Extended-spectrum beta-lactamases (ESBL) and AmpC producing-Escherichia coli have spread worldwide, but data about ESBL-producing-E. coli in the Northern and Eastern regions of Europe is scant. The aim of this study has been to describe the phenotypical and molecular epidemiology of different ESBL/AmpC/Carbapenemases genes in E. coli strains isolated from the Baltic States (Estonia, Latvia, and Lithuania), Norway and St. Petersburg (Russia), and to determine the predominant multilocus sequence type and single nucleotide polymorphisms diversity of E. coli isolates deduced by whole genome sequencing (WGS). A total of 10,780 clinical E. coli strains were screened for reduced sensitivity to third-generation cephalosporins. They were collected from 21 hospitals located in Estonia, Latvia, Lithuania, Norway and St. Petersburg during a 5 month period in 2012. The overall prevalence of ESBL/AmpC strains was 4.7% by phenotypical test and 3.9% by sequencing. We found more strains with the ESBL/AmpC phenotype and genotype in St. Petersburg and Latvia than other countries. Of phenotypic E. coli strains, 85% contained confirmed ESBL genes (including bla(CTX-M), bla(TEM-29), bla(TEM-71)), AmpC genes (bla(CMY-59), bla(ACT-12/-15/-20), bla(ESC-6), bla(FEC-1), bla(DHA-1)), or carbapenemase genes (bla(NDM-1)). bla(CTX-M-1), bla(CTX-M-14) and bla(CTX-M-15) were found in all countries, but bla(CTX-M-15) prevalence was higher in Latvia than in St. Petersburg (Russia), Estonia, Norway and Lithuania. The dominating AmpC genes were bla(CMY-59) in the Baltic States and Norway, and bla(DHA-1) in St. Petersburg. E. coli strains belonged to 83 different sequence types, of which the most prevalent was ST131 (40%). In conclusion, we generally found low ESBL/AmpC/Carbapenemase prevalence in E. coli strains isolated in Northern/Eastern Europe. However, several inter-country differences in distribution of particular genes and multilocus sequence types were found.

This study has evaluated the correlation between different carbapenemases detection methods on carbapenem non-susceptible Klebsiella pneumoniae strains from Northern and Eastern Europe; 31 institutions in 9 countries participated in the research project, namely Finland, Estonia, Latvia, Lithuania, Russia, St. Petersburg, Poland, Belarus, Ukraine, and Georgia. During the research program, a total of 5,001 clinical K. pneumoniae isolates were screened for any carbapenem non-susceptibility by the disk diffusion method, Vitek 2 or Phoenix system following the EUCAST guideline on detection of resistance mechanisms, version 1.0. Strains isolated from outpatients and hospitalized patients from April 2015 to June 2015 were included. All types of samples (blood, pus, urine, etc.) excluding fecal screening or fecal colonization samples have been represented. In total, 171 carbapenemase screening-positive K. pneumoniae isolates (3.42%) were found and characterized. Several methods were used for detection of carbapenemases production, including Luminex assay (PCR and hybridization), whole genome sequencing, MALDI-TOF based Imipenem degradation assay, and immunochromatography testing. Minimal inhibitory concentration determination for Meropenem by agar-based gradient method was also used. Finally, 83 K. pneumoniae strains were carbapenemase negative by all confirmation methods (49.4% of all screening-positive ones), 74-positive by three methods (44.0%), 8-positive by two methods (4.8%) and 3-positive by only one method (1.8%). The sensitivity of the tests was 96.3% for Whole genome sequencing and MALDI-TOF assay (both three undetected cases), and 95.1% for Luminex-Carba (4 undetected cases). The most commonly detected carbapenemases were NDM (n = 54) and OXA-48 (n = 26), followed by KPC-2, VIM-5, and OXA-72 (one case of each). Our results showed that different types of carbapenemases can be detected in the countries involved in the project. The sensitivity of our methods for carbapenemase detection ( including screening as a first step and further confirmation tests) was >95%, but we would recommend using different methods to increase the sensitivity of detection and make it more precise.

