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To evaluate the antibacterial, antibiofilm and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug‐resistant (MDR) bacteria. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration of Biofilm (MICB50), as well as synergistic and antivirulence assays for eight diterpenes against MDR. The tests revealed that two diterpenes (named 1 and 5) showed the best results, with MIC and MBC between 12.5 and 50 μg/mL against most MDR bacteria. These diterpenes exhibited promising MICB50 in concentration between 3.12–25 μg/mL but showed no synergistic antimicrobial activity. In the assessment of antivirulence activity, diterpenes 1 and 5 inhibited only one of the virulence factors evaluated (Dnase) produced by some strains of S. aureus at subinhibitory concentration (6.25 μg/mL). Results obtained indicated that diterpenes isolated from Copaifera oleoresin plays an important part in the search of new antibacterial and antibiofilm agents that can act against MDR bacteria. [ABSTRACT FROM AUTHOR]

IntroductionImplant-based breast reconstruction (IBR) is the predominant breast reconstruction technique post-mastectomy, with bacterial infections being a significant complication affecting patient recovery and quality of life. The following study aimed to determine the microbiological features of the causative agents responsible for breast implant infections, with more attention paid to the comparative analysis of Gram-positive and Gram-negative bacteria and their presentation.MethodsWe conducted a retrospective analysis of 214 patients who presented with periprosthetic infection and underwent implant removal following implant-based breast reconstruction at Humanitas Research Hospital and Istituto Europeo di Oncologia between January 2018 and March 2024.ResultsThe study revealed that Gram-positive bacteria were more prevalent, with Staphylococcus species, particularly Staphylococcus aureus, being the most isolated pathogen in both institutions (∼39.96%). In contrast, Gram-negative bacteria were less frequent, with a higher proportion of these pathogens being multi-resistant strains. A significant difference was observed (p = 0.007), indicating that individuals with normal BMI have a higher prevalence of Gram-positive infections (88.46%), whereas obese and overweight patients had higher proportions of Gram-negative infections (23.53% and 28.89%, respectively). In addition, smoking status was also significantly associated with pathogen distribution (p = 0.032), with active and past smokers being related to higher percentages of polymicrobial infections. Furthermore, positive prophylactic MSSA/MRSA swabs were significantly more associated with Staphylococcus aureus infections compared to those with negative results (p =

Introduction: Antimicrobial Resistance is a serious public health problem, which is aggravated by the ability of the microorganisms to form biofilms. Therefore, new therapeutic strategies need to be found, one of them being the use of cationic dendritic systems (dendrimers and dendrons). Methods: The aimof this study is to analyze the in vitro antimicrobial efficacy of six cationic carbosilane (CBS) dendrimers and one dendron with peripheral ammonium groups against multidrug-resistant bacteria, some of them isolated hospital strains, and their biofilms. For this purpose, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and minimum eradication biofilm concentration (MBEC) studies were carried out. In addition, the cytotoxicity on Hela cells of those compounds that proved to be the most effective was analyzed. Results: All the tested compounds showed in vitro activity against the planktonic forms of methicillin-resistant Staphylococcus aureus and only the dendrimers BDSQ017, BDAC-001 and BDLS-001 and the dendron BDEF-130 against their biofilms. On the other hand, only the dendrimers BDAC 001, BDLS-001 and BDJS-049 and the dendron BDEF-130 were antibacterial in vitro against the planktonic forms of multidrug-resistant Pseudomonas aeruginosa, but they lacked activity against their preformed biofilms. In addition, the dendrimers BDAC-001, BDLS-001 and BDSQ-017 and the dendron BDEF-130 exhibited a good profile of cytotoxicity in vitro. Discussion: Our study demonstrates the possibility of using the four compounds mentioned above as possible topical antimicrobials against the clinical and reference strains of multidrug-resistant bacteria. [ABSTRACT FROM AUTHOR]

IntroductionAntimicrobial Resistance is a serious public health problem, which is aggravated by the ability of the microorganisms to form biofilms. Therefore, new therapeutic strategies need to be found, one of them being the use of cationic dendritic systems (dendrimers and dendrons).MethodsThe aim of this study is to analyze the in vitro antimicrobial efficacy of six cationic carbosilane (CBS) dendrimers and one dendron with peripheral ammonium groups against multidrug-resistant bacteria, some of them isolated hospital strains, and their biofilms. For this purpose, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and minimum eradication biofilm concentration (MBEC) studies were carried out. In addition, the cytotoxicity on Hela cells of those compounds that proved to be the most effective was analyzed.ResultsAll the tested compounds showed in vitro activity against the planktonic forms of methicillin-resistant Staphylococcus aureus and only the dendrimers BDSQ017, BDAC-001 and BDLS-001 and the dendron BDEF-130 against their biofilms. On the other hand, only the dendrimers BDAC 001, BDLS-001 and BDJS-049 and the dendron BDEF-130 were antibacterial in vitro against the planktonic forms of multidrug-resistant Pseudomonas aeruginosa, but they lacked activity against their preformed biofilms. In addition, the dendrimers BDAC-001, BDLS-001 and BDSQ-017 and the dendron BDEF-130 exhibited a good profile of cytotoxicity in vitro.DiscussionOur study demonstrates the possibility of using the four compounds mentioned above as possible topical antimicrobials against the clinical and reference strains of multidrug-resistant bacteria.

