Search

Diarrheal diseases are of great concern worldwide and are responsible for considerable morbidity and mortality. This study investigated the epidemiology and the antibiotic susceptibility of bacterial enteropathogens among diarrheal patients of all ages in Crete, Greece during 2011-2022. Stool specimens were tested by conventional cultural methods for Salmonella, Shigella, Campylobacter, diarrheagenic Escherichia coli (EPEC, STEC), Yersinia enterocolitica, Aeromonas species and Clostridioides difficile. Antimicrobial susceptibility was determined by the disk diffusion method for Enterobacterales, Campylobacter and Aeromonas, and by the gradient diffusion method for C. difficile. Of the 26,060 stool samples from patients of any age, 1,022 (3.9%) were positive for bacterial enteropathogens. Campylobacter spp. were the most commonly isolated bacteria (56.4%), followed by Salmonella enterica (32.3%), and E. coli (EPEC, STEC) (6.5%). Toxigenic C. difficile was isolated from 341 out of 8,848 diarrheal specimens examined (3.9%). Resistance to ampicillin was observed in 12.4% of Salmonella, 66.7% of Shigella and 34.8% of E. coli (EPEC, STEC) isolates. Resistance to trimethoprim/sulfamethoxazole was observed in 5.8% of Salmonella, 33.3% of Shigella, and 15.1% of E. coli (EPEC, STEC) isolates. High rates of ciprofloxacin resistance (77.3%) were detected among Campylobacter isolates, while resistance to erythromycin was observed in 2.4% of them. All C. difficile isolates were susceptible to vancomycin and metronidazole. Our findings suggest declining trends in prevalence of bacterial enteropathogens, except for Campylobacter spp. and changes in the susceptibility rates to antimicrobials. Continuous surveillance of prevalence and antimicrobial susceptibility of bacterial enteropathogens is mandatory for implementing targeted and effective prevention and infection control measures. [ABSTRACT FROM AUTHOR]

Simple Summary: The objective of this study was to investigate, for the first time in Greece, the prevalence of ESBL producers in swine populations and to correlate their occurrence with risk factors. A total of 214 fecal samples were collected from the farms from December 2019 to April 2021. A subset of 78 (78/214, 36.5%) ESBL producers were identified as Escherichia coli (E. coli, 88.5%), Klebsiella pneumoniae spp. pneumoniae (K. pneumoniae, 3.8%), Proteus mirabilis (P. mirabilis, 5.1%), Enterobacter cloacae complex (E. cloacae complex, 1.3%) and Salmonella enterica spp. diarizonae (S. enterica spp. diarizonae, 1.3%). CTX-M, SHV and TEM genes were detected along with genes conferring resistance to fluoroquinolones, aminoglycosides, sulfonamides, trimethoprim, macrolides and colistin. This study displayed high antimicrobial resistance rates in the Greek swine industry, and our results are alarming for both human and animal health. This study aimed to estimate the prevalence of extended-spectrum β-lactamase-producing (ESBL) bacteria in swine. Thus, 214 fecal samples were collected from suckling and weaned piglets from 34 farms in Greece (out of an overall population of about 14,300 sows). A subset of 78 (36.5%) ESBL producers were identified as E. coli (69/78, 88.5%), K. pneumoniae spp. pneumoniae (3.8%), P. mirabilis (5.1%), E. cloacae complex (1.3%) and S. enterica spp. diarizonae (1.3%). Resistance to at least one class of non-β-lactam antibiotics was detected in 78 isolates. Among the E. coli strains, resistance was identified with regard to aminoglycosides (n = 31), fluoroquinolones (n = 49), tetracycline (n = 26) and trimethoprim/sulfamethoxazole (n = 46). Of the three K. pneumoniae spp. pneumoniae, two displayed resistances to aminoglycosides and all were resistant to fluoroquinolones, tetracyclines and trimethoprim/sulfamethoxazole. As for the four P. mirabilis isolates, three had a resistant phenotype for aminoglycosides and all were resistant to imipenem, fluoroquinolones, tetracyclines and trimethoprim/sulfamethoxazole. Molecular characterization of the isolates revealed the presence of CTX-M, SHV and TEM genes, as well as of genes conferring resistance to fluoroquinolones, aminoglycosides, sulfonamides, trimethoprim, macrolides and colistin. High levels of antimicrobial resistance (AMR) were demonstrated in Greek swine herds posing a concern for the efficacy of treatments at the farm level as well as for public health. [ABSTRACT FROM AUTHOR]

