Etiological spectrum and antimicrobial resistance of the most frequently isolated pathogens, associated with urinary tract infections in ambulatory patients

Introduction: Urinary tract infections (UTIs) are among the most common infections both in the community and in the hospital setting.Aim: The aim of this study is to investigate the etiological spectrum and antimicrobial resistance of most frequently isolated pathogens, associated with UTIs in ambulatory patients in Varna city, Bulgaria during a seven-month period (October 2020–April 2021).Materials and Methods: A total of 1600 urine samples, collected from patients with suspected UTIs were tested. Screening for bacterial growth was done by HM&L Uroquattro instrument (ALIFAX, Italy). Species identification and antimicrobial susceptibility testing were performed by VITEK 2 Compact System (bioMerieux) and Kirby-Bauer disk diffusion method.Results: E. coli was the most commonly isolated uropathogen regardless of the age group (48%, n = 61), followed by Enterococcus faecalis (33%, n = 42) and other representatives of order Enterobacterales (13.3%, n = 18). The resistance rates in the group of Gram-negative isolates (n = 79) in decreasing order were as follows: ampicillin, 64.5% > trimethoprim/sulfamethoxazole, 36% > ciprofloxacin, 29.1% > amoxicillin-clavulanic acid, 27.8% > cefuroxime, levofloxacin, 21.5% > fosfomycin, 13.1% > ceftriaxone, 12.6% > ceftazidime, 10.1% > gentamicin, nitrofurantoin, 6.5% > nitroxoline, 4.9%. The resistance rates among the isolates of E. faecalis (n = 42) were as follows: ciprofloxacin, 28.6% > gentamicin, 23.8% > levofloxacin, 19% > nitrofurantoin, 4.7% > amoxicillin, 2.4%. No resistance to meropenem, amikacin, vancomycin, and teicoplanin was found in the studied collection of isolates (n = 127).Conclusion: The etiological spectrum of UTIs in ambulatory patients was dominated by E. coli, followed by E. faecalis. In the group of Gram-negative uropathogens, high resistance rates to ampicillin, trimethoprim/sulfamethoxazole and quinolones were detected. Third-generation cephalosporins, fosfomycin, nitrofurantoin and nitroxoline retained very good activity. Among Enterococcus faecalis isolates, the second most commonly isolated bacterial species, a decreased activity of quinolones was found too, but the aminopenicillins and nitrofurantoin remain highly active

Investigation of Bacteraemia and Invasive Fungal Infections in Patients Following Autologous and Allogeneic Hematopoietic Stem Cell Transplantation // Проучване върху бактериемиите и инвазивните микотични инфекции при пациенти след автоложна и алогенна хематопоетична стволово-клетъчна трансплантация

The study aimed to conduct a clinical-microbiological investigation on bacteraemia and invasive mycotic infections in patients after autologous and allogeneic hematopoietic stem cell transplantation, carried out in the period 01.01.2019 – 31.12.2021 at the Transplantation ward of the Clinical Haematology clinic of St. Marina University Hospital, Varna. A total of 74 patients and the obtained 107 clinically significant non-duplicate microbial isolates were studied. The incidence and risk factors for bacteraemia and invasive mycotic infections have been studied and analysed. The etiological spectrum and susceptibility to antimicrobials of microbial causative agents of bloodstream infections have been analysed. The gastrointestinal tract has been confirmed as an important source of infectious complications, and intestinal colonisation with MDR bacteria has proven to be a significant risk factor for the development of bacteraemia. Carbapenem-resistant isolate E. cloacae complex has been identified from a faecal sample carrier of blaVIM-1. Carbapenem-resistant isolate A. baumannii from blood culture, carrier of the blaOXA-48-like gene, has been identified. Carbapenem-resistant isolates Pseudomonas composti and Pseudomonas mendocina from a faecal sample have been identified as carriers of blaVIM-2. Resistance to 3-generation cephalosporins, carbapenems, methicillin and glycopeptides is associated with the blaCTX-M-15, blaVIM, mecA and vanA genes.Целта на настоящия дисертационен труд е да се извърши клинико-микробиологично прочуване върху бактериемиите и инвазивните микотични инфекции при пациенти след автоложна и алогенна хематопоетична стволово-клетъчна трансплантация, извършени в периода 01.01.2019 – 31.12.2021г. в Отделението по трансплантации към Клиника по клинична хематология на УМБАЛ „Света Марина”― гр. Варна. Проучени са общо 74 пациенти и получените от тях 107 клинично значими неповтарящи се микробни изолати. Проучени и анализирани са честотата и рисковите фактори за бактериемии и инвазивни микотични инфекции. Анализиран е етиологичният спектър и чувствителността към антимикробни лекарствени средства на микробните причинители на инфекциите на кръвта. Гастроинтестиналният тракт се потвърди като важен източник за инфекциозни усложнения, а чревната колонизация с MDR бактерии се доказа като значим рисков фактор за развитие на бактериемии. Идентифициран е карбапенем-резистентен изолат E. cloacae complex от фекална проба, носител на blaVIM-1. Идентифициран е карбапенем-резистентен изолат A. baumannii от хемокултура, носител на blaOXA-48-like гена. Идентифицирани са карбапенем-резистентни изолати Pseudomonas composti и Pseudomonas mendocina oт фекална проба като носители на blaVIM-2. Резистентността към 3-генерация цефалоспорини, карбапенеми, метицилин и гликопептиди, се асоциира с носителство на blaCTX-M-15, blaVIM, mecA и vanA гените