Introduction: Antimicrobial resistance and the rapid spread of multiresistant bacteria represent one of the main public health problem in limited resources countries. This issue is significantly worsening since the COVID-19 pandemic due to the unreasonably increased antibiotics prescription to patients with confirmed SARS-CoV-2 infection. The aim of this study was to examine whether COVID-19 pandemic (2020, 2021) was associated with increased antibiotic consumption in inpatient and outpatient settings in the middle size urban region (Republic of Srpska/Bosnia and Herzegovina) in comparison to period before the pandemic (2019). Additionally, we aimed to determine antimicrobial resistance and the presence of multiresistant bacteria in the regional hospital ("Saint Apostol Luka" Hospital Doboj) in 2021. Methodology: The consumption of antibiotics in inpatient was calculated as Defined Daily Dose per one hundred of patient-days. The consumption of antibiotics in outpatient was calculated as Defined Daily Dose per thousand inhabitants per day. Resistance of bacteria to antibiotics is expressed as a rates and density for each observed antibiotic. The rate of resistance was calculated as a percentage in relation to the total number of isolates of individual bacteria. The density of resistance of isolated bacteria against a specific antibiotic was expressed as the number of resistant pathogens/1000 patient days. Results: Antibiotic consumption in hospital setting registered during 2019, 2020 and 2021 was as follows: carbapenems (meropenem: 0.28; 1.91; 2.33 DDD/100 patient-days, respectively), glycopeptides (vancomycin: 0.14; 1.09, 1.54 DDD/100 patient-days, respectively), cephalosporins (ceftriaxone: 6.69; 14.7; 14.0 DDD/100 patient-days, respectively) and polymyxins (colistin: 0.04; 0.25; 0.35 DDD/100 bed-days, respectively). Consumption of azithromycin increased drastically in 2020, and dropped significantly in 2021 (0.48; 5.61; 0.93 DDD/100 patientdays). In outpatient setting, an increase in the consumption of oral forms of azithromycin, levofloxacin and cefixime, as well as parenteral forms of amoxicillinclavulanic acid, ciprofloxacin and ceftriaxone, was recorded. In 2021, antimicrobial resistance to reserve antibiotics in hospital setting was as follows: Acinetobacter baumanii to meropenem 66.0%, Klebsiella spp to cefotaxime 67.14%, Pseudomonas to meropenem 25.7%. Conclusion: Recent COVID-19 pandemic was associated with increased antibiotic consumption in inpatient and outpatient settings, with characteristic change of pattern of azithromycin consumption. Also, high levels of antimicrobial resistance to reserve antibiotics were registered in hospital setting with low prevalence of identified pathogen-directed antimicrobial prescription. Strategies toward combat antimicrobial resistance in the Doboj region are urgently needed. [ABSTRACT FROM AUTHOR]

Abstract Background The discovery of new molecules with antimicrobial properties has been a promising approach, mainly when related to substances produced by bacteria. The use of substances produced by bees has evidenced the antimicrobial action in different types of organisms. Thus, the use of bacteria isolated from larval food of stingless bees opens the way for the identification of the new molecules. The effect of supernatants produced by these bacteria was evaluated for their ability to inhibit the growth of bacteria of clinical interest. Furthermore, their effects were evaluated when used in synergy with antibiotics available in the pharmaceutical industry. Results A few supernatants showed an inhibitory effect against susceptible and multiresistant strains in the PIC assay and the modulation assay. Emphasizing the inhibitory effect on multidrug-resistant strains, 7 showed an effect on multidrug-resistant Escherichia coli (APEC), Klebsiella pneumoniae carbapenemase (KPC), multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Staphylococcus aureus (MRSA) in the PIC assay. Of the supernatants analyzed, some presented synergism for more than one species of multidrug-resistant bacteria. Nine had a synergistic effect with ampicillin on E. coli (APEC) or S. aureus (MRSA), 5 with penicillin G on E. coli (APEC) or KPC, and 3 with vancomycin on KPC. Conclusion In summary, the results indicate that supernatants produced from microorganisms can synthesize different classes of molecules with potent antibiotic activity against multiresistant bacteria. Thus, suggesting the use of these microorganisms for use clinical tests to isolate the molecules produced and their potential for use.

Introduction: Antimicrobial resistance and the rapid spread of multiresistant bacteria represent one of the main public health problem in limited resources countries. This issue is significantly worsening since the COVID-19 pandemic due to the unreasonably increased antibiotics prescription to patients with confirmed SARS-CoV-2 infection. The aim of this study was to examine whether COVID-19 pandemic (2020, 2021) was associated with increased antibiotic consumption in inpatient and outpatient settings in the middle size urban region (Republic of Srpska/Bosnia and Herzegovina) in comparison to period before the pandemic (2019). Additionally, we aimed to determine antimicrobial resistance and the presence of multiresistant bacteria in the regional hospital (“Saint Apostol Luka” Hospital Doboj) in 2021.Methodology: The consumption of antibiotics in inpatient was calculated as Defined Daily Dose per one hundred of patient-days. The consumption of antibiotics in outpatient was calculated as Defined Daily Dose per thousand inhabitants per day. Resistance of bacteria to antibiotics is expressed as a rates and density for each observed antibiotic. The rate of resistance was calculated as a percentage in relation to the total number of isolates of individual bacteria. The density of resistance of isolated bacteria against a specific antibiotic was expressed as the number of resistant pathogens/1000 patient days.Results: Antibiotic consumption in hospital setting registered during 2019, 2020 and 2021 was as follows: carbapenems (meropenem: 0.28; 1.91; 2.33 DDD/100 patient-days, respectively), glycopeptides (vancomycin: 0.14; 1.09, 1.54 DDD/100 patient-days, respectively), cephalosporins (ceftriaxone: 6.69; 14.7; 14.0 DDD/100 patient-days, respectively) and polymyxins (colistin: 0.04; 0.25; 0.35 DDD/100 bed-days, respectively). Consumption of azithromycin increased drastically in 2020, and dropped significantly in 2021 (0.48; 5.61; 0.93 DDD/100 patient-days). In outpatient setting, an increase in the consumption of oral forms of azithromycin, levofloxacin and cefixime, as well as parenteral forms of amoxicillin-clavulanic acid, ciprofloxacin and ceftriaxone, was recorded. In 2021, antimicrobial resistance to reserve antibiotics in hospital setting was as follows: Acinetobacter baumanii to meropenem 66.0%, Klebsiella spp to cefotaxime 67.14%, Pseudomonas to meropenem 25.7%.Conclusion: Recent COVID-19 pandemic was associated with increased antibiotic consumption in inpatient and outpatient settings, with characteristic change of pattern of azithromycin consumption. Also, high levels of antimicrobial resistance to reserve antibiotics were registered in hospital setting with low prevalence of identified pathogen-directed antimicrobial prescription. Strategies toward combat antimicrobial resistance in the Doboj region are urgently needed.