Wild and feral birds are known to be involved in the maintenance and dissemination of clinically-important antimicrobial-resistant pathogens, such as extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae. The aim of our study was to evaluate the presence of ESBL- and carbapenemase-producing Escherichia coli among wild and feral birds from Greece and to describe their antimicrobial resistance characteristics. In this context, fecal samples of 362 birds were collected and cultured. Subsequently, the antimicrobial resistance pheno- and geno-type of all the obtained E. coli isolates were determined. A total of 12 multidrug-resistant (MDR), ESBL-producing E. coli were recovered from eight different wild bird species. Eleven of these isolates carried a blaCTX-M-1 group gene alone or in combination with blaTEM and one carried only blaTEM. AmpC, fluoroquinolone, trimethoprim/sulfamethoxazole, aminoglycoside and macrolide resistance genes were also detected. Additionally, one carbapenemase-producing E. coli was identified, harboring blaNDM along with a combination of additional resistance genes. This report describes the occurrence of ESBL- and carbapenemase-producing E. coli among wild avian species in Greece, emphasizing the importance of incorporating wild birds in the assessment of AMR circulation in non-clinical settings. [ABSTRACT FROM AUTHOR]

Background: The increase in carbapenem-resistant Klebsiella pneumoniae (CRKP) infections is of great concern because of limited treatment options. New antimicrobials were recently approved for clinical therapy. This study evaluated the epidemiology of carbapenemase-producing K. pneumoniae isolates collected at a Greek university hospital during 2017–2020, and their susceptibilities to ceftazidime–avibactam (CAZ/AVI), meropenem–vaborbactam (M/V), imipenem–relebactam (I/R), eravacycline, plazomicin, and comparators. Methods: Minimum inhibitory concentrations (MICs) were evaluated by Etest. Only colistin MICs were determined by the broth microdilution method. Carbapenemase genes were detected by PCR. Selected isolates were typed by multilocus sequence typing (MLST). Results: A total of 266 carbapenemase-producing K. pneumoniae strains were isolated during the 4-year study period. Among them, KPC was the most prevalent (75.6%), followed by NDM (11.7%), VIM (5.6%), and OXA-48 (4.1%). KPC-producing isolates belonged mainly to ST258 and NDM producers belonged to ST11, whereas OXA-48- and VIM producers were polyclonal. Susceptibility to tigecycline, fosfomycin, and colistin was 80.5%, 83.8%, and 65.8%, respectively. Of the novel agents tested, plazomicin was the most active inhibiting 94% of the isolates at ≤ 1.5 μg/ml. CAZ/AVI and M/V inhibited all KPC producers and I/R 98.5% of them. All OXA-48 producers were susceptible to CAZ/AVI and plazomicin. The novel β-lactam/β-lactamase inhibitors (BLBLIs) tested were inactive against MBL-positive isolates, while eravacycline inhibited 61.3% and 66.7% of the NDM and VIM producers, respectively. Conclusions: KPC remains the predominant carbapenemase among K. pneumoniae, followed by NDM. Novel BLBLIs, eravacycline, and plazomicin are promising agents for combating infections by carbapenemase-producing K. pneumoniae. However, the emergence of resistance to these agents highlights the need for continuous surveillance and application of enhanced antimicrobial stewardship. [ABSTRACT FROM AUTHOR]

