Mobile genetic elements and clonal dynamics of antibiotic-resistant hospital-acquired bacteria

Over the past decades antimicrobial resistance rates are rapidly growing and have provoked the emergence of multidrug-resistant bacterial pathogens. Of particular concern are nosocomial outbreaks and the clonal spread of antibiotic-resistant bacteria representing a major threat for the healthcare system and especially to susceptible patient populations. One of the aims of this PhD project was to investigate the spread of three bacterial species commonly involved in nosocomial infections: vancomycin-resistant Enterococcus faecium (VREfm) and third-generation cephalosporin-resistant (3GCR) Klebsiella pneumoniae recovered from screening samples of patients admitted to six university hospitals in Germany, and carbapenem-resistant Acinetobacter baumannii (CRAb) from two hospitals in Bolivia. Between 2014 and 2018 a steady increase in the prevalence of VREfm (2014, 0.8%; 2015, 1.2%; 2016, 1.3%; 2017, 1.5%; 2018, 2.6%) was observed in six university hospitals in Germany. In the present cohort the sequence type (ST) 117 was identified as the predominant clone followed by ST80, ST203, ST78 and ST17. Furthermore, vanB was the most common glycopeptide resistance determinant among the colonising isolates while the vast majority of the ST117 isolates were vanB-positive. A remarkable clonal dissemination of the vanB-positive cluster type (CT) 71 subpopulation of the ST117 clone was identified among VREfm. In contrast, other STs, such as ST80, formed mostly local clusters restricted to single study centres. The ST117/CT71/vanB VREfm clone was widespread over six geographically separated centres and was endemic and indicated that the epidemiological profile of VREfm in Germany has changed in the past five years. Conversely, patients on hospital admission in Germany were colonised with a diverse population of 3GCR K. pneumoniae complex isolates. Over the study period an increase in the prevalence of 3GCR K. pneumoniae complex (2016, 0.8%; 2017, 0.9%; 2018, 1.1%) was observed. The clinically relevant K. pneumoniae was the predominant species in the present study, but a few representatives of Klebsiella quasipneumoniae and Klebsiella variicola were also identified. Among 3GCR K. pneumoniae isolates CTX-M-15 was the most common acquired β-lactamase followed by TEM-1B. Carbapenem-resistance was rare among the colonising isolates with only one K. variicola isolate harbouring a carbapenemase, OXA-181. Lastly, no clonal expansion and only small clusters of closely related isolates were identified, suggesting that a diverse K. pneumoniae population is circulating in the participating study centres. The clonal spread of CRAb isolates obtained from two hospitals in Bolivia was demonstrated in the present thesis. Among A. baumannii 51 were identified as carbapenem-resistant. The vast majority of the CRAb isolates were identified as ST25 or a single locus variant of it, ST991. The latter ST was only identified in one of the hospitals while ST25 was predominant in the second hospital. Moreover, all CRAb isolates harboured OXA-23 on a Tn2008 transposon while no other carbapenemase was detected. All but one of the CRAb isolates belonged to the international clone (IC) 7 and formed five transmission clusters. Furthermore, one CRAb isolate was assigned as IC4. These results suggested that several IC7 OXA-23-positive CRAb clones are endemic and are circulating in two hospitals in Bolivia. Horizontal gene transfer and mobile genetic elements (MGEs) are the main drivers of the evolution, diversification and spread of antibiotic resistance genes (ARGs) in bacteria. This thesis analysed and characterised MGEs including plasmids, transposons and insertion sequences (ISs) catalysing the mobilization of ARGs in A. baumannni clinical isolates. For the first time the carbapenemase blaNDM-6, a blaNDM-1 variant, was identified in a CRAb isolate recovered in northern Spain in 2019. The ST85 CRAb clustered together with the recently described and widespread clonal lineage IC9. Furthermore, in the latter isolate NDM-6 was detected in two copies and in a novel genetic environment linked to MGEs. Novel insights into MGEs harbouring ARGs in A. baumannii IC4, IC5 and IC7 representatives from Bolivia were observed. A diverse array of transposons, plasmids and resistance islands, such as strA and strB harboured by a large plasmid in the IC4 CRAb and by a chromosome encoded resistance island in the IC5 isolate, were identified in the present study. Furthermore, MGEs, e.g. a small plasmid or the Tn2008 carrying the blaOXA-23, were found across different ICs. These data reflect the prevalence of MGEs in A. baumannii and the strong link between the spread of ARGs and the mobilome. Bacteria can be clonal but yet different. The extent of clonal heterogeneity associated with MGEs in bacterial populations was also discussed for three extensive drug-resistant K. pneumoniae colonising isolates from Germany. The isolates were assigned to the high-risk clone ST147 and were armed in addition with a wide repertoire of ARGs, including the plasmid encoded carbapenemase OXA-181. Of particular interest was an IncR plasmid harbouring in total 12 resistance determinants and a wide variety of ISs. The K. pneumoniae isolates were closely related but diversity including inversions or deletions in the proximity to MGEs within the IncR plasmid was identified. Nevertheless, this genetic variation did not affect the resistance phenotype of the three K. pneumoniae isolates. These data demonstrated the influence of MGEs on genome plasticity and their contribution to heterogeneity within closely related isolates. Another example of clonal heterogeneity was detected in a CRAb outbreak in a German university hospital. The CRAb isolates harboured the acquired β-lactamase NDM-1 embedded in a transposon adjacent to the aminoglycoside modifying enzyme AphA6. Moreover, a second carbapenemase, OXA-23, was carried by the CRAb isolates. By cgMLST analysis the isolates were closely related and formed a transmission cluster. However, one patient was co-infected with two near identical CRAb isolates, i.e. one NDM-1-positive isolate and one isolate lacking NDM-1 and AphA6. Nevertheless, the NDM-1-negative isolate was still carbapenem-resistant because of the presence of blaOXA-23. The loss of the antibiotic resistance determinants NDM-1 and AphA6 could be attributed to a transposition event. MGEs associated with ARGs can lead to genetic variation during the course of an outbreak but not necessarily alter the resistance phenotype. Also, a co-infection of two closely related but phenotypically different E. faecium isolates was discussed in the present study. Both isolates were obtained from the same blood culture and were identified as ST203. Furthermore, one isolate was VREfm while the second was vancomycin-susceptible E. faecium (VSEfm). Molecular epidemiology of the two isolates revealed that the VREfm and VSEfm were closely related. In the VSEfm isolate, a 12 kb plasmid was detected which was also present in the VREfm isolate. However, in the VREfm the latter plasmid carried also the vanA gene cluster embedded in a Tn1546-type transposon as also the resistance genes ant(6)-Ia, erm(B) and cat-like and two more replicons indicating the presence of a chimeric plasmid. Here, MGEs and clonal diversity led to a heterogenous resistance phenotype within closely related isolates. Taken all together, this thesis documents the clonal spread and diversity of three hospital-acquired bacterial species but also highlights the dynamics of MGEs contributing to genome plasticity and the genetic diversity within closely related isolates

