Emergence of NDM-1-Producing Pseudomonas aeruginosa Nosocomial Isolates in Attica Region of Greece.

Here, we report on the emergence and spread of multidrug-resistant NDM-1-producing P. aeruginosa isolates from patients hospitalized in the Attica region, Greece, in 2022 to provide data on their resistome, their virulome, the genetic environment of blaNDM-1, and their molecular epidemiology. A total of 17 carbapenem-resistant P. aeruginosa isolates identified as NDM-producers by immunochromatography at the hospital level were sent to the Central Public Health Laboratory, in the frame of the laboratory surveillance of carbapenem-resistant pathogens, for further characterization. The initial screening for genetic AMR determinants was carried out by PCR and the MDR Direct Flow Chip assay. Typing was performed by MLST and DLST, the latter in a subset of isolates. Further analysis was performed by whole-genome sequencing (WGS) of six isolates from both hospitals to analyze their entire genomes and elucidate their genetic relatedness. All isolates were allocated to international high-risk clones, sixteen to ST773 and one to ST308. Five ST773 and the sole ST308 isolate were found to harbor the blaNDM-1 gene, along with various other ARGs integrated into their chromosomes, as well as with a wide variety of virulence genes. The blaNDM-1 gene was located in the integrative and conjugative elements ICE6600-like and ICETn43716385 in ST773 and ST308 isolates, respectively. Single-nucleotide polymorphism analysis of the five ST773 isolates indicated their clonal spread in both hospitals. These results suggested that two different molecular events contributed to the emergence of NDM-1-producing P. aeruginosa isolates in Athenian hospitals, highlighting the need for ongoing surveillance.

History repeats itself: consumption of a local traditional roast pork meat recipe leads to Salmonella ser. Give cases in Greece.

INTRODUCTION: An outbreak of gastroenteritis due to Salmonella Give, a very rarely identified serotype in human isolates in Greece, occurred in participants of a religious festival in a rural area of southern Greece, in September 2022. The objectives of this study were to describe the outbreak in terms of epidemiology, identify the vehicle of transmission of the foodborne pathogen and recommend prevention measures. METHODS: The outbreak was linked to the consumption of a local traditional recipe of roasted pork meat served by a street food vendor. In 2018, the same food item, served in a restaurant in the same region, was implicated in another S. Give outbreak. RESULTS: Outbreak investigations revealed that outbreak-associated isolates, of food and human origin, belonged to the same S. Give strain. Significant deficiencies regarding food safety practices were identified. CONCLUSION: Technical knowledge about pathogen transmission paths is important in order for both food handlers and consumers to follow hygiene and sanitary measures, mainly in cases of mass gatherings, where large quantities of food are prepared, handled, cooked and served. Efficient official supervision, mainly during summer festivals, is required in order to avoid recurrence of foodborne infections by different combinations of pathogens/food commodities.

SARS-CoV-2 seroprevalence among children in Greece during Omicron variant period.

The Omicron variant is associated with increased transmissibility, but evidence about the impact of Omicron in seropositivity of children is limited. This study aims to evaluate SARS-CoV-2 seroprevalence in children during the different variants' subperiods. A prospective multicenter seroprevalence study was conducted in 7 University public hospitals in Greece from November 2021 to August 2022 (3 subperiods: November 2021-February 2022, March 2022-May 2022, June 2022-August 2022). Children from different age groups, admitted to the hospital or examined in outpatient clinics for reasons other than COVID-19 were enrolled. Neutralizing antibodies (Nabs), anti-Spike (anti-S) and anti-nucleocapsid (anti-N) SARS-CoV-2 IgG in serum were evaluated. A total of 2127 children (males:57,2%; median age:4,8years) were enrolled. Anti-N IgG seropositivity increased from 17,8% in the first sub-period to 40,7% in the second sub-period and then decreased in the third sub-period (36,7%). Anti-S IgG seropositivity appeared to have an increasing trend over the study period, starting from 34,8% and reaching 80,7%. Children aged 1-4 years old have significantly higher anti-N IgG titers compared to children aged 0-1 years old (p < 0,001). Infants have significantly lower anti-S IgG titers compared to all other age groups (p < 0,001). Immunocompromised children and infants have the lowest seropositivity for NAbs.Conclusions During the Omicron period, seropositivity significantly increased, as a result of higher transmissibility. Neonates and infants have lower antibody titers compared to other age groups, while young children aged 1-4 years old present higher antibody titers, suggesting that this age group may mount a higher antibody response. Continuous surveillance seroprevalence studies are needed in children, in order to identify the true extent of SARS-CoV-2 and guide the planning of adequate public health measures.