Objective. This study aimed to describe Salmonella epidemiology and antimicrobial resistance in Greek children over the period of 2011-2017. Materials and Methods. A 7-year retrospective study (2011-2017) was performed, based on data recorded by the National Reference Centre for Salmonella, among children aged =14 years. Epidemiological data, serovar distribution and antimicrobial resistance patterns were recorded. Results. Overall, 2347 Salmonella isolates were collected (27 typhoidparatyphoid). Salmonellosis cases increased by almost 2-fold in 2017 compared to 2011. The highest rates were reported in August, with infants being the most vulnerable group (17.9%). The majority of isolates were identified in stool samples (91%). Boys slightly outnumbered girls (~1.05:1). Salmonella Enteritidis was the most prevalent serovar (28.5%), followed by Salmonella Typhimurium (12.2%) and Salmonella monophasic Typhimurium (10.4%). Non-typhoid isolates displayed low resistance rates to 3rd generation cephalosporins (1%) and ciprofloxacin (0.3%), while the corresponding resistance of typhoid isolates was 10% and 5% respectively. An increasing trend of Salmonella monophasic Typhimurium was recorded, associated with high rates of multidrug resistance, reaching a percentage of 97.8% in 2017. Conclusions. Salmonellosis epidemiology in Greek children is comparable to previously published European data. Antimicrobial resistance rates to 3rd-generation cephalosporins and ciprofloxacin for non-typhoid and typhoid-paratyphoid remain low. Notably, there is an increasing prevalence of Salmonella monophasic Typhimurium isolates, associated with multiple antimicrobial resistance. [ABSTRACT FROM AUTHOR]

B Dear Editor: b New Delhi Metallo (NDM)- -lactamases producing bacteria have become a great threat to public health, due to their fast and wide geographical spread in recent years.[1] These enzymes hydrolyze all -lactams except aztreonam and are not inhibited by the novel -lactamase inhibitors such as avibactam, relebactam, and vaborbactam. During the past 5 years (2015-2020) ~1.9% (107 out 5660) of I E. coli i isolated from humans in Thessaly were resistant to carbapenems; among them 0.7% were positive for NDM-1 and belonged to various sequence types (STs) such as 744, 998, 410, 4380, 12, 683, and 46. Surveillance cultures showed that only one microorganism, one I Escherichia coli i (B103), was resistant to carbapenems, with MICs of imipenem and meropenem 64 and 32 mg/L, respectively. [Extracted from the article]

Simple Summary: Moellerella wisconsensis is a potentially zoonotic pathogen that has sporadically been isolated from animals and humans. In the present study, we describe the occurrence of the organism among 445 wild bird and 2000 human fecal samples, in the context of an investigation regarding antimicrobial resistant bacteria in Greece. According to our results, 0.9% (n = 4) of the examined wild birds were found to be colonized by M. wisconsensis, while no human was a carrier of the bacterium. Out of the total number of four M. wisconsensis strains that we detected, three presented resistance to 3rd generation cephalosporins, were phenotypically confirmed to produce extended spectrum beta lactamases (ESBLs) and harbored blaCTX-M-1. Resistance to tetracyclines, aminoglycosides and trimethoprim/sulfamethoxazole was additionally detected in three, two and one of the ESBL isolates, respectively. This is the first report that presents the dissemination of M. wisconsensis in wild bird from Greece and describes CTX-M-1 production in multidrug resistant wild birds' isolates of this bacterial species. Moellerella wisconsensis is an Enterobacteriaceae with unclarified dispersion and pathogenicity. During an ongoing investigation about antimicrobial resistance in Greece, the occurrence of M. wisconsensis was evaluated among wild birds and humans. A total of 445 wild bird and 2000 human fecal samples were collected and screened for the presence of the organism. Subsequently, all M. wisconsensis strains were phenotypically and molecularly characterized regarding their antimicrobial resistance characteristics. Four M. wisconsensis were isolated from a common pheasant (Phasianus colchicus), two Eurasian magpies (Pica pica) and a great white-fronted goose (Anser albifrons). Among these four strains, the three latter presented resistance to 3rd generation cephalosporins, were phenotypically confirmed to produce ESBLs and were found to harbor blaCTX-M-1. The three ESBL isolates additionally exhibited resistance to tetracyclines, while resistance to aminoglycosides was detected in two of them and to trimethoprim/sulfamethoxazole in one. No Moellerella wisconsensis strains were retrieved from the human samples tested. This is the first report that provides evidence of M. wisconsensis dissemination among wild birds in Greece, describing CTX-M-1 production in multidrug resistant wild birds' isolates of this bacterial species. [ABSTRACT FROM AUTHOR]

