuális fertőzöttségi prevalencia melletti alacsony pozitív prediktív értékek alapján az általunk értékelt gyorstesztek jelenleg nem alkalmasak a SARS-CoV-2-vírusfertőzöttség (PCR-pozitivitás) kimutatására az általános populációban. Az Anhui és a Clungene gyorstesztek negatív eredményei a jelenlegi 6%-os prevalencia mellett mintegy 95%-os valószínűséggel jelzik a SARS-CoV-2-vírusexpozíció hiányát. Az Anhui és a Clungene – SARS-CoV-2 vírus elleni IgM- és IgG-antitesteket kimutató – gyorstesztek alkalmazása a COVID–19-fertőzés differenciáldiagnosztikájában szakmailag vállalhatatlan. Orv Hetil. 2020; 161(20): 807–812.

Various dimeric derivatives of the glycopeptide antibiotic teicoplanin were prepared with the aim of increasing the activity of the parent compound against glycopeptide-resistant bacteria, primarily vancomycin-resistant enterococci. Starting from teicoplanin, four covalent dimers were prepared in two orientations, using an α,ω-bis-isothiocyanate linker. Formation of a dimeric cobalt coordination complex of an N-terminal L-histidyl derivative of teicoplanin pseudoaglycone has been detected and its antibacterial activity evaluated. The Co(III)-induced dimerization of the histidyl derivative was demonstrated by DOSY experiments. Both the covalent and the complex dimeric derivatives showed high activity against VanA teicoplanin-resistant enterococci, but their activity against other tested bacterial strains did not exceed that of the monomeric compounds.

Pleuromutilin is a fungal diterpene natural product with antimicrobial properties, semisynthetic derivatives of which are used in veterinary and human medicine. The development of bacterial resistance to pleuromutilins is known to be very slow, which makes the tricyclic diterpene skeleton of pleuromutilin a very attractive starting structure for the development of new antibiotic derivatives that are unlikely to induce resistance. Here, we report the very first synthetic modifications of pleuromutilin and lefamulin at alkene position C19–C20, by two different photoinduced addition reactions, the radical thiol-ene coupling reaction, and the atom transfer radical additions (ATRAs) of perfluoroalkyl iodides. Pleuromutilin were modified with the addition of several alkyl- and aryl-thiols, thiol-containing amino acids and nucleoside and carbohydrate thiols, as well as perfluoroalkylated side chains. The antibacterial properties of the novel semisynthetic pleuromutilin derivatives were investigated on a panel of bacterial strains, including susceptible and multiresistant pathogens and normal flora members. We have identified some novel semisynthetic pleuromutilin and lefamulin derivatives with promising antimicrobial properties.

The protracted global COVID-19 pandemic urges the development of new drugs against the causative agent SARS-CoV-2. The clinically used glycopeptide antibiotic, teicoplanin, emerged as a potential antiviral, and its efficacy was improved with lipophilic modifications. This prompted us to prepare new lipophilic apocarotenoid conjugates of teicoplanin, its pseudoaglycone and the related ristocetin aglycone. Their antiviral effect was tested against SARS-CoV-2 in Vero E6 cells, using a cell viability assay and quantitative PCR of the viral RNA, confirming their micromolar inhibitory activity against viral replication. Interestingly, two of the parent apocarotenoids, bixin and β-apo-8′carotenoic acid, exerted remarkable anti-SARS-CoV-2 activity. Mechanistic studies involved cathepsin L and B, as well as the main protease 3CLPro, and the results were rationalized by computational studies. Glycopeptide conjugates show dual inhibitory action, while apocarotenoids have mostly cathepsin B and L affinity. Since teicoplanin is a marketed antibiotic and the natural bixin is an approved, cheap and widely used red colorant food additive, these readily available compounds and their conjugates as potential antivirals are worthy of further exploration.