WHAT IS KNOWN: • Seroprevalence surveys among children may be extremely useful, in order to properly monitor the immunity, either natural or acquired, through the quantification of IgG antibodies and to plan further immunization policies. • There are variations in the seroprevalence of COVID-19 between the different periods, according to the vaccination rates, the type of circulating variant and the transmissibility of the virus. • The Omicron variant is associated with increased transmissibility, but evidence about the impact of Omicron in seropositivity of children is limited. WHAT IS NEW: • In this large multicenter seroepidemiological study, SARS-CoV-2 seroprevalence rate in children is higher during the Omicron period in comparison to the previous pandemic waves, due to the high transmissibility of the virus and the increased rates of reinfection. • Neonates and infants have lower antibody titers compared to other age groups, while young children aged 1­4 years old present higher antibody titers, indicating that the children of this age group mount a higher antibody response. • This study provides essential information about immunity and the level of protection in the pediatric population, as neutralizing antibodies were evaluated, in addition to the anti-N and anti-S IgG antibodies.

A Community Waterborne Salmonella Bovismorbificans Outbreak in Greece.

BACKGROUND: In August 2022, the Hellenic National Public Health Organisation was notified about a gastroenteritis outbreak in town A in Southern Greece. Investigations aimed to identify the source and implement control measures. METHODS: Case definition categories were used in a 1:3 case-control study. Cases and controls were interviewed about various exposures. Cases' stool samples were cultured on agar plates and characterised by serotyping, antimicrobial susceptibility testing and Pulse Field Gel Electrophoresis (PFGE). Environmental investigations included tap water sampling for microbiological and chemical analysis in town A and inspection of the water supply system. RESULTS: We identified 33 cases (median age: 17 years). Tap water consumption was the only significant risk factor for gastroenteritis (OR = 5.46, 95% CI = 1.02-53.95). Salmonella (S.) Bovismorbificans isolated from eight stool and one tap water samples had identical PFGE profiles. No resistant isolates were identified. Residual chlorine levels were lower than the acceptable limits before and during the outbreak. We advised consumption of bottled water and adherence to strict hand hygiene rules until tap water was declared suitable for drinking. CONCLUSIONS: Epidemiological and molecular data revealed a waterborne S. Bovismorbificans outbreak in town A. We recommend local water safety authorities to ensure that residual chlorine levels comply with the legislation towards water safety planning, to mitigate risks.

Healthcare-associated infections and antimicrobial use in acute care hospitals in Greece, 2022; results of the third point prevalence survey.

BACKGROUND: The burden of healthcare-associated infections (HAIs) and the extent of antimicrobial use (AU) are periodically recorded through Point Prevalence Surveys (PPS) in acute care hospitals coordinated by the European Centre for Disease Prevention and Control (ECDC). In previous PPSs, Greece demonstrated increased HAI and AU prevalence: 9% and 54.7% in 2011-2012, and 10% and 55.6% in 2016-2017, respectively. The 2022 PPS aimed to estimate HAIs and AU indicators among inpatients, especially amid the COVID-19 pandemic. METHODS: A cross-sectional study was conducted in 50 hospitals during October-December 2022, in Greece. Patients admitted before 8.00 a.m. of the survey day were observed. Patients with at least one HAI or receiving at least one antimicrobial agent were included. Data were collected by hospital infection control teams. Hospital and ward-level variables were analysed. RESULTS: From 9,707 inpatients, 1,175 had at least one HAI (12.1%), and 5,376 were receiving at least one antimicrobial (55.4%). Intensive care unit patients had the highest HAI (45.7%) and AU (71.3%) prevalence. Of the 1,408 recorded HAIs, lower respiratory tract (28.9%), bloodstream (20%), and urinary tract infections (13.1%) were the most common. Among 1,259 isolates, Klebsiella (20.5%) and Acinetobacter (12.8%) were most frequently identified. Resistance to first-level antibiotic markers was 69.3%. Among the 9,003 antimicrobials, piperacillin-tazobactam (10.9%), and meropenem (7.7%) were frequently prescribed. The ratio of broad-spectrum to narrow-spectrum antibiotics was 1.4. As defined by the 2021 WHO AWaRe (Access, Watch, Reserve) classification, restricted classes of Watch and Reserve agents comprised 76.7% of antibiotics. Usual indications were treatment of community-acquired infections (34.6%) and HAIs (22.9%). For surgical prophylaxis, cefoxitin was commonly used (20.2%), and typical courses (75.7%) lasted more than one day. HAI and AU prevalence were positively associated with bed occupancy (p = 0.027) and secondary hospitals (p = 0.014), respectively. CONCLUSIONS: The 2022 PPS highlighted the increasing trend of HAI prevalence and high AU prevalence in Greece, the emergence of difficult-to-treat pathogens, and the extensive use of broad-spectrum antimicrobials. Strengthening infection control and antimicrobial stewardship programs in hospital settings is essential.