Background Extended-spectrum β-lactamases (ESBLs) have emerged as an important mechanism of β-lactam resistance among community uropathogens. We characterized the ESBLs of a collection of Escherichia coli isolates recovered from outpatients with urinary tract infection during nationwide surveillance conducted from 2005 to 2006 in Greece, and evaluated the in vitro activity of mecillinam and mecillinam/clavulanate against them. Materials and methods ESBLs were characterized with PCR and sequencing. In vitro interactions were evaluated with agar dilution with and without clavulanate (4 mg/L) using an inoculum of 104 or 106 cfu/spot as well as with time–kill methodology. Results Among 48 ESBL producers, 47 (97.9%) were susceptible to mecillinam. CTX-M-type enzymes were produced by 87.2%, with CTX-M-3 being the most prevalent. SHV enzymes were found in 10.6%, VEB enzymes in 2.1%, TEM enzymes in 19.2% and OXA-type enzymes in 12.8%. Synergy with clavulanate was detected in 60.4% using the agar dilution method and in 43.8% using the time–kill methodology. An inoculum effect was detected in 64.6% of isolates, but this phenomenon was inverted and synergy was evidenced for 85.4% with clavulanate. When a high inoculum was used, 60.4% (29/48) were resistant to mecillinam, but 97.9% (47/48) were susceptible in the presence of clavulanate. Conclusions CTX-M-type enzymes were the most prevalent among ESBL-producing E. coli uropathogens in Greece. Mecillinam may be useful in uncomplicated cystitis caused by ESBL producers with low MICs. The addition of the inhibitor could improve and extend the activity of mecillinam, even in the setting of infection with a high bacterial inoculum, and merits clinical evaluation. [ABSTRACT FROM PUBLISHER]

Objectives The extended-spectrum β-lactamase (ESBL) PER-1 initially disseminated among Pseudomonas aeruginosa strains in Turkey. Despite reports from other European countries, such strains have not been detected in Greece until now. We describe the first blaPER-1-positive P. aeruginosa isolates from Greece and their genetic environment. Methods From January 2008 to December 2009, 287 consecutive non-duplicate P. aeruginosa isolates with reduced susceptibility or resistance to ceftazidime (MIC >8 mg/L) were screened for ESBL production with a modified boronic acid-based double-disc synergy test. Phenotypically ESBL-positive isolates were subjected to agar dilution, PFGE and multilocus sequence typing (MLST). Broad-spectrum bla genes were identified by PCR and sequencing. Plasmid analysis and conjugation experiments were performed. The location of the blaPER-1 gene was detected by Southern blotting and its genetic environment was characterized using inverse PCR. Results Five isolates were phenotypically positive for ESBL production, exhibited resistance to cefepime, ceftazidime, aztreonam and meropenem, and carried the blaPER-1 gene. MLST showed that they belonged to sequence type (ST) 235, which belongs to the international clonal complex 11. Four isolates had the same PFGE pattern. Southern blotting revealed the chromosomal location of the blaPER-1 gene. Analysis of the blaPER-1 flanking regions showed identity to transposon Tn1213 downstream and 1406 bp upstream of blaPER-1. Further upstream, an orfA gene and ISPa12 were identified; both were truncated by the insertion of IS6100. Conclusions This study confirmed the presence of PER-1-producing P. aeruginosa strains in Greece. The chromosomal location of blaPER-1, as part of a truncated transposon, suggests clonal expansion rather than horizontal gene transfer. [ABSTRACT FROM PUBLISHER]