The aim of this study was to compare the prevalence of different virulence factor (VF) genes in extended-spectrum beta-lactamase (ESBL) producing Escherichia coli strains isolated from the Baltic Sea region. A total of 432 strains of phenotypically ESBL positive E. coli were collected from 20 institutions located in Estonia, Latvia, Lithuania, and the region of St. Petersburg in Russia from January to May 2012 and analyzed for phylogenetic group and prevalence of 23 VF genes. The strains were collected from clinical material (urine, blood, wound, and respiratory tract). Bacterial isolates were compared according to phylogenetic group, clinical material, and geographical origin. Most of the VF genes were concentrated within phylogenetic group B2 and/or D. When comparing strains isolated from different countries, it was found that strains originating from Estonia and Latvia belonged mainly to group B2 and strains from Lithuania and Russia mainly to groups B2 and D. The P-fimbrial adhesin gene papEF was more prevalent in Russian strains, colicin gene cvaC in Lithuanian strains, and capsular gene kpsMTII in Latvian strains; serum resistant gene traT was less prevalent in Estonian strains. The regional differences of VF genes remained statistically significant after taking into account the phylogenetic distribution in the countries.

The spread of carbapenemase-producing Enterobacteriaceae is a global problem; however, no exact data on the epidemiology of carbapenemase in the Baltic countries and St. Petersburg area is available. We aimed to evaluate the epidemiology of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in the Baltic States and St. Petersburg, Russia, and to compare the different methods for carbapenemase detection. From January to May 2012, all K. pneumoniae (n = 1983) and E. coli (n = 7774) clinical isolates from 20 institutions in Estonia, Latvia, Lithuania, and St. Petersburg, Russia were screened for carbapenem susceptibility. The IMP, VIM, GIM, NDM, KPC, and OXA-48 genes were detected using real-time PCR and the ability to hydrolyze ertapenem was determined using MALDI-TOF MS. Seventy-seven strains were found to be carbapenem nonsusceptible. From these, 15 K. pneumoniae strains hydrolyzed ertapenem and carried the bla(NDM) gene. All of these strains carried integron 1 and most carried integron 3 as well as genes of the CTX-M-1 group. No carbapenemase-producing E. coli or K. pneumoniae strains were found in Estonia, Latvia, or Lithuania; however, NDM-positive K. pneumoniae was present in the hospital in St. Petersburg, Russia. A MALDI-TOF MS-based assay is a suitable and cost-effective method for the initial confirmation of carbapenemase production.

The Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) commenced in 2004 to longitudinally monitor global changes in bacterial susceptibility to a suite of antimicrobial agents. The current study examined the activity of tigecycline and comparators against isolates collected across Eastern Europe between 2004 and 2010. Minimum inhibitory concentrations were determined using Clinical and Laboratory Standards Institute (CLSI) broth microdilution methodologies. Antimicrobial susceptibility was determined using CLSI interpretive criteria, and tigecycline susceptibility was established using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. This study included 10 295 Gram-negative and 4611 Gram-positive isolates from 42 centres. Extended-spectrum β-lactamases (ESBLs) were reported among 15.3% of Escherichia coli and 39.3% of Klebsiella pneumoniae isolates; the highest rates were observed in Turkey (30.9%) and Bulgaria (53.8%), respectively. Imipenem-non-susceptible K. pneumoniae were identified only in Turkey. ESBL-positive E. coli were highly susceptible to imipenem (95.1%), meropenem (98.0%) and tigecycline (98.5%). Most antimicrobials showed poor activity against Acinetobacter baumannii and Pseudomonas aeruginosa. Vancomycin resistance was noted among 0.9% of Enterococcus faecalis and 11.7% of Enterococcus faecium isolates. High rates of susceptibility were reported for linezolid (99.7%) and tigecycline (100%) against E. faecium. One-quarter of Staphylococcus aureus isolates were meticillin-resistant S. aureus (MRSA), with the highest rate in Romania (51.5%); all MRSA were susceptible to linezolid, tigecycline and vancomycin. Antimicrobial resistance is high in much of Eastern Europe, with considerable variation seen among countries. Tigecycline and the carbapenems retain excellent activity against many pathogens from Eastern Europe; linezolid and vancomycin are active against most Gram-positive pathogens.

