Editorial for Special Issue "Effects of Probiotics on Health".

Since 1987, when Professor Sherwood Gorbach discovered, characterized, and commercialized the first probiotic Lactobacillus rhamnosus GG, a total of over 17,000 publications have been indexed in PubMed under "probiotic" and "health", which is an extensive amount of research on the specific bacteria and yeasts defined as "live microorganisms that, when administered in adequate amounts, exert a health benefit on the host" [...].

Special Issue "An Update on Lactobacillus": Editorial.

As indicated in the introduction to this Special Issue, as of 2020, the original genus Lactobacillus comprised over 260 recognized species, a figure which is probably much higher now [...].

COVID-19-Associated Pulmonary Aspergillosis in Intensive Care Unit Patients from Poland.

Coronavirus disease 2019 (COVID-19) has been shown to be a favoring factor for aspergillosis, especially in a severe course requiring admission to the intensive care unit (ICU). The aim of the study was to assess the morbidity of CAPA among ICU patients in Poland and to analyze applied diagnostic and therapeutic procedures. Medical documentation of patients hospitalized at the temporary COVID-19 dedicated ICU of the University Hospital in Krakow, Poland, from May 2021 to January 2022 was analyzed. In the analyzed period, 17 cases of CAPA were reported with an incidence density rate of 9 per 10 000 patient days and an incidence rate of 1%. Aspergillus fumigatus and Aspergillus niger were isolated from lower respiratory samples. Antifungal therapy was administered to 9 patients (52.9%). Seven patients (77.8%) received voriconazole. The CAPA fatality case rate was 76.5%. The results of the study indicate the need to increase the awareness of medical staff about the possibility of fungal co-infections in ICU patients with COVID-19 and to use the available diagnostic and therapeutic tools more effectively.

Corrigendum: SARS-CoV-2 antibody response after mRNA vaccination in healthcare workers with and without previous COVID-19, a follow-up study from the University Hospital in Krakow, Poland.

[This corrects the article DOI: 10.3389/fimmu.2022.1071204.].

PDIA, an Iminosugar Compound with a Wide Biofilm Inhibitory Spectrum Covering Both Gram-Positive and Gram-Negative Human Bacterial Pathogens.

Many difficult-to-treat human infections related to catheters and other indwelling devices are caused by bacteria residing in biofilms. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. Therefore, many different approaches have been researched to destroy or inhibit biofilm production by bacteria. Different iminosugars (IS) were reported to inhibit biofilm formation in S. mutans, S. aureus, and P. aeruginosa. The aim of this study was to look for a spectrum of the activity in one of these IS. The iminosugar PDIA beta-1-C-propyl-1,4-dideoxy-1,4-imino-L-arabinitol was tested in vitro at the same concentration against 30 different strains of the most important Gram-negative and Gram-positive human pathogens looking for their biofilm production and viability at different time intervals. It appeared that PDIA inhibited biofilm production of Enterobacter spp., P. aeruginosa, Enterococcus spp. and S. aureus in 8 h, and Klebsiella spp., Acinetobacter spp. and S.epidermidis in 24 h. PDIA caused no growth inhibition of the tested bacteria at a concentration of 0.9 mM. Our results indicate a broad-spectrum biofilm inhibitory activity of PDIA. which may be the basis for future application studies that will help in control of the associated device and biofilm-related infections caused by a wide spectrum of the causative agents.

SARS-CoV-2 antibody response after mRNA vaccination in healthcare workers with and without previous COVID-19, a follow-up study from a university hospital in Poland during 6 months 2021.