The effect of erythropoietin on acute renal ischemia: experimental study in rats

The effect of erythropoietin on acute renal ischemia.Experimental study in rats.Erythropoietin (EPO) exhibits pleiotropic properties. The aim of this study was to investigate the effect of EPO on acute renal ischemia/reperfusion (RI/R). Male Wistar rats randomly divided into two groups: I/R (n=12) and EPO I/R group (500 IU/Kg, i.p, 20 min prior ischemia, n=15), were subjected to bilateral renal ischemia for 45 min. Three subgroups were defined in each group, in which reperfusion occurred in 6, 24 and 48 hours respectively. Rats subjected to identical surgical procedure without occlusion of renal pedicles constituted the control group (n=6). Renal injury was assessed by measurement of serum biochemical markers (urea and creatinine) and histological grading. The expression of Cyt c, nNOS, iNOS, eNOS and COX-2 was studied immunohistochemically, while Fas/FasL, nNOS and Cyt c were evaluated by RT-PCR. I/R caused deterioration of the biochemical markers and installation of histological lesions. EPO pretreatment reduced I/R-induced tubular injury and ameliorated renal function. Fas/FasL and Cyt c mRNA were isolated from normal kidneys. Fas/FasL mRNA expression did not change in both groups. RI/R caused an increase in the gene and protein expression of Cyt c (mostly in 48 and 6hrs respectively). EPO limited gene expression of Cyt c in 48hrs and restricted its protein expression mostly in 6hrs. The expression of nNOS in normal kidneys was decreased in 6hrs of reperfusion, while it tended to be restored later. EPO maintained its expression in the controls’ levels in 6hrs. Limited and faint expression of iNOS was observed in normal kidneys. iNOS immunostaining was gradually increased from 6 to 24hrs of reperfusion in tubules and vessels. EPO restrained the intensity of iNOS expression. The presence of eNOS was evident in normal renal vessels and tubules. An induction of eNOS expression occurred in 6 and 24hrs of reperfusion, while in the EPO group it was noted only in 24hrs and in tissues with severe damage. COX-2 is normally expressed in macula densa and tubules. An increase of COX-2 was noted in 6hrs, which subsided later. EPO restricted the inductive peak of 6hrs. Conclusively, the administration of EPO was renoprotective. RI/R and EPO did not affect the expression of Fas/FasL. The early induction of Cyt c suggests its participation in the subsequent injury installation. The beneficial effect of EPO manifests itself through the intrinsic apoptotic pathway. nNOS participates in normal renal function. Its early, post-ischemic reduction, except of consequence of injury, was possibly directly harmful. The inductive effect of EPO on nNOS correlated with an increased number of viable tubules. iNOS post-ischemic induction correlated with the installation of tubular injury. Its attenuation by EPO is a result of its anti-inflammatory and antioxidant properties. The increase of eNOS subsided after the installation of severe injury. The effect of EPO was not related to eNOS directly. COX-2 participates in renal homeostatic mechanisms. Its induction during reperfusion is interpreted as a further activation of these functions or/and as a trigger for inflammation. The beneficial effect of EPO restricts the mobilisation of homeostatic mechanisms or/and the harmful role of COX-2.