Olympia ZarkotouTzaneio General Hospital of Piraeus · Department of Microbiology
Olympia Zarkotou
MD, PhD
About
55
Publications
8,831
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1,624
Citations
Citations since 2017
Publications
Publications (55)
Background
Bacterial co-infections in COVID-19 patients represent a significant challenge for clinicians and can impact outcomes. Rapid identification of bacterial co-pathogens improves management, and is crucial to avoid inappropriately administered antimicrobials. We evaluated the use of a multiplex PCR assay in the early detection of respiratory...
Background:
Bloodstream infections (BSI) caused by highly resistant pathogens in non-ICU COVID-19 departments pose important challenges.
Methods:
We performed a comparative analysis of incidence and microbial epidemiology of BSI in COVID-19 vs. non-COVID-19, non-ICU departments between 1 September 2020-31 October 2021. Risk factors for BSI and i...
Fungal necrotizing skin and soft tissue infection (NSSTI) represents a rare clinical entity. An extremely rare case of NSSTI, following an open tibia fracture in a 36-year-old male caused by both Syncephalastrum spp. and Fusarium solani species complex (SC) is presented. The infection was diagnosed through direct microscopy, cultures and histology....
Isolated post-traumatic cerebral mucormycosis represents an extremely rare and severe disease. A case of isolated cerebral mucormycosis infection caused by Lichtheimia spp. in a 21-year-old multi-trauma patient is presented. The patient was hospitalized in the intensive care unit and underwent craniotomy due to brain injuries. Two weeks following t...
This study aimed to investigate the effects of a 4-year antibiotic stewardship program (ASP) in a tertiary hospital. We monitored data for 2015 (pre-intervention) and 2016–2019 (post-intervention) about antibiotic consumption (DDD/100 bed days), Clostridioides difficile infections (CDIs), resistance rates, length of stay (LOS), and annual antibioti...
Background
Antimicrobial resistance (AMR) is an increasing threat to public health and antimicrobial consumption is a primary driver of resistance. Many studies have shown that the implementation of an antibiotic stewardship program (ASP) improves prescribing of antibiotics and can reduce AMR. Purpose of the study was to assess the impact of a succ...
Influenza is an acute viral infection of the respiratory system, which is mainly caused by influenza viruses type A and B (ΙΝΑ, ΙΝΒ) in humans, with high transmissibility. Seasonal influenza outbreaks cause significant mortality and morbidity each year. The aim of the present study was to record the incidence of seasonal influenza cases in General...
IntroductIon/AIm: Chronic bacterial prostatitis (CBP) is an inflammatory condition of the prostate, characterized by relapses and remissions. Due to trends in bacterial susceptibility , persistence, recurrence and reinfection are considered frequent. The aim of our study was to investigate recurrences and reinfections and to determine bacterial sus...
Introduction/Aim: Despite accumulated knowledge, several microbiological aspects of chronic bacterial prostatitis (CBP) remain uncertain. The aim of our study was to determine microbiological characteristics on our CBP population. Materials: The material of this retrospective study consisted in bacterial isolates from urine and/or prostatic secreti...
Introduction/Aim: Despite accumulated knowledge, several microbiological aspects of chronic bacterial prostatitis (CBP) remain uncertain. The aim of our study was to determine microbiological characteristics on our CBP population.
Materials: The material of this retrospective study consisted in bacterial isolates from urine and/or prostatic secret...
Background
The aim of this study was to estimate the impact of bloodstream infections (BSIs) caused by carbapenem-resistant Gram-negative (CRGN) pathogens on hospital costs, mortality and length of stay (LOS).
Methods
All patients hospitalized for ≥3 days in the Intensive Care Unit (ICU) of a tertiary-care general hospital from 1/1/2015 to 31/12/2...
Objectives:
NDM-producing Enterobacteriaceae clinical isolates remain uncommon in the European region. We describe the emergence and broad dissemination of one successful NDM-1-producing Klebsiella pneumoniae clone in Greek hospitals.
Methods:
During a 4 year survey (January 2013-December 2016), 480 single-patient carbapenem non-susceptible K. p...
