Catch Effectiveness Revealed by Site-Related Differences in Capture-Mark-Recapture Methods: A Butterfly Metapopulation Study.

Understanding metapopulation structures is very important in the context of ecological studies and conservation. Crucial in this respect are the abundances of both the whole metapopulation and its constituent subpopulations. In recent decades, capture-mark-recapture studies have been considered the most reliable means of calculating such abundances. In butterfly studies, individual insects are usually caught with an entomological net. But the effectiveness of this method can vary for a number of reasons: differences between fieldworkers, in time, between sites etc. This article analyses catch effectiveness data with respect to two subpopulations of the Apollo butterfly (Parnassius apollo) metapopulation in the Pieniny National Park (Polish Carpathians). The results show that this parameter varied significantly between sites, probably because of differences in microrelief and plant cover. In addition, a method is proposed that will include information on catch effectiveness for estimating the sizes of particular subpopulations and will help to elucidate the structure of the entire metapopulation.

Intraseasonal asynchrony as a factor boosting isolation within a metapopulation: The case of the clouded apollo.

This article discusses the influence of phenology-related intraseasonal asynchrony on metapopulation dynamics and stability. As the part played by intraseasonal asynchrony is as yet unclear and poorly described, greater account of it should be taken in both metapopulation research and conservation practice. The subpopulations of the Parnassius mnemosyne metapopulation studied here are strongly isolated because of the phenological shift between them, despite the relatively small physical distances between them. This isolation is the result of a significant temporal shift in the species' flight periods in the main metapopulation centers: in some seasons its flight times in the different subpopulations did not overlap at all. The predicted results of such strong intraseasonal asynchrony are not altogether clear. On the one hand, they reduce the vulnerability of the entire metapopulation to the effects of short-term random disasters. On the other, the ever-greater isolation of subpopulations may cause the metapopulation to become a nonequilibrium one, which will have a serious impact on its long-term survival.

Ammonolysis of Cobalt Molybdenum Oxides - In Situ XRD Study.

The reduction of cobalt molybdenum oxide under an ammonia atmosphere resulting in the formation of ternary interstitial nitride Co3Mo3N was studied. Intermediate phases were identified by an in situ powder X-ray diffraction using a reaction chamber. It was supplemented by a thermogravimetric analysis of the process. The presence of intermediate phases, CoMoO4, Co2Mo3O8, Mo2N, metallic cobalt, and Co2Mo3N, was observed. A synthesis route of Co3Mo3N by an ammonolysis method was proposed.

On the reintroduction of the endangered thick-shelled river mussel Unio crassus: The importance of the river's longitudinal profile.

Freshwater mussels of the order Unionida provide important ecosystem functions and services. Unfortunately, some previously widespread species are now seriously endangered. To restore the historical range of the population of Unio crassus in the Biala River, southern Poland, the species was reintroduced into a series of 'stepping stones' joining two remnant populations. During the first phase of the study, the relationships between the abundance of U. crassus, physical habitat, and water quality were studied to assess reintroduction potential. In general, chemical water quality improved upstream from the existing population, favouring the decision for reintroduction, whereas morphological variables worsened. Mussel abundance was correlated negatively with the elevation and slope of channel, organic matter contents, and pH (exceeding 8.0), but positively with silt presence, water conductivity, and concentrations of HCO3-, Ca2+, and NO3-. During the second phase, adult individuals were introduced into one type of functional habitat-marginal channel sectors with still water and fine sediment. Despite the initial very high rate of reproduction in some parts of the upper reach of the river, the juveniles were ultimately recruited only in the lower part of the restored range, resulting in a very rapid change in recruitment at a channel slope of 1.8‰. Recruitment was positively related to silt content, conductivity, and Ca2+ and HCO3- ions, negatively to channel elevation and slope, and water pH. The host fish species showed no correlation with abiotic habitat features within the studied reach. These results imply that most of the habitat traits related to U. crassus occurrence depended on the river's longitudinal profile, not on the chemical water quality, and that final success of introduction should be evaluated after several years.

