Multiresistant Acinetobacter Baumannii Research Articles

Comparing the Outcomes of Cefoperazone/Sulbactam-Based and Non-Cefoperazone/Sulbactam-Based Therapeutic Regimens in Patients with Multiresistant Acinetobacter baumannii Infections-A Meta-Analysis.

The addition of sulbactam restores the complete range of cefoperazone activity against bacteria and extends its spectrum of action to include the Acinetobacter species. The effectiveness of cefoperazone/sulbactam against multiresistant Acinetobacter baumannii has not been investigated. The purpose of the current meta-analysis was to compare the efficacy of cefoperazone/sulbactam-based therapeutic regimens and non-cefoperazone/sulbactam-based therapeutic regimens in the treatment of multiresistant Acinetobacter baumannii infections. The current meta-analysis of 10 retrospective studies provides evidence that cefoperazone/sulbactam-based therapeutic regimens are superior to non-cefoperazone/sulbactam-based therapeutic regimens in terms of 30-day mortality and clinical improvement in patients with multiresistant Acinetobacter baumannii infections. The risk of mortality was reduced by 38% among multiresistant Acinetobacter baumannii infections in patients who received cefoperazone/sulbactam-based therapeutic regimens. The cefoperazone/sulbactam-based combination therapy was superior to the cefoperazone/sulbactam monotherapy in terms of 30-day mortality when both therapeutic regimens were compared to the tigecycline monotherapy in patients with multiresistant Acinetobacter baumannii infections.

Microencapsulation of Origanum heracleoticum L. and Thymus vulgaris L. essential oils – Novel strategy to combat multi-resistant Acinetobacter baumannii

Within the global rise of antimicrobial resistance enhanced by the COVID-19 pandemic, where Acinetobacter baumannii has been distinguished as an emerging multi-resistant pathogen, essential oils, become the focus of novel therapeutic approaches. Hypothesizing that encapsulated Origanum heracleoticum L. and Thymus vulgaris L. essential oils could express multi-target approach against A. baumannii, this study aimed to develop microencapsulated systems with optimal technological qualities using 2-hydroxypropyl-β-cyclodextrin as a carrier, and to evaluate their pharmacological potential against A. baumannii, and their morphological and physicochemical characteristics, safety and stability profiles. The highest yield and encapsulation efficiency were obtained with 1:10 essential oil to carrier, and 1.5:10 carrier to water w/w ratios. The formation of inclusion complexes was confirmed by Fourier Transform Infrared Spectroscopy. Both microencapsulates achieved improved homogeneity, particle surface, and thermal stability compared with the pure carrier. Dominant bioactive compounds (carvacrol and p-cymene in O. heracleoticum essential oil, and thymol and p-cymene in T. vulgaris essential oil) remained the most abundant after encapsulation. While non-encapsulated essential oils revealed similar antimicrobial activity towards clinical A. baumannii isolates obtained from COVID-19 patients, encapsulated O. heracleoticum essential oil inhibited the bacterial growth at lower concentrations than T. vulgaris essential oil microencapsulate. All samples significantly reduced the formation of A. baumannii biofilm, for at least 53.90% towards the most infective isolate according to the Caenorhabditis elegans assay. Further, in silico molecular docking study revealed strong interaction pattern of carvacrol and thymol with the outer membrane protein A, which is the main factor for the A. baumannii biofilm formation. Cytotoxicity investigation on human lung A549 cells showed high survival rate in the presence of all tested concentrations, and the stability study revealed notable preservation of the bioactives’ content and pharmacological potential. Altogether, microencapsulated essential oils exhibited a multi-target approach towards A. baumannii, with satisfactory preserving capability during storage.

Bacteriological aspects of bacteremia in the intensive care unit of the Mohammed V Military Hospital: 10 months prospective study.