Emergence and persistent spread of carbapenemase-producing Klebsiella pneumoniae high-risk clones in Greek hospitals, 2013 to 2022.

BackgroundPreliminary unpublished results of the survey of carbapenem- and/or colistin-resistant Enterobacterales (CCRE survey) showed the expansion of carbapenemase-producing Klebsiella pneumoniae (CPKP) sequence type (ST) 39 in 12 of 15 participating Greek hospitals in 2019.AimWe conducted a rapid survey to determine the extent of spread of CPKP high-risk clones in Greek hospitals in 2022 and compare the distribution of circulating CPKP clones in these hospitals since 2013.MethodsWe analysed whole genome sequences and epidemiological data of 310 K. pneumoniae isolates that were carbapenem-resistant or 'susceptible, increased exposure' from Greek hospitals that participated in the European survey of carbapenemase-producing Enterobacteriaceae (EuSCAPE, 2013-2014), in the CCRE survey (2019) and in a national follow-up survey (2022) including, for the latter, an estimation of transmission events.ResultsFive K. pneumoniae STs including ST258/512 (n = 101 isolates), ST11 (n = 93), ST39 (n = 56), ST147 (n = 21) and ST323 (n = 13) accounted for more than 90% of CPKP isolates in the dataset. While ST11, ST147 and ST258/512 have been detected in participating hospitals since 2013 and 2014, KPC-2-producing ST39 and ST323 emerged in 2019 and 2022, respectively. Based on the defined genetic relatedness cut-off, 44 within-hospital transmission events were identified in the 2022 survey dataset, with 12 of 15 participating hospitals having at least one within-hospital transmission event.ConclusionThe recent emergence and rapid spread of new high-risk K. pneumoniae clones in the Greek healthcare system related to within-hospital transmission is of concern and highlights the need for molecular surveillance and enhanced infection prevention and control measures.

Epidemiology and Resistance Phenotypes of Carbapenem-Resistant Klebsiella pneumoniae in Corfu General Hospital (2019-2022): A Comprehensive Time Series Analysis of Resistance Gene Dynamics.

Antimicrobial resistance is a significant global health challenge, with Klebsiella pneumoniae being one of the most common antibiotic-resistant pathogens. This study provides an in-depth analysis of the prevalence and resistance patterns of antibiotic-resistant Klebsiella pneumoniae in the General Hospital of Corfu, Greece, between 2019 and 2022, with the aim of understanding the potential impact of the COVID-19 pandemic on the epidemiology of this bacterium. Utilizing a retrospective epidemiological approach, this study analyzed 212 isolates obtained from the hospital's Microbiology Department. These isolates were subjected to genotypic and phenotypic identification, with resistance genes (bla-KPC, bla-NDM, bla-VIM, bla-OXA-48, and mcr-1) and antibiotic resistance patterns as the primary focus. The results revealed a significant shift in resistance gene prevalence, with a notable increase in bla-KPC from 16.67% in 2021 to 58.46% in 2022, and a decrease in bla-NDM from 81.48% in 2021 to 38.46% in 2022. In terms of antibiotic resistance patterns, there was a consistent increase in resistance to amikacin and a significant decrease in resistance to ceftazidime/avibactam. These findings underscore the dynamic nature of carbapenem-resistant Klebsiella pneumoniae (CRKP) resistance and highlight the need for ongoing surveillance and adaptive therapeutic strategies in the face of evolving resistance patterns.