Η επίδραση της ερυθροποιητίνης στην οξεία νεφρική ισχαιμία. Πειραματική μελέτη σε επίμυες.Η ερυθροποιητίνη (ΕΡΟ) εμφανίζει πλειοτροπικές ιδιότητες. Σκοπός της μελέτης ήταν η διερεύνηση της επίδρασης της ΕΡΟ στην οξεία νεφρική ισχαιμία/επαναιμάτωση (ΝΙ/Ε). Άρρενες επίμυες Wistar υποβλήθηκαν σε αμφοτερόπλευρη NΙ/Ε 45 λεπτών. Χωρίστηκαν τυχαία στις ομάδες Ι/Ε (n=34) και EPΟ (χορήγηση 500 IU/kg, i.p, 20 λεπτά πριν την ισχαιμία, n=36). Σε κάθε ομάδα ορίστηκαν τρεις υποομάδες, στις οποίες η επαναιμάτωση ολοκληρώθηκε στις 6, 24 και 48 ώρες αντίστοιχα. Χειρουργηθέντες επίμυες που δεν υποβλήθηκαν σε ισχαιμία αποτέλεσαν τους μάρτυρες (n=10). Η νεφρική βλάβη εκτιμήθηκε με βιοχημικούς δείκτες (ουρία και κρεατινίνη) και διαβάθμιση της έκτασης της σωληναριακής βλάβης. Η έκφραση των Cyt c, nNOS, iNOS, eNOS και COX-2 μελετήθηκε ανοσοϊστοχημικά και των Fas/FasL, nNOS και Cyt c με RT-PCR. Η ΝΙ/Ε προκάλεσε επιδείνωση των βιοχημικών δεικτών και εγκατάσταση ιστολογικών αλλοιώσεων. Στην ομάδα EPΟ διαπιστώθηκαν χαμηλότερες τιμές βιοχημικών δεικτών και μικρότερης έκτασης σωληναριακή βλάβη (p<0,05). mRNA των Fas/FasL και Cyt c απομονώθηκαν από τους φυσιολογικούς νεφρούς. Το Fas/FasL mRNA δεν μεταβλήθηκε στις δύο ομάδες. Η ΝΙ/Ε προκάλεσε αύξηση της γονιδιακής και πρωτεϊνικής έκφρασης του Cyt c (κυρίως στις 48 και στις 6 ώρες αντίστοιχα). Η ΕΡΟ μείωσε την γονιδιακή έκφραση του Cyt c στις 48 ώρες, ενώ περιόρισε την πρωτεϊνική έκφρασή του κυρίως στις 6 ώρες. Η έκφραση της nNOS στους φυσιολογικούς νεφρούς μειώθηκε σημαντικά στις 6 ώρες επαναιμάτωσης, ενώ στη συνέχεια έτεινε να αποκατασταθεί. Η ΕΡΟ διατήρησε την έκφραση της nNOS στις 6 ώρες στα επίπεδα των μαρτύρων. Περιορισμένη έκφραση της iNOS παρατηρείται στους φυσιολογικούς νεφρούς. Η iNOS ανοσοαντίδραση αυξήθηκε σταδιακά από τις 6 στις 24 ώρες επαναιμάτωσης στα σωληνάρια και αγγεία. Η ΕΡΟ περιόρισε την ένταση της iNOS έκφρασης μεταϊσχαιμικά. Η eNOS εκφράζεται στα φυσιολογικά σωληνάρια και αγγεία. Επαγωγή της σημειώθηκε στις 6 και 24 ώρες στην ομάδα Ι/Ε, ενώ στην ΕΡΟ ήταν εμφανής μόνο στις 24 και στους ιστούς με μεγάλη βλάβη. Η COX-2 εκφράζεται φυσιολογικά σε πυκνές κηλίδες και σωληνάρια. Επαγωγή της σημειώθηκε στις 6 ώρες επαναιμάτωσης, η οποία στη συνέχεια υποχώρησε. Η ΕΡΟ περιόρισε αυτήν την επαγωγική αιχμή της COX-2 των 6 ωρών. Συμπερασματικά, η χορήγηση της ΕΡΟ ήταν νεφροπροστατευτική. Η ΝΙ/Ε και η ΕΡΟ δεν επηρέασαν την έκφραση των Fas/FasL. Η πρώιμη επαγωγή του Cyt c υποδηλώνει συμμετοχή του στην μεταγενέστερη εγκατάσταση βλάβης. Η ευεργετική δράση της ΕΡΟ εκδηλώνεται μέσω του ενδογενούς αποπτωτικού μονοπατιού. Η nNOS συμμετέχει στη φυσιολογική νεφρική λειτουργία. Η πρώιμη εξασθένιση της μετά την ισχαιμία, εκτός από επακόλουθο της βλάβης, είναι πιθανά άμεσα επιζήμια. Η επαγωγική δράση της ΕΡΟ στην nNOS συσχετίζεται με αυξημένο αριθμό βιώσιμων σωληναρίων. Η μεταϊσχαιμική επαγωγή της iNOS συνδέθηκε με την εγκατάσταση σωληναριακής βλάβης. Η εξασθένιση της iNOS από την ΕΡΟ είναι αποτέλεσμα των αντιφλεγμονωδών και αντιοξειδωτικών ιδιοτήτων της. Η αύξηση της eNOS στη ΝΙ/Ε υποχώρησε μετά την εγκατάσταση σοβαρής βλάβης. Η δράση της ΕΡΟ δεν συσχετίζεται άμεσα με την eNOS. Η COX-2 συμμετέχει στους ομοιοστατικούς νεφρικούς μηχανισμούς. Η επαγωγή της στη ΝΙ/Ε ερμηνεύεται ως περαιτέρω ενεργοποίηση αυτών των μηχανισμών ή/και ως πυροδότηση φλεγμονής. Η ευεργετική δράση της ΕΡΟ περιορίζει την κινητοποίηση των μηχανισμών ομοιόστασης ή/και τον επιβλαβή ρόλο της COX-2