Bacteremia is responsible for high rates of morbidity and mortality. The increasing prevalence of multidrug-resistant (MDR) bacteria in intensive care units (ICU) is a growing concern. Hence, prior knowledge of bacterial epidemiology and resistance phenotypes is required to optimize these infections' management. The objective of this study was to determine the epidemiological profile of bacteremia in ICU settings, as well as the place occupied by MDR bacteria in these infections. It is a prospective study carried out over 10 months on episodes of bacteremia in the ICU of Mohammed V Military Teaching Hospital (Rabat, Morocco). Microorganism growth was detected using fluorescent technology, species identification was based on morphological and biochemical characteristics. Antimicrobial susceptibility testing was performed following the recommendations of the Antibiogram Committee of the French Society of Microbiology (CA-SFM) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Among 504 hospitalized patients, sixty-one (12.1%) presented at least one episode of bacteremia. Forty patients (65.6% of bacteremic patients) presented at least one episode of bacteremia due to MDR bacteria. Male gender, cardiovascular diseases, diabetes and previous hospitalization were significant risk factors for the acquisition of MDR bacteremia. Isolated bacteria were mainly Gram-negative bacilli (GNB) (n = 62; 68.9%) dominated by Acinetobacter baumannii (n = 19; 21.1%) and Klebsiella pneumoniae (n = 16; 17.8%). MDR bacteria were represented by multi-resistant Acinetobacter baumannii (n = 19; 44.2%), extended-spectrum beta-lactamases-producing Enterobacterales (n = 9; 20.9%) and carbapenem-resistant Enterobacterales (n = 7; 16.3%). Carbapenems (n = 40; 65.6%), Aminoglycosides (n = 32; 52.5%) and Polypeptides (n = 24; 39.3%) were the most used antimicrobials. Mortality rates were 66.6% (n = 40) and 85% (n = 43) in patients with non MDR bacteremia and MDR bacteremia respectively. Limiting the spread of MDR bacteria and improving the management of bacteremic patients require continuous monitoring of bacteremia as well as adapting the therapeutic and preventive strategy.

Selection and Identification of a DNA Aptamer for Multidrug-Resistant Acinetobacter baumannii Using an In-House Cell-SELEX Methodology.

Infections caused by multidrug-resistant A. baumannii are a worldwide health concern with high mortality rates. Rapid identification of this infectious agent is critical as it can easily spread with difficult or no options for treatment. In this context, the development of reliable and economically viable detection and therapeutic methodologies are still challenging. One of the promising solutions is the development of nucleic acid aptamers capable of interacting with bacteria. These aptamers can be used for specific recognition of infectious agents as well as for blocking their functions. Cell-SELEX technology currently allows the selection and identification of aptamers and is flexible enough to target molecules present in an entire bacterial cell without their prior knowledge. However, the aptamer technology is still facing many challenges, such as the complexity of the screening process. Here, we describe the selection and identification of a new aptamer A01, using an in-house whole-cell SELEX-based methodology, against multi-resistant Acinetobacter baumannii, with rapid execution and low cost. In addition, this protocol allowed the identification of the aptamer A01 with the whole A. baumannii cell as a target. The aptamer A01 demonstrated a binding preference to A. baumannii when compared to K. pneumoniae, C. albicans, and S. aureus in fluorescence assays. Although the time-kill assay did not show an effect on bacterial growth, the potential bactericidal or bacteriostatic cannot be totally discarded. The new categorized aptamer (A01) displayed a significant binding affinity to MDR A. baumannii.

Phenotypic and Molecular Characterization of Nonfermenting Gram-Negative Bacilli Causing Peritonitis in Peritoneal Dialysis Patients.