ABSTRACT An outbreak of hospital-acquired Acinetobacter baumannii infections, caused by a bla OXA-23 -positive carbapenem-resistant strain belonging to international clone II/ST2, was detected in Latvia. The strain was partially equipped with the armA gene and the intI1-aacA4-catB8-aadA1-qacE Δ 1 class 1 integron. In addition, the strain carried AbaR25, a novel AbaR4-like resistance island of ∼46,500 bp containing structures similar to the previously described AbaR22 and Tn 6167 islands. AbaR25 was characterized by the occurrence of a second copy of Tn 6022a interrupted by Tn 2006 carrying the bla OXA-23 gene.

Previous studies on the epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Latvia are lacking. ESBL-producing Klebsiella pneumoniae (n = 32) were subjected to pulsed-field gel electrophoresis (PFGE) and selected isolates to multi-locus sequence typing (MLST). Species identification and susceptibility testing were performed using VITEK2, and sequencing of bla(CTX-M) was performed in selected isolates. PFGE revealed one major clone (n = 23), with most of the isolates derived from the ICU. The clone harboured bla(CTX-M-15), was sequence type 199 and comprised two ertapenem non-susceptible isolates. This is the first report of an ESBL outbreak in Latvia, and calls for increased epidemiological typing of ESBL-producing Enterobacteriaceae, as well as improved infection control routines.

First Detection of Vancomycin Resistant Enterococcus faecium in Latvia Enterococci have become one of the most important nosocomial pathogens in advanced treatment facilities. Though they are not considered as very pathogenic bacteria, their high levels of antimicrobial resistance are the subject of major concern. Particularly epidemiologically important are vancomycin-resistant enterococci (VRE) due to high risk of transmission of vancomycin resistance genes to staphylococci. We describe the first outbreak of VRE in a Latvian multidisciplinary hospital.

Clostridium difficile Associated Disease Clinical and Molecular Data Introduction. A balanced microflora of the gastrointestinal tract plays a significant role in the protection of an organism. Dramatic changes may take place in the composition of normal microflora during antibacterial therapy, because part of sensitive microorganisms die and microflora detrimental to an organism proliferates there causing gastrointestinal tract disorders (7). C. difficile is an important agent causing gastrointestinal tract disorders. It may induce manifestations ranging from asymptomatic colonization of the gastrointestinal tract to severe diarrhea, pseudomembranous colitis, toxic megacolon, intestinal perforation, and death. All these severity levels are included in the term Clostridium difficile associated disease (CDAD). A patient at risk for C. difficile is an elderly person with a severe principal disease, who receives long-term inpatient treatment, has been receiving antibiotics, antacid and antiulcer agents for a long time, has had a gastrointestinal surgical intervention or any organ transplantation, which is always related to immune suppression (11). Aim of the study. Molecular typing of Latvian strains of C. difficile and clinical data analysis. Materials and methods. The research includes data collected during the time period from August 2006 to the end of 2008 from three Latvian hospitals. A pure culture of C. difficile bacteria was isolated and cultured from fecal material. Ribotyping was done by amplification of specific regions of the 16S and 23S RNA genes and amplification products were separated in 1.5% agarose gel. Results. Fecal samples of 500 patients having manifestations of clinical symptoms of CDAD were microbiologically and molecularly studied from August 2006 to the end of 2008. 130 samples were tcdA + tcdB + toxin-positive. Conclusions. All samples were cultured on agar in anaerobic conditions. As a result, 55 pure cultures were obtained. The average age of patients is 65 years. Women get infected more frequently than men. In 95% patients CDAD was induced by antibacterial therapy. In 86% cases, having received a positive response for C.difficile antibacterial therapy is changed. Disease development risk factors are previous antibacterial therapy, previous hospitalization, GIT manipulations and C.difficile infection in anamnesis. The biggest number of CDAD patients was found in Nephrology Department of P. Stradins Clinical University Hospital. A hypervirulent Cl.difficile ribotype 027 was not found in Latvia yet, bat 16 different ribotypes were determined using Bionumerics software. 4 of them are domineering ribotypes with 17, 14, 5 and 4 isolates in every group.