The dual role of Escherichia coli in the course of ulcerative colitis.

BACKGROUND: This study examines the dual role of Escherichia coli in the course of ulcerative colitis (UC). The intestinal microbiota is considered to play an important role in UC pathogenesis, but how E. coli contributes to inflammation in UC is still unknown. On the one hand, we demonstrated that there was a significant increase in the number of E. coli at the sites of inflammation in patients with UC, which can lead to immune system activation, whilst, on the other hand, E. coli may contribute to the resolution of inflammatory reactions since E. coli can inhibit hydroxyl radical formation by eliminating substrates of the Fenton reaction, by assimilating ferrous iron (Fe2+) and inducing the decomposition of hydrogen peroxide (H2O2). On this way, E. coli may affect the initiation and/or prolongation of remission stages of UC. METHODS: Ten E. coli strains were isolated from the colonic mucosa of patients in the acute phase of UC. Using PCR, we examined the presence of genes encoding catalases (katG and katE) and proteins participating in iron acquisition (feoB, fepA, fhuA, fecA, iroN, fyuA, and iutA) in these E. coli strains. To determine if iron ions influence the growth rate of E. coli and its ability to decompose H2O2, we grew E. coli in defined culture media without iron (M9(-)) or with ferrous ions (M9(Fe2+)). Expression levels of genes encoding catalases were examined by real-time PCR. RESULTS: All investigated E. coli strains had catalase genes (katG, katE), genes coding for receptors for Fe2+ (feoB) and at least one of the genes responsible for iron acquisition related to siderophores (fepA, fhuA, fecA, iroN, fyuA, iutA). E. coli cultured in M9(Fe2+) grew faster than E. coli in M9(-). The presence of Fe2+ in the media contributed to the increased rate of H2O2 decomposition by E. coli and induced katG gene expression. CONCLUSIONS: E. coli eliminates substrates of the Fenton reaction by assimilating Fe2+ and biosynthesizing enzymes that catalyze H2O2 decomposition. Thus, E. coli can inhibit hydroxyl radical formation, and affects the initiation and/or prolongation of remission stages of UC.

Device-associated pneumonia of very low birth weight infants in Polish Neonatal Intensive Care Units.

PURPOSE: Late-Onset Pneumonia (LO-PNEU) is still the most important complication associated with the hospitalization of infants with very low birth weight (<1501g). The purpose of this paper is to summarize the results of an ongoing surveillance program defining LO-PNEU as associated or not associated with respiratory support in the NICU and distribution of causative pathogens from the Polish Neonatology Surveillance Network (PNSN). MATERIALS AND METHODS: Surveillance of infections was conducted in the years 2009-2011 at six Polish NICUs. RESULTS: The incidence was 3.1/1000 NICU patient days (pds). The mean gestational age and birth weight among infants with LO-PNEU were significantly lower. The VAP incidence was of 18.2/1000 NICU pds for mechanically ventilated (MV) infants, while the rates for those receiving only CPAP were as low as 7.7/1000 NICU pds. MV significantly increased the risk of PNEU, but MV or CPAP for <10 days did not increase the risk of LO-PNEU. Significantly associated with LO-PNEU was the use of central or peripheral venous catheters and total parenteral nutrition for longer periods. Microorganisms isolated in cases of LO-PNEU were Gram-positive cocci (53.5%) and Gram-negative rods, with predominating E. coli. Non fermentative bacilli were significantly more frequent in cases of VAP than in other cases. CONCLUSIONS: Observed incidence rates associated with VAP and CPAP-PNEU, were higher than in other national surveillance systems and expressing the feasibility of lowering the risk of LO-PNEU and increasing patient safety. The incidence of pneumonia was found to be lower when using CPAP as compared to using MV.