(1) Background: Peritonitis due to nonfermenting Gram-negative bacilli (NF-GNB) is a dramatic complication of peritoneal dialysis (PD) with bad outcomes. Previous studies of PD-related peritonitis due to Pseudomonas species have shown a low-resolution rate, without a high resistance rate to antipseudomonal antibiotics. This suggests that bacterial virulence factors can act and influence peritonitis evolution. This study aimed to describe the microbiological characteristics of NF-GNB causing PD-related peritonitis and analyze their influence on the outcome. (2) Methods: We analyze the 48 isolates from NF-GNB peritonitis, which were stored in our culture collection regarding bacterial resistance, biofilm, and other virulence factors’ production, and clonal profile. Additionally, we collected data on treatment and outcomes from patients’ clinical registers. (3) Results: The etiologies were species of Pseudomonas (50%), Acinetobacter (36%), and other NF-GNB (14%). There was a high (75%) proportion of biofilm producer lineages. The in vitro susceptibility rate of Pseudomonas spp. to amikacin, ciprofloxacin, and ceftazidime was significantly greater than that of Acinetobacter spp. and other species; however, there was a similar low-resolution rate (<45%) among the episodes attributable to them. Pseudomonas species have a polyclonal profile, while we found a clone of five multiresistant Acinetobacter baumannii over an 8-year interval (2000–2008), which suggest an origin from the healthcare environment. (4) Conclusions: We are not able to identify any predictor of outcome, but it is possible that biofilm and others virulence factors can act in concert and contribute to the bad outcome.

Aerosolized antibiotics – can they save us?

Introduction. In neonatal intensive care units, a serious complication for critical ill patients is represented by ventilator-associated pneumonia (VAP), most often caused by multiresistant Gram-negative bacteria. The treatment of this condition is very challenging, and neonatologists must take into consideration the side effects of broad-spectrum intravenous medications. According to different studies, aerosolized antibiotics could be efficient and safe for treating pulmonary infections in newborns. Case presentation. We report three cases of two extremely low birth weight (ELBW) premature babies and one late preterm with asphyxia who required long-term ventilatory support and who subsequently developed VAP, with the aggravation of their condition. Cultures from tracheal aspirates identified multiresistant Acinetobacter baumannii, rising issues regarding the therapeutic strategy. Colistin is a drug known to be active on most species of Acinetobacter in vitro, but for small premature babies there are concerns regarding its nephro- and neurotoxicity. Therefore, we chose to treat our patients with inhalatory colistimethate sodium for 14-21 days, given twice a day, as monotherapy in one case and as adjunctive therapy in the others, with clinical and bacteriological resolution. All babies could have been extubated and had a good respiratory outcome. Conclusions. In newborns with multiresistant VAP, aerosolized antibiotics can be beneficial and without systemic effects. The doses and regimens are yet to be standardized, but our experience confirms the studies that demonstrate this is a valid treatment which can be used alone or in association with intravenous antibiotics.

Pegylated LyeTx I-b peptide is effective against carbapenem-resistant Acinetobacter baumannii in an in vivo model of pneumonia and shows reduced toxicity

The World Health Organization (WHO) has been warning about the importance of developing new drugs against superbugs. Antimicrobial peptides are an alternative in this context, most of them being involved in innate immunity, acting in various ways, and some even showing synergism with commercial antimicrobial agents. LyeTx I-b is a synthetic peptide derived from native LyeTx I, originally isolated from Lycosa erythrognatha spider venom. Although LyeTx I-b is active against several multidrug-resistant bacteria, it shows some hemolytic and cytotoxic effects. To overcome this hindrance, in the present study we PEGylated LyeTx I-b and evaluated its toxicity and in vitro and in vivo activities on pneumonia caused by multi-resistant Acinetobacter baumannii. PEGylated LyeTx I-b (LyeTx I-bPEG) maintained the same MIC value as the non– PEGylated peptide, showed anti-biofilm activity, synergistic effect with commercial antimicrobial agents, and did not induce resistance. Moreover, in vivo experiments showed its activity against pneumonia. Additionally, LyeTx I-bPEG reduced hemolysis up to 10 times, was approximately 2 times less cytotoxic to HEK-293 cells and 4 times less toxic to mice in acute toxicity models, compared to LyeTx I-b. Our results show LyeTx I-bPEG as a promising antimicrobial candidate, significantly active against pneumonia caused by multidrug-resistant A. baumannii.