Aim of the study was blood samples from 401
patients, 141 children and 260 adults (123 male/137
female), were tested, from January 2013 until
December 2016. Ninety (90/137) women were
examined as part of their prenatal medical plan,
while the remaining patients manifested symptoms
suspicious for (PB19) infection such as fever, rush,
joint pain, leu...
The emergence of Acinetobacter baumannii with resistance to colistin (ABRC) led to the investigation of daptomycin as an adjunctive to colistin for these isolates. In this study, one ABRC carbapenemase-producing bloodstream isolate was examined. Minimum inhibitory concentrations (MICs) were >512, >512 and 8 µg/mL for imipenem, daptomycin and colist...
Carbapenem-resistant Klebsiella pneumoniae cause important healthcare-associated infections worldwide. An outbreak of ST11 OXA-48-producing K. pneumoniae isolates (OXA-48-Kp) occurred in Tzaneio Hospital in 2012 and was contained until 2014, when OXA-48-Kp reemerged. The present study involved 19 bloodstream infection (BSI) OXA-48-Kp recovered from...
The aim of this study was to investigate the effect of the implementation of an antibiotic stewardship program (ASP) on antibiotic consumption in our 428-bed hospital. The Infection Control Committee implemented an ASP beginning in January 2016, aiming to reduce inappropriate antibiotic use through improved prescribing practices. The ASP included b...
Abstract
Susceptibility testing for colistin remains challenging primarily due to its inherent properties. We evaluated colistin stability in
agar and reproducibility of colistin MICs obtained by agar dilution, broth macro- and micro-dilution and MIC gradient strips on
3
–
7 iterations of each method using clinical
Klebsiella pneumoniae
(susceptibl...
We evaluated an infection control (IC) program influenced by personnel and material resource shortages on the incidence of bloodstream infections (BSI) due to carbapenem-resistant Klebsiella pneumoniae (CRKP), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA) in an endemic region. Between January 2010 and December 2015, all BSI epis...
Objectives:
To study the performance of the rapid chromogenic βLACTA test for the rapid detection of expanded-spectrum cephalosporin (ESC) nonsusceptibility among Enterobacteriaceae, in a region endemic for potent β-lactamases.
Methods:
The βLACTA test was applied prospectively on 235 consecutive Enterobacteriaceae clinical isolates and163 previ...
In a previous nationwide study in Greece, OXA-58 was the sole carbapenemase present among carbapenem-resistant Acinetobacter baumannii (CRAB) isolated between 2000 and 2009. In this study, the antibiotic resistances, carbapenemase gene content and clonal relatedness of 194 single-patient CRAB clinical isolates collected randomly during 2015 from 11...
Background:
The best available treatment against carbapenemase-producing Enterobacteriaceae (CPE) is unknown. The objective of this study was to investigate the effect of appropriate therapy and of appropriate combination therapy on mortality of patients with bloodstream infections (BSIs) due to CPE.
Methods:
In this retrospective cohort study,...
Objective:
To develop a score to predict mortality in patients with bloodstream infections (BSIs) due to carbapenemase-producing Enterobacteriaceae (CPE).
Patients and methods:
A multinational retrospective cohort study (INCREMENT project) was performed from January 1, 2004, through December 31, 2013. Patients with clinically relevant monomicrob...
Objectives
We utilized whole-genome mapping (WGM) and WGS to characterize 12 clinical carbapenem-resistant Klebsiella pneumoniae strains (TGH1–TGH12).
Methods
All strains were screened for carbapenemase genes by PCR, and typed by MLST, PFGE (XbaI) and WGM (AflII) (OpGen, USA). WGS (Illumina) was performed on TGH8 and TGH10. Reads were de novo asse...
Excessive and inappropriate use of antibiotics enhances the emergence of antimicrobial resistance, resulting into a vicious cycle. Continuous surveillance of antibiotic consumption and implementation of antibiotic stewardship programs (ASP) is an important component of infection control interventions. Greece is a high endemicity area for multidrug...