Antimicrobial susceptibility testing and reporting practices of public hospital microbiology laboratories in Greece, 2022: A national observational survey and call for action.

Antimicrobial resistance (AMR) in Greece is among the highest across the European Union/European Economic Area (EU/EEA), with high AMR rates even to last-line antibiotics. To better understand the clinical microbiology laboratory practices and capacities in species identification and antimicrobial susceptibility testing (AST) across public healthcare establishments in Greece, we sent a questionnaire to 98 of 128 public hospital microbiology laboratories between 1 February and 1 April 2022. Of the 73.5% (72/98) that responded, 51.4% (37/72) reported using EUCAST guidelines. Two of three laboratories used an automated instrument for species identification and AST for all laboratory samples. Broth microdilution for colistin susceptibility testing was used by 46 of the laboratories, more frequently in larger (> 400 beds) versus smaller (< 400 beds) hospitals (90.5% (19/21) vs 52.9% (27/51) respectively, p = 0.011). MALDI-TOF mass spectrometry was available in one of 10 laboratories, and more often in larger compared to smaller hospitals (p = 0.035). Although the majority of laboratories had a laboratory information system (LIS) in place, only half had the capacity to extract data directly from the LIS for the purpose of AMR surveillance; 73.6% (53/72) used restrictive antibiograms. Public microbiology laboratory AMR capacities in Greece require improvement, prioritising interventions for EUCAST guidelines implementation.

Influenza transmission during COVID-19 measures downscaling in Greece, August 2022: evidence for the need of continuous integrated surveillance of respiratory viruses.

After the near absence of influenza and other respiratory viruses during the first 2 years of the COVID-19 pandemic, an increased activity of mainly influenza A(H3N2) was detected at the beginning of August 2022 in Greece on three islands. Of 33 cases with respiratory symptoms testing negative for SARS-CoV-2 with rapid antigen tests, 24 were positive for influenza: 20 as A(H3N2) subtype and four as A(H1N1)pdm09 subtype. Phylogenetic analysis of selected samples from both subtypes was performed and they fell into clusters within subclades that included the 2022/23 vaccine strains. Our data suggest that influenza can be transmitted even in the presence of another highly infectious pathogen, such as SARS-CoV-2, with a similar transmission mode. We highlight the need for implementing changes in the current influenza surveillance and suggest a move from seasonal to continuous surveillance, especially in areas with a high number of tourists. Year-round surveillance would allow for a timelier start of vaccination campaigns and antiviral drugs procurement processes.

Real life treatment experience and outcome of consecutively hospitalised patients with SARS-CoV-2 pneumonia by Omicron-1 vs Delta variants.

BACKGROUND: Omicron-1 COVID-19 is less invasive in the general population than previous viral variants. However, clinical course and outcome of hospitalised patients with SARS-CoV-2 pneumonia during the shift of the predominance from Delta to Omicron variants are not fully explored. METHODS: During January 2022 consecutively hospitalised patients with SARS-CoV-2 pneumonia were analysed. SARS-CoV-2 variants were identified by a 2-step pre-screening protocol and randomly confirmed by whole genome sequencing analysis. Clinical, laboratory and treatment data split by type of variant were analysed along with logistic regression of factors associated to mortality. RESULTS: 150 patients [mean age (SD) 67.2(15.8) years, male 54%] were analysed. Compared to Delta (n = 46), Omicron-1 patients (n = 104) were older [mean age (SD): 69.5(15.4) vs 61.9(15.8) years, p = 0.007], with more comorbidities (89.4% vs 65.2%, p = 0.001), less obesity (BMI >30Kg/m2 in 24% vs 43.5%, p = 0.034) but higher vaccination rates for COVID-19 (52.9% vs 8.7%, p < 0.001). Severe pneumonia (48.7%), pulmonary embolism (4.7%), need for invasive mechanical ventilation (8%), administration of dexamethasone (76%) and 60-day mortality (22.6%) did not significantly differ. Severe SARS-CoV-2 pneumonia independently predicted mortality [OR 8.297 (CI95% 2.080-33.095), p = 0.003]. Remdesivir administration (n = 135) was protective from death both in unadjusted and adjusted models [OR 0.157 (CI95% 0.026-0.945), p = 0.043. CONCLUSIONS: In a COVID-19 department the severity of pneumonia that did not differ between Omicron-1 and Delta variants predicted mortality whilst remdesivir remained protective in all analyses. Death rates did not differ between SARS-CoV-2 variants. Vigilance and consistency with prevention and treatment guidelines for COVID-19 is mandatory regardless of the predominant SARS-CoV-2 variant.