Des infections par Staphylococcus aureus resistant a la methicilline acquises dans la communaute (co-SARM) ont ete rapportees partout dans le monde. L'article suivant presente les caracteristiques du premier co-SARM isole en Lettonie. Une souche de LPV-SARM IV ST30 a ete isolee dans un prelevement nasal et le catheter veineux central d'un patient presentant de la fievre et des deficiences polyviscerales. Le profil de l'electrophorese en champ pulse de cette souche etait indiscernable du profil de souches SARM SE00-3 isolees en Suede en 2002-2003 chez 29 patients. Cette souche est liee a la zone du Pacifique Sud et son emergence en Suede et en Lettonie demontre sa dissemination a l'echelle mondiale.

En todo el mundo se han detectado infecciones por Staphylococcus aureus resistente a la meticilina adquiridas en la comunidad (CA-SARM). Este articulo presenta la caracterizacion del primer CA-SARM aislado en Latvia. Una cepa de PVL-SARM IV ST30 fue aislada de una muestra nasal y del cateter venoso central de un paciente con fiebre y fallo multiorganico. El perfil de electroforesis en campo pulsado de esta cepa era indistinguible del perfil de cepas MRSA SE00-3 aisladas en Suecia en 2002-2003 procedentes de 29 pacientes. Esta cepa esta ligada al area del Pacifico Sur y su emergencia en Suecia y en Latvia es una prueba de su diseminacion al nivel mundial.

No mundo inteiro foram detectadas infeccoes por Staphylococcus aureus resistente a meticilina adquiridas em comunidade (CA-SARM). Este artigo presenta a caracterisacao do primeiro CA-SARM isolado na Letonia. Uma estirpe de PVL-SARM IV ST30 foi isolada de uma amostra nasal e do cateter venoso central de um paciente com febre e falha multiorganica. O perfil de electroforese em campo pulsatil de essa estirpe era indistinguivel do perfil de estirpes MRSA SE00-3 isoladas na Suecia em 2002-2003 originarias de 29 pacientes. Esta estirpe esta ligada a area do Pacifico Sul e a sua emergencia na Suecia e na Letonia e uma prova da sua disseminacao ao nivel mundial.

Une premiere enquete de prevalence du taux d'infections nosocomiales (IN) a ete menee dans deux hopitaux de Lettonie. Au moment de l'enquete, 17,5% des patients (226/1291) presentaient des signes d'infection ou etaient deja traites pour une infection. Le taux de prevalence global etait de 5,6% pour les IN (72/1291) et 12,7% (164/1291) pour les infections communautaires. L'infection des plaies operatoires etaient l'IN la plus courante (62%), suivie des infections des voies respiratoires (IVR) (7,5%) et des infections urinaires (6,4%). Le taux d'IN augmentait avec l'âge des patients, et etait plus eleve dans les unites de soins intensifs et les services de chirurgie, ainsi que chez les patients sous perfusion ou avec une sonde urinaire. L'investigation microbiologique a montre des resultats positifs chez 29% des patients presentant une IN. Un traitement antibiotique a ete administre a 22,3% des patients hospitalises (288/1291) et la cefazoline prescrite pour 62% d'entre eux (182/288).

En dos hospitales letones se realizo el primer estudio de prevalencia de la tasa de infecciones nosocomiales (IN). En el momento del estudio, el 17,5% (226/1291) de los pacientes presentaba sintomas o estaba siendo tratado de la infeccion. La tasa de prevalencia global fue del 5,6% (72/1291) para IN y del 12,7% para infecciones comunitarias (164/1291). La infeccion quirurgica (Surgical site infection; SSI) fue la infeccion nosocomial mas comun (62%), seguida de la infeccion del tracto respiratorio (respiratory tract infection; RTI) (7,5%), y la del tracto urinario (urinary tract infection; UTI) (6,4%). La tasa de IN fue superior cuanto mayor era la edad del paciente, asi como en unidades de cuidados intensivos y en quirofanos, y en personas con dispositivos intravenosos o cateteres urinarios. La investigacion microbiologica dio resultados positivos en el 29% de los pacientes (21/72) con IN. Al 22,3% (288/1291) de los pacientes ingresados se le administro tratamiento antibacteriano y al 62% (182/288) de ellos se receto cefazolina. Los resultados de este estudio se utilizaran para planificar una encuesta nacional de prevalencia.

The study has been worked out in VSIA “Pauls Stradins Clinical University Hospital”. Defence: on the 14 November, 2011-10-12 in the Hippocrates Lecture Room of the Riga Stradins University, Dzirciema Street 16, Riga.