Marjanca Starčič Erjavec

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• PhD
• Professor at University of Maribor

Iron uptake plays an important role in the persistence of Escherichia coli in the host and for its survival in the environment, and it is known that E. coli has a variety of siderophore systems for iron uptake. We investigated the ability to produce siderophores, the genetic diversity of the siderophores and their correlation with virulence-associa...

Background: Short-chain fatty acids (SCFAs), which are produced by the microbial fermentation of undigested carbohydrates, play an important role in the metabolism and physiology of the host. SCFAs are involved in the regulation of maternal metabolism during pregnancy and influence weight gain, glucose metabolism, and metabolic hormones. Methods: I...

The widespread use of disinfectants and antiseptics has led to the emergence of nosocomial pathogens that are less sensitive to these agents, which in combination with multidrug resistance (MDR) can pose a significant epidemiologic risk. We investigated the susceptibility of nosocomial Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa...

Short-chain fatty acids (SCFAs), which are produced by the microbial fermentation of undigested carbohydrates, play an important role in the metabolism and physiology of the host. SCFAs are involved in the regulation of maternal metabolism during pregnancy and influence weight gain, glucose metabolism and metabolic hormones. In 2017, women who were...

The diarrheagenic Escherichia coli (DEC) is the major cause of diarrheal diseases in Africa, including Ethiopia. However, the genetic diversity of E. coli pathotypes found in Ethiopia has not been studied well. This study aimed to characterize potential DEC belonging to enteropathogenic (EPEC), Shiga toxin-producing (STEC), enteroaggregative (EAEC)...

The use of antibiotics in agriculture and subsequent environmental pollution are associated with the emergence and spread of multidrug-resistant (MDR) bacteria including Escherichia coli . The aim of this study was to detect antimicrobial resistance, resistance genes and mobile genetic elements of 72 E. coli strains isolated from faeces of healthy...

The global spread of antimicrobial resistance genes (ARGs) in Escherichia coli is a major public health concern. The aim of this study was to investigate the genomic characteristics of extended-spectrum β-lactamase (ESBL)-producing and third-generation cephalosporin-resistant E. coli from a previously obtained collection of 260 E. coli isolates fro...

Biofilms as a form of adaptation are beneficial for bacterial survival and may be hot spots for horizontal gene transfer, including conjugation. The aim of this research was to characterize the biofilm biomass, viable cell ratios and conjugative transfer of the pOX38 plasmid, an F-plasmid derivative, from the Escherichia coli N4i pOX38 strain (dono...

Strains of various bacterial species and their products, which are involved in the decomposition of complex substances, are used for the formation and maintenance of a balanced host’s gut microbiota. The biological properties (bacterial cell surface hydrophobicity, adhesion, antagonistic activity towards other strains and resistance to biological f...

The Escherichia coli ŽP strain (ŽP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ŽP per oral adminis...

Cattle are a reservoir of pathogenic and potentially pathogenic Escherichia coli ( E. coli ) strains, which can pose a threat to human and animal health. The aim of the study was to evaluate the occurrence of 22 virulence-associated genes (VAGs), as well as the prevalence of antimicrobial drug resistance and three different bla -genes among 49 E. c...

Escherichia coli is known to be an important uropathogenic agent. Several models were developed for investigating the uropathogensis of E. coli, including the recent biomimetic porcine urothelial in vitro model. The aim of this study was to assess the cytokine response of the cells of the biomimetic porcine urothelial model to different E. coli str...

Due to the spread of antibiotic-resistant bacteria, new alternatives to antibiotics and ways to prevent infections are being sought. Bacteriocin-producing bacteria are therefore attracting attention due to their probiotic potential as a safe alternative to antimicrobial drugs. The aim of this work was to determine the prevalence of bacteriocin-enco...

In this study 35 Escherichia coli isolates obtained from sampled dishwashers rubber seals were analysed with polymerase chain reactions (PCR) using specific primers for phylogenetic group, multilocus sequence type (MLST) determination the presence of 43 virulence-associated genes (VAGs) linked with intestinal and extraintestinal E. coli infections...