Overview of Mpox Outbreak in Greece in 2022-2023: Is It Over?

In May 2022, for the first time, multiple cases of mpox were reported in several non-endemic countries. The first ever case of the disease in Greece was confirmed on 8 June 2022, and a total of 88 cases were reported in the country until the end of April 2023. A multidisciplinary response team was established by the Greek National Public Health Organization (EODY) to monitor and manage the situation. EODY's emergency response focused on enhanced surveillance, laboratory testing, contact tracing, medical countermeasures, and the education of health care providers and the public. Even though management of cases was considered successful and the risk from the disease was downgraded, sporadic cases continue to occur. Here, we provide epidemiological and laboratory features of the reported cases to depict the course of the disease notification rate. Our results suggest that measures for raising awareness as well as vaccination of high-risk groups of the population should be continued.

Simultaneous Multiple-Stages Mpox Genital Lesions on the Same Site in a Traveler to Greece: A Case Report.

A 47-year-old Caucasian traveller from an mpox (formerly monkeypox and also best suited abbreviated MPX)-endemic country was referred for a skin rash, of recent onset, confined to the genital area. The rash consisted of erythematous umbilicated papules, vesicles and pustules with a characteristic white ring. The lesions were observed simultaneously at different stages of progression on the same anatomical site, a clinical presentation that is not encountered frequently. The patient was febrile, fatigued and had blood-tinged cough. The clinical suspicion of mpox was raised, and the initial real-time PCR identified a non-variola orthopox virus, which was confirmed at the National Reference Laboratory to belong to the West African clade.

COVID-19 Burden in Long-Term Care Facilities in the Omicron Era: Public Health Action Not Yet Redundant.

Since the beginning of the pandemic, public health authorities have provided support to long-term care facilities (LTCFs) for the implementation of risk mitigation measures. Nevertheless, the necessity of these measures has been doubted, especially after vaccines and antiviral treatment became available. Here, we present the burden of COVID-19 infection in LTCFs during the first 9 months of 2022 across Greece. We tested the possible association of LTCF characteristics and public health response with the occurrence of clusters (two or more linked cases in LTCFs) with facilities recording one case as reference. After excluding LTCFs with sporadic cases, we tested the effect of the abovementioned variables on attack rate (cases/total number of persons in the LTCF). The disease burden in LTCFs was high and substantially varied among facilities, with hospitalization and case fatality rates ranging from 2 to 80% (median 14%, IQR 27%) and from 1 to 50% (median 5%, IQR 7%), respectively. The probability of transmission inside the facility increased when notification of public health authorities was delayed (p-Value < 0.001) after adjusting for vaccination status and phase of the pandemic. Results showed that active support from public health authorities is still important in reducing the burden in LTCFs.

COVID-19 and Antimicrobial Resistance: Data from the Greek Electronic System for the Surveillance of Antimicrobial Resistance-WHONET-Greece (January 2018-March 2021).

Changes in hospitals' daily practice due to COVID-19 pandemic may have an impact on antimicrobial resistance (AMR). We aimed to assess this possible impact as captured by the Greek Electronic System for the Surveillance of Antimicrobial Resistance (WHONET-Greece). Routine susceptibility data of 17,837 Gram-negative and Gram-positive bacterial isolates from blood and respiratory specimens of hospitalized patients in nine COVID-19 tertiary hospitals were used in order to identify potential differences in AMR trends in the last three years, divided into two periods, January 2018-March 2020 and April 2020-March 2021. Interrupted time-series analysis was used to evaluate differences in the trends of non-susceptibility before and after the changes due to COVID-19. We found significant differences in the slope of non-susceptibility trends of Acinetobacter baumannii blood and respiratory isolates to amikacin, tigecycline and colistin; of Klebsiella pneumoniae blood and respiratory isolates to meropenem and tigecycline; and of Pseudomonas aeruginosa respiratory isolates to imipenem, meropenem and levofloxacin. Additionally, we found significant differences in the slope of non-susceptibility trends of Staphylococcus aureus isolates to oxacillin and of Enterococcus faecium isolates to glycopeptides. Assessing in this early stage, through surveillance of routine laboratory data, the way a new global threat like COVID-19 could affect an already ongoing pandemic like AMR provides useful information for prompt action.