Necrotizing descending mediastinitis by Acinetobacter Baumannii in an out-patient: a case report

BackgroundComplicated cervico-facial cellulitis is an infectious disease which can have fatal prognosis. Necrotizing descending mediastinitis is a rare and fatal complication of cervico-thoracic cellulitis. This is the case of necrotizing descending mediastinitis complicating by a multi-resistant Acinetobacter Baumannii in a 27-year-old female, with early management of hemodynamic, respiratory and surgical emergencies, and very careful post-operative care, resulting in very satisfying outcome.Case presentationThe patient presented was first treated with broad spectrum antibiotics for Ludwig’s angina for 10 days, then presented with a swelling of sub-mandibular, sub-mental, and cervical regions, a mild respiratory distress, with clinical enhancement of dyspnea in proclive position, tachycardia of 100 beats per minute, and arterial blood pressure of 10/5.Clinical exam showed a tight trismus, with oral opening inferior to 1 cm, no inflammatory signs in facial and cervical swollen areas, and a saturation of 95% in proclive position. Auscultation suspected a pericardial effusion.CT scan with and without injected contrast medium showed diffuse abscesses of sub-mental, sub-mandibular, retro-pharyngeal, para-pharyngeal regions, along with mediastinal abscesses and pericardial effusion. Trans-thoracic ultrasound showed 2 cm pericardial effusion, preserved function of myocardium, and without signs of tamponade.The diagnosis of necrotizing descending mediastinitis with pericardial effusion was established.The patient underwent a course of wide spectrum antibiotic therapy, low doses of cathecholamine, and a surgical drainage through cervical approach of all implicated zones. The surgical dissection was thorough and difficult due to diffuse fibrosis found in tissues of cervical regions. Two hundred milliliters of pus was evacuated, with a placement of surgical drains and Delbet blades.Bacteriological exam found an Acinetobacter Baumannii sensitive to colistin only.The post-operative outcome showed clinical and biological enhancement; however, a residual mediastinal collection appeared in control CT scan after 48 h, which indicated a surgical revision through mediastinoscopy.The post-operative outcome was satisfying with stabilized clinical, biological, and radiological aspects.ConclusionsNecrotizing descending mediastinitis is an infectious disease correlated with a very elevated mortality rate, and management is based on airway control, antibiotic therapy, and surgical treatment, as well as the post-operative intensive unit care.Early diagnosis and appropriate management enhances outcome and decreases mortality significantly.

ANTIMICROBIAL THERAPY DURING CANCER TREATMENT: A CASE REPORT

Introduction. Penile cancer (pc) is a rare cancer. The standardized incidence rate of pc in russia is 0.82 cases per 100,000 males. On average, 58 % of patients (20–96 %) with pc have a local infection process: tumor decay, the presence of erosion, tumor ulceration, inflammatory changes in regional lymph nodes, etc. During hospitalization nosocomial pathogens may be possible causes of infection in ulcerative lesions.The aim of the study was to present the results of the treatment of tumor ulcer in a patient with penile cancer infected with multiresistant acinetobacter baumannii and klebsiella pneumoniae.Material and methods. We present a clinical observation of 54-year-old patient diagnosed with penile cancer pt4n3m0, with ulceration of the tumor, localized at the root of the penis and ulceration of metastatic lymph nodes in the left inguinal region and subsequent infection with highly resistant nosocomial microorganisms.Results. The patient received 6 courses of paclitaxel, ifosfamide and cisplatin with clinical effect, such as significant reduction of the tumor and therapeutic pathomorphosis of 3-rd degree. Then ileo-inguinal lymphadenectomy was performed on the left. A few months later the tumor continued to grow in the left groin area. During the 2nd line of chemotherapy (cisplatin, docetaxel and capecitabine), the patient had grade iii–iv neutropenia, febrile neutropenia. High fever and localized infection in the area of tumor ulceration with multiresistant hospital microorganisms was detected. Combined antibiotic therapy had temporary effect. After isolation of multiresistant carbapenemresistant k. Pneumoniae from the ulcer, the patient was prescribed ceftazidim/avibactam 2.5 g 3 times a day. Clinical effect, such as defervescence and significant reduction of the ulceration zone was seen subsequently.Conclusion. Etiotropic antibacterial therapy of the infected tumor ulcer resulted in a significant reduction in the manifestation of the infection process, allowing antitumor therapy to be continued, as well as surgery to be performed.