Introduction: Healthcare workers (HCWs) from the beginning of the pandemic have been at risk of exposure to SARS-CoV-2, so they were vaccinated as first. Objectives: The purpose of the study was to determine the level of antibodies against SARS-CoV-2 in HCWs before and after vaccination with mRNA preparations according to previous COVID- 19. Patients and methods: The HCWs from the University Hospital in Krakow completed two surveys: the baseline survey before receiving the first dose of vaccine (in January 2021) and the follow-up survey in June 2021. In parallel, two blood samples were collected from each participant at baseline and at follow-up. Total anti-SARS-CoV-2 antibody levels were measured using the ECLIA technique. Results: At baseline, 41.1% of HCWs had positive antibody test results, and at follow-up, the vaccinated HCWs had almost 100 times higher antibody levels than the unvaccinated HCWs. Participants under 30 years of age had significantly higher antibody levels in June than older HCWs. Among participants with positive antibody test results in January, HCWs who had experienced asymptomatic COVID-19 had more than five times higher antibody levels in June than HCWs self-reported severe COVID-19. In total, 86.9% of HCWs received Comirnaty or Spikevax. The incidence rate of COVID-19 in the unvaccinated vs. vaccinated group was 13 times higher, 20.5% and 1.9% respectively. Conclusions: These results confirm the effectiveness of vaccination in the prevention of COVID-19 in HCWs. It is worth getting vaccinated regardless of previous infection. Furthermore, vaccination among HCWs under 30 years of age induced more effective antibody production compared to older individuals.

Preparedness of Health Care Workers and Medical Students in University Hospital in Krakow for COVID-19 Pandemic within the CRACoV Project.

Backgrounds Health care workers' (HCWs) knowledge of and compliance with personal protective procedures is a key for patients' and personnel safety. The aim of this study was to assess which factors are associated with higher self-evaluations of training on infection prevention and control (IPC) and higher self-assessment of IPC practices used by HCWs regarding COVID-19 in University Hospital in Krakow, Poland, in January 2021. Material and methods This was an online survey on the preparedness for COVID-19 epidemic of medical/non-medical staff and medical students. Questions included in the survey concerned participants' socio-demographic characteristics, hospital staff involvement in the training, knowledge about the hand hygiene, and adherence to IPC measures. Knowledge and Performance Index (K&PI) based on selected questions was constructed for to reflect both subjective (self-evaluation) of preparedness and objective IPC knowledge and skills of HCWs participated in the IPC training. Results A total of 1412 health care workers, including 129 medical students, participated in the study. The largest group, 53.6%, was made up of nurses and paramedics. Age of respondents significantly correlated with knowledge of IPC and with K&PI. The mean age of workers with high K&PI was 42.39 ± 12.53, and among those with low, 39.71 ± 13.10, p < 0.001. 51% UHK workers participated in IPC training, but 11.3% of physicians, 28.8% of other HCWs, and 55.8% of students did not know the IPC standard precaution. Most participants, 72.3%, felt that they had received sufficient training; however, 45.8% of students declined this. There was no correlation between self-reported preparedness and the K&PI, indicating that self-reported preparedness was inadequate for knowledge and skills. Nurses and paramedics assessed their knowledge most accurately. Participants with low K&PI and high subjective evaluation constituted a substantial group in all categories. Students least often overestimated (23.8%) and most often (9.6%) underestimated their knowledge and skills. Conclusions Our study revealed inadequate IPC practice, especially as it refers to the training programme. We confirmed the urgent need of including theory and practice of IPC in curricula of health professions' training in order to provide students with knowledge and skills necessary not only for future pandemic situations but also for everyday work.

Explanatory survival model for nursing home residents- a 9-year retrospective cohort study.