Urinary tract infections can be severe, sometimes fatal, diseases whose etiological pathogens are predominantly uropathogenic strains of E. coli (UPEC). To investigate the UPEC pathogenesis, several models have already been established with minor or major disadvantages. The aim was to develop a simple, fast, and inexpensive biomimetic in vitro mode...

Широкое применение в урологической практике биологических и искусственных материалов, на поверхности которых формируются бактериальные биопленки, повышает риск персистенции возбудителя в организме. На сегодняшний день остро стоит проблема катетер-ассоциированных инфекций мочевыводящих путей (ИМВП), которые чаще всего вызваны штаммами уропатогенной...

The increasing prevalence of antimicrobial resistant Enterobacteriaceae in poultry farm complexes is a serious problem, hence new treatment strategies and antimicrobial agents are searched for, among them probiotics. Genetically modified strains of Escherichia coli carrying conjugative plasmids with bacteriocin genes are a novel possibility of prev...

Conjugation is recognized as a mechanism driving dissemination of antibacterial resistances and virulence factors among bacteria. In the presented work conjugative transfer frequency into clinical uropathogenic E. coli strains (UPEC) isolated from patients with symptomatic urinary tract infections was investigated. From 93 obtained UPEC strains onl...

Intra-amniotic infection and inflammation (IAI) affect fetal development and are highly associated with preterm labor and premature rupture of membranes, which often lead to adverse neonatal outcomes. Human amniotic membrane (hAM), the inner part of the amnio-chorionic membrane, protects the embryo/fetus from environmental dangers, including microb...

The fetal membranes provide a supportive environment for the growing embryo and later fetus. Due to their versatile properties, the use of fetal membranes in tissue engineering and regenerative medicine is increasing in recent years. Moreover, as microbial infections present a crucial complication in various treatments, their antimicrobial properti...

Recent research has indicated that dysbiosis of the gut microbiota can lead to an altered circadian clock of the mammalian host. Herein we developed an original system that allows real-time circadian studies of human HepG2 hepatoma cells co-cultured with bacteria. The HepG2 cells with stably integrated firefly luciferase reporter under the control...

Urinary tract infections (UTIs) represent a serious global health issue, especially due to emerging multidrug-resistant UTI-causing bacteria. Recently, we showed that the human amniotic membrane (hAM) could be a candidate for treatments and prevention of UPEC and Staphylococcus aureus infections. However, its role against multidrug-resistant bacter...

Urinary tract infections (UTIs) represent a serious global health issue, especially due to emerging multidrug-resistant UTI-causing bacteria. Recently, we showed that the human amniotic membrane (hAM) could be a candidate for treatments and prevention of UPEC and Staphylococcus aureus infections. However, its role against multidrug-resistant bacter...

Gestational diabetes (GDM) is characterized by insufficient insulin secretion and hyperglycemia during pregnancy that is accompanied by changes in gut microbiota composition. Gut microbiota mediates its effects on the host primarily through its metabolites. Recently, in vitro studies suggested that indole, produced by the gut microbiota from dietar...

Escherichia coli strains isolated from case of colibacillosis in Russian poultry farms in the region of Perm Krai were analyzed for their sensitivity to main antibiotics and bacteriocins. Sensitivity profiles for 9 antibiotics and 20 bacteriocins were determined with the disc diffusion method and the overlay test, respectively. Further, with the PC...

The burden of tuberculosis (TB) in Slovenia is low due to good ongoing preventive measures. However, analysis of data obtained from the Registry for Tuberculosis and National Reference Laboratory for Mycobacteria at University Clinic of Respiratory and Allergic Diseases Golnik from January 2000 to December 2017 revealed that the number of nontuberc...

Urinary tract infections are among the most common bacterial infections in humans. Moreover, they are highly recurrent and increasingly often resistant to antibiotics. The antimicrobial properties of the amniotic membrane (AM), the innermost layer of fetal membranes, have been briefly reported in the literature, however, the results of published st...