Species diversity and antimicrobial resistance of Staphylococcus spp. isolates associated with catheter-related bloodstream infections in patients after hematopoietic stem cell transplantation

Introduction: The human body is colonized by a large number of different bacterial and fungal species, with most microorganisms inhabiting the skin, oral cavity, and the lower parts of the gastrointestinal tract.Aim: The aim of this study was to investigate the species diversity of clinically significant Staphylococcus spp. isolates, obtained from blood cultures of patients with central venous catheter (CVC) following hematopoietic stem cell transplantation (HSCT) during the period January 2019–December 2020, as well as to test their susceptibility to a set of antimicrobials.Materials and Methods: A total of 21 non-duplicate clinically significant staphylococcal isolates from blood cultures of 17 patients with implemented CVCs following HSCT were obtained. The Bactec and Phoenix automated systems (BD, USA) were used for identification and antimicrobial susceptibility testing. Results: In the collected group of 21 isolates, 85.7% were coagulase-negative staphylococci (CoNS): S. epidermidis, n = 12; S. haemolyticus, n = 4; S. hominis, n = 2, and 3 isolates were identified as S. aureus. Methicillin resistance was 85.7% and was detected only in the CoNS group. In decreasing order, the resistance rates in CoNS group were as follows: 100% for penicillin and cefoxitin > 83.3% erythromycin > 72.2% ciprofloxacin > 61.1% gentamicin > 44.4% for clindamycin and trimethoprim/sulfamenthoxazole. No resistance to vancomycin, teicoplanin, and linezolid was found. S. aureus isolates demonstrated preserved susceptibility to all antimicrobials with exception to penicillin.Conclusion: In the present study, CoNS were identified as the most common cause of catheter-related bloodstream infections (BSIs) in patients following HSCT, with S. epidermidis being the predominant species. All CoNS isolates were methicillin-resistant, but also exhibited reduced susceptibility to other antimicrobials and thus causing difficult-to-treat infectious complications in patients after HSCT

Molecular epidemiology of carbapenem-resistant Enterobacteriaceae isolated from patients in COVID-19 wards and ICUs in a Bulgarian University Hospital