Waterborne outbreak in a rural area in Greece during the COVID-19 pandemic: contribution of community pharmacies.

INTRODUCTION: On 15 June 2020, the National Public Health Organization was informed about the identification of two cases of Escherichia coli Ο157 infection in a small town in the Peloponnese Region in Greece and we suspected an outbreak. METHODS: We asked the local pharmacist to assist us to verify the outbreak by providing the daily number of over-the-counter anti-diarrheal drugs sold from 20 May 2020 onwards. The pharmacist asked customers with gastroenteritis to submit stool samples at the local hospital. Samples were tested for 22 pathogens. We conducted a 1 : 1 case-control study. Cases and controls were retrieved from the pharmacy client list. Chlorination records of the water supply system were retrieved, and water samples were tested for microbiological indicators and viruses. RESULTS: The increased number of sales of anti-diarrheal drugs verified the outbreak. Overall, 58 cases and 57 controls were recruited for the study. Tap water consumption (odds ratio (OR)=10.9, 95% confidence interval (CI)=3.1-38.0, p<0.001) and consumption of ice cubes made from tap water (OR=39.3, 95%CI=10.3-150.9, p<0.001) were independently associated with gastroenteritis occurrence. Eleven stool samples were tested; one was positive for shigatoxin-producing E. coli, one for enteropathogenic E. coli, four for E. coli Ο157 and one for Salmonella spp. Four samples tested negative. Five water samples collected on 18 June tested negative. The residual chlorine on 5 and 14 June ranged from 0.12 mg/L to 0.14 mg/L. CONCLUSION: This was the first investigation of a waterborne outbreak in Greece performed with the collaboration of a local pharmacy. The COVID-19 pandemic favored the use of alternative resources and channels of communication with the local population, which can also be used in the future, especially in remote areas of the country.

The Rising Burden of Salmonellosis Caused by Monophasic Salmonella Typhimurium (1,4,[5],12:i:-) in Greece and New Food Vehicles.

Monophasic Salmonella typhimurium is of increasing importance worldwide. Here we present the available data regarding monophasic S. typhimurium from 2007 to 2019 in Greece, in order to assess its public health impact. Surveillance data, data on antimicrobial resistance, molecular typing by pulsed-field gel electrophoresis (PFGE), and results of the investigation of monophasic S. typhimurium outbreaks were analyzed. Overall, 403 cases were identified; 329 (81.6%) sporadic and 74 (18.4%) related to two community outbreaks in 2017. A total of 305 isolates from sporadic cases tested for antimicrobial resistance revealed resistance to ampicillin, streptomycin, sulphamethoxazole, and tetracycline (41.3%). Some 23.3% were further resistant to trimethoprim and 5.2% were also resistant to chloramphenicol. Outbreak 1 in 2017 with 37 identified cases was attributed to the consumption of raw milk from a vending machine and isolates were resistant to ampicillin, streptomycin, sulphamethoxazole, tetracycline, and trimethoprim. Outbreak 2 also with 37 cases was attributed to the consumption of pork and isolates were resistant to the five above mentioned antibiotics plus chloramphenicol. The number of human monophasic S. typhimurium isolates is low; however, since 2009, it has been among the five most frequently identified serotypes in Greece. Investigation of the outbreaks revealed that other vehicles apart from pork may be implicated in the occurrence of outbreaks.

Public health and clinical implications of multidrug-resistant shigellosis cases in a reception centre for refugees/migrants, Greece, October-December 2019.

From October to December 2019, 18 shigellosis cases (median age: 4.3 years, range: 0-21) were identified in the Reception Center for refugees/migrants on the Greek island of Samos. Fifteen cases (83.3%) were Afghani. Median time from arrival to symptoms onset was 53 days (40-101). Isolates from 14 cases, serotyped as Shigella flexneri 1b, and from three cases, serotyped as S. sonnei phase S (I), presented a multidrug-resistant phenotype. S. flexneri 1b isolates also produced extended-spectrum ß-lactamases. Shigella flexneri 2a isolate from the remaining case was resistant to sulfomethoxazole, trimethoprim and pefloxacin. Improvement of hygiene and strengthening of laboratory investigation is needed.