PURPOSE: There is a gap in the literature regarding the analysis of long-term survival and mortality risk factors among disabled and multimorbid institutionalized populations. The study aimed to analyze 9-year survival, investigate mortality factors, and develop an explanatory survival model for nursing home residents. MATERIALS AND METHODS: A retrospective cohort study with a 9-year follow-up (2009-2018) was conducted among 96 residents of a nursing home with Barthel index ≤ 40. The study was based on baseline measurements performed in 2009, which included results obtained on geriatric scales: Mini Nutritional Assessment Short-Form (MNA-SF) and Abbreviated Mental Test Score (AMTS). Information on demographics, comorbidities, pharmacotherapy, transfers and deaths came from medical records. Kaplan-Meier curves were used to estimate and present survival data. Factors associated with mortality were determined using Cox proportional hazard models. RESULTS: The median survival was 2.9 years. Mortality during the follow-up period was 83%. Kaplan-Meier curves showed that residents with normal nutritional status (p = 0.002) and taking aspirin (p = 0.005) had a better 9-year survival. The multivariable Cox regression model revealed that the risk of mortality (Hazard Ratio, HR) increased in older age (HR=1.04), male gender (HR=2.08), with risk of malnutrition (HR=3.91), malnutrition (HR=4.84), and presence of urinary incontinence (HR=2.14). The aspirin use was the strongest protective factor against death (HR=0.40). CONCLUSION: The aspirin use was associated with better long-term survival for nursing home residents. Factors associated with higher mortality among residents include older age, male gender, poor nutritional status, and urinary incontinence. BRIEF SUMMARY: We are the first to report the beneficial effects of a low-dose of aspirin on the long-term survival of disabled, institutionalized populations with multimorbidity. Furthermore, this study presents an explanatory model of survival for nursing home residents and identifies the long-term mortality risk factors among disabled residents with multimorbidity.

What factors influence the long-term survival of nursing home residents with severe disabilities?

B a c k g r o u n d / A i m: Factors influencing the survival of the nursing home population have not yet been clearly defined. The aim of the study was to investigate the impact of nutritional, mental, functional, disease and pharmacological factors on the survival of nursing home residents with severe disabilities. Material and Methods: A retrospective cohort study was conducted with a 9-year follow-up period among nursing home residents with a Barthel score ≤40. The initial assessment included the following scales: Mini Nutritional Assessment Short-Form (MNA-SF), Abbreviated Mental Test Score (AMTS), the Barthel Index, and blood pressure (BP) measurements. Comorbidities, medications and all-cause mortality were extracted from medical records. The analyzed cohort was divided into two groups: Deceased - residents who died ≤3 years and Survivors - those who survived >3 years of observation. R e s u l t s: Survivors (n = 40) and Deceased (n = 48) did not differ significantly in terms of age, sex, systolic and diastolic BP, the Barthel Index, number of diseases and medications used. Survivors had significantly higher scores in MNA-SF (p <0.001) and AMTS (p <0.003) than Deceased. Moreover, Survivors had hypertension significantly more often and took aspirin and ACE inhibitors (p <0.05). The multivariable logistic regression analysis showed that the MNA-SF score significantly affected mortality [OR = 0.62, (95%CI, 0.46-0.84), p <0.001]. C o n c l u s i o n: Higher MNA-SF scores were a factor that significantly affected the survival of nursing home residents, while functional status assessed using the Barthel Index had no effect on survival. MNA-SF was found to be a useful tool for assessing the risk of death in a nursing home.

Is treated hypertension associated with a lower 1-year mortality among older multimorbid residents of long-term care facilities?

INTRODUCTION: Long-term care facility (LTCF) residents are typically excluded from clinical trials due to multimorbidity, dementia, and frailty, so there are no clear evidence-based rules for treating arterial hypertension in this population. Moreover, the role of hypertension as mortality risk factor in LTCFs has not yet been clearly established. OBJECTIVES: The study aimed to investigate whether treated hypertension is associated with lower mortality among older LTCF residents with multimorbidity. PATIENTS AND METHODS: The study was performed in a group of 168 residents aged ≥ 65 years in three LTCFs. Initial assessment included blood pressure (BP) measurements and selected geriatric scales: MNA-SF, AMTS and ADL. Hypertension, comorbidities, pharmacotherapy, antihypertensive drugs and mortality during one-year follow-up were extracted from the medical records. The data was compared in groups: Survivors and Deceased. RESULTS: Survivors and Deceased revealed similar age, DBP, number of diseases, medications, and antihypertensive drugs. However, Deceased had significantly lower SBP (P <0.05) and presented significantly worse functional, nutritional and cognitive status than Survivors (P <0.001). Hypertension (P <0.001) and antihypertensive therapy (P <0.05) were significantly more frequent among Survivors. Significantly more of the hypertensive-treated than other multimorbid residents survived the follow-up (P <0.001). Logistic regression analysis showed that treated hypertension had a protective effect on mortality [OR = 0.11 (95% CI, 0.03-0.39); P <0.001]. CONCLUSIONS: One-year survival of LTCF residents with treated hypertension was significantly higher than the others. Appropriate antihypertensive therapy may be a protective factor against death in frail nursing home residents, even in short period of time.