Ten analogues of a teicoplanin pseudoaglycon derivative have been synthesized with the aim of optimizing the in vitro activity of the compound against VanA type vancomycin resistant enterococci (VRE) isolated from hospitalized patients. Teicoplanin, vancomycin, and oritavancin were used as reference antibiotics for the antibacterial evaluations. One of the new derivatives exhibited far superior activity than the original compound. The in vitro MICs measured were comparable to that of oritavancin against the investigated VRE strains.

Great efforts have been made to limit the transmission of carbapenemase-producing Enterobacteriaceae (CPE), however, the intestinal reservoir of these strains and its modulation by various antibiotics remain largely unexplored. Our aim was to assess the effects of antibiotic administration (ampicillin, ceftazidime, ciprofloxacin) on the establishment and elimination of intestinal colonization with a CTX-M-15 ESBL and OXA-162 carbapenemase producing Klebsiella pneumoniae ST15 (KP5825) in a murine (C57BL/6 male mice) model. Whole genome sequencing of KP5825 strain was performed on an Illumina MiSeq platform. Conjugation assays were carried out by broth mating method. In colonization experiments, 5 × 106 CFU of KP5825 was administered to the animals by orogastric gavage, and antibiotics were administered in their drinking water for two weeks and were changed every day. The gut colonization rates with KP5825 were assessed by cultivation and qPCR. In each of the stool samples, the gene copy number of blaOXA-162 and blaCTX-M-15 were determined by qPCR. Antibiotic concentrations in the stool were determined by high pressure liquid chromatography and a bioanalytical method. The KP5825 contained four different plasmid replicon types, namely IncFII(K), IncL, IncFIB and ColpVC. IncL (containing the blaOXA-162 resistance gene within a Tn1991.2 genetic element) and IncFII(K) (containing the blaCTX-M-15 resistance gene) plasmids were successfully conjugated. During ampicillin and ceftazidime treatments, colonization rate of KP5825 increased, while, ciprofloxacin treatments in both concentrations (0.1 g/L and 0.5 g/L) led to significantly decreased colonization rates. The gene copy number blaOXA-162 correlated with K. pneumoniae in vivo, while a major elevation was observed in the copy number of blaCTX-M-15 from the first day to the fifteenth day in the 0.5 g/L dose ceftazidime treatment group. Our results demonstrate that commonly used antibiotics may have diverse impacts on the colonization rates of intestinally-carried CPE, in addition to affecting the gene copy number of their resistance genes, thus facilitating their stable persistance and dissemination.

Gastrointestinal carriage of multidrug-resistant (MDR) bacteria is one of the main risk factors for developing serious, difficult-to-treat infections. Given that there is currently no all-round solution to eliminate colonization with MDR bacteria, it is particularly important to understand the dynamic process of colonization to aid the development of novel decolonization strategies. The aim of our present study was to perform metataxonomic analyses of gut microbiota dynamics during colonization with an extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Klebsiella pneumoniae (ECKP) strain in mice, additionally, to ascertain the effects of antibiotic administration (ampicillin, ceftazidime, and ciprofloxacin) on the establishment and elimination of ECKP intestinal colonization. We have found that the phyla Bacteroidetes and Firmicutes were most dominant in all of the treatment groups, however, Bacteroidetes was more common in the groups treated with antibiotics compared to the control group. Significant differences were observed among the different antibiotic-treated groups in beta but not alpha diversity, implying that the difference is the relative abundance of some bacterial community members. Bacteria from the Lachnospiraceae family (including Agathobacter, Anaerostipes, Lachnoclostridium 11308, Lachnospiraceae UCG-004, Lachnospiraceae NK3A20 group 11318, Lachnospiraceae NK4A136 group 11319, Roseburia, and Tyzzerella) showed an inverse relationship with the carriage rate of the ECKP strain, whereas members of Enterobacteriaceae and the ECKP strain have shown a correlational relationship. Our results suggest that the composition of the microbial community plays a primary role in the MDR-colonization rate, whereas the antibiotic susceptibility of individual MDR strains affects this process to a lesser extent. Distinct bacterial families have associated into microbial clusters, collecting taxonomically close species to produce survival benefits in the gut. These associations do not develop at random, as they may be attributed to the presence of specific metabolomic networks. A new concept should be introduced in designing future endeavors for MDR decolonization, supplemented by knowledge of the composition of the host bacterial community and the identification of bacterial clusters capable of suppressing or enhancing the invader species.