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Background: Prophylactic antibiotics are still controversial during allogeneic hematopoietic stem cell transplantation (allo-HSCT). In our transplant center, we suspended antibiotic prophylaxis during allo-HSCT in 2017., Objective: The main objective of this study was the detailed analysis of the potentially beneficial impact of omittance of standard antibiotic prophylaxis during allo-HSCT in survival and Graft-versus-Host disease (GvHD) development, especially with consideration of confounding factors and competing events. Secondary objectives were the evaluation of the risk of severe infections and transplant-related mortality without antibiotic prophylaxis, the detailed assessment of bacterial and viral infections including multiresistant pathogens as well as occurrence of relapse in both groups. This study aims to support the development of future antibiotic strategies in allo-HSCT., Study Design: We retrospectively analyzed patient outcome in the time periods before (between December 2012 and February 2017) and after suspension (between March 2017 and June 2020) of antibiotic prophylaxis during allo-HSCT. Relevant clinical outcome parameters of the patients (n = 221) were collected by chart-review in the two groups (with antibiotic prophylaxis n = 101 versus without antibiotic prophylaxis n = 120). All patients were 18 years or older. Propensity score methods were used to adjust for potentially confounding patient characteristics. To address competing events, transitions between moderate/severe acute and chronic GvHD, relapse and death were analyzed using an inverse-propensity score weighted multistate modeling approach., Results: While we observed a trend towards an improved outcome in the cohort without antibiotic prophylaxis, the inverse-propensity-score-weighted analyses did not show significant differences between the two groups in overall survival (OS) (P = .811) or development of acute GvHD (aGvHD) grade 3/4 (P = .158) and chronic moderate/severe GvHD (cGvHD) (P = .686). Multistate analysis respecting competing events revealed comparable estimated probabilities without antibiotic prophylaxis versus with antibiotic prophylaxis in OS (35.0% [95% CI: 28.2%-42.7%] versus 35.3% [95% CI: 27.8%-41.1%]) as well as development of aGvHD grade 3/4 (7.7% [95% CI: 5.9%-12.2%] vs. 10.6% [95% CI: 7.7%-15.7%]) and moderate/severe cGvHD (21.0% [95% CI: 17.7%-30.0%] vs. 23.8% [95% CI: 19.6%-31.4%]). Similar analyses showed also no significant differences in relapse rate, transplant-related mortality, relapse-related mortality, or GvHD-free/relapse-free survival between the two groups. An observed increase in severe infections without antibiotic prophylaxis did not lead to a significantly higher mortality rate. Viral reactivation and detection of multiresistant bacteria were comparable, yet a higher incidence of Clostridioides difficile infections was observed in patients receiving antibiotic prophylaxis., Conclusion: Our study supports previous reports of noninferiority of allo-HSCT without use of antibiotic prophylaxis with close monitoring and rapid intervention, if infection is suspected. The trend towards improved outcomes without antibiotic prophylaxis, however, might not only be due to the absence of antibiotic prophylaxis but also due to additional progresses in the field over the recent years. While the present study is too small to draw definite conclusions, these results strongly warrant further multicenter studies addressing the potential benefit of omitting antibiotic prophylaxis during allo-HSCT., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

This work describes the evaluation the potentiating activity of antibiotics by campesterol (1) and its derivatives (2-11) against multiresistant strains of Staphylococcusaureus 10, Escherichia coli 06 and Pseudomonas aeruginosa 24 employing the microdilution test. When subjected to the in vitro potentiating activity bioassay, all compounds showed a potentiating effect associated with norfloxacin against E. coli and P. aeruginosa with a reduction in the MIC of the antibiotic of up to 75%. These compounds also reduced the MIC of gentamicin by 37% to 87% in S. aureus and E. coli. Additionally, molecular docking studies were conducted to gain a deeper understanding of the interactions between the appropriate proteins and the most effective compounds (2, 4, 9, and 10 against E. coli; 1, 2, 3, 5, 8, and 9 against S. aureus), including antibiotics. This paper registers for the first time the in vitro and in silico studies on the action of compounds 1-11 in antibiotic potentiation., (© 2024 Wiley‐VCH GmbH.)

Abstract Background Severe infections and multidrug-resistant pathogens are common in critically ill patients. Antimicrobial stewardship (AMS) and therapeutic drug monitoring (TDM) are contemporary tools to optimize the use of antimicrobials. The A-TEAMICU survey was initiated to gain contemporary insights into dissemination and structure of AMS programs and TDM practices in intensive care units. Methods This study involved online survey of members of ESICM and six national professional intensive care societies. Results Data of 812 respondents from mostly European high- and middle-income countries were available for analysis. 63% had AMS rounds available in their ICU, where 78% performed rounds weekly or more often. While 82% had local guidelines for treatment of infections, only 70% had cumulative antimicrobial susceptibility reports and 56% monitored the quantity of antimicrobials administered. A restriction of antimicrobials was reported by 62%. TDM of antimicrobial agents was used in 61% of ICUs, mostly glycopeptides (89%), aminoglycosides (77%), carbapenems (32%), penicillins (30%), azole antifungals (27%), cephalosporins (17%), and linezolid (16%). 76% of respondents used prolonged/continuous infusion of antimicrobials. The availability of an AMS had a significant association with the use of TDM. Conclusions Many respondents of the survey have AMS in their ICUs. TDM of antimicrobials and optimized administration of antibiotics are broadly used among respondents. The availability of antimicrobial susceptibility reports and a surveillance of antimicrobial use should be actively sought by intensivists where unavailable. Results of this survey may inform further research and educational activities.

Background: The discovery of new molecules with antimicrobial properties has been a promising approach, mainly when related to substances produced by bacteria. The use of substances produced by bees has evidenced the antimicrobial action in different types of organisms. Thus, the use of bacteria isolated from larval food of stingless bees opens the way for the identification of the new molecules. The effect of supernatants produced by these bacteria was evaluated for their ability to inhibit the growth of bacteria of clinical interest. Furthermore, their effects were evaluated when used in synergy with antibiotics available in the pharmaceutical industry. Results: A few supernatants showed an inhibitory effect against susceptible and multiresistant strains in the PIC assay and the modulation assay. Emphasizing the inhibitory effect on multidrug-resistant strains, 7 showed an effect on multidrug-resistant Escherichia coli (APEC), Klebsiella pneumoniae carbapenemase (KPC), multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Staphylococcus aureus (MRSA) in the PIC assay. Of the supernatants analyzed, some presented synergism for more than one species of multidrug-resistant bacteria. Nine had a synergistic effect with ampicillin on E. coli (APEC) or S. aureus (MRSA), 5 with penicillin G on E. coli (APEC) or KPC, and 3 with vancomycin on KPC. Conclusion: In summary, the results indicate that supernatants produced from microorganisms can synthesize different classes of molecules with potent antibiotic activity against multiresistant bacteria. Thus, suggesting the use of these microorganisms for use clinical tests to isolate the molecules produced and their potential for use. [ABSTRACT FROM AUTHOR]