In vitro activity of nitroxoline against carbapenem-resistant Acinetobacter baumannii isolated from the urinary tract

Background The old antimicrobial nitroxoline is currently repurposed for oral treatment of uncomplicated urinary tract infections (UTIs). Objectives To investigate the in vitro activity of nitroxoline against carbapenem-resistant Acinetobacter baumannii (CRAb). Methods From an international collection of previously well-characterized clinical A. baumannii isolates, 34 isolates from urinary tract sources with different carbapenem-resistance mechanisms were selected. Nitroxoline activity was analysed with broth microdilution (BMD), disc diffusion (DD) and within an in vitro biofilm model. MICs of meropenem and imipenem were assessed with BMD. Susceptibility to ciprofloxacin and trimethoprim/sulfamethoxazole was investigated using DD. Escherichia coli ATCC 25922 and A. baumannii NCTC 13304 were used for quality control. Results All isolates were carbapenem resistant (MIC90 >32 mg/L for meropenem and imipenem) and most isolates were resistant to ciprofloxacin (33/34) and trimethoprim/sulfamethoxazole (31/34). Nitroxoline yielded MIC50/90 values of 2/2 mg/L (MIC range 1-2 mg/L) and inhibition zone diameters ranging from 20 to 26 mm. In contrast, for definite eradication of biofilm-associated CRAb in vitro, higher nitroxoline concentrations (>= 16 to >= 128 mg/L) were necessary for all isolates. Conclusions Nitroxoline showed excellent in vitro activity against a collection of CRAb despite high resistance rates to other antimicrobials for parental and oral therapy of A. baumannii UTI. Currently, nitroxoline is recommended for the treatment of uncomplicated UTI in Germany with a EUCAST breakpoint limited to uncomplicated UTI and E. coli (S <= 16 mg/L). Nitroxoline could be a promising drug for oral treatment of lower UTI caused by CRAb. More data are warranted to correlate these findings with in vivo success rates