Many studies report an increase in antimicrobial resistance of Gram - negative bacteria during the COVID-19 pandemic. Our aim was to evaluate the epidemiological relationship between carbapenemresistant (CR) Enterobacteriaceae isolates from patients in COVID-19 wards and to investigate the main mechanisms of carbapenem resistance in these isolates during the period April 2020-July 2021. A total of 45 isolates were studied: Klebsiella pneumoniae (n = 37), Klebsiella oxytoca (n = 2), Enterobacter cloacae complex (n = 4) and Escherichia coli (n = 2). Multiplex PCR was used for detection of genes encoding carbapenemases from different classes (blaKPC, blaIMP, blaVIM, blaNDM, blaOXA-48). For epidemiological typing and analysis, ERIC PCR was performed. Two clinical isolates of E. cloacae, previously identified as representatives of two dominant hospital clones from the period 2014-2017, were included in the study for comparison. In the CR K. pneumoniae group, 23 (62.2%) carried blaKPC, 13 (35.1%) blaNDM, 10 (27.0%) blaVIM, and 9 (24.3%) were positive for both blaKPC and blaVIM. The blaKPC was identified also in the two isolates of K. oxytoca and blaVIM in all E. cloacae complex isolates. The two CR isolates of E. coli possessed blaKPC and blaOXA-48 genes. Epidemiological typing identified 18 ERIC profiles among K. pneumoniae, some presented as clusters of identical and/or closely related isolates. The carbapenem resistance in the studied collection of isolates is mediated mainly by blaKPC. During the COVID-19 pandemic intrahospital dissemination of CR K. pneumoniae, producing carbapenemases of different molecular classes, as well as continuing circulation of dominant hospital clones of multidrug-resistant E. cloacae complex was documented

Invasive Pulmonary Aspergillosis in Patients with Haematological Malignancies and Hematopoietic Stem Cell Transplantation: a Single-Center Study

Aim: The aim of this study was to evaluate the clinical significance of Aspergillus Galactomannan antigen (GM) test for the diagnosis of invasive pulmonary aspergillosis (IPA) in patient with hematological malignancies, including patients undergoing hematopoietic stem cell transplantation (HSCT).Materials and methods: Between January 2016 and June 2019, ninety patients were tested for GM. A total of 134 blood and 19 bronchoalveolar lavage (BAL) samples were analyzed using Platelia Aspergillus Ag Enzyme-Immuno Assay (Bio-Rad Laboratories). The median age of patients was 63 years (range 25–81). Fifty-six patients (62.2%) were male. All patients were allocated into five groups on the basis of their GM results.Results: A positive GM antigen test was detected in 16 patients (17.7%). Of these, ten had positive serum samples (group I). After re-testing, 1 patient from group I gave a negative result. Five patients with negative serum samples gave positive BAL results (group II). One patient had positive both serum and BAL samples (group III). Fifteen GM positive patients (9 from group I, group II, and III) were categorized as probable IPA. Thirty-six patients (40%) negative for GM (group IV) were considered with a possible IPA. IPA was excluded in 38 patients (42.2%) (group V). Anti-mould therapy was initiated in all 15 patients who were considered to be cases with probable IPA. IPA was the immediate cause of death in 3 cases (25%).Conclusions: Our results demonstrated the clinical applicability of the GM test for screening of IPA in high-risk patients with hematological malignancies and HSCT

Retinopathy of prematurity screening: evaluation of a first screening

Purpose: Retinopathy of prematurity (ROP) screening concerns preterm infants born before 32 weeks of amenorrhea and/or weighting less than 1500 grams. First screening occurs usually 4 to 6 weeks after birth and always after 31 weeks of amenorrhea. The purpose of this study was to investigate the number of examinations performed before the first signs of retinopathy, in order to determine the best time for first screening.Methods: This retrospective study enrolled preterm infants born before 32 weeks of amenorrhea and/or weighting less than 1500 grams in the University Hospital of Dijon, France, between 11/15/2012 and 12/31/2013. All preterm babies benefited from a ROP screening by fundus photography with a wide field camera. First screening was realized 4 to 6 weeks after birth and after 31 weeks of amenorrhea. All photographs were analysed. Population characteristics, number of examinations before first signs of retinopathy, term at first examination, at first signs of retinopathy and at the most severe signs of retinopathy were noted.Results: Hundred and eight preterm infants were enrolled; 33 were affected by ROP. Median [IQR] term was 29.6 [27.0 ; 31.0] weeks of amenorrhea. Median weight was 1118 [915 ; 1431] grams. Median number of examinations in preterm infants with ROP was 7 [4 ; 9]. Median term at first screening, at first signs of retinopathy and at more severe signs of retinopathy were 31.7 [30.9 ; 32.1], 33.7 [32.3 ; 35.0], 36.9 [35.6 ; 37.9] weeks of amenorrhea, respectively. Median number of examinations before first signs of retinopathy was 1 [1 ; 2]. In 25 preterm infants weighting less than 1000 grams, median term at first signs of retinopathy was 33.3 [32.3 ; 34.6], versus 34.8 [34.3 ; 35.2] in 8 preterm infants weighting more than 1000 grams (p=0.03).Conclusions: In ROP, the time of first screening is not well defined. According to our series, a first screening at 33 weeks of amenorrhea seems optimal