Abstract Background and aims Bacterial infections are common in patients with decompensated liver cirrhosis and a leading cause of death. Reliable data on antibiotic resistance are required to initiate effective empiric therapy. We here aim to assess the antimicrobial resistance profile of bacteria among patients with liver cirrhosis and infection. Methods Overall, 666 cirrhotic patients admitted to Hannover Medical School between January 2012 and April 2018 with ascites were assessed for bacterial infection. In case of infection, bacteria cultured from microbiological specimens of ascites, blood or urine were identified and analyzed for resistances against common antibiotic agents. Furthermore, analyses compared two periods of time and community-acquired vs. nosocomial infections. Results In 281 patients with infection, microbiological sampling was performed and culture-positive results were obtained in 56.9%. Multidrug-resistant (MDR)-bacteria were found in 54 patients (19.2%). Gram-positive organisms were more common (n = 141/261, 54.0%) and detected in 116/192 culture-positive infections (60.4%). Comparing infections before and after 2015, a numerical decline for MDR-bacteria (23.8% vs. 15.6%, p = 0.08) was observed with a significant decline in meropenem resistance (34.9% vs. 19.5%, p = 0.03). MDR-bacteria were more frequent in the case of nosocomial infections. Of note, in ascites the majority of the tested bacteria were resistant against ceftriaxone (73.8%) whereas significantly less were resistant against meropenem (27.0%) and vancomycin (25.9%). Conclusions In our tertiary center, distinct ratios of gram-positive infection with overall low ratios of MDR-bacteria were found. Adequate gram-positive coverage in the empiric therapy should be considered. Carbapenem treatment may be omitted even in nosocomial infection. In contrast, 3rd generation cephalosporins cannot be recommended even in community-acquired infection in our cirrhotic population.

Aims: Assess the antibacterial and antioxidant effects of ethanol extracts of Portuguese propolis samples when combined with gentamicin, a widely used aminoglycoside antibiotic, or with honey, collected from the same apiary as propolis. Methods and Results: Using the agar dilution method and DPPH free radical scavenging assay, antimicrobial and antioxidant synergistic effects between propolis and gentamicin or honey were assessed. Synergism between propolis and gentamicin was observed for all the tested extracts and against all the indicator bacteria, with particular interest against the Methicillin‐Resistant Staphylococcus aureus (MRSA) with a threefold decrease of the gentamicin MIC if mixed with 25 µg ml−1 propolis. Likely to propolis and gentamicin, mixtures of sub‐MIC concentrations of propolis and honey enhanced the antibacterial action of each individual natural product against the majority of the strains. However, propolis antioxidant capacity decreased along with higher honey content in the mixture. Conclusions: Propolis has a strong synergistic effect when combined with gentamicin, allowing the reduction of the therapeutic dose of this drug. Propolis and honey mixtures also display a stronger antibacterial effect than the activity exhibited by each sample when tested individually, whereas the high antioxidant capacity of propolis seems to be not affected when in combination with honey. Significance and Impact of Study: When mixed with honey, propolis antioxidant potential is maintained, or just slightly reduced up to 1:1 dilution, and show synergistic antibacterial effects, allowing to optimize the use of this usually scarce natural resource. Also, considering the antibiotic resistance problem, natural beehive products, alone or in the mixture, are promising alternatives to retard the outbreak of microbial resistance. [ABSTRACT FROM AUTHOR]

The aim of the work – to study in vivo the effectiveness of the simultaneous and alternate use of the Lactobacillus rhamnosus GG and Saccharomyces boulardii metabolite complex with an antibacterial preparation in a guinea pig model of skin wound infected with a multiresistant Pseudomonas aruginosa strain to validate prospects for its application in the development of add-on preparations to antibiotic therapy. Materials and methods. The metabolite complex of lactobacteria and saccharomycetes was obtained by culturing cells of probiotic microorganisms in their own ultrasonic disintegrates (MLS). The following were applied to wounds infected with the multiresistant strain of P. aeruginosa twice daily: 0.9 % sodium chloride solution (control group, К), amikacin – AB (group L I), simultaneously AB with MLS (group L II), alternately AB and MLS (group L III). The dynamics of planimetric indicators of wounds (sizing, calculation of the healing area, healing rate, healing rate coefficient, reparative effect) was carried out on days 1, 5, 8 and 11. Antimicrobial activity was evaluated by bacteriological examination of a material from wound samples with identification and determination of the number of colony forming units (CFU) of the pathogen. Results. The combined anti-pseudomonas activity of amikacin and the L. rhamnosus GG and S. boulardii metabolite complex was established. Decreased CFU of P. aeruginosa and acceleration of reparative processes in wounds were observed in groups L I, L II, L III compared to K on days 5 and 8 (P < 0.05). The greater effectiveness of the first proposed alternate method of using AB and MLS was proved in contrast with their simultaneous application. The wound surface areas in L III group were smaller relative to L II (1.8 and 5.0 times, P = 0.03), and L I (2.8 and 9.0 times, P = 0.04) on days 5 and 8, respectively. The increase in synergistic antimicrobial activity due to the new approach of alternate effect was probably due to an increase in antibiotic susceptibility of the test cultures. Conclusions. The presented in the work results of the pronounced synergistic effect of combined using amikacin and the metabolite complex of Lactobacillus rhamnosus GG and Saccharomyces boulardii confirm its promise for practical medicine and the pharmaceutical industry. The data obtained open the potential for developing add-on preparations to antibiotic therapy based on metabolite complexes for the treatment of infected wounds.