Contribution of RND-Type Efflux Pumps in Reduced Susceptibility to Biocides in Acinetobacter baumannii

Bacterial efflux pumps are among the key mechanisms of resistance against antibiotics and biocides. We investigated whether differential expression levels of the RND-type efflux pumps AdeABC and AdeIJK impacted the susceptibility to commonly used biocides in multidrug-resistant Acinetobacter baumannii. Susceptibility testing and time-kill assays of defined laboratory and clinical A. baumannii strains with different levels of efflux pump expression were performed after exposure to the biocides benzalkonium chloride, chlorhexidine digluconate, ethanol, glucoprotamin, octenidine dihydrochloride, and triclosan. While the impact of efflux pump expression on susceptibility to the biocides was limited, noticeable differences were found in kill curves, where AdeABC expression correlated with greater survival after exposure to benzalkonium chloride, chlorhexidine digluconate, glucoprotamin, and octenidine dihydrochloride. AdeABC expression levels did not impact kill kinetics with ethanol nor triclosan. In conclusion, these data indicate that the overexpression of the RND-type efflux pumps AdeABC and AdeIJK contributes to the survival of A. baumannii when exposed to residual concentrations of biocides

Mobile Genetic Elements Harboring Antibiotic Resistance Determinants in Acinetobacter baumannii Isolates From Bolivia

Using a combination of short- and long-read DNA sequencing, we have investigated the location of antibiotic resistance genes and characterized mobile genetic elements (MGEs) in three clinical multi-drug resistant Acinetobacter baumannii. The isolates, collected in Bolivia, clustered separately with three different international clonal lineages. We found a diverse array of transposons, plasmids and resistance islands related to different insertion sequence (IS) elements, which were located in both the chromosome and in plasmids, which conferred resistance to multiple antimicrobials, including carbapenems. Carbapenem resistance might be caused by a Tn2008 carrying the bla(OXA-23) gene. Some plasmids were shared between the isolates. Larger plasmids were less conserved than smaller ones and they shared some homologous regions, while others were more diverse, suggesting that these big plasmids are more plastic than the smaller ones. The genetic basis of antimicrobial resistance in Bolivia has not been deeply studied until now, and the mobilome of these A. baumannii isolates, combined with their multi-drug resistant phenotype, mirror the transfer and prevalence of MGEs contributing to the spread of antibiotic resistance worldwide and require special attention. These findings could be useful to understand the antimicrobial resistance genetics of A. baumannii in Bolivia and the difficulty in tackling these infections

Acinetobacter baumannii analysis by core genome multi-locus sequence typing in two hospitals in Bolivia: endemicity of international clone 7 isolates (CC25)

In total, 95 Acinetobacter baumannii isolates recovered from patients from two hospitals in Cochabamba, Bolivia were studied. The presence of class D and B beta-lactamases was investigated using polymerase chain reaction, and antimicrobial susceptibility testing was performed by agar dilution and broth microdilution. The resistance rate to carbapenems was 53.7%. All carbapenem-resistant A. baumannii (CRAb, n = 51) and four carbapenem-susceptible isolates were further analysed by whole-genome sequencing. The resulting genome assemblies were used to identify the acquired resistome, and core genome multi-locus sequence typing (cgMLST) was used to determine their molecular epidemiology. All but one of the CRAb isolates (n = 50) belonged to international clone (IC) 7 and they clustered into five sequence types; on cgMLST, they were found to be separated by >= 40 alleles. All CRAb isolates carried bla(OXA-23) on transposon Tn2008. Metallo-beta-lactamases were not detected. These data show that dissemination of several IC7 A. baumannii clones harbouring the carbapenem resistance determinant bla(OXA-23) is occurring in these two hospitals in Cochambamba. (C) 2019 Elsevier B.V. and International Society of Chemotherapy. All rights reserved

Prevalence of RND efflux pump regulator variants associated with tigecycline resistance in carbapenem-resistant Acinetobacter baumannii from a worldwide survey