The effect of oral administration of Escherichia coli ŽP strain carrying a conjugative plasmid encoding the colicin E7 on the composition of the intestinal chyme microbiota of chickens was studied. It was shown that E. coli ŽP was present in the chyme of chickens 6-24 days of age in all experimental groups. In the microbiota of the control group (n...

Bacterial antimicrobial resistance is worldwide rising and is already reaching worrisome levels, hence WHO released the priority bacterial pathogen list for research and development of new antimicrobial agents. ŽP strain, a new Nissle 1917 based antimicrobial strain harbors a bacteriocin, colicin ColE7, bacterial conjugationbased “kill” – “anti-kil...

Purpose Due to the emergence and spread of bacterial strains resistant to antibiotics, the development of new antimicrobials is imperative. The antimicrobial effect of the amniotic membrane (AM) has been explored to a limited extent so far. Materials and methods We collected 12 biological samples of AM homogenates and tested their antimicrobial ef...

Abstract Background Both obesity and gestational diabetes (GDM) are associated with adverse outcomes. Diet during pregnancy impacts weight gain and fetal growth. Therefore, we aimed to explore non-pharmacological treatment success depending on pre-pregnancy body weight and its association with large for gestational age (LGA) infants in women with G...

Purpose: Due to the emergence and spread of bacterial strains resistant to antibiotics, the development of new antimicrobials is imperative. The antimicrobial effect of the amniotic membrane (AM), the innermost part of placenta, has been explored to a limited extent so far. Materials and Methods:We collected 12 biological samples of AM homogenates,...

Purpose: Due to the emergence and spread of bacterial strains resistant to antibiotics, the development of new antimicrobials is imperative. The antimicrobial effect of the amniotic membrane (AM), the innermost part of placenta, has been explored to a limited extent so far. Materials and Methods:We collected 12 biological samples of AM homogenates,...

Purpose: Due to the emergence and spread of bacterial strains resistant to antibiotics, the development of new antimicrobials is imperative. The antimicrobial effect of the amniotic membrane (AM), the innermost part of placenta, has been explored to a limited extent so far. Materials and Methods:We collected 12 biological samples of AM homogenates,...

The antimicrobial effect of the amniotic membrane (AM), the innermost part of placenta, has been explored to a limited extent so far. To quantify and better understand the mechanisms behind antibacterial effect of AM, we followed the growth of three common pathogens, uropathogenic Escherichia coli(UPEC), Staphylococcus aureus and Serratia marcescen...

Escherichia coli may innocuously colonize the intestine of healthy subjects or may instigate infections in the gut or in other districts. This study investigated intestinal E. coli isolated from 20 healthy adults. Fifty-one strains were genotyped by molecular fingerprinting and analyzed for genetic and phenotypic traits, encompassing the profile of...

The antimicrobial effect of the amniotic membrane (AM), the innermost part of placenta, has been explored to a limited extent so far. To quantify and better understand the mechanisms behind antibacterial effect of AM, we followed the growth of three common pathogens, uropathogenic Escherichia coli(UPEC), Staphylococcus aureus and Serratia marcescen...

Objective. To study the colonization activity of clinical strains of uropathogenic Escherichia coli (UPEC) against various types of urological catheters. Materials and Methods. Biofilms of E. coli (n = 6) were formed for 24 h according to the standard method. Urological catheters made from latex, polyvinylchloride, silicon and silver-coated sil...

Mycobacteria belonging to Mycobacterium (M.) avium complex (MAC) and M. abscessus complex (MABSC) are the most frequent causes of mycobacteriosis in the world. In the last few years MAC and MABSC taxonomy was rapidly changing due to new molecular methods conveying the possibility to differentiate between species. New techniques are able to identify...

Significance and impact of the study: Bacterial antimicrobial resistance is worldwide rising and causing deaths of thousands of patients infected with multi-drug resistant bacterial strains. In addition, there is a lack of efficient alternative antimicrobial agents. The significance of our research is the use of a number of methods (real-time PCR,...