Aims: N‐chlorotaurine (NCT) is a body‐own mild oxidizing antiseptic that can be applied topically as a well‐tolerated anti‐infective at many body sites. The objective of this study was to demonstrate its activity against representative nosocomial multidrug‐resistant bacteria. Methods and Results: The bactericidal activity of NCT was tested in quantitative killing assays against a panel of multiresistant Gram‐positive and Gram‐negative clinical isolates. N‐chlorotaurine (1%, 55 mmol l−1) reduced the number of CFU of strains of methicillin‐resistant Staphylococcus aureus, linezolid‐resistant Staphylococcus epidermidis, vancomycin‐resistant, and linezolid‐ and vancomycin‐resistant Enterococcus faecium, 3MRGN and 4MRGN Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae by at least 2 log10 steps after 15 min and completely or nearly to the detection limit after 30 min at pH 7·1 and 37°C. Conclusion: The activity of NCT against these clinical isolates is similar to that against non‐resistant ATCC strains and therefore not influenced by antibiotic resistance. This can be explained by the oxidizing and chlorinating mechanism of action of NCT, which leads to an attack of multiple targets in the microorganisms. Significance and Impact of the Study: The bactericidal spectrum of NCT is not restricted by resistance against antibiotics. Therefore, it can be used against resistant strains, too. [ABSTRACT FROM AUTHOR]

Background: Severe infections and multidrug-resistant pathogens are common in critically ill patients. Antimicrobial stewardship (AMS) and therapeutic drug monitoring (TDM) are contemporary tools to optimize the use of antimicrobials. The A-TEAMICU survey was initiated to gain contemporary insights into dissemination and structure of AMS programs and TDM practices in intensive care units. Methods: This study involved online survey of members of ESICM and six national professional intensive care societies. Results: Data of 812 respondents from mostly European high- and middle-income countries were available for analysis. 63% had AMS rounds available in their ICU, where 78% performed rounds weekly or more often. While 82% had local guidelines for treatment of infections, only 70% had cumulative antimicrobial susceptibility reports and 56% monitored the quantity of antimicrobials administered. A restriction of antimicrobials was reported by 62%. TDM of antimicrobial agents was used in 61% of ICUs, mostly glycopeptides (89%), aminoglycosides (77%), carbapenems (32%), penicillins (30%), azole antifungals (27%), cephalosporins (17%), and linezolid (16%). 76% of respondents used prolonged/continuous infusion of antimicrobials. The availability of an AMS had a significant association with the use of TDM. Conclusions: Many respondents of the survey have AMS in their ICUs. TDM of antimicrobials and optimized administration of antibiotics are broadly used among respondents. The availability of antimicrobial susceptibility reports and a surveillance of antimicrobial use should be actively sought by intensivists where unavailable. Results of this survey may inform further research and educational activities. [ABSTRACT FROM AUTHOR]

Background and Aims: Bacterial infections are common in patients with decompensated liver cirrhosis and a leading cause of death. Reliable data on antibiotic resistance are required to initiate effective empiric therapy. We here aim to assess the antimicrobial resistance profile of bacteria among patients with liver cirrhosis and infection.Methods: Overall, 666 cirrhotic patients admitted to Hannover Medical School between January 2012 and April 2018 with ascites were assessed for bacterial infection. In case of infection, bacteria cultured from microbiological specimens of ascites, blood or urine were identified and analyzed for resistances against common antibiotic agents. Furthermore, analyses compared two periods of time and community-acquired vs. nosocomial infections.Results: In 281 patients with infection, microbiological sampling was performed and culture-positive results were obtained in 56.9%. Multidrug-resistant (MDR)-bacteria were found in 54 patients (19.2%). Gram-positive organisms were more common (n = 141/261, 54.0%) and detected in 116/192 culture-positive infections (60.4%). Comparing infections before and after 2015, a numerical decline for MDR-bacteria (23.8% vs. 15.6%, p = 0.08) was observed with a significant decline in meropenem resistance (34.9% vs. 19.5%, p = 0.03). MDR-bacteria were more frequent in the case of nosocomial infections. Of note, in ascites the majority of the tested bacteria were resistant against ceftriaxone (73.8%) whereas significantly less were resistant against meropenem (27.0%) and vancomycin (25.9%).Conclusions: In our tertiary center, distinct ratios of gram-positive infection with overall low ratios of MDR-bacteria were found. Adequate gram-positive coverage in the empiric therapy should be considered. Carbapenem treatment may be omitted even in nosocomial infection. In contrast, 3rd generation cephalosporins cannot be recommended even in community-acquired infection in our cirrhotic population. [ABSTRACT FROM AUTHOR]

We here report the case of a 2-year-old patient with a primary central nervous system lymphoma of B-cell origin. Due to their past medical history of repeated respiratory tract infections and the marked chemotherapy-associated toxicity and infectious comorbidity, we suspected that the patient also suffered from an inherited immune deficiency disorder. Despite the lack of classical pathognomonic symptoms for ataxia teleangiectasia and missing evidence for a cancer predisposition syndrome in the family, genetic testing identified biallelic germline mutations, including the rare pathogenic variant c.3206delC (p.Pro1069Leufs*2), in the ataxia telangiectasia-mutated (ATM) gene. The case highlights the importance of searching for immune deficiency disorders associated with primary central nervous system lymphoma before treatment initiation and the urgent need to develop novel treatment strategies for cancer patients with underlying immunodeficiency syndromes. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) is a major public health threat of global proportions, which has the potential to lead to approximately ten million deaths per year by 2050. Pressured by this wicked problem, in 2014, the World Health Organization launched a call for member states to share AMR data through the implementation of the Global Antimicrobial Resistance Surveillance System (GLASS), to appropriately scale and monitor the general situation world-widely. In 2017, Brazil joined GLASS and, in 2018, started its own national antimicrobial surveillance program (BR-GLASS) to understand the impact of resistance in the country. We compiled data obtained from the complete routine of three hospitals' microbiology labs during the year of 2018. This pilot data sums up to 200,874 antimicrobial susceptibility test results from 11,347 isolates. It represents 119 different microorganisms recovered from 44 distinct types of clinical samples. Specimens came from patients originating from 301 Brazilian cities, with 4,950 of these isolates from presumed Healthcare-Associated Infections (HAIs) and the other 6,397 community-acquired cases. The female population offered 58% of the collected samples, while the other 42% were of male origin. The urinary tract was the most common topography (6,372/11,347 isolates), followed by blood samples (2,072/11,347). Gram-negative predominated the bacterial isolates: Escherichia coli was the most prevalent in general, representing 4,030 isolates (89.0% of these from the urinary tract). Coagulase-negative Staphylococci were the most prevalent bacteria in blood samples. Besides these two species, the ESKAPE group have consolidated their prevalence. Regarding drug susceptibility results, 141,648 (70.5%) were susceptible, 9,950 (4.9%) intermediate, and 49,276 (24.5%) resistant. Acinetobacter baumannii was the most worrisome microorganism, with 65.3% of the overall antimicrobial susceptibility tests showing resistance, followed by ESBL-producing Klebsiella pneumoniae, with a global resistance rate of 59%. Although this is a pilot project (still limited to one state), this database shows the importance of a nation-wide surveillance program,[153mm][-12mm] Q14 especially considering it already had patients coming from 301 distinct counties and 18 different states. The BR-GLASS Program is an ongoing project that intends to encompass at least 95 hospitals distributed in all five geographical regions in Brazil within the next 5 years.