Abstract: The molecular epidemiology of VIM-producing Enterobacteriaceae isolated at the beginning of an epidemic in the Intensive Care Unit (ICU) of a university hospital in Athens, Greece, was studied. All Gram-negative organisms isolated from March 2004 to November 2005 positive for metallo-β-lactamase (MBL) production were submitted to polymerase chain reaction (PCR) and sequencing, to repetitive sequence-based PCR (Rep-PCR) for molecular typing, and to S1 nuclease digestion for plasmid DNA characterisation. Conjugation experiments and isoelectric focusing were performed to identify co-existing β-lactamases. Amongst 23 patients, 12 suffered one or more clinical infections. Eighty-two isolates representing one isolate per clone, source and ICU patient were studied, including Klebsiella pneumoniae (77), Enterobacter cloacae (2), Citrobacter freundii (1) and Pseudomonas aeruginosa (2). High clonal diversity was detected amongst the K. pneumoniae, with 10 distinct clones identified. Conjugation was successful in 54.5% of K. pneumoniae, and five different-sized plasmids were detected. All K. pneumoniae and both E. cloacae isolates shared the same bla VIM-1-containing class 1 integron structure also carrying aacA7, dhfrI and aadA1 gene cassettes. The C. freundii isolate carried a different integron that included bla VIM-1 and aac(6′)-IIc. Both P. aeruginosa isolates were positive for bla VIM-2. It was not possible to identify specific clones with the potential to cause clinical infections. In conclusion, a multiclonal cluster of MBL-producers was responsible for the first cases of colonisation and/or infection in the ICU. A single integron structure, common in Greek hospitals, efficiently disseminated between clones and species, suggesting that the epidemic was mainly the result of successful horizontal transfer of mobile genetic material rather than the result of horizontal transfer of one or a few clones. [Copyright &y& Elsevier]

Carbapenemases increasingly have been reported in Enterobacteriaceae in the past 10 years. Klebsiella pneumoniae carbapenemases have been reported in the United States and then worldwide, with a marked endemicity at least in the United States and Greece. Metalloenzymes (Verona integron-encoded metallo-β-lactamase, IMP) also have been reported worldwide, with a higher prevalence in southern Europe and Asia. Carbapenemases of the oxacillinase-48 type have been identified mostly in Mediterranean and European countries and in India. Recent identification of New Delhi metallo-β-lactamase-1 producers, originally in the United Kingdom, India, and Pakistan and now worldwide, is worrisome. Detection of infected patients and carriers with carbapenemase producers is necessary for prevention of their spread. Identification of the carbapenemase genes relies mostly on molecular techniques, whereas detection of carriers is possible by using screening culture media. This strategy may help prevent development of nosocomial outbreaks caused by carbapenemase producers, particularly K. pneumoniae. [ABSTRACT FROM AUTHOR]

Extended-spectrum β-lactamases (ESBLs) are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. β-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBLproducing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBLproducing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens. [ABSTRACT FROM AUTHOR]

An Escherichia coli strain with decreased susceptibility to carbapenems was isolated from a hospitalised patient in Athens, Greece. The strain was resistant to all β-lactams, including aztreonam, whereas the MIC of imipenem and meropenem was 0.5 mg/L. A positive EDTA–disk synergy test suggested the production of a metallo-β-lactamase. PCR experiments revealed the presence of the blaVIM-2, blaIBC-1 and bla tem-1 genes. Resistance to β-lactams was not transferable by conjugation. This is the first report of a clinical isolate of E. coli producing VIM-2, and the first report of the coexistence of blaVIM-2 and blaIBC-1 in a single clinical isolate. [ABSTRACT FROM AUTHOR]