Supplementation of standard antibiotic therapy with oral probiotics for bacterial vaginosis and aerobic vaginitis: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: This multicentre, randomised, double-blind, placebo-controlled trial was performed to determine whether the use of oral probiotic preparation (prOVag®) containing three Lactobacillus strains together with standard metronidazole treatment and also targeted antibiotic treatment (following the failure of metronidazole therapy) could reduce the recurrence rates of bacterial vaginosis (BV) and aerobic vaginitis (AV). METHODS: Patients at private gynaecological clinics in Poland with histories of recurrent BV/AV and current symptoms were randomly allocated to receive metronidazole and probiotic or placebo, and assessed monthly on visits II and III-V. The total number of study visits was 5-6 (I, II, II bis - if applicable, III, IV, V). One probiotic or placebo capsule was administered with metronidazole/targeted antibiotic twice daily for 10 days; during follow up, patients took one capsule daily for 10 days perimenstrually. Clinical examination and vaginal swabbing were performed at each visit. Primary outcomes were clinical or microbiological BV/AV recurrence and probiotic safety. Secondary outcomes were vaginal pH, Nugent score, and Lactobacillus counts in the vaginal microbiota. Safety analysis was performed in 578 (probiotic, n = 285; placebo, n = 293) 18-50-year-old women who were randomised. RESULTS: BV/AV was confirmed microbiologically in 241 (probiotic, n = 118; placebo, n = 123) participants, who continued the trial. Data from 154 (probiotic, n = 73; placebo, n = 81) participants who completed the study were analysed to determine the efficacy of prOVag. Additional analyses included 37 (probiotic, n = 22; placebo, n = 15) participants who received targeted antibiotics and probiotics or placebo. prOVag lengthened the time to clinical relapse of BV/AV symptoms up to 51 % (p < 0.05) compared with placebo; AV relapse was delayed by up to 76 % (p < 0.05). Probiotic use also reduced and maintained low vaginal pH and Nugent score, and increased vaginal Lactobacillus counts following standard treatment. CONCLUSION: This study demonstrated that oral probiotics lengthened remission in patients with recurrent BV/AV and improved clinical and microbiological parameters. TRIAL REGISTRATION: NCT01993524 ; 20 November 2013.

Efficacy and safety of a vaginal medicinal product containing three strains of probiotic bacteria: a multicenter, randomized, double-blind, and placebo-controlled trial.

OBJECTIVE: The main objective of this study was to evaluate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether Lactobacillus colonization promotes normalization and maintenance of pH and Nugent score. PATIENTS AND METHODS: The study was a multicenter, randomized, double-blind, and placebo-controlled trial. Altogether, 376 women were assessed for eligibility, and signed informed consent. One hundred and sixty eligible women with abnormal, also called intermediate, vaginal microflora, as indicated by a Nugent score of 4-6 and pH >4.5 and zero or low Lactobacillus count, were randomized. Each participant was examined four times during the study. Women were randomly allocated to receive either the probiotic preparation inVag(®), or a placebo (one capsule for seven consecutive days vaginally). The product inVag includes the probiotic strains Lactobacillus fermentum 57A, Lactobacillus plantarum 57B, and Lactobacillus gasseri 57C. We took vaginal swabs during visits I, III, and IV to determine the presence and abundance of bacteria from the Lactobacillus genus, measure the pH, and estimate the Nugent score. Drug safety evaluation was based on analysis of the types and occurrence of adverse events. RESULTS: Administration of inVag contributed to a significant decrease (between visits) in both vaginal pH (P<0.05) and Nugent score (P<0.05), and a significant increase in the abundance of Lactobacillus between visit I and visits III and IV (P<0.05). Molecular typing revealed the presence of Lactobacillus strains originating from inVag in 82% of women taking the drug at visit III, and 47.5% at visit IV. There was no serious adverse event related to inVag administration during the study. CONCLUSION: The probiotic inVag is safe for administration to sustainably restore the healthy vaginal microbiota, as demonstrated by predominance of the Lactobacillus bacteria in vaginal microbiota.

Methodological Aspects of the Potential Use of Dendrochronological Techniques When Analyzing the Long-Term Impact of Tourism on Protected Areas.

Intensification of pedestrian tourism causes damage to trees near tourist tracks, and likewise changes the soil structure. As a result, one may expect that annual amount of trees growing near tracks is significantly lower than deeper in the forest. However, during the study of the long-term impact of tourism on the environment (determined from tree increment dynamics), some methodological problems may occur. It is particularly important in protected areas where law and administrative regulations related to nature conservation force research to be conducted using small samples. In this paper we have analyzed the data collected in the Polish part of the Tatra National Park in the two study plots divided into two zones each: the area directly under the influence of the tourist's trampling and the control group. The aim of such analyses was to present the potential effects of the factors which may affect the results of dendrochronological analysis: (i) small size of samples that affects their representativeness, (ii) spatial differences in the rates of the process, as a result of spatial variability of environmental factors and (iii) temporal differences in the rates of the process. This study confirms that the factors mentioned above could significantly influence the results and should be taken into consideration during the analysis.

Epidemiology, antibiotic consumption and molecular characterisation of Staphylococcus aureus infections--data from the Polish Neonatology Surveillance Network, 2009-2012.

BACKGROUND: Our aim was to determine and characterize S. aureus (SA) isolated from infections in newborns for antibiotic resistance, virulence factors, genotypes, epidemiology and antibiotic consumption. METHODS: Prospective surveillance of infections was conducted. Data about antibiotic treatment were analyzed. Antimicrobial susceptibility was assessed. PCR amplification was used to detect resistance and virulence genes. Typing methods such as PFGE, spa-typing and SCCmec were used. RESULTS: SA was found to be associated with 6.5% of infections. Methicillin-Resistant Staphylococcus aureus accounted for 32.8% of SA-infections. An incidence of MRSA-infections was 1.1/1000 newborns. MRSA-infections were diagnosed significantly earlier than MSSA-infections in these newborns (14th day vs. 23rd day (p=0.0194)). MRSA-infections increased the risk of newborn's death. Antibiotic consumption in both group was similar, but a high level of glycopeptides-usage for MSSA infections was observed. In the MRSA group, more strains were resistant to erythromycin, clindamycin, gentamicin and amikacin than in the MSSA group. Hla gene was present in 93.9% of strains, and seg and sei in 65.3% of strains, respectively. One dominant clone was found among the 14 MRSA isolates. Fifteen strains belonging to SCCmec type IV were spa-t015 and one strain belonging to SCCmec type V was spa-t011. CONCLUSIONS: Results obtained in the study point at specific epidemiological situation in Polish NICU (more detailed studies are recommended). High usage of glycopeptides in the MSSA infections treatment indicates the necessity of antimicrobial stewardship improvement and introducing molecular screening for early identification of infections.

Mode of delivery and other risk factors for Escherichia coli infections in very low birth weight infants.

BACKGROUND: Infections in newborns remain one of the most significant problems in modern medicine. Escherichia coli is an important cause of neonatal bloodstream and respiratory tract infections and is associated with high mortality. The aim of our study was to investigate the epidemiology of E. coli infection in Polish neonatal intensive care units (NICUs) and resistance to antibiotics, with particular reference to the safety of very low birth weight infants. METHODS: Continuous prospective infection surveillance was conducted in 2009-2012 in five NICUs, including 1,768 newborns whose birth weight was <1.5 kg. Escherichia coli isolates from different diagnostic specimens including blood, tracheal/bronchial secretions and others were collected. All isolates were tested using disk diffusion antimicrobial susceptibility methods. Pulsed-field gel electrophoresis was used to determine the possible horizontal transfer of E. coli among patients. RESULTS: The incidence of E. coli infections was 5.4% and 2.0/1,000 patient-days. The occurrence of E. coli infections depended significantly on the NICU and varied between 3.9% and 17.9%. Multivariate analysis that took into account the combined effect of demographic data (gender, gestational age and birth weight) and place of birth showed that only the place of hospitalisation had a significant effect on the E. coli infection risk. The highest levels of resistance among all E. coli isolates were observed against ampicillin (88.8%) and amoxicillin/clavulanic acid (62.2%). Among E. coli isolates, 17.7% were classified as multidrug resistant. Escherichia coli isolates showed different pulsotypes and dominant epidemic clones were not detected. CONCLUSIONS: Our data indicate that antibiotic prophylaxis in the presence of symptoms such as chorioamnionitis and premature rupture of membranes did not help reduce the risk of E. coli infection. Multivariate analysis demonstrated only one significant risk factor for E. coli infection among infants with a birth weight <1.5 kg, that is, the impact of the NICU, it means that both neonatal care and care during pregnancy and labour were found to be significant.

Late-onset bloodstream infections of Very-Low-Birth-Weight infants: data from the Polish Neonatology Surveillance Network in 2009-2011.

BACKGROUND: Late-Onset Bloodstream Infections (LO-BSI) continue to be one of the most important complications associated with hospitalization of infants born with very low birth weight (VLBW). The aims of this study were to assess the epidemiology of LO-BSI together with the risk factors and the distribution of causative pathogens at six Polish neonatal intensive care units that participated in the Polish Neonatology Surveillance Network from January 1, 2009 to December 31, 2011. METHODS: The surveillance covered 1,695 infants whose birth weights were <1501 grams (VLBW) in whom LO-BSI was diagnosed >72 hours after delivery. Case LO-BSI patients were defined according to NeoKISS. RESULTS: Four hundred twenty seven episodes of LO-BSI were diagnosed with a frequency of 25.3% and an incidence density of 6.7/1000 patient-days (pds). Results of our multivariate analysis demonstrated that surgical procedures and lower gestational age were significantly associated with the risk of LO-BSI. Intravascular catheters were used in infants with LO-BSI significantly more frequently and/or for longer duration: Central venous cathters (CVC) (OR 1.29) and Peripheral venous catheters (PVC) (OR 2.8), as well as, the total duration of total parenteral nutrition (13 vs. 29 days; OR 1.81). Occurrence of LO-BSI was significantly associated with increased the length of mechanical ventilation (MV) (OR 2.65) or the continuous positive airway pressure (CPAP) (OR 2.51), as well as, the duration of antibiotic use (OR 2.98). The occurrence of more than one infection was observed frequently (OR 9.2) with VLBW with LO-BSI. Microorganisms isolated in infants with LO-BSI were dominated by Gram-positive cocci, and predominantly by coagulase-negative staphylococci (62.5%). CONCLUSIONS: Independent risk factor for LO-BSI in VLBV infants are: low gestational age and requirement for surgery. The incidence rates of LO-BSI especially CVC-BSI were higher in the Polish NICUs surveillance than those of other national networks, similar to the central- and peripheral utilization ratio.

The general status of patients and limited physical activity as risk factors of Methicillin-resistant Staphylococcus aureus occurrence in long-term care facilities residents in Krakow, Poland.

BACKGROUND: The aim of this study was to investigate the epidemiology and resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from long-term care facilities (LTCF) residents and to analyze the potential risk factors for MRSA occurrence, defined as MRSA colonization and/or infection. METHODS: Point prevalence (PPS) and prospective incidence continuous study (CS) was carried out on a group of 193 residents in 2009-2010. RESULTS: Overall MRSA occurred (with or without infection) among 17.6% of residents. There was 16 cases of infections with SA aetiology, of which 10 (58.8%) were caused by MRSA. The MRSA prevalence in PPS was 12.9%, in CS infection incidence rate was 5.2%. Factors associated with MRSA occurrence were: general status of patients, limited physical activity, wound infections (odds ratio, OR 4.6), ulcers in PPS (OR 2.1), diabetes (OR 1.6), urinary catheterization (OR 1.6) and stool incontinence (OR 1.2). CONCLUSIONS: Our data indicate a need for screening of MRSA before hospitalization or transfer to rehabilitation centres, especially in a group of residents with limitations in physical activity - i.e. with the highest risk of MRSA. Results also suggest the need for contact precautions in patients with high risk of MRSA occurrence, only. Focus on the high-risk population might be a solution for the cost-effective surveillance.

Adherence of group B streptococci to human rectal and vaginal epithelial cell lines in relation to capsular polysaccharides as well as alpha-like protein genes - pilot study.

Streptococcus agalactiae (Group B Streptococci, GBS) constitutes a risk factor for infections of the newborns born by colonized mothers. The adherence of GBS to epithelial cells has been proved to be an important factor in the colonization of mucus membranes of both human rectum and vagina. The objective of the study was to assess the adhesion of the selected GBS strains to the human colon adenocarcinoma cell line (HT-29) and human epidermoid vulvo-vaginal cells (A-431) in relation to the capsular polysaccharides and alpha-like protein genes. GBS strains from the human sources belonging to Ia, Ib, II, III and V serotypes possessing different surface alpha-like protein genes such as the alp 2, alp 3, bca, epsilon and rib in the conventional adherence assay were examined. The adherence of GBS strains to the HT-29 cell line was considerably higher than to the A-431 cell line. For GBS serotype Ia and III, a significant difference between the adhesion to the HT-29 and A-431 cell lines was presented. The adhesion of GBS strains to the HT-29 cell line depended on alpha-like protein genes. The most adhesive ones were the GBS strains containing the rib and alp 2 genes. The adherence of GBS strains to the A-431 cell line depended on both their serotype and alpha-like protein genes. Serotype III adhered to the A-431 cells most tightly, particularly the strains containing the rib and alp 2 genes. GBS strains containing the rib gene adhered to the HT-29 and A-431 cell lines more firmly than GBS strains containing other alpha-like protein genes.

Bacterial infections of the lower genital tract in fertile and infertile women from the southeastern Poland.

OBJECTIVES: The objective of the study was to investigate the detection rates of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Gardnerella vaginalis, Escherichia coli, Streptococcus agalactiae and Enterococcus faecalis, showing no clinical signs of an ongoing, acute inflammatory state of the vagina and/or the cenrvix, in fertile and infertile women. MATERIAL AND METHODS: The study encompassed 161 women, including 101 women treated for infertility and 60 fertile women who had already given birth to healthy children. The material for the presence of C. trachomatis, N. gonorrhoeae, M. genitalium, M. hominis and U. urealyticum was collected from the cervical canal and analyzed by PCR. Furthermore, BD ProbeTec ET system was used to detect C. trachomatis infection. Vaginal swabs were collected for classification of bacterial vaginosis and aerobic vaginitis and assessed according to the Nugent score, as well as by traditional culture methods. RESULTS: U. urealyticum was identified in 9% of the infertile women and in 8% of controls. Presence of M. hominis was demonstrated only in the former (4%) and C. trachomatis only in latter (3%). N. gonorrhoeae and M. genitalium were not found in any of the examined women. The frequency of aerobic vaginitis in both groups was estimated at 12%. There were 7% bacterial vaginosis cases in the study group, and none in the control group (p=0.0096). CONCLUSIONS: Despite having no symptoms of an ongoing acute inflammation of the reproductive tract, many women may experience permanent or periodic shifts of equilibrium of the vaginal and/or cervical microflora. BV develops more frequently in infertile patients when compared to the fertile women.

Molecular characterization and drug resistance of Escherichia coli strains isolated from urine from long-term care facility residents in Cracow, Poland.

BACKGROUND: The aim of this study was to assess the prevalence of multidrug-resistant Escherichia coli and extended-spectrum â-lactamases (ESBL) pathogens isolated from asymptomatic bacteriuria and urinary tract infections (UTIs), and the relationship between the phylogeny, antimicrobial resistance, and virulence among isolates in residents of 3 long-term care facilities (LTCF) in Krakow, Poland. MATERIAL AND METHODS: This was point prevalence study and prospective infection control in a group of 217 people. Urine samples were examined with standard microbiological methods and screened for the presence of blaCTX-M, blaSHV, and blaTEM. E. coli isolates were screened for 6 common virulence factors (VFs) and classified according to the rapid phylogenetic grouping technique. RESULTS: Among all the strains tested, 14 isolates (13.9%) expressed ESBL activity. A significant proportion of isolates were resistant to ciprofloxacin (32.7%, n=33). Resistance to trimethoprim/sulfamethoxazole was identified among 45 isolates (44.5%). Independent risk factors for the presence of an ESBL-producing strain were: UTI, urinary and/or fecal incontinence, bedridden, and low values of the Barthel and Katz Indexes. Gene sequencing identified 8 blaCTX-M-15, 1 blaCTX-M-3, 9 blaTEM-1, and 1 blaSHV-12. Among E. coli, no relationship between number of VF genes and phylogeny was found. The most prevalent virulence factor was fimH (82.1%). CONCLUSIONS: The findings of this study emphasize the need for further research on the epidemiology of multi-drug resistant organisms (MDRO) and ESBL in LTCF, including transmission patterns, rates of infection, and factors associated with infections. It may be necessary to extend the requirements and precautions to MDRO and ESBL-producers.

Molecular epidemiology, plasmid analysis, virulence, and resistance of Escherichia coli isolated from neonatal intensive care units in Poland.

We investigated the set of Escherichia coli isolates originating from newborns in relation to resistance, virulence factors (VFs), phylogenetic groups, plasmid replicon typing, and genotypes. The most isolates were clustered in ECOR group B2. Extended-spectrum beta-lactamase phenotype was found in 27.7% of isolates. The ST131 clone was detected among 33 strains, 12 of which carried the CTX-M-15 gene. Most VFs were detected among ST131 isolates and in the B2 group. IbeA gene was found more frequently in the blood isolates, while the iha gene, in the urine isolates. The 3 most prevalent replicon types were IncFIB, IncF, and IncFIA.

Possible role of Escherichia coli in propagation and perpetuation of chronic inflammation in ulcerative colitis.

BACKGROUND: This study investigated a possible role of Escherichia coli in propagation and perpetuation of the chronic inflammation in ulcerative colitis (UC). The lesions of UC are located superficially on the rectal and/or colonic mucosa. It is suggested that the commensal bacteria of the digestive tract may play a role in the pathogenesis of UC. Several studies have demonstrated proliferation of E. coli in the gut of UC patients. An increase in the number of E. coli in the inflamed tissue is most probably related to the abundance of iron ions produced by the bacteria. METHODS: Colon mucosal biopsies were collected from 30 patients with acute-phase UC, both from tissues with inflammatory changes (n = 30) and unchanged tissue with no inflammatory changes (n = 30) from the same patient. Biopsies were also taken from 16 patients with irritable bowel syndrome diarrhea who comprised the control group. Quantitative and qualitative analysis of the biopsy specimens was performed using culture methods and real-time polymerase chain reaction (PCR). Genotyping of the E. coli isolates was done using pulsed-field gel electrophoresis. Multiplex PCR was used to compare the E. coli strains for the presence of genes responsible for synthesis of iron acquisition proteins: iroN, iutA, iha, ireA, chuA, and hlyA. RESULTS: We demonstrated that there was a significant increase in the number of E. coli at the sites of inflammation in patients with UC compared to the control group (P = 0.031). Comparative analysis of the restriction patterns of E. coli isolated from inflammatory and unchanged tissues showed that the local inflammatory changes did not promote specific E. coli strains. There was a significant difference in the frequency of the iroN gene in E. coli isolated from patients with UC as compared to the control group. CONCLUSIONS: The increase in the numbers of E. coli in the inflammatory tissues is related to the presence of chuA and iutA genes, which facilitate iron acquisition during chronic intestinal inflammatory processes.