Effect of a Short-Time Probiotic Supplementation on the Abundance of the Main Constituents of the Gut Microbiota of Term Newborns Delivered by Cesarean Section-A Randomized, Prospective, Controlled Clinical Trial.

The gut microbiota plays a pivotal role in the maintenance of human health. Numerous factors, including the mode of delivery, impact early gut colonization in newborns. Recent research focuses on the use of probiotics in the prevention of gut dysbiosis in newborns delivered by cesarean section (CS). The objective of this study was to determine whether a probiotic supplement given to newborns delivered by CS during their stay in the maternity ward alters the pattern of early gut colonization by lactic acid bacteria versus potential pathogens. A prospective, randomized trial was conducted. In total, 150 newborns, born at 38-40 weeks gestational age and delivered by CS, were included in the study. They were randomized into the intervention group, supplemented orally with a probiotic containing Bifidobacterium breve PB04 and Lactobacillus rhamnosus KL53A, and the control group. Stool samples were obtained on days 5 and 6 of life and after one month of life and were analyzed for the presence and abundance of the main groups of bacteria. An application of two probiotic bacteria during the first days of life after CS resulted in quick and abundant colonization by days 5 and 6, with high populations of L. rhamnosus and B. breve. The applied bacterial strains were present in the majority of neonates one month after. The supplementation of term neonates delivered by cesarean section immediately after birth with a mixture of L. rhamnosus and B. breve enriched the gut microbiota composition with lactic acid bacteria.

Coagulase-Negative Staphylococci Contained in Gut Microbiota as a Primary Source of Sepsis in Low- and Very Low Birth Weight Neonates.

BACKGROUND: There are only a few reports in the literature about translocation of coagulase-negative staphylococci (CoNS) as a primary cause of sepsis in neonates, although CoNS are among a short list of "translocating" bacteria when present in abundance. METHODS: 468 blood samples, 119 stool samples, and 8 catheter tips, from 311 neonates, were tested for presence of microorganisms. CoNS strains isolated from the blood and stool or from blood and catheter tip of the same newborn at approximately the same time were paired and typed with PFGE (Pulse-Field Gel Electrophoresis) method. The strains were then tested for the presence of adherence genes and biofilm formation. RESULTS: The strains with identical PFGE profiles in comparison to those with non-identical profiles differed in terms of the pattern of the virulence genes and showed a lack of the genes related to adherence, but more often presence of IS256, which is related to virulence. They also were phenotypically unable to adhere to intestinal Caco2 cells. CONCLUSIONS: A considerable proportion of CoNS strains isolated from bloodstream of VLBW/LWB neonates was identical to the strains isolated from faeces of the same neonates at the same time. These observations may offer indirect evidence indicating that at least some CoNS can translocate from the gastrointestinal tract of the premature neonates into the bloodstream and thus cause generalized infection.

Neonate Bloodstream Infections in Organization for Economic Cooperation and Development Countries: An Update on Epidemiology and Prevention.