Hospital acquired infections (HAI) and antimicrobial resistance represent a serious threat to patient safety and healthcare systems globally and especially in our country. Hand hygiene (HH) promotion seems to be the cornerstone of infection control interventions as it is the most important measure to prevent transmission of pathogens by healthcare...
We compared six colistin susceptibility testing (ST) methods in 61 carbapenem-non-susceptible Klebsiella pneumoniae (n=41) and Acinetobacter baumannii (n=20) with provisionally elevated colistin MICs by the routine ST. Colistin MICs were determined by broth microdilution (BMD) as reference method, BMD with 0.002% polysorbate 80 (P80) (BMD-P80), aga...
Dependence on linezolid was recently described as significant growth acceleration of linezolid-resistant Staphylococcus epidermidis (LRSE) isolates upon linezolid exposure. We investigated the possible contribution of linezolid dependence to LRSE dissemination in Greece.
Linezolid resistance rates were estimated in six tertiary hospitals located th...
Rhodococcus equi infection in humans was first reported in 1967. Since the advent of the AIDS epidemic, the reported cases of human infection increased dramatically and Rhodococcus equi has become an important opportunistic pathogen in immunocompromised patients. The presented case is a necrotizing pneumonia in a 45-year-old HIV-positive man who re...
This report describes the case of dry gangrene after a crab bite. Vibrio vulnificus is associated with sepsis after eating contaminated seafood, and necrotizing soft tissue infections after wound exposure to contaminated water. Infections are opportunistic and usually involving immunocompromized patients or patients with underlying diseases.
Background
Biliary stenting is a well-established method to treat patients with malignant and benign biliary diseases. However, occlusion of plastic biliary stents is considered as a drawback and bacterial colonization seems to be the key factor in this process.
Methods
During a 3-year period, 51 plastic biliary stents were extracted from 42 patie...
Carbapenemase-producing Enterobacteriaceae (CPE) are rapidly spreading worldwide. Early detection of CPE fecal carriers is essential for effective infection control. We evaluated the performance of a combined meropenem disk test (CDT) for rapidly differentiating CPE, directly from rectal swabs. The screening method was applied in 189 rectal swabs f...
The aim is to describe the epidemiological and laboratory investigation of a nosocomial outbreak of gastroenteritis and the effectiveness of control measures. In April 2011, an outbreak of gastroenteritis occurred in patients and personnel of the Orthopedic Department of Tzaneio General Hospital, Piraeus, Greece. The hospital infection control comm...
We aim to describe the epidemiological and laboratory investigation of a nosocomial outbreak of gastroenteritis and the effectiveness of control measures. In April 2011, an outbreak of gastroenteritis occurred in patients and personnel of the Orthopedic Department of Tzaneio General Hospital, Piraeus, Greece. The hospital infection control committe...
Introduction: Chronic prostatitis displays a variety of symptoms (mainly local pain exhibiting variability in
origin and intensity). The purpose of this article is to briefly present the preliminary results of our study
examining the role of phytotherapeutic agents in the treatment of chronic prostatitis patients.
Material and Method. The study was...
We examined the effect of applying the updated 2010 Clinical and Laboratory Standards Institute (CLSI) susceptibility breakpoints for extended-spectrum cephalosporins (ESCs) to detect extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. In total, 202 ESBL-producing, plasmidic AmpC- and carbapenemase-negative isolates derived from sepa...
We document linezolid dependence among 5 highly linezolid-resistant (LRSE) Staphylococcus epidermidis bloodstream isolates that grew substantially faster at 32 µg/mL linezolid presence. These isolates carried the mutations T2504A and C2534T in multiple 23S rRNA copies and 2 mutations leading to relevant amino acid substitutions in L3 protein. Linez...
Objectives:
First detected in Enterobacteriaceae isolates in Turkey, the OXA-48 carbapenemase has gradually disseminated in the wider Mediterranean area and Europe. Despite reports from other European regions, until now no such isolates have been detected in Greece. We describe the characteristics of the first outbreak caused by OXA-48-producing K...