It has been proposed that changes in microbiota due to nonsteroidal anti-inflammatory drugs (NSAIDs) alter the composition of bile, and elevation of hydrophobic secondary bile acids contributes to small intestinal damage. However, little is known about the effect of NSAIDs on small intestinal bile acids, and whether bile alterations correlate with mucosal injury and dysbiosis. Here we determined the ileal bile acid metabolome and microbiota 24, 48 and 72 h after indomethacin treatment, and their correlation with each other and with tissue damage in rats. In parallel with the development of inflammation, indomethacin increased the ileal proportion of glycine and taurine conjugated bile acids, but not bile hydrophobicity. Firmicutes decreased with time, whereas Gammaproteobacteria increased first, but declined later and were partially replaced by Bilophila, Bacteroides and Fusobacterium. Mucosal injury correlated negatively with unconjugated bile acids and Gram-positive bacteria, and positively with taurine conjugates and some Gram-negative taxa. Strong positive correlation was found between Lactobacillaceae, Ruminococcaceae, Clostridiaceae and unconjugated bile acids. Indomethacin-induced dysbiosis was not likely due to direct antibacterial effects or alterations in luminal pH. Here we provide the first detailed characterization of indomethacin-induced time-dependent alterations in small intestinal bile acid composition, and their associations with mucosal injury and dysbiosis. Our results suggest that increased bile hydrophobicity is not likely to contribute to indomethacin-induced small intestinal damage.

The increasingly wide use of next-generation sequencing technologies has revolutionised our knowledge of microbial environments associated with human skin, gastrointestinal tract and blood. The collective set of microorganisms influences metabolic processes, affects immune responses, and so directly or indirectly modulates disease. Rosacea is a skin condition of abnormal inflammation and vascular dysfunction, and its progression is affected by Demodex mites on the skin surface. When looking into the effects influencing development of rosacea, it is not only the skin microbiome change that needs to be considered. Changes in the intestinal microbiome and their circulating metabolites, as well as changes in the blood microbiome also affect the progression of rosacea. Recent research has confirmed the increased presence of bacterial genera like Acidaminococcus and Megasphera in the intestinal microbiome and Rheinheimera and Sphingobium in the blood microbiome of rosacea patients. In this review we discuss our current knowledge of the interactions between the immune system and the skin, gut and blood microbiome, with particular attention to rosacea diagnostic opportunities.

Our aim was to analyze characteristics of treatment failure with intravenous tigecycline monotherapy among adults with severe Clostridioides (Clostridium) difficile infection (CDI). A single-centre observational cohort study was performed between 2014 and 2018. Data were collected by charts review, diagnosis and severity were determined by ESCMID guidelines. Primary outcome was treatment failure, secondary outcomes were in-hospital mortality, relapse, colectomy, and complication rates. Independent predictors of failure were identified using logistic regression. Altogether 110 patients were included, failure occurred in 37.3%. Patients with failure frequently had chronic heart and pulmonary co-morbidities, peritonitis, higher CRP levels, ICU admittance rates and need for total parenteral nutrition and vasopressors. Mostly, CDI-specific mortality and complications contributed to failure. Relapse rates were similar. Chronic pulmonary disease, ileus, total parenteral nutrition, and duration of tigecycline therapy were predictors of failure. We conclude that severe CDI cases with higher risk for tigecycline monotherapy failure might be identified by contributing factors.