Background Greece is facing an endemic situation with carbapenem-resistant pathogens in the hospital sector. The Central Public Health Laboratory (CPHL) is the main laboratory for the surveillance of the carbapenem resistance mechanisms, accepting resistant isolates from hospitals on a voluntary basis. The aim of the present study is to evaluate the epidemiology of carbapenem-resistant Enterobacteriaceae (CRE) isolated in Greek hospitals the period 2014–2018 and their susceptibility to other antibiotic classes. Methods A total of 843 CRE isolates (741 Klebsiella spp. 47 Enterobacter spp. 35 Escherichia coli , and 20 others) have been submitted from 36 hospitals throughout the country (Figure 1) to the CPHL. They originated from different clinical specimens (295 urine, 157 blood, and 107 other) or surveillance cultures (185 rectal and 23 pharyngeal swabs) or unknown (n = 76). Carbapenemase genes were detected by PCR targeting blaKPC, blaNDM, blaVIM, and bla OXA-48. Resistance to aminoglycosides and fluoroquinolones was tested with the disk diffusion method according to EUCAST guidelines. Results The isolates were found positive for several carbapenemase genes (Table 1). Overall, KPC-2 (36%) was the predominant carbapenemase, followed by the metalloenzymes NDM (28%) and VIM (18%) while OXA-48 ranked fourth (7%). KPC enzyme was predominant among Klebsiella spp isolates followed by NDM, whereas among Enterobacter , E.coli , and other species, the VIM metalloenzyme predominated. Simultaneous detection of two carbapenemase genes was found in 30 (4%) isolates: 14 blaKPC/blaVIM, 4 blaKPC/blaNDM, 1 blaKPC/blaOXA-48, 5 blaNDM/blaVIM, 5 blaNDM/blaOXA-48, and 1 blaVIM/blaOXA-48. In 63 isolates (7%), the carbapenem resistance was attributed to other mechanisms, mainly production of ESBL or AmpC plus porin loss. In total, 590 (70%) CRE isolates exhibited a multidrug-resistant phenotype being simultaneously resistant to aminoglycosides and fluoroquinolones. Conclusion The CRE isolates' diversity, regarding bacterial species, carbapenemase types and combinations and their temporal and spatial distribution mandate a more structured, continuous laboratory surveillance to monitor the ongoing carbapenem and multidrug resistance evolution and inform infection control and public health actions. Disclosures All authors: No reported disclosures [ABSTRACT FROM AUTHOR]

The prevalence of multidrug resistant, extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is increasing worldwide. The present study aimed to provide an overview of the multidrug resistance phenotype and genotype of ESBL-producing Escherichia coli (E. coli) isolates of livestock and wild bird origin in Greece. Nineteen phenotypically confirmed ESBL-producing E. coli strains isolated from fecal samples of cattle (n = 7), pigs (n = 11) and a Eurasian magpie that presented resistance to at least one class of non β-lactam antibiotics, were selected and genotypically characterized. A DNA-microarray based assay was used, which allows the detection of various genes associated with antimicrobial resistance. All isolates harbored blaCTX-M-1/15, while blaTEM was co-detected in 13 of them. The AmpC gene blaMIR was additionally detected in one strain. Resistance genes were also reported for aminoglycosides in all 19 isolates, for quinolones in 6, for sulfonamides in 17, for trimethoprim in 14, and for macrolides in 8. The intI1 and/or tnpISEcp1 genes, associated with mobile genetic elements, were identified in all but two isolates. This report describes the first detection of multidrug resistance genes among ESBL-producing E. coli strains retrieved from feces of cattle, pigs, and a wild bird in Greece, underlining their dissemination in diverse ecosystems and emphasizing the need for a One-Health approach when addressing the issue of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Abstract: hyplex®-MBL ID Multiplex PCR-ELISA, a novel method for identifying metallo-β-lactamase genes directly in clinical specimens, was evaluated using a consecutive collection of 326 samples from three hospitals in Greece characterized by high prevalence of VIM producers. The method exhibited high sensitivity (98.0%) and specificity (98.6%) and was proven reliable in detecting bla VIM genes in blood, urine, pus, and sputum samples that, as confirmed by conventional methods, contained various VIM-producing species. Future multicenter studies should be considered for the thorough evaluation of this method and its potential diagnostic utility. [ABSTRACT FROM AUTHOR]