Chemical Profiling, Antioxidant and Antibacterial Activities of Essential Oil From Englerastrum gracillimum Th. C. E. Fries Growing in Niger

In the present study, the chemical composition, antioxidant and antibacterial activities of the essential oil obtained by hydrodistillation of the aerial parts of Englerastrum gracillimum Th. C. E. Fries growing in Niger were investigated. Gas chromatography-mass spectrometry (GC–MS) analysis of the essential oil resulted in the identification of 42 compounds representing 97.9% of the total oil constituents. The major compounds of the essential oil were: α-humulene (30.5%), followed by cubenol (19.8%), γ-muurolene (14.0%), ( E)-β-caryophyllene (5.8%), β-gurjunene (5.2%), and curzerene (4.9%). The antioxidant activity of the essential oil was determined by using the free radical-scavenging activity (2,2 diphenyl-1-picrylhydrazyl: DPPH˙) and ferric reducing antioxidant power assays. The essential oil showed good antioxidant potential with both methods. The antibacterial activity was evaluated against multi-resistant Acinetobacter baumannii P1483, extended-spectrum β-lactamase (ESBL) -Escherichia coli Bu8566, Salmonella spp. H1548, Proteus mirabilis Bu190 , Enterobacter cloacae Bu147, Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 700603), methicillin-resistant Staphylococcus aureus P1123, Enterococcus faecium H3434, and Staphylococcus aureus (ATCC 25923) using the agar disc diffusion and microdilution methods. The essential oil exhibited good antibacterial activity. The highest antibacterial effect was observed against Staphylococcus aureus ATCC 25923 and methicillin-resistant Staphylococcus aureus P1123 with minimal inhibitory concentration (MIC) values of 0.03 mg/mL and 0.06 mg/mL, respectively. These data are of scientific importance for the valorization of aromatic and medicinal plants of Niger, especially E. gracillimum. This study reports for the first time the antioxidant and antibacterial activities of this essential oil.

Multi-resistant Acinetobacter baumannii emergence associated with healthcare infections: Meta-analysis

The high resistance to antimicrobials has made hospitals a potentially dangerous environment for the development of HAIs, especially when associated with multi-resistant bacteria such as A. baumannii. The work aimed to evaluate the incidence of multidrug-resistant Acinetobacter baumannii described in the literature through a meta-analysis. A meta-analysis of a qualitative and quantitative nature was carried out in which original articles and review articles that presented data on the occurrence and existence of multidrug resistance in Acinetobacter baumannii were evaluated. The Scientific Electronic Library on Line (SciELO) and Medical Literature Analysis and Retrieval System Online (Pubmed / MEDLINE) databases were consulted using the descriptors "Acinetobacter baumannii," "multi-resistance," "IRAS," "incidence." Most studies were carried out in 2018. In general, most studies were cross-sectional 85.00% (n = 17) and cohort 15.00% (n = 3). In the selected studies, 5877 cases were reported, of which 3544 corresponded to multi-resistant species of Acinetobacter. The cumulative prevalence ratio corresponded to 0.603 with a 95% confidence interval [0.590 to 0.615]. The analysis of the temporal trend of the Ratio of the prevalence of multidrug-resistant Acinetobacter baumanni according to the year of the selected studies indicated that the PR suffered a decline in 2009 and 2013 and a new tendency to increase from 2015 and suffered small fluctuations until 2019, the trend did not show significant (R2 = 0.0772). Therefore, the MDR profile is worrying, given the currently available therapeutic alternatives.