Introduction: At the end of March, 2020, rapid tests detecting the presence of antiviral IgM and IgG antibodies against SARS-CoV-2 virus were introduced in Hungary for the identification of SARS-CoV-2 infection (COVID-19 disease). Aim: We evaluated two rapid tests (Anhui and Clungene) in comparison with those of real-time PCR tests considered as the gold standard in the detection of infection. Method: Between 16, March and 14, April, 2020, we performed rapid IgM and IgG detecting tests without PCR; PCR without rapid tests; and PCR WITH rapid tests in 4140, 3210 and 1654 patients, respectively. (Out of these 1654 patients, Anhui and Clungene tests were used for testing in 625 and 1029 patients, respectively.) Patients were considered as positive in PCR and rapid tests when PCR positivity and IgM or IgG positivity occurred at any time, respectively. (Note: Clungene test is also marketed as 'Lungene'.) Results: The prevalence of PCR positivity in 4864 patients tested with PCR was 6.3%. The sensitivity and specificity of Anhui and Clungene tests were 33.3% and 72.85%, and 35.48% and 85.02%, respectively. At 6% PCR positivity, the positive and negative predictive values of Anhui and Clungene were 7.28%, 94.48%, 13.13%, and 95.38%, respectively. Conclusion: The low positive predictive values indicate that Anhui and Clungene rapid tests detecting the presence of anti-IgM and anti-IgG against SARS-CoV-2 virus infection are not suitable for screening SARS-CoV-2 vírus infection in the general population. These results strongly support that Anhui and Clungene rapid tests detecting IgM and IgG antibodies against SARS-CoV-2 virus should not be used in the differential diagnosis of infection. Orv Hetil. 2020; 161(20): 807-812.Bevezetés: 2020. március végén a SARS-CoV-2-vírusfertőzöttség (COVID–19-betegség) diagnosztizálására megjelentek Magyarországon a vírussal szembeni specifikus antitestek jelenlétét kimutató gyorstesztek. Célkitűzés: Munkánkban két gyorsteszt, az Anhui és a Clungene teszt diagnosztikai teljesítményét értékeltük a fertőzés kimutatásában arany standardnak számító ’real-time’ (valós idejű) PCR (a továbbiakban: PCR) vizsgálati eredmények alapján. Módszer: 2020. március 16. és április 14. között intézetünk 20 120, COVID–19-fertőzéssel kapcsolatos rekordot küldött be az országos adatszolgáltató rendszeren keresztül. Ebben 4140 személynél csak IgM és IgG jelenlétét kimutató gyorstesztvizsgálat történt; 3210 személynél csak PCR-teszt, 1654 személynél pedig PCR- és gyorstesztvizsgálat (Anhui: 625, Clungene: 1029) végzésére maximum 3 nap eltéréssel is sor került. PCR-pozitívnak azt a személyt tekintettük, akinél bármikor PCR-pozitivitás fordult elő, illetve antitestpozitívnak azt, akinél IgM- és/vagy IgG-pozitivitást észleltünk. (Megjegyzés: a Clungene tesztet Lungene néven is forgalmazzák.) Eredmények: A 4864, PCR-rel vizsgált személy közül 308 volt PCR-pozitív (a PCR-pozitivitás prevalenciája 6,3% volt). A PCR alapján az Anhui gyorsteszt szenzitivitása 33,3%, specificitása 72,85%; a Clungene gyorsteszt szenzitivitása 35,48%, specificitása 85,02% volt. 6%-os PCR-pozitivitási prevalencia esetén a pozitív és a negatív prediktív érték az Anhui gyorsteszt esetében 7,28%, illetve 94,48%, míg a Clungene gyorsteszt esetében 13,13%, illetve 95,38% volt. Következtetés: Az aktuális fertőzöttségi prevalencia melletti alacsony pozitív prediktív értékek alapján az általunk értékelt gyorstesztek jelenleg nem alkalmasak a SARS-CoV-2-vírusfertőzöttség (PCR-pozitivitás) kimutatására az általános populációban. Az Anhui és a Clungene gyorstesztek negatív eredményei a jelenlegi 6%-os prevalencia mellett mintegy 95%-os valószínűséggel jelzik a SARS-CoV-2-vírusexpozíció hiányát. Az Anhui és a Clungene – SARS-CoV-2 vírus elleni IgM- és IgG-antitesteket kimutató – gyorstesztek alkalmazása a COVID–19-fertőzés differenciáldiagnosztikájában szakmailag vállalhatatlan. Orv Hetil. 2020; 161(20): 807–812.