• Carbapenem-resistance rate of 29.6% in Klebsiella pneumoniae in Greece. • The most prevalent genes were KPC (40.3%) followed by VIM (14.2%) carbapenemases. • Co-resistance to carbapenem and colistin was found in 213 (73.9%) isolates. • mgrB inactivation was the most common mechanism of colistin resistance (69.5%). • No mcr colistin variants were found, indicating this gene has not spread in humans. In Greece, the spread of carbapenem-resistant Enterobacteriaceae in humans has led to the reintroduction of colistin as a therapeutic agent. Unfortunately, colistin resistance with different mechanisms has emerged. The present work aims to determine the prevalence of carbapenem and colistin resistance and the corresponding mechanisms in Klebsiella pneumoniae clinical isolates from Greece. From 2014 to 2017, 288 carbapenem-resistant K. pneumoniae clinical strains were gathered from a collection of 973 isolates from eight different hospitals in Greece. Antibiotic susceptibility testing was performed using three different methods. Screening of carbapenem and colistin resistance genes was conducted using polymerase chain reaction (PCR) amplification and sequencing. Among the 288 (29.6 %) carbapenem-resistant isolates, 213 (73.9%) were colistin-resistant (minimum inhibitory concentration [MIC] >2 mg/L). The KPC type was the most common carbapenemase gene (116; 40.3%), followed by VIM (41; 14.2%), NDM (33; 11.5%) and OXA-48 (22; 7.6%). Moreover, 44 (15.3%) strains co-produced two types of carbapenemases. No mcr genes were detected for colistin resistance but mutations in chromosomal genes were found. These included inactivation of the mgrB gene for 148 (69.5%) strains, including insertion sequences for 94 (44.1%), nonsense mutations for 4 (1.9%) and missense mutations for 24 (11.3%). Moreover, PCR amplification of mgrB gene was negative for 26 (12.2%) strains. Finally, 65 (30.5%) colistin-resistant strains exhibited a wild-type mgrB , the mechanisms of which remain to be elucidated. This study shows that K. pneumoniae clinical strains in Greece are resistant to both carbapenems and colistin and this is endemic and is likely chromosomally encoded. [ABSTRACT FROM AUTHOR]

During 2014-2016, a total of 248 carbapenem-resistant Klebsiella pneumoniae (CARB-R Kp) were recovered in a Greek intensive care unit (ICU), the colistin resistance (COL-R) rates among CARB-R Kp from bloodstream infections (BSIs) were determined, and molecular characterization and the in vitro susceptibility of CARB-R+COL-R Kp to ceftazidime/avibactam were performed. The majority of CARB-R Kp from BSIs ( n  = 53) were OXA-48 (43.4%) and KPC (33.9%) producers, but no statistically significant differences were observed for the clinical characteristics of ICU patients affected by OXA-48 and other carbapenemase-producing K. pneumoniae . CARB-R+COL-R Kp ( n  = 28) represented 52.8% of 53 CARB-R Kp recovered from BSIs. The increase in the COL-R rates from 2014 to 2015 was mainly associated with the diffusion of extensively drug-resistant ( XDR) OXA-48-co-producing CTX-M-15-like K. pneumoniae , assigned to multilocus-sequence typing ST101, possessing alterations in the mgrB loci. Ceftazidime/avibactam was active against all OXA-48 and KPC producers. Thus, the spread of XDR Kp possessing different types of carbapenemases further complicates the infection control strategies for the management of XDR Kp, whereas ceftazidime/avibactam may be a reasonable alternative to colistin for the treatment of XDR Kp in settings with low prevalence of metallo-β lactamase-producing K. pneumoniae .

The article discusses the endoscopy-linked transmission of carbapenem-resistant Klebsiella pneumoniae producing KPC-2 beta-lactamase. Researchers found that all Klebsiella pneumoniae carbapenemase (KPC) isolates were identical to a previously determined Klebsiella pneumoniae ST258-type clone that became an epidemic in Greece. The article details the case study of an 85-year-old individual suffering from bladder cancer who incurred an extended-spectrum beta lactamase (ESBL).