Antibacterial Activity of Endostemon tereticaulis (Poir.) M. Ashby Essential Oil and Ethanolic Extract Against Resistant Pathogenic Bacteria

Endostemon tereticaulis (poir.) M.Ashby is a species of the Lamiaceae family present in Niger. This plant is used in traditional medicine due to its various biological potentialities. The present study investigated the chemical composition of the essential oil and the antibacterial activity of the essential oil and ethanolic extract of Endostemon tereticaulis against resistant pathogenic bacteria. Gas chromatography-mass spectrometry analysis of the essential oil led to the identification of 43 compounds representing 99.55% of the total essential oil. The major components were caryophyllene oxide (15.17%) followed by α-humulene (13.96%), α-copaene (11.75%), ( E)-β-caryophyllene (8.44%), and δ-cadinene (6.78%). The antibacterial activity was tested against multiresistant Acinetobacter baumannii P1483, Salmonella spp. H1548, extended-spectrum β-lactamase- Escherichia coli Bu8566, Enterobacter cloacae Bu147, Proteus mirabilis Bu190 , Pseudomonas aeruginosa (ATCC 27853), Klebsiella pneumoniae (ATCC 700603), Escherichia coli (ATCC 25922), Enterococcus faecium H3434, methicillin-resistant Staphylococcus aureus P1123, and Staphylococcus aureus (ATCC 25923). The antibacterial assays revealed that the essential oil was more active than the ethanolic extract against the studied bacteria with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values ranging from 0.06 to 2 mg/mL. Also, the ethanolic extract was effective against the bacteria tested with MIC and MBC values ranging from 0.12 to 3 mg/mL. This study showed that Endostemon tereticaulis essential oil is rich in bioactive compounds. Ethanolic extract and essential oil exhibited potential antibacterial activity. These results provide a scientific basis for the use of this plant in traditional medicine. The current study described for the first time the antibacterial activity of Endostemon tereticaulis.

Antimicrobial property of halogenated catechols

Bacterial infection associated with multidrug resistance (MDR) bacteria is increasingly becoming a significant public health risk. Herein, we synthesized a series of halogenated dopamine methacrylamide (DMA), which contains a catechol side chain modified with either chloro-, bromo-, or iodo-functional group. Catechol is a widely used adhesive moiety for designing bioadhesives and coatings. However, the intrinsic antimicrobial property of catechol has not been demonstrated before. These halogenated DMA were incorporated into hydrogels, copolymers, and coatings and exhibited more than 99% killing efficiencies against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. More importantly, hydrogel containing chlorinated DMA demonstrated broad-spectrum antimicrobial activities towards multiple MDR bacteria, which included methicillin resistant S. aureus (MRSA), vancomycin resistant enterococci (VRE), multi antibiotics resistant Pseudomonas aeruginosa (PAER), multi antibiotics resistant Acinetobacter baumannii (AB) and carbapenem resistant Klebsiella pneumoniae (CRKP). These hydrogels also demonstrated the ability to kill bacteria in a biofilm while exhibiting low cytotoxic. Based on molecular docking and molecular dynamics simulation, Cl-functionalized catechol can potentially inhibit bacterial fatty acid synthesis at the enoyl-acyl carrier protein reductase (FabI) step. The combination of moisture-resistant adhesive property, inherent antimicrobial property, and the versatility of incorporating halogenated DMA into different polymeric materials greatly enhanced the potential for using these monomers for designing multifunctional bioadhesives and coatings.

Combined Use of the Ab105-2φΔCI Lytic Mutant Phage and Different Antibiotics in Clinical Isolates of Multi-Resistant Acinetobacter baumannii.

Phage therapy is an abandoned antimicrobial therapy that has been resumed in recent years. In this study, we mutated a lysogenic phage from Acinetobacter baumannii into a lytic phage (Ab105-2phiΔCI) that displayed antimicrobial activity against A. baumannii clinical strain Ab177_GEIH-2000 (isolated in the GEIH-REIPI Spanish Multicenter A. baumannii Study II 2000/2010, Umbrella Genbank Bioproject PRJNA422585, and for which meropenem and imipenem MICs of respectively, 32 µg/mL, and 16 µg/mL were obtained). We observed an in vitro synergistic antimicrobial effect (reduction of 4 log–7 log CFU/mL) between meropenem and the lytic phage in all combinations analyzed (Ab105-2phiΔCI mutant at 0.1, 1 and 10 MOI and meropenem at 1/4 and 1/8 MIC). Moreover, bacterial growth was reduced by 8 log CFU/mL for the combination of imipenem at 1/4 MIC plus lytic phage (Ab105-2phiΔCI mutant) and by 4 log CFU/mL for the combination of imipenem at 1/8 MIC plus lytic phage (Ab105-2phiΔCI mutant) at both MOI 1 and 10. These results were confirmed in an in vivo model (G. mellonella), and the combination of imipenem and mutant Ab105-2phiΔCI was most effective (p < 0.05). This approach could help to reduce the emergence of phage resistant bacteria and restore sensitivity to antibiotics used to combat multi-resistant strains of Acinetobacter baumannii.