Background: Effective antimicrobial treatment is key to reduce mortality associated with bacterial sepsis in patients on intensive care units (ICUs). Dose adjustments are often necessary to account for pathophysiological changes or renal replacement therapy. Extracorporeal membrane oxygenation (ECMO) is increasingly being used for the treatment of respiratory and/or cardiac failure. However, it remains unclear whether dose adjustments are necessary to avoid subtherapeutic drug levels in septic patients on ECMO support. Here, we aimed to evaluate and comparatively assess serum concentrations of continuously applied antibiotics in intensive care patients being treated with and without ECMO.Methods: Between October 2018 and December 2019, we prospectively enrolled patients on a pneumological ICU in southwest Germany who received antibiotic treatment with piperacillin/tazobactam, ceftazidime, meropenem, or linezolid. All antibiotics were applied using continuous infusion, and therapeutic drug monitoring of serum concentrations (expressed as mg/L) was carried out using high-performance liquid chromatography. Target concentrations were defined as fourfold above the minimal inhibitory concentration (MIC) of susceptible bacterial isolates, according to EUCAST breakpoints.Results: The final cohort comprised 105 ICU patients, of whom 30 were treated with ECMO. ECMO patients were significantly younger (mean age: 47.7 vs. 61.2 years; p < 0.001), required renal replacement therapy more frequently (53.3% vs. 32.0%; p = 0.048) and had an elevated ICU mortality (60.0% vs. 22.7%; p < 0.001). Data on antibiotic serum concentrations derived from 112 measurements among ECMO and 186 measurements from non-ECMO patients showed significantly lower median serum concentrations for piperacillin (32.3 vs. 52.9; p = 0.029) and standard-dose meropenem (15.0 vs. 17.8; p = 0.020) in the ECMO group. We found high rates of insufficient antibiotic serum concentrations below the pre-specified MIC target among ECMO patients (piperacillin: 48% vs. 13% in non-ECMO; linezolid: 35% vs. 15% in non-ECMO), whereas no such difference was observed for ceftazidime and meropenem.Conclusions: ECMO treatment was associated with significantly reduced serum concentrations of specific antibiotics. Future studies are needed to assess the pharmacokinetic characteristics of antibiotics in ICU patients on ECMO support. [ABSTRACT FROM AUTHOR]

Several scientific researches seek to find plant extracts that have curative and prophylactic potential for different pathologies. Currently, very few therapeutic options due to increased bacterial resistance, make necessary the search for new antimicrobial agents from plant extracts and other natural products are applied as pharmaceuticals, mainly in Brazil offering an immense biodiversity. Therefore, the objective was to identify the antimicrobial activity of Forficata bahuina and evaluate the smallest inhibitory concentration in clinical standard strains and isolates of multiresistant hospital origin. To the discovery of the antibacterial potential were used sheets Bahuinia forficata (Mororó/cow Pata). The antibacterial activity of the extract was analyzed by the microdilution broth method, wherein the inoculum was prepared to a concentration of 5 x 105 CFU / mL, from 0.5 McFarland suspension (1.5 x 108 CFU/mL) obtained from fresh colonies of selected bacteria. crude leaf extract, showed broad antibacterial activity against the three multiresistant bacteria of nosocomial origin, thus ensuring an experimental analytical evidence of great potential, allowing the detailed study to find new antibacterial agents of natural origin.

Abstract Background Multiresistant bacteria (MRB) is an increasing problem. Early identification of patients with MRB is mandatory to avoid transmission and to target the antibiotic treatment. The emergency department (ED) is a key player in the early identification of patients who are colonized with MRB. There is currently sparse knowledge of both prevalence and risk factors for colonization with MRSA, ESBL, VRE, CPE and CD in acutely admitted patients in Western European countries including Denmark. To develop evidence-based screening tools for identifying carriers of resistant bacteria among acutely admitted patients, systematic collection of information on risk factors and exposures is required. Since a geographical variation is suspected, it is desirable to include emergency departments across the country. The aim of this project is to provide a comprehensive overview of prevalence and risk factors for MRSA, ESBL, VRE, CPE and CD colonization in patients admitted to Danish ED’s. The objectives are to describe the prevalence and demography of resistance, co-infections, to identify risk factors for carrier state and to develop and validate a screening tool for identification of carriers. Methods Multicenter descriptive and analytic cross-sectional survey from January–May 2018 of around 10.000 acutely admitted patients > 18 years in 8 EDs for carrier state and risk factors for antibiotic resistant bacteria. Information about the background and possible risk factors for carrier status together with swabs from the nose, throat and rectum is collected and analyzed for MRSA, ESBL, VRE, CPE and CD. The prevalence of the resistant bacteria are calculated at hospital level, regional level and national level and described with relation to residency, sex, age and risk factors. A screening model for identification of carrier stage of resistant bacteria is developed and validated. Discussion The study will provide the prevalence of colonized patients with resistant bacteria on arrival to the ED and variation in demographic patterns, and will develop a clinical tool to identify certain risk groups. This will enable the clinician to target antibiotic treatments and to reduce the in-hospital spreading of resistant bacteria. This knowledge is important for implementing and evaluating antimicrobial stewardships, screening and infection control strategies. Trial registration Clinicaltrials.gov: NCT03352167 (registration date: 20. November 2017).