Objectives KPC-possessing Klebsiella pneumoniae have been found to be widespread in several regions but are still rarely detected in Europe. We describe the characteristics of an outbreak caused by KPC producers in a tertiary care Greek hospital. Methods During a 12 month period (October 2007–September 2008), 47 patients in Hippokration University Hospital yielded K. pneumoniae isolates that exhibited reduced susceptibility to carbapenems and were phenotypically positive for carbapenemase production but negative for metallo-β-lactamase (MBL) production. Single patient isolates were tested by Vitek 2, Etest, agar dilution MICs, phenotypic assays and PFGE. Carbapenemase and other β-lactamase genes were identified by PCR and sequencing. Patient records were retrospectively reviewed to access co-morbidities, antibiotic exposure prior to infection and outcome. Results The 47 K. pneumoniae isolates exhibited various susceptibilities to imipenem and meropenem; all were non-susceptible to ertapenem and several other antibiotics but most were susceptible to gentamicin, colistin and tigecycline. PFGE classified the isolates into two clonal types, with the predominant type, which was closely related to that of hyperepidemic strains from the USA and Israel, comprising three subtypes. All isolates carried the blaKPC-2 gene; 45 also carried blaSHV-12 and 29 blaTEM-1. Patients were hospitalized in nine different units. The median length of hospital stay prior to KPC isolation was 21 days; 38 patients (80.9%) had evidence of clinical infection due to a KPC producer and 16 (34%) had bacteraemia. The crude mortality rate was 27.7%. A β-lactam/β-lactamase inhibitor combination was the most frequently administered antimicrobial prior to KPC isolation (20 patients; 42.5%), whereas only nine patients (19.1%) had prior carbapenem use. Conclusions This study presents for the first time a wide intrahospital spread of KPC-producing K. pneumoniae clones in a European hospital. The KPC producers were rapidly disseminated in several units, indicating the difficulty in restraining such multidrug-resistant clones when they have been established in a hospital environment. [ABSTRACT FROM AUTHOR]

: Objectives To investigate the first KPC carbapenemase-producing Klebsiella pneumoniae isolate from a Greek hospital, including phenotypic methods to aid recognition of this resistance type. : Methods A carbapenem-resistant clinical isolate of K. pneumoniae was recovered from a hospitalized Greek patient. Detailed susceptibility testing was carried out by the agar dilution method. The isolate was screened by phenotypic and genotypic assays for the presence of various β-lactamases. Boronic acid disc tests were performed to show the ability of these tests to detect production of the KPC enzymes. The potential for conjugal transfer of carbapenem resistance was examined by biparental matings, plasmid analysis and PCR studies. : Results The isolate possessed on the same self-transferable plasmid the KPC-2 carbapenemase and the SHV-12 extended-spectrum β-lactamase. Although the isolate did not produce an AmpC-type enzyme, the production of KPC-2 was associated with positive boronic acid disc tests using cephamycins and cefotaxime as well as cefepime and carbapenems as substrates. : Discussion KPC-2-possessing K. pneumoniae clinical isolates seem to have been introduced in our region. Boronic acid disc tests using boronic acid in combination with carbapenems or cefepime may help the phenotypic detection of KPC enzymes and their distinction from plasmid-mediated AmpC enzymes. [ABSTRACT FROM AUTHOR]

Objective To study the possible distribution of metallo-β-lactamases among nosocomial Pseudomonas isolates in a Greek hospital with a recent high prevalence of carbapenem-resistant Pseudomonas isolates. Methods All carbapenem-resistant (imipenem- and/or meropenem-resistant) (MICs > 8 mg/L) Pseudomonas non-replicate isolates recovered from clinical infections in the Microbiology Laboratory of Saint Demetrios Hospital, Thessaloniki, Greece, from April 1998 to November 2000 were studied for the presence of metallo-β-lactamases. They were tested by a disk diffusion test, PCR analysis, and nucleotide sequencing. DNA fingerprints were obtained by pulsed-field gel electrophoresis (PFGE) of Xba I-digested chromosomal DNA. Results In total, 24 carbapenem-resistant isolates (23 P. aeruginosa and one P. putida ) were recovered. The serotypes observed among the P. aeruginosa isolates were, in order of decreasing frequency, O:11 (52%), O:3 and O:12 (17% each), and O:6 (13%). PFGE grouped 17 of the P. aeruginosa isolates into four clusters, each containing from two to seven isolates, while the remaining isolates exhibited unique genotypes. bla [sub VIM-2] was detected in the P. putida isolate and a P. aeruginosa serotype O:3 isolate. The latter strain was genotypically distinct from other contemporaneous or older carbapenem-resistant P. aeruginosa Greek isolates. Conclusion These findings suggest that, although the prevalence of metallo-β-lactamases is low, the integron-associated bla [sub VIM] genes can spread to P. aeruginosa serotypes that have not been previously associated with carbapenem resistance in our region, as well as to other pseudomonal species. [ABSTRACT FROM AUTHOR]