Molecular characterization of carbapenem-resistant Acinetobacter baumannii using WGS revealed missed transmission events in Germany from 2012-15.

Infection and colonization with multi-resistant Acinetobacter baumannii causes therapeutic and economic problems in the nosocomial setting. Due to the sensitivity issue of screening schemes for A. baumannii, it is difficult to implement adequate transmission prevention measures. The high discriminatory power of WGS for transmission-chain analysis provides us with the necessary tool to study and identify transmission events. We retrospectively sequenced and analysed 39 A. baumannii isolates from 2012-15 to search for possible missed transmission events. Molecular typing by WGS was performed for non-repetitive (n=39) carbapenem-resistant A. baumannii. Retrospective assessment of patient records was performed to investigate and confirm possible transmission events. Between July 2012 and September 2015, A. baumannii was isolated from 268 patients, of which 16% (42/268) were carbapenem resistant. Thirty-nine of these isolates were recoverable and sequenced. Fifteen percent (6/39) of these were resistant to all antibiotics tested. Most isolates belong to the circulating IC2 clonal type. SNP analysis revealed four potential outbreak clusters. Two of these clusters showed high concordance with the local spatio-temporal epidemiology, suggesting that transmission events were very likely. Our data suggest that there were two independent transmission events, which would have been missed by conventional MLST owing to high clonality. The routine implementation of WGS can optimize surveillance and initiation of suitable containment measures. In addition, emerging resistance to salvage therapy is a major therapeutic problem and should be monitored closely.

INFECTIONS CAUSED BY ACINETOBACTER BAUMANNII IN CANCER PATIENTS

The purpose of the study was to evaluate the frequency of isolation of multi-resistant Acinetobacter baumannii in cancer patients and identify the mechanisms of resistance to carbapenems.Material and Methods. We analyzed 942 strains of A. baumannii isolated from clinical samples of cancer patients in the period 2014–16. The level of resistance to ampicillin-sulbactam, piperacillin-tazobactam, ceftazidime, cefepime, imipenem, meropenem, ciprofloxacin, amikacin, and to other antibiotics was determined. Carbapenem-resistant (Car-R) strains were examined for the presence of carbapenemases.Results. Between 2014 and 2016, the number of strains resistant to: ampicillin-sulbactam was 95.5–74.6 % (p≤0.0001), piperacillin – tazobactam 64.3–98.1 % (p&lt;0.01), ceftazidime – 66.1–44.3 % (p≤0.0001), cefepime – 94.7–98.3 % (p≤0.01), ciprofloxacin – 95.8–91.8 % (p&lt;0.05), amikacin – 77.7–91.0 % (p≤0.0001). An increase in the number of Car-R strains from 77.2 % in 2014 to 84.1 % in 2015 (p&lt;0.05) and up to 90.0 % in 2016 (p&lt;0.05) was observed. The resistance to imipenem was 100 %. The analysis of 6 strains in relation to acquired carbapenemases revealed the production of serine carbapenemases of the OXA-23 group in 100 % of cases.Conclusion. A. baumannii remains to be highly resistant to almost all classes of antibiotics, and the resistance to carbapenems is caused by the production of carbapenemases OXA-23.

Synergistic Effect of Ceftazidime-Avibactam with Meropenem against Panresistant, Carbapenemase-Harboring Acinetobacter baumannii and Serratia marcescens Investigated Using Time-Kill and Disk Approximation Assays.