Bacterial infections are frequent complications of liver cirrhosis, accounting for severe clinical courses, and increased mortality. The reduction of the negative clinical impact of infections may be achieved by a combination of prophylactic measures to reduce the occurrence, early identification, and management. Spontaneous bacterial peritonitis (SBP), urinary tract infections, pneumonia, cellulitis, and spontaneous bacteremia are frequent in cirrhosis. The choice of initial empirical antimicrobial therapy should be based on both site, severity, and origin of infection (community-acquired, nosocomial, or healthcare-associated) and on antibiotic resistance patterns. 3rd generation cephalosporins are generally indicated as empirical therapy in most community-acquired cases. However, for nosocomial and healthcare-associated infections, due to a high rate of multidrug-resistant (MDR) pathogens, a broader spectrum treatment is appropriate. In order to prevent antibiotic resistance emergence, microbiological cultures should be collected, and a de-escalation applied when antimicrobial susceptibility tests are available. Standard measures to prevent infections and the identification of carriers of MDR bacteria are essential strategies to prevent infections in cirrhosis. Antibiotic prophylaxis should be applied only to gastrointestinal bleeding, SBP recurrence prevention, and cirrhotics at high risk of a first episode of SBP. [ABSTRACT FROM AUTHOR]

Staphylococcus spp. are bacteria involved in human and animal infections. They are resistant to antimicrobials and have become a major public health concern. In recent years, there has been a significant increase in methicillin-resistant Staphylococcus strains and vancomycin is the drug of choice for the treatment of such isolates. However, the minimum inhibitory concentration (MIC) of vancomycin necessary to combat this microorganism has been showing an increase. The aim of the present study was to determine the susceptibility profile of the Staphylococcus spp. of domestic and wild animals to vancomycin, using the microdilution in broth and E-test® techniques, as well as comparing the results of both tests. Of the 50 isolates tested, 47 (94 %) were sensitive to vancomycin in the microdilution and 43 (86 %) were sensitive to vancomycin in the E-test®. Seven (14 %) isolates had an intermediate result showing a risk to public health since the detection of these isolates may precede the occurrence of isolates resistant to vancomycin. In addition, the mecA gene was detected in 78 % of the tested samples. Six of the seven isolates with intermediate resistance to vancomycin were carriers of the mecA gene, showing that these isolates had a potential risk of becoming resistant. Thus, control measures must be taken to prevent the spread of these isolates with intermediate resistance and preserve the effectiveness of this antimicrobial for the treatment of infections caused by multiresistant Staphylococcus spp. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to examine the effect of some natural compounds against multidrug-resistant bacteria. Methods: Forty-three bacterial strains were collected. Disc diffusion and minimum inhibitory concentration (MIC) tests were carried out for natural compounds including quercetin, Acacia nilotica, Syzygium aromaticum, and Holothuria atra. Scanning electron microscope analysis and bacterial DNA apoptosis assays were performed. Results: Staphylococcus aureus strains were resistant to imipenim, ampicillin, and penicillin. Most Escherichia coli strains were resistant to amoxicillin, clavulanat, and ampicillin. Finally, tigecycline was effective with Klebsiella pneumoniae and was resistant to all antibiotics. Only S aromaticum had an antibacterial effect on K pneumoniae. Most S aureus strains were sensitive to S aromaticum, A nilotica, and quercetin. All examined natural extracts had no effect on E coli . Holothuria atra had no effect on any of the strains tested. Minimum inhibitory concentration and minimum bactericidal concentration values for examined plants against S aureus were 6.25 to 12, 1.6 to 3.2, and 9.12 to 18.24 mg/mL, respectively. Syzygium aromaticum was active against K pneumoniae with an MIC of 12.5 mg/mL. Scanning electron microscope analysis performed after 24 and 48 hours of incubation showed bacterial strains with distorted shapes and severe cell wall damage. Syzygium aromaticum, quercetin, and A nilotica showed clear fragmentations of S aureus DNA. Conclusions: Current findings confirmed the beneficial effect of using natural products such as clove (S aromaticum), quercetin, and A nilotica as a promising therapy to overcome multidrug resistant bacteria. [ABSTRACT FROM AUTHOR]

Multidrug resistance mediated by β-lactamase in Gram-negative bacilli is a serious public health problem. Sewers are considered reservoirs of multiresistant bacteria due to presence of antibiotics that select them and favor their dissemination. The present study evaluated the antibiotic resistance profile and β-lactamases production in Gram-negative bacilli isolates from hospital sewage and urban wastewater treatment plants (UWWTP) in Brazil. Bacteria were isolated and identified with biochemical tests. Antibiotic susceptibility testing was performed by the disk-diffusion method and detection of extended-spectrum β-lactamase and carbapenemases by enzymatic inhibitor and conventional PCR. Differences in resistance to amoxicillin clavulanic, aztreonam, cefepime, and cefotaxime were observed in hospital sewage compared with urban sewage (p < 0.05). The multidrug-resistant phenotype was observed in 33.3% of hospital sewage isolates (p = 0.0025). β-lactamases genes were found in 35.6% of isolates, with the most frequent being blaKPC and blaTEM (17.8%), and blaSHV and blaCTX-M (13.3% and 8.9%, respectively). The data obtained are relevant, since the bacteria detected are on the priority pathogens list from the World Health Organization and hospital sewage could be released untreated into the municipal collection system, which may favor the spread of resistance. Changes in hospital sewage discharge practices, as well as additional technologies regarding effluent disinfection in the UWWTP, can prevent the spread of these bacteria into the environment and negative impact on water resources. [ABSTRACT FROM AUTHOR]

We here report the case of a 2-year-old patient with a primary central nervous system lymphoma of B-cell origin. Due to their past medical history of repeated respiratory tract infections and the marked chemotherapy-associated toxicity and infectious comorbidity, we suspected that the patient also suffered from an inherited immune deficiency disorder. Despite the lack of classical pathognomonic symptoms for ataxia teleangiectasia and missing evidence for a cancer predisposition syndrome in the family, genetic testing identified biallelic germline mutations, including the rare pathogenic variant c.3206delC (p.Pro1069Leufs*2), in the ataxia telangiectasia-mutated (ATM) gene. The case highlights the importance of searching for immune deficiency disorders associated with primary central nervous system lymphoma before treatment initiation and the urgent need to develop novel treatment strategies for cancer patients with underlying immunodeficiency syndromes.