Objectives: To determine the most common tigecycline resistance mechanisms in carbapenem-resistant Acinetobacter baumannii isolates obtained during the global Tigecycline Evaluation Surveillance Trial (TEST). Methods: Tigecycline MICs were determined by broth microdilution. WGS was used to screen for the previously identified tigecycline resistance mechanisms, as well as mutations in resistance-nodulation-cell division (RND)-type efflux pump regulators. Results: From a total 313 isolates, 113 genetically unique tigecycline-resistant isolates were analysed. The most frequent and worldwide distributed mechanism associated with tigecycline resistance was disruption of adeN, which encodes the repressor of the RND efflux pump AdeIJK, either by IS elements or nucleotide deletions causing premature stop codons. However, mutations Leading to amino acid substitutions and disruption by IS elements within the two-component regulatory system adeRS, which regulates expression of the AdeABC efflux pump, correlate with higher tigecycline MICs, but these were found Less frequently and were mainly restricted to Southern European countries. Furthermore, an altered version of tviB was identified in several tigecycline-resistant isolates that did not have putative resistance mutations within RND-type regulators. The resistance determinants tet(A) and tet(X), as well as resistance mutations in putative resistance determinants trm, plsC, rrf, msbA and genes encoding 30S ribosomal proteins, were not identified in any isolate. Conclusions: The most prevalent tigecycline resistance mechanisms were caused by alterations in the regulators of RND-type efflux pumps. These data provide the basis for further characterization of regulator alterations and their contribution to increased efflux and tigecycline resistance, and also should be taken into account in drug discovery programmes to overcome the contribution of efflux pumps

Characterization of a vancomycin-resistant Enterococcus faecium isolate and a vancomycin-susceptible E. faecium isolate from the same blood culture

Objectives: To characterize two Enterococcus faecium isolates with different resistance phenotypes obtained from the same blood culture. Methods: The isolates were identified by MALDI-TOF MS and antimicrobial susceptibility testing (AST) was performed using a VITEK (R) 2 AST P592 card and Etest. WGS was performed on the MiSeq and MinION sequencer platforms. Core-genome MLST (cgMLST) and seven-Loci MLST were performed. Plasmid anaLysis was performed using S1-PFGE followed by Southern-blot hybridization. Results: Both E. faecium isolates were ST203. AST revealed that one was a vancomycin-resistant E. faecium (VREfm) isolate and the other was a vancomycin-susceptible E. faecium (VSEfm) isolate. The VREfm isolate harboured the vanA gene cluster as part of a Tn1546-type transposon encoded on a 49 kb multireplicon (repl, rep2 and rep7a) plasmid (pAML0157.1). On the same plasmid, ant(6)-Ia, cat-Like and erm(B) were encoded. The VSEfm isolate harboured a rep2 plasmid (pAML0158.1), 12 kb in size, which was present in full length as part of pAML0157.1 from the VREfm isolate. The vanA-encoding pAML0157.1 was a chimera of the rep2 pAML0158.1 and a second DNA segment harbouring vanA, ant(6)-Ia, erm(B) and cat-Like, as well as the replicons repl and rep7a. By cgMLST analysis, the VREfm and VSEfm isolates were identical. Conclusions: Our results demonstrate that the VREfm and VSEfm blood culture isolates represented ST203 and were identical. The investigated heterogeneous resistance phenotypes resulted from the acquisition or Loss of plasmid segments in the enterococcal isolates. These data illustrate that mobile genetic elements may contribute to the spread of vancomycin resistance among enterococci and to the genotypic and phenotypic variation within clonal isolates

Distribution of sandflies (Diptera, Psychodidae) in two Ionian islands and Northern Greece

A field study on the distribution of phlebotomine sandflies was carried out during summer months of 2009 and 2010 in eight sites in two Ionian islands and in northern Greece. A total of 490 sandflies (74.5% females) were collected. Six species of the Phlebotomus genus and two of the Sergentomyia genus were identified. The species with the widest distribution in the islands were Phlebotomus neglectus (32.8%), Phlebotomus similis (30.3%), Phlebotomus tobbi (16.7%), and P. perfiliewi (15.9%), whereas P. simici (50%), P. neglectus (24.5%), and P. tobbi (9.6%) predominated in the mainland. As most of these species are proven or suspected vectors of human and animal pathogens, prevention measures have to be taken in these areas during the summer months when sandflies are active