Molecular Epidemiology of Multi-Drug Resistant Pseudomonas aeruginosa Isolates from Hospitalized Patients in Greece.

Resistant Pseudomonas aeruginosa isolates are one of the major causes of both hospital-acquired infections (HAIs) and community-acquired infections (CAIs). However, management of P. aeruginosa infections is difficult as the bacterium is inherently resistant to many antibiotics. In this study, a collection of 75 P. aeruginosa clinical isolates from two tertiary hospitals from Athens and Alexnadroupolis in Greece was studied to assess antimicrobial sensitivity and molecular epidemiology. All P. aeruginosa isolates were tested for susceptibility to 11 commonly used antibiotics, and the newly introduced Double Locus Sequence Typing (DLST) scheme was implemented to elucidate the predominant clones. The tested P. aeruginosa isolates presented various resistant phenotypes, with Verona Integron-Mediated Metallo-ß-lactamase (VIM-2) mechanisms being the majority, and a new phenotype, FEPR-CAZS, being reported for the first time in Greek isolates. DLST revealed two predominant types, 32-39 and 8-37, and provided evidence for intra-hospital transmission of the 32-39 clone in one of the hospitals. The results indicate that DLST can be a valuable tool when local outbreaks demand immediate tracking investigation with limited time and financial resources.

Eight-year trends in the relative isolation frequency and antimicrobial susceptibility among bloodstream isolates from Greek hospitals: data from the Greek Electronic System for the Surveillance of Antimicrobial Resistance - WHONET-Greece, 2010 to 2017.

BackgroundAntimicrobial resistance (AMR) changes over time and continuous monitoring provides insight on trends to inform both empirical treatment and public health action.AimsTo survey trends in relative isolation frequency (RIF) and AMR among key bloodstream pathogens using data from the Greek Electronic System for the Surveillance of AMR (WHONET-Greece).MethodsThis observational study looked into routine susceptibility data of 50,488 blood culture isolates from hospitalised patients in 25 tertiary hospitals, participating in the WHONET-Greece for trends over time between January 2010 and December 2017. Only the first isolate per species from each patient was included. Hospital wards and intensive care units (ICUs) were analysed separately.ResultsDuring the study, the RIF of Acinetobacter baumannii increased in wards, as did the proportion of A. baumannii isolates, which were non-susceptibleto most antibiotics in both wards and ICUs. Coincidently, Klebsiella pneumoniae RIF declined while the respective rates of non-susceptible isolates to carbapenems and gentamicin increased. Pseudomonas aeruginosa RIF remained stable but decreasing proportions of non-susceptible isolates to all studied antibiotics, except imipenem were observed. Escherichia coli RIF increased as did the proportion of isolates non-susceptible to third-generation cephalosporins, carbapenems and fluoroquinolones. Concerning Staphylococcus aureus, a decline in the percentage of meticillin resistant isolates in ICUs was found, while the percentages of Enterococcus faecium isolates with non-susceptibility to vancomycin stayed stable.ConclusionsRecognising these trends over time is important, since the epidemiology of AMR is complex, involving different 'bug and drug' combinations. This should be taken into consideration to control AMR.

Synergistic activity of colistin with azidothymidine against colistin-resistant Klebsiella pneumoniae clinical isolates collected from inpatients in Greek hospitals.

BACKGROUND: New antibiotics are urgently needed to treat multi-drug resistant infections; however, production of novel antibiotics is diminishing. Synergistic combination drug therapy to enhance the activity of available antibiotics may improve management of patients with resistant infections. METHODS: Colistin-resistant Klebsiella pneumoniae isolates were collected from inpatients in 10 Greek hospitals and used to study combination activity of colistin plus azidothymidine. Combination activity was evaluated with the sum of fractional inhibitory concentrations (ΣFIC) using the mini checkerboard broth microdilution method. RESULTS: A hundred individual strains were tested. Synergistic activity was noted in 79% (79/100) of isolates and additive activity in the remaining 21% (21/100). ΣFIC50 and ΣFIC90 were 0.28 and 0.56, respectively. CONCLUSION: Colistin with azidothymidine exhibited promising synergistic activity against colistin-resistant Klebsiella pneumoniae isolates warranting further investigation of the combination.