The limited scope of antiviral drugs and increasing problem of antiviral drug resistance represent a global health threat. Glycopeptide antibiotics and their lipophilic derivatives have emerged as relevant inhibitors of diverse viruses. Herein, we describe a new strategy for the synthesis of dual hydrophobic and lipophobic derivatives of glycopeptides to produce selective antiviral agents without membrane‐disrupting activity. Perfluorobutyl and perfluorooctyl moieties were attached through linkers of different length to azido derivatives of vancomycin aglycone and teicoplanin pseudoaglycone, and the new derivatives were evaluated against a diverse panel of viruses. The teicoplanin derivatives displayed strong anti‐influenza virus activity at nontoxic concentrations. Some of the perfluoroalkylated glycopeptides were also active against a few other viruses such as herpes simplex virus or coronavirus. These data encourage further exploration of glycopeptide analogues for broad antiviral application., Plan F: Perfluoroalkylated blocks were incorporated into azido glycopeptide derivatives of vancomycin and teicoplanin. The teicoplanin derivatives displayed strong antiviral activity against a diverse panel of viruses at nontoxic concentrations. The vancomycin derivatives showed cytotoxicity, while being inactive against influenza viruses. Perfluorobutylated teicoplanins displayed excellent antibacterial activity against a panel of Gram‐positive bacteria.

Antibiotic resistance is one of the major challenges in healthcare of our time. To meet this challenge, we designed and prepared guanidine and lipophilic guanidine derivatives of the glycopeptide antibiotic teicoplanin to armed them with activity against the most threatening nosocomial bacteria, multiresistant enterococci. From teicoplanin and its pseudoaglycone, a series of N-terminal guanidine derivatives have been prepared with free and amide C-terminal parts. Six aliphatic and aromatic lipophilic carbodiimides were prepared and used for the synthesis of lipophilic guanidine teicoplanin conjugates. All new N-terminal guanidine antibiotics showed high activity against a standard panel of Gram-positive bacteria. Four selected derivatives displayed excellent antibacterial activity against a series of nosocomial VanA Enterococcus faecium strains.

To describe the characteristics of adult invasive H. influenzae disease, 34 patients diagnosed at a single tertiary center between 2004 and 2017 were analyzed in a retrospective case series study. The annual estimated incidence was 0.1 cases/100.000 inhabitants. Dominant source of infection was pneumonia accompanied by sepsis (62%) and caused by nontypeable strains (74%) with low ampicillin resistance (14%). Survival (94%) and complication rates were high (35%). Main empirical treatments were ceftriaxone or levofloxacine.

Host defense peptides are preferably administered as topical therapeutic agents. We have investigated whether peptide A3-APO can enter the circulation when applied to the ear skin. Efficacy of peptide monotherapy as transdermal administration option was assessed in a systemic mouse Acinetobacter baumannii model. A3-APO reduced mortality and demonstrated a statistically significant reduction of blood bacterial counts, regardless whether it was administered prior or after bacterial challenge. The peptidic metabolite of A3-APO was efficacious when applied to the ear or tail.