Susceptibility of ceftazidime-avibactam and in vitro synergy with meropenem were investigated using disk approximation and time-kill assays against 11 multiresistant Acinetobacter baumannii isolates harboring oxacillinases and 5 Serratia marcescens isolates carrying blaKPC-2 Ceftazidime-avibactam was very active and synergistic with meropenem against multiresistant S. marcescens isolates. On the other hand, only the A. baumannii isolates coharboring blaOXA-23 and blaOXA-117 displayed synergy. The disk approximation technique presented good sensitivity for synergism in S. marcescens infection.

Karbapeneme dirençli, çoklu ilaç direnci fenotipi gösteren Acinetobacter baumannii suşlarında polimiksin B, minosiklin, kolistin ve fosfomisin duyarlılıklarının belirlenmesi

Objective: In this study, the sensitivity of minocycline, polymyxin B, cholestin and phosphomycin to carbapenem resistant multiresistant Acinetobacter baumannii (A. baumannii) strains (resistant to three or more antibiotic groups) isolated from patients in Ankara Training and Research Hospital It was aimed.Material and Method: Eighty nosocomial A. baumanii strains with a carbapenem resistant multidrug resistance phenotype were included in the study. Sensitivities of minocycline, polymyxin B and phosphomycin were determined by disc diffusion test and colistin susceptibility test by disk diffusion and E-test methods.Results: Eighty (100%) polymyxin B, 75 (93,75%) minocycline sensitive and 4 (5%) medium susceptible to 80 carbapenem resistant A.baumannii strains were evaluated by disc diffusion method. 75 (93.5%) were sensitive to colistin, 5 (6.25%) were moderately sensitive to colistin and 2 (2.5%) were sensitive to phosphomycin. By e-test, all 80 strains (100%) were detected as susceptible to colistin. The MIC range for colistin was 0.125-1.5 μg / ml, the MIC 50 value was 025 μg / ml (the MIC range was found to be 0.5 μg / ml). Conclusion: Polymyxin B and minocycline could be used in therapy because phosphomycin B and susceptibility rates were high in empirical treatment of carbamazepine resistant multispecific A.baumannii strains in our hospital. Phosphomycin could not be used in treatment because of high resistance rate.

Genetic Relationship of Multi-Resistant Acinetobacter baumannii Isolates in Kingdom of Saudi Arabia

Genetic Relationship of Multi-Resistant Acinetobacter baumannii Isolates in Kingdom of Saudi Arabia

High rates of meticillin-resistant Staphylococcus aureus among asylum seekers and refugees admitted to Helsinki University Hospital, 2010 to 2017.

IntroductionAntimicrobial resistance is increasing rapidly in countries with low hygiene levels and poorly controlled antimicrobial use. The spread of resistant bacteria poses a threat to healthcare worldwide. Refugees and migrants from high-prevalence countries may add to a rise in multidrug-resistant (MDR) bacteria in low-prevalence countries. However, respective data are scarce.MethodsWe retrospectively collected microbiological and clinical data from asylum seekers and refugees treated at Helsinki University Hospital between January 2010 and August 2017.ResultsOf 447 asylum seekers and refugees (Iraq: 46.5%; Afghanistan: 10.3%; Syria: 9.6%, Somalia: 6.9%); 45.0% were colonised by MDR bacteria: 32.9% had extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE), 21.3% meticillin-resistant Staphylococcus aureus (MRSA), 0.7% carbapenemase-producing Enterobacteriaceae (CPE), 0.4% multiresistant Pseudomonas aeruginosa (MRPA), 0.4% multiresistant Acinetobacter baumannii (MRAB); no vancomycin-resistant Enterococcus (VRE) were found. Two or more MDR bacteria strains were recorded for 12.5% of patients. Multivariable analysis revealed geographical region and prior surgery outside Nordic countries as risk factors of MRSA colonisation. Young age (< 6 years old), short time from arrival to first sample, and prior hospitalisation outside Nordic countries were risk factors of ESBL-PE colonisation.ConclusionWe found MDR bacterial colonisation to be common among asylum seekers and refugees arriving from current conflict zones. In particular we found a high prevalence of MRSA. Refugees and migrants should, therefore, be included among risk populations requiring MDR screening and infection control measures at hospitals.