Eighty-six Escherichia coli strains from feces of either wild brown bears or those living in a zoo were screened for phylogenetic groups using the revisited Clermont phylotyping method and the prevalence of 24 virulence-associated genes (VAGs) of extraintestinal pathogenic E. coli (ExPEC). Our results showed that most strains of E. coli in bears be...

Previous investigations have indicated that the reservoir of extraintestinal pathogenic E. coli (ExPEC) strains is the intestinal microbiota. Nevertheless, studies focused on the prevalence of potential ExPEC strains among the bowel microbiota in healthy human individuals practically do not exist and a strong bias towards pathogenic strains among t...

Prokaryotes are generally characterized by vast genomic diversity that has been shaped by mutations, horizontal gene transfer, bacteriocins and phage predation. Enormous genetic diversity has developed as a result of stresses imposed in harsh environments and the ability of microorganisms to adapt. Two examples of prokaryotic diversity are presente...

This present study was performed to investigate genetic diversity of Escherichia coli isolates from healthy cattle while comparing two methods namely, PCR assay for enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) and amplified fragment length polymorphism (AFLP). Our study showed that ERIC-PCR is an appropriate/efficient method...

Colicins are toxic proteins with a narrow killing spectrum that are produced by colicinogenic Escherichia coli strains. The aim of this study was to analyse systematically whether extra-intestinal virulence potential is linked to colicin (in)sensitivity. In total, 102 well-characterized E. coli isolates from skin and soft-tissue infections (SSTIs)...

The main goal of our study was to explore whether the use of multimedia in genetics instruction contributes more than other instructional modes to students' knowledge and comprehension, depending on their gender. In a quasi-experimental design, four comparable groups of 3rd and 4 th grade high school students were taught the process of gene express...

A total of 99 E. coli urinary tract isolates were investigated for phylogenetic groups and 21 virulence related genes in relation to fluoroquinolone and sulfamethoxazole/trimethoprim resistance. We found that the B2 group was by far the most prevalent among susceptible isolates, while resistant isolates were more evenly distributed among groups A,...

The main goal of this study was to explore whether the use of multimedia in genetics instruction contributes more to students' knowledge and comprehension than other instructional modes. We were also concerned with the influence of different instructional modes on the retention of knowledge and comprehension. In a quasi-experimental design, four co...

TcpC, a new Toll/interleukin-1 receptor domain-containing protein of uropathogenic Escherichia coli involved in the suppression of innate immunity, was found in 2008. The aim of the present study was to determine the prevalence of tcpC and its association with virulence factors and phylogenetic groups among strains from a collection of 212 E. coli...

The aim of the presented study was to estimate the prevalence, distribution and associations of different pathogenicity islands (PAI I536 to PAI IV536, PAI IJ96, PAI IIJ96, PAI ICFT073 and PAI IICFT073), iron uptake systems (genes iutA, iucD, iroN, iroCD, fyuA, irp2, iha, ireA, and hbp) and plasmids among extraintestinal pathogenic Escherichia coli...

Escherichia coli strains frequently are isolated from skin and soft tissue infections (SSTI); however, their virulence potential has not yet been extensively studied. In the present study, we characterized 102 E. coli SSTI strains isolated mostly from surgical and traumatic wounds, foot ulcers, and decubitus. The strains were obtained from the Inst...

During routine quality control testing of diagnostic methods for Shiga toxin-producing Escherichia coli (STEC) using stool samples spiked with STEC, it was observed that the Shiga toxin could not be detected in 32 out of 82 samples tested. Strains of E. coli isolated from such stool samples were shown to be responsible for this inhibition. One part...

110 uropathogenic Escherichia coli (UPEC) strains obtained from the Institute of Microbiology and Immunology of the Medical Faculty in Ljubljana, Slovenia were screened with molecular biology methods for the well characterized adhesin gene sequences: fimH (Type 1 fimbriae), papC, papGII andpapGIII (P-fimbriae), sfa (S-fimbriae) and afa/dra (Afa/Dr...

Methods 110 uropathogenic Escherichia coli strains (UPEC) obtained from the Institute of Microbiology and Immunology of the Medical Faculty in Ljubljana were screened by PCR with primers specific for the following toxin encoding genes: hlyA (haemolysin), cnf1 (cytotoxic necrotising factor 1), usp (uropathogenic specific protein USP) and ibeA (invas...