We evaluated the Vitek2, Etest, and MIC Test Strip (MTS) methods of tigecycline susceptibility testing with 241 expanded-spectrum
cephalosporin-resistant and/or carbapenem-resistant Enterobacteriaceae and Acinetobacter baumannii clinical isolates by using dry-form broth microdilution (BMD) as the reference method. The MIC50/90s were as follows: BMD...
The diabetic foot infections may threaten the integrity of the limb. With the cooperation of the clinical departments and the laboratory, the severity of the infection can be estimated, so that the appropriate treatment will be instituted to prevent the serious complications of the disease. In this study, the frequency of the isolation of pathogens...
Clin Microbiol Infect 2011; 17: 1798–1803
Bloodstream infections (BSIs) caused by Klebsiella pneumoniae carbapenemases (KPC)-producing K. pneumoniae (KPC-KP) are associated with high mortality rates. We investigated outcomes, risk factors for mortality and impact of appropriate antimicrobial treatment in patients with BSIs caused by molecularly con...
Eikenella corrodens infections occur quite often in adults, whereas they are uncommon in pediatric patients. We report two cases of children with acute appendicitis due to E. corrodens. In the first. case, the infection was mixed with Pseudomonas aeruginosa, but in the second the organism was isolated in pure culture. Both patients recovered after...
Ôhe term prostatitis is broadly used to describe inflammation of the prostate associated with a variety of lower urinary tract symptoms and signs and sexual dysfunction. Prostatitis poses an international health problem and several epidemiological studies suggest a worldwide prevalence greater than 20%. Recently prostatitis has been classified into...
A matched 1:3 case-control study investigated factors predicting colistin-resistant versus colistin-susceptible KPC-producing
Klebsiella pneumoniae acquisition and its impact on patient outcomes. Case patients were more often admitted from other institutions (P = 0.019) and had longer therapy with β-lactam/β-lactamase inhibitors (P = 0.002) and hig...
The genus Lactobacillus is a rather diverse group of gram positive, non-spore-forming rods. More than one hundred species are recognised at present. Lactobacilli are members of the lactic acid bacteria. They are characterized by the formation of lactic acid as a sole or main end product of carbohydrate metabolism. According to their fermentation pr...
Brucellosis is an endemic disease in Greece, and occasionally complications and relapses of the disease create diagnostic difficulties. The aim of the present study was the assessment of the serological findings of patients who presented in our hospital with symptoms of acute or chronic brucellosis during a four-year period. The follow up concerned...
Background: The purpose of this study was to investigate the relative frequency of enteropathogens, viruses and parasites, in patients hospitalized with diarrhoea, in order to provide the appropriate therapy. Methods: Over a period of one year (2008) 4,800 faecal samples were examined from patients (adults and children) who were hospitalized with f...
Objectives: To investigate in a prospective study the infection rate, the bacteriology and the outcome of wound infections following posterior spinal instrumentation in children and young adolescents during 1993–96.
Methods: Fifty patients, who underwent spinal instrumentation because of paralytic scoliotic deformity, were followed by the surgeon,...
Projects
Project (1)
we focus on key areas of CR addressing pertinent questions that have hitherto not been answered. We will study the genetic differences among colistin-resistant Enterobacteriaceae (CRE) that are either derived from in-vitro morbidostat model and from in-vivo G. mellonella model, to be later proven as novel genetic markers of CR on clinical and veterinary samples, and to explore the emergence, creation and implications of CRE for the clinical and veterinary sector. In the context of the current state-of-the-art situation, the proposed project thus addresses three major goals: (i) to identify major molecular mechanisms or genetic determinants of CR in Gram-negative bacteria; (ii) to compare the clinical emergence of antibiotic resistance with the one generated in-vitro and in animal models; (iii) to assess fitness, long-term persistence, and virulence potential of CRE. To address these goals, the following research activities are proposed: 1, Strain typing; 2, In-vitro generation of CR; 3, Genome sequencing and comparative genome analysis; 4, Target gene sequencing and protein expression studies; 5, Assessment of CR stability; 6, Fitness studies and 7, Associated mortality and pathogenicity.