This contribution describes the experiences with three careers: leading and building an academic research institute, heading a research area in a multinational pharma company and founding and leading a biotech company, which saw its first drug successfully enter the market in its 11th year of existence. The three positions had very different challenges, the common denominator for success was good and innovative science. However, research in a commercial environment, in addition to scientific excellence, also means to demonstrate the likely commercial success of the particular research. The most challenging, but at the same time the most interesting mission was the foundation of a new company, securing the financial means and developing the drugs, which had been discovered, in the clinics. [ABSTRACT FROM AUTHOR]

Antibiotic resistance represents a global threat. In recent years, an alarming increase in cases of infections with multidrug resistant bacteria has been reported. In this context, it is necessary to find new therapeutic approaches. Dendrimers are new artificial macromolecules with a highly branched three dimensional structure. Recently, many researchers have focused on investigating the possible applications of dendrimers in different medical fields. Dendrimers proved to be useful in the treatment of bacterial infections. They exhibit antibacterial effects or act as carriers for antibiotics. Thus, dendrimers may be a promising weapon against multidrug resistant bacteria, but several peculiarities of these molecules, like their cytotoxicity, biodisponibility, half life etc. should also be considered. [ABSTRACT FROM AUTHOR]

Colistin is used as a last-line antibiotic for the treatment of Gram-negative multiresistant bacteria. Due to its high nephrotoxicity, Therapeutic Drug Monitoring (TDM) is recommended for dose adjustment. We aimed to evaluate the available evidence of TDM in patients given colistin to treat Gram-negative infections. In this paper, we offer an overview, using an electronic search of the literature (published up to June 2019, without language restrictions) that compares the clinical outcomes and measurements of colistin TDM. Ultimately, the Therapeutic Drug Monitoring (TDM) of colistin in Plasma could prevent nephrotoxicity risk.

This study was carried out to test the essential oil from C. ambrosioides leaves and its main constituent, α-Terpinene, in an antibacterial activity assay. As well, it was evaluated ability reduce resistance to norfloxacin and ethidium bromide was compared the Staphylococcus aureus 1199B whith 1199 wild type strain. The MIC of the C. ambrosioides essential oil and α-Terpinene were determined by microdilution method. The MIC of the essential oil and α-Terpinene presented a value ≥ 1024 μg/mL. However, when associated with antibacterials, the essential oil from C. ambrosioides leaves significantly reduced the MIC of antibiotics and ethidium bromide, characterizing an efflux pump inhibition. The C. ambrosioides essential oil, despite having no direct antibacterial activity against the S. aureus 1199B strain, showed a potentiating action when associated with antibacterial agents, this being attributed to an inhibition of efflux pumps. [ABSTRACT FROM AUTHOR]

As evolutionarily optimised defence compounds, antimicrobial peptides (AMPs) represent a powerful tool against bacterial infections. Ranalexin, an AMP found in the skin of the American bullfrog ( Rana catesbeiana ), is primarily active against Gram-positive bacteria, with minimum inhibitory concentrations (MICs) of 8–16 mg/L, but shows weaker activity against Gram-negative bacteria (MICs > 64 mg/L). By substitution of six N -terminal amino acids by saturated fatty acids [decanoic acid (C10:0) to myristic acid (C14:0)], lipopeptide derivatives with enhanced antimicrobial activity were developed. The antimicrobial capacity of the peptides was tested against different bacterial strains, including multiresistant clinical isolates. C13C3lexin, the most potent derivative, showed MICs of 2–8 mg/L against Gram-positive bacteria and 2–16 mg/L against Gram-negative bacteria. In time–kill studies, it was clearly shown that ranalexin and the lipopeptide C13C3lexin function as concentration-dependent, fast-acting substances against different bacteria. Cell viability assays revealed that cytotoxicity towards human cells increases with the chain length of the attached fatty acid (IC 50 , 12.74–108.10 µg/mL). Furthermore, using positron emission tomography (PET) imaging, pharmacokinetic studies of 68 Ga-labelled ranalexin and its derivatives were performed for the first time. Here it was demonstrated that ranalexin is rapidly cleared via the kidneys within 1 h post-injection. In contrast, the lipopeptide showed greatly extended circulation in the bloodstream and a shift from renal to hepatic accumulation characteristics. Therefore, the more favourable pharmacokinetics and enhanced antimicrobial activity clearly demonstrate the potential of the lipopeptide AMPs as novel ammunition against emerging multiresistant bacterial pathogens. [ABSTRACT FROM AUTHOR]

Introduction: Urinary tract infections (UTI) in patients with neurogenic lower urinary tract dysfunction (NLUTD) are defined as complicated UTI requiring antibiotic treatment. As the emergence of multiresistant strains is a serious problem, we assessed the feasibility of nonantibiotic treatment of UTI in patients with NLUTD. Materials and Methods: In a prospective study evaluating the usefulness of UTI prophylaxis, participants could opt for either antibiotic or nonantibiotic treatment of breakthrough UTI. If either symptoms persisted for 48 h or a febrile UTI occurred, antibiotic treatment based on microbiological testing was mandatory. Treatment efficacy, complications, and emergency hospital visits were assessed. Results: Within the observation period (1 year), the 25 participants developed 206 UTI. Seven febrile UTI required immediate antibiotic treatment. Of the remaining 199 UTI, patients chose antibiotic treatment in 104 events, whereas in 95 events, patients chose either nonantibiotic interventions (n = 80) or no treatment at all (n = 15). Success rates were 78.8% for antibiotic treatment, 67.5% with nonantibiotic treatments, and 26% without therapy. Of the 7 patients with initially febrile UTI, 2 required hospitalization due to septicemia. Conclusions: Nonantibiotic treatment seems to be a feasible alternative to antibiotic therapy in patients with complicated UTI as well, provided there is no fever. [ABSTRACT FROM AUTHOR]

Until recently, it was thought that Antarctica was a sterile continent due to extreme environmental conditions. In fact, this cold continent is one of the most diverse in terms of microorganisms. In the present study, the bacterial isolate Pseudomonas sp. 6A1 was obtained from marine sediments originating from the Fildes Peninsula Bay, King George Island, Antarctica. Subsequently, this isolate was identified as Pseudomonas mandelii. To arrive at this conclusion, molecular studies were performed using the 16S rRNA and multilocus sequence analysis. Both techniques were used to construct phylogenetic trees, revealing 99.99% similarity between the 6A1 strain and P. mandelii. To provide phenotypic support for this finding, BIOLOG GN2 and API20 NE tests, as well as assimilation assays with different carbon sources, were performed. These tests revealed 87% similarity with P. mandelii. This result was primarily due to an inability of the 6A1 strain to reduce nitrates, as well as to variations in the assimilation of different carbon sources. Another important phenotypic difference was alginate hyperproduction by 6A1, a trait never before described in a P. mandelii strain. Finally, the 6A1 strain was found to present multiple antibiotic resistances. Altogether, these results confirm the first case of P. mandelii isolation from the Antarctic. [ABSTRACT FROM AUTHOR]