It is well documented that uropathogenic Escherichia coli (UPEC) isolates resistant to nalidixic acid have reduced virulence potential. Our goal was to assess whether UPEC isolates resistant to chloramphenicol, tetracycline and streptomycin also exhibit reduced virulence potential. Among 110 human UPEC isolates, the prevalences of the virulence fac...

The aim of the presented study was to identify the similarity of the plasmid pRK100 RepFIIA replicon (replication region) with similar replicons of other known plasmids of Enterobacteriaceae. For this purpose, within the determined nucleotide sequence of pRK100, theRepFIIA replicon rep genes/regions were identified. The nucleotide sequences of the p...

One hundred and ten UTI Escherichia coli strains, from Ljubljana, Slovenia, were analyzed for antibiotic resistances, mobile DNA elements, serotype, and phylogenetic origin. A high prevalence of drug resistance and multidrug resistance was found. Twenty-six percent of the isolates harbored a class 1 integron, while a majority of the strains (56%) h...

In search for the evolutionary origin of the conjugative F-like plasmid pRK100, the plasmid's functional replication regions were identified. Additionally targeted genetic analysis was used to investigate origins of other regions of the plasmid. Construction of minireplicons via ligation of Tn1725 with plasmid fragments and targeted cloning of puta...

Conjugative transfer of F-like plasmids is a tightly regulated process. The TraJ protein is the main positive activator of the tra operon which encodes products required for conjugative transfer of F-like plasmids. Nucleotide sequence analysis revealed potential Lrp and H-NS binding sites in the traJ regulatory region. Expression of a traJ-lacZ fus...

Plasmids are extrachromosomal DNA elements that can be found in prokaryotic as well as in eukaryotic cells. They can vary in size and genetic make-up. The plasmid pRK100, which is the study subject of this thesis, is a large (145 kb) natural conjugative plasmid, which was isolated from an uropathogenic E. coli strain. Genetic characterisation of pR...

The TraJ protein is a central activator of F-like plasmid conjugal transfer. In a search for regulators of traJ expression, we studied the possible regulatory role of the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex in traJ transcription using a traJ-lacZ reporter system. A comparison of the enzyme activities in the wild-type Escherichia c...

The aim of the presented study was to identify the similarity of the pRKI00 tra region with tra regions of other conjugative plasmids of Enterobacteriaceae.For this purpose several tra genes were amplified with PCR and the nucleotide sequences of the obtained PCR products were determined. The pRKI OO's nucleotide sequences were compared to the nucl...

Seventy-eight bacterial isolates from human, animal, and plant hosts, representing eight species of the family Enterobacteriaceae, were screened for F-like plasmid sequences. Of the examined human Escherichia coli strains, 28% harbored one or two of the three F-like, RepFI replication regions, while 35% of the examined animal and all phytopathogeni...

Twenty-four haemolytic Escherichia coli strains were isolated from dogs with diarrhea. The strains were serotyped and analysed by polymerase chain reaction (PCR) for genes encoding virulence factors associated with E. coli that cause diarrhea in animals. Adhesion antigen production was deduced from haemagglutination experiments. Sodium dodecyl sulf...

On Apr 4, 2003 this sequence version replaced gi:9651862.

Uropathogenic Escherichia coli strains express chromosomal and plasmid-encoded virulence-associated factors such as specific adhesins, toxins and iron-uptake systems. A CoIV plasmid (pRK100) of a uropathogenic strain and its host KS533 were studied. The host strain encodes the K1 capsule, and P and S fimbriae, but neither haemolysin nor the cytotox...

Methods 110 uropathogenic Escherichia coli strains (UPEC) obtained from the Institute of Micro- biology and Immunology of the Medical Faculty in Ljubljana were screened by PCR with primers specific for the following toxin encoding genes: hlyA (haemolysin), cnf1 (cytotoxic necrotising factor 1), usp (uropathogenic specific protein USP) and ibeA (inv...