The term neonatal sepsis is used to describe a generalized bloodstream infection of bacterial, viral, or fungal origin which is associated with hemodynamic changes and other clinical symptoms and signs, however, there is no unified definition. There are no basic criteria regarding differentiation of early-onset sepsis (EOS) versus late-onset sepsis (LOS). Stratification used in studies on neonatal sepsis also rarely includes the general condition of the newborn according to unambiguous assessment at birth, which hampers the establishment of a clear, uniform epidemiological description of neonatal sepsis. We aim to review the published data about the epidemiology and microbiology of sepsis in Organization for Economic Cooperation and Development (OECD) countries. Data was also collected on sepsis prevention programs that can be implemented in neonatal units. The outcomes of interest were incidence or incidence density of EOS and LOS, microbiology of EOS and LOS, and data on the methodology of the research, in particular the criteria for inclusion and exclusion of newborns from the study. Pubmed, EMBASE, LILACS Embase, Scopus, and Google Scholar were used. For the preselection step, inclusion criteria included: "bloodstream infection" or "neonatal sepsis" (MesH), "very low birth weight", and "country" full-text studies, human, and English language. Exclusion criteria included: studies published in languages other than English and studies available only as an abstracts. For proper selection, inclusion criteria included: information about epidemiology or microbiology bloodstream infection (BSI), study population and case definitions, exclusion criteria, narrative reviews, commentaries, case studies, pilot studies, study protocols, pediatric studies, and only clinical data (without microbiology or epidemiology) or studies with only one etiological factor analysis. The data review indicated the lack of an unequivocal, unified definition and no unambiguous basic criteria with regard to differentiation of EOS versus LOS. Among infants <1500 g, studies reported an EOS rate from 7% to 2%. For studies using other definitions (mostly all inborn babies), the rate of EOS ranged from 1% to 3%. The LOS incidences were much more varied among countries; the highest rates were in the multicenter studies focused on very low birth weight (VLBW) infants. The main pathogens in EOS are GBS and Gram-negative bacteria in LOS. Our review data shows that LOS microbiology is very diverse and that Gram-positive cocci, especially staphylococci, predominate versus Gram-negative rods. Unfortunately, the lack of uniform, international prevention programs results in high newborn morbidity and insufficient postnatal prevention of late-onset infections.

Lactobacilli with superoxide dismutase-like or catalase activity are more effective in alleviating inflammation in an inflammatory bowel disease mouse model.

PURPOSE: Some lactobacilli, which possess superoxide dismutase-like activity and catalase activity naturally, have strong antioxidative properties. The aim of this study was to identify such strains and check which of them play a crucial role in alleviating intestinal inflammation. METHODS: We selected two Lactobacillus strains for use in animal studies: L. plantarum 30B (which has the highest catalase activity) and L. acidophilus 900 (which has the highest dismutase-like activity). Forty mice (C57B1/6J) were divided into four experimental groups with ten mice in each group. Group I (control group) was not supplemented with Lactobacillus, group II (catalase group) was orally supplemented with L. plantarum 30B, group III (dismutase-like group) was supplemented with L. acidophilus 900, and group IV (mixed group) was supplemented with both Lactobacillus strains. For 23 days, the temperature and body mass of each mouse were recorded and fecal samples for microbiological examination were collected. On day 23, the animals were sacrificed, and their intestines were removed for microbiological and histopathological studies. RESULTS: Compared to the control group, the highest drop in the body temperature was observed in groups II (P<0.05) and IV (P<0.05). Similarly, groups II (P<0.05) and IV (P<0.05) had the highest drop in body mass. Moreover, histopathological evaluation of colon fragments showed intracryptic abscesses in these groups. Group III mice showed most limited degree of inflammation. CONCLUSION: Lactobacillus strains with dismutase-like activity are more effective in alleviating intestinal inflammation than strains producing catalase, suggesting that superoxide anion radical decomposition is crucial in this process.

Effects of oral probiotic supplementation on gut Lactobacillus and Bifidobacterium populations and the clinical status of low-birth-weight preterm neonates: a multicenter randomized, double-blind, placebo-controlled trial.