Alteration of erythrocyte membrane polyunsaturated fatty acids in preterm newborns with retinopathy of prematurity

Projet OmegaROP.International audienceExtremely preterm infants are at high risk for retinopathy of prematurity (ROP), a potentially blinding disease characterized by abnormalities in retinal vascularization. Whereas animal studies revealed that n-3 polyunsaturated fatty acids (PUFAs) may be of benefit in preventing ROP, human studies conducted on preterm infants during the 1st weeks of life showed no association between blood n-3 PUFA bioavailability and ROP incidence and/or severity, probably because of the influence of nutrition on the lipid status of infants. In the OmegaROP prospective cohort study, we characterized the erythrocyte concentrations of PUFAs in preterm infants aged less than 29 weeks gestational age (GA) without any nutritional influence. We show that GA is positively associated with the erythrocyte n-6 to n-3 PUFA ratio, and particularly with the ratio of arachidonic acid (AA) to docosahexaenoic acid (DHA), in infants with ROP. A time-dependent accumulation of AA at the expense of DHA seems to occur in utero in erythrocytes of preterm infants who will develop ROP, thus reinforcing previous data on the beneficial properties of DHA on this disease. In addition, preliminary data on maternal erythrocyte membrane lipid concentrations suggest modifications in placental transfer of fatty acids. Documenting the erythrocyte AA to DHA ratio at birth in larger cohorts might be useful to set up new prognostic factors for ROP

Modification of erythrocyte membrane phospholipid composition in preterm newborns with retinopathy of prematurity: The omegaROP study

International audienceN-3 polyunsaturated fatty acids (PUFAs) may prevent retinal vascular abnormalities observed in oxygen-induced retinopathy, a model of retinopathy of prematurity (ROP). In the OmegaROP prospective cohort study, we showed that preterm infants who will develop ROP accumulate the n-6 PUFA arachidonic acid (ARA) at the expense of the n-3 PUFA docosahexaenoic acid (DHA) in erythrocytes with advancing gestational age (GA). As mice lacking plasmalogens ―That are specific phospholipids considered as reservoirs of n-6 and n-3 PUFAs― Display a ROP-like phenotype, the aim of this study was to determine whether plasmalogens are responsible for the changes observed in subjects from the OmegaROP study. Accordingly, preterm infants aged less than 29 weeks GA were recruited at birth in the Neonatal Intensive Care Unit of University Hospital Dijon, France. Blood was sampled very early after birth to avoid any nutritional influence on its lipid composition. The lipid composition of erythrocytes and the structure of phospholipids including plasmalogens were determined by global lipidomics using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). LC-HRMS data confirmed our previous observations by showing a negative association between the erythrocyte content in phospholipid esterified to n-6 PUFAs and GA in infants without ROP (rho = −0.485, p = 0.013 and rho = −0.477, p = 0.015 for ethanolamine and choline total phospholipids, respectively). Phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) species with ARA, namely PtdCho16:0/20:4 (rho = −0.511, p < 0.01) and PtdEtn18:1/20:4 (rho = −0.479, p = 0.015), were the major contributors to the relationship observed. On the contrary, preterm infants developing ROP displayed negative association between PtdEtn species with n-3 PUFAs and GA (rho = −0.380, p = 0.034). They were also characterized by a positive association between GA and the ratio of ethanolamine plasmalogens (PlsEtn) with n-6 PUFA to PlsEtn with n-3 PUFAs (rho = 0.420, p = 0.029), as well as the ratio of PlsEtn with ARA to PlsEtn with DHA (rho = 0.843, p = 0.011). Altogether, these data confirm the potential accumulation of n-6 PUFAs with advancing GA in erythrocytes of infants developing ROP. These changes may be partly due to plasmalogens