A multilayer mat for dispensing colistin sulfate through a body surface was prepared by electrospinning. The fabricated system comprised various polyvinyl alcohol fibrous layers prepared with or without the active ingredient. One of the electrospun layers contained water-soluble colistin sulfate and the other was prepared from the same polymer type and composition without the active drug and was finally heat-treated. The heat treatment modified the supramolecular structure and conferred the polymer nanofibre with the rate-controlling function. The microstructure of different layers was tracked by positron annihilation lifetime spectroscopy, and detailed morphological analysis of the fibre mats was performed using a scanning electron microscope. The drug-release profiles of various layer arrangements were studied in relation to their antimicrobial activity. The finite element method was applied to overcome the challenge of diffusion-controlled drug release from multilayer polymer scaffolds. The finite element method was first verified using analytical solutions for a simple arrangement (one drug-loaded swellable fibre and one rate-controlling nonswellable fibre) under perfect sink conditions and in a well-stirred finite volume. The effect of alternate layer arrangements on the drug-release profiles was also investigated to plan for controlled topical drug release from fibrous scaffolds. This design is expected to aid in increasing local effectiveness, thus reducing the systemic loading and the consequent side effects of colistin.

Background Although Streptococcus agalactiae is the leading causative agent of neonatal sepsis and meningitis, recently it is increasingly isolated from non-pregnant adults. The relation between its presence in the genitourinary tract and manifested clinical symptoms of STD patients remains an open question. In this study, a complex epidemiological investigation of GBS isolates from a venerology clinic was performed. Methods Ninety-six GBS isolates were serotyped and their genetic relatedness determined by PFGE. MLST was also performed for a subset of 20 isolates. The antibiotic susceptibility was tested with agar dilution. Surface proteins and the ST-17 hypervirulent clone was detected by PCR. Results The serotype prevalence was the following: V (29.2%), III (27.1%), Ia (22.9%), IV (10.4%), II (5.2%) and Ib (4.2%). A strong association was demonstrated between surface protein genes and serotypes. All isolates were fully susceptible to penicillin, but erythromycin and clindamycin resistance was high (41.7 and 35.4%, respectively), and 8 phenotypically macrolide sensitive isolates carried the ermB gene. 21.9% of all strains belonged to the hypervirulent ST17 clone, most being of serotype III and all were rib +. We found a few serotype IV isolates belonging to several STs and one serotype V/ST110 strain, containing a 44-bp deletion in the atr allele. Conclusions The presence of silent ermB genes is of worry, as their expression upon macrolide exposure could lead to unforeseen therapeutic failure, while clindamycin is used for intrapartum antibiotic prophylaxis, in case of penicillin allergy. The other alarming result is the high prevalence of ST17 among these strains from STD patients, who could be sources of further infections. This is the first report from Hungary providing both serotyping and genotyping data of GBS isolates. These results could be helpful for vaccine production as the major vaccine candidates are capsular antigens or surface proteins.

Background Community-acquired sepsis is a life-threatening systemic reaction, which starts within ≤72 h of hospital admittance in an infected patient without recent exposure to healthcare risks. Our aim was to evaluate the characteristics and the outcomes concerning community-acquired sepsis among patients admitted to a Hungarian high-influx national medical center. Methods A retrospective, observational cohort study of consecutive adult patients hospitalized with community-acquired sepsis during a 1-year period was executed. Clinical and microbiological data were collected, patients with pre-defined healthcare associations were excluded. Sepsis definitions and severity were given according to ACCP/SCCM criteria. The primary outcome was in-hospital all-cause mortality. Secondary outcomes were intensive care unit (ICU) admittance, length-of-stay (LOS), source control and bacteraemia rates. Statistical differences were explored with classical comparison tests, predictors of in-hospital all-cause mortality were modelled by multivariate logistic regression. Results 214 patients (median age 60.0 ± 33.1 years, 57% female, median Charlson score 4.0 ± 5.0) were included, 32.7% of them (70/214) had severe sepsis, and 28.5% (61/214) had septic shock. Prevalent sources of infections were genitourinary (53/214, 24.8%) and abdominal (52/214, 24.3%). The causative organisms were dominantly E. coli (60/214, 28.0%), S. pneumoniae (18/214, 8.4%) and S. aureus (14/214, 6.5%), and bacteraemia was documented in 50.9% of the cases (109/214). In-hospital mortality was high (30/214, 14.0%), and independently associated with shock, absence of fever, male gender and the need for ICU admittance, but source control and de-escalation of empirical antimicrobial therapy were protective. ICU admittance was 27.1% (58/214), source control was achieved in 18.2% (39/214). Median LOS was 10.0 ± 8.0, ICU LOS was 8.0 ± 10.8 days. Conclusions Community-acquired sepsis poses a significant burden of disease with characteristic causative agents and sources. Patients at a higher risk for poor outcomes might be identified earlier by the contributing factors shown above.

Influenza A and B viruses are a global threat to human health and increasing resistance to the existing antiviral drugs necessitates new concepts to expand the therapeutic options. Glycopeptide derivatives have emerged as a promising new class of antiviral agents. To avoid potential antibiotic resistance, these antiviral glycopeptides are preferably devoid of antibiotic activity. We prepared six vancomycin aglycone hexapeptide derivatives with the aim of obtaining compounds having anti-influenza virus but no antibacterial activity. Two of them exerted strong and selective inhibition of influenza A and B virus replication, while antibacterial activity was successfully eliminated by removing the critical N-terminal moiety. In addition, these two molecules offered protection against several other viruses, such as herpes simplex virus, yellow fever virus, Zika virus, and human coronavirus, classifying these glycopeptides as broad antiviral molecules with a favorable therapeutic index. ispartof: PHARMACEUTICALS vol:13 issue:7 ispartof: location:Switzerland status: published

Bis-alkylthio maleimido derivatives have been prepared from teicoplanin pseudoaglycon by reaction of its primary amino group with N-ethoxycarbonyl bis-alkylthiomaleimides. Some of the new derivatives displayed excellent antibacterial activity against resistant bacteria.

Lymphogranuloma venereum is a sexually transmitted infection caused by the Chlamydia trachomatis serovars L1-3. It has been found to be endemic in tropical countries. In the last decades several cases have been reported in Western Europe, particularly in men who have sex with men population infected with human immunodeficiency virus. The authors present three cases of lymphogranuloma venereum infections, observed at their department in 2013 and 2014. The three human immunodeficiency virus infected patients who belonged to men who have sex with men population had casual sexual contacts in Western Europe. The symptoms included urethral discharge, discomfort and inguinal lymphadenomegaly in two patients, and rectal pain, discharge and perianal ulceration in one patient. The diagnosis was confirmed by nucleic acid amplification test performed in samples obtained from urethral discharge and exudate of perianal ulcer; lymphogranuloma venereum 2b serovars were demonstrated in two patients and serovar 2 in one patient. Doxycyclin (daily dose of two times 100 mg for 21 days) resolved the symptoms in all cases. The authors conclude that lymphogranuloma venereum is a diagnostic challenge in Hungary, too. It is important to be aware of the altered clinical features of this disease to prevent complications and spreading.A lymphogranuloma venereum a Chlamydia trachomatis L1–3 szerovariánsa által terjesztett nemi betegség, amely korábban elsősorban a trópusi éghajlatú országokban volt elterjedt. Az elmúlt évtizedekben Nyugat-Európában számos esetet jelentettek, elsősorban a humán immundeficientia vírus fertőzött homoszexuális férfi populációban. A szerzők intézetében 2013-ban két esetet, 2014-ben egy esetet diagnosztizáltak. A szerzők e három humán immundeficientia vírus fertőzött homoszexuális férfi kórtörténetét ismertetik, akik nyugat-európai tartózkodásuk alatti alkalmi kapcsolatok során fertőződtek meg. Két esetben urethralis fluor, diszkomfort és inguinalis lymphadenomegalia, egy esetben analis diszkomfort, illetve perianalis ulceratio volt a vezető klinikai tünet. Az urethralis váladékból, illetve a perianalis ulcus váladékából végzett célzott real-time polimeráz láncreakció vizsgálat eredménye két esetben lymphogranuloma venereum L2b, egy esetben L2 szerovariánst igazolt. Doxycyclinkezelést követően a betegek gyógyultak. A lymphogranuloma venereum a jövőben vélhetően fokozódó kihívást jelent, így ismerete számos szakterületen fontos a késői szövődmények megelőzése és a kórkép további terjedésének megállítása céljából. Orv. Hetil., 2015, 156(1), 36–40.

A selection of nine derivatives of teicoplanin pseudoaglycon were tested in vitro against clinical vancomycin-resistant Enterococcus strains possessing vanA, vanB or both genes. The bacteria were characterized by PCR for the identification of their resistance genes. The tested compounds contain lipoic acid, different carbohydrates and aryl groups as lipophilic moieties. About one-third of the teicoplanin-resistant strains were shown to be susceptible to one or more of the glycopeptide derivatives.

A series of lipophilic teicoplanin pseudoaglycon derivatives, including alkyl-, aryl-, calixarene- and protected sugar-containing conjugates, were prepared using azide-alkyne click chemistry. Out of the conditions applied, the CuSO

The peptides Api88 and Onc72 are highly efficient to treat Escherichia coli bacteremia in mice. Here we extended the animal studies to a systemic murine infection model using a multidrug-resistant carbapenemase-producing Klebsiella pneumoniae clinical isolate. When administered intraperitoneally three times at 2.5, 5 and 10 mg/kg bodyweight to CD-1 mice infected with a KPC-producing K. pneumoniae strain, both Api88 and Onc72 reduced the bacterial counts by at least 5 log₁₀ units, indicating that both peptides are active in vivo. Both peptide treatments increased significantly the survival rates and average survival times compared to untreated animals for all doses except for the highest dose of Onc72. This dose reduced the bacterial counts so fast that it most likely induced a sudden release of large amounts of toxic materials from the killed bacteria reducing the survival time even below that of untreated mice. In conclusion, both peptides were efficient in the lethal murine K. pneumoniae infection model, but the treatment protocol (i.e. dose and time points) has to be further optimized based on future pharmacokinetic studies.

Proline-rich antibacterial peptides protect experimental animals from bacterial challenge even if they are unable to kill the microorganisms in vitro. Their major in vivo modes of action are inhibition of bacterial protein folding and immunostimulation. Here we investigated whether the proline-rich antibacterial peptide dimer A3-APO was able to inhibit Bacillus cereus enterotoxin production in vitro and restrict the proliferation of lethal toxin-induced Bacillus anthracis replication in mouse macrophages. After 24 h incubation, peptide A3-APO and its single chain metabolite reduced the amount of properly folded B. cereus diarrhoeal enterotoxin production in a concentration-dependent manner leading to only 10-25% of the original amount of toxin detectable by a conformation-sensitive immunoassay. Likewise, after 4 h incubation, A3-APO restricted the proliferation of B. anthracis in infected macrophages by 40-45% compared to untreated cells both intracellularly and in the extracellular cell culture milieu. Although the peptide had a minimal inhibitory concentration of >512 mg/L against B. anthracis in vitro, in systemic mouse challenge models it improved survival by 20- 37%, exhibiting statistically significant cumulative efficacy when administered at 3x5 mg/kg intraperitoneally or intramuscularly. We hypothesize that the activity in isolated murine macrophages and in vivo is due to deactivation of bacterial toxins. Bacterial protein folding inhibition in synergy with other types of antimicrobial modes offers a remarkable novel strategy in combating resistant or life-threatening infections.