AIM: Probiotic bacteria administered directly after birth to preterm neonates may improve gastrointestinal function and may reduce the incidence of late-onset sepsis, which is a frequent complication in this group. PURPOSE: The main objective of this study was to evaluate whether a new probiotic bacterial mixture of Lactobacillus rhamnosus KL53A and Bifidobacterium breve PB04 given to preterm, low-birth-weight neonates would influence composition of their gut microbiota and sepsis rates. PATIENTS AND METHODS: This study was a multicenter, randomized, double-blind, placebo-controlled trial conducted in clinical centers of neonatal care in Poland. A probiotic or placebo preparation was given twice daily to 181 preterm low-birth-weight neonates who were eligible for enteral feeding between July 2012 and July 2013. The probiotic was given to 90 neonates, while placebo was given to 91 neonates. The gut microbiota was monitored by microbiological analysis of stool samples. Sepsis episodes were detected on the basis of clinical and laboratory findings and confirmed by blood cultures. RESULTS: Tested probiotic administration resulted in continuous increase of the Lactobacillus and Bifidobacterium counts in the gut microbiota. The applied tested strains successfully colonized the neonates gut since they were present in over 90% of stool samples, which was confirmed by molecular analysis. Regardless of the study group (probiotic or placebo), B. breve colonization correlated with lower staphylococcal sepsis incidence, which was irrespective of whether probiotics were given. No sepsis case caused by strains included in study probiotic was recorded. CONCLUSION: Appropriately selected and characterized probiotic bacteria may be safely given to preterm neonates to normalize their distorted gut microbiota and may contribute to lower staphylococcal sepsis rates.

Genital Chlamydia trachomatis infections in young adults - a school-based bio-behavioural study in urban areas, Poland, 2012 to 2015.

Context and AimOne of the most common sexually transmitted pathogens disproportionately affecting young people is Chlamydia trachomatis (CT). This study aimed to assess prevalence of CT among sexually active students (aged 18-19 years) in their final years of high school education in Warsaw and Krakow. Methods: The sample was selected from 61 clusters, each cluster representing one school. We described city, sex, type of school and their association with CT prevalence. To account for non-responders we applied inverse probability weighting. Results: Our study population consisted of 3,136 young adults eligible for CT screening, of whom 2,326 reported having had sexual intercourse within past 12 months. Of the 950 students who agreed to be tested, 39 were infected with CT. Weighted prevalence of CT was 3.9% (95% confidence interval (CI): 2.7-5.1); however, prevalence in the students in Warsaw (6.6%; 95% CI: 3.5-12.4) was six times higher (prevalence ratio (PR) = 5.9; 95% CI: 2.0-17.3) than in Krakow (1.1%; 95% CI: 0.5-2.6). In both settings, female students attending vocational-technical schools were most affected; the prevalence in this group was more than five times higher (PR = 5.2; 95% CI: 1.7-15.6) compared with female peers in high schools and more than three times higher (PR = 3.3; 95% CI: 1.0-10.7) compared with male peers attending vocational-technical schools. Conclusion: Our study suggested prevalence of CT infection among young people in Poland comparable with the European average, supporting implementation of a CT control programme as recommended in international guidelines.

Treatment of Cardiovascular Diseases Among Elderly Residents of Long-term Care Facilities.

BACKGROUND: The prevalence of cardiovascular diseases among nursing home residents is high but little is known whether pharmacologic therapy recommended by actual medication guidelines is followed by facility's staff. AIM: To evaluate the adherence to actual guidelines for treatment of cardiovascular diseases among older adult residents of long-term care (LTC) facilities. MATERIAL AND METHODS: The cross-sectional study was performed from December 2009 to November 2010 among 189 elderly residents aged ≥60 years in 3 LTC facilities in Poland: 1 long-term care hospital (LTCH) and 2 nursing homes (NHs). The initial evaluation included analysis of medical documentation (all diagnosed diseases and used drugs), blood pressure (BP) measurements and performance of Mini Nutritional Assessment Short-Form (MNA-SF), Abbreviated Mental Test Score (AMTS), Activities of Daily Living (ADL) score, and Barthel Index. Prescribed medication for hypertension (HT), heart failure (HF), and coronary heart disease (CHD) were compared to current European Cardiology Society (ESC), and European Society of Hypertension (ESH) medication guidelines. Residents were divided into 3 subgroups: with HT, HF, and CHD. Results were presented as means and standard deviation. Groups were compared using Mann-Whitney U test for nonparametric data and chi-square test to assess differences in distribution of categorical variables. P values <.05 were considered statistically significant. RESULTS: CHD was diagnosed among 114 residents (60.3%) but only 60.5% of them were treated with aspirin (ASA), 45.6% with beta-blockers (BBs), 60.5% with angiotensin-converting enzyme inhibitor (ACEI), and 24.6% with statins. HF observed in 75% of cases was treated by using ACEI (54.7%), BBs (45.3%), loop diuretics (LDs, 36%), mineralocorticoid-receptor antagonists (MRAs, 21.3%). HT was diagnosed among 98 study participants (51.9%) and in the majority of cases (76.6%) was well controlled (mean BP: 133.7 ± 17.6/73.8 ± 10.2 mmHg). The most popular antihypertensive drugs were ACEIs (77.6%), BBs (40.8%) and calcium channel blockers (CCBs, 26.5%) whereas thiazides, alpha-blockers (ABs), and angiotensin receptor blockers (ARBs) were used less frequently. CONCLUSION: In summary, the study showed that insufficient treatment of cardiovascular diseases among elderly residents of LTC facilities could be a potential risk factor of poor prognosis.

Experimental model for acute kidney injury caused by uropathogenic Escherichia coli.

INTRODUCTION: Acute kidney injury (AKI) is the rapid deterioration of renal function, diagnosed on the basis of an increase in serum creatinine and abnormal urinary parameters. AKI is associated with increased risk of mortality or chronic kidney disease (CKD). The aim of the study was to develop an experimental model for AKI resulting from Escherichia coli-induced pyelonephritis. E. coli was isolated from a patient with clinical symptoms of urinary tract infection (UTI). MATERIAL/METHODS: The study included three groups of female Wistar rats (groups 1, 2 and 3), in which pyelonephritis was induced by transurethral inoculation with highly virulent E. coli (105, 107 and 109 cfu/ml, respectively). Urine and blood samples for analysis were obtained prior to the inoculation (day 0), as well as 7, 14 and 21 days thereafter. RESULTS: Aside from a microbiological examination of urine samples, daily urine output, serum creatinine (CreaS), creatinine clearance (CrCl), interleukin 6 (IL-6), fractional excretion of sodium (FENa) and fractional excretion of urea (FEUrea) were determined. A histopathological examination of kidney and urinary bladder specimens was conducted as well. While UTI-related pyelonephritis developed irrespective of E. coli inoculum size, AKI was observed only following transurethral administration of E. coli at the intermediate and high dose, i.e. 107 and 109 cfu/ml, respectively (group 2 and 3). DISCUSSION: An increase in CreaS and abnormal diuresis were accompanied by changes in parameters specific for various forms of AKI, i.e. FENa and FEUrea. Based on these changes, administration of E. coli at 107 cfu/ml was demonstrated to induce renal AKI, whereas inoculation with 109 cfu/ml seemed to cause not only ascending pyelonephritis, but perhaps also bacteremia and urosepsis (prerenal component of AKI).

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.

Effects of the Selected Iminosugar Derivatives on Pseudomonas aeruginosa Biofilm Formation.

A lack of an effective way to eliminate pathogenic bacteria hidden in the biofilm is a major problem in the treatment of chronic bacterial infections. Iminosugar derivatives are potential candidates for inhibitors of enzymes taking part in the biosynthesis of exopolysaccharides, which are forming bacterial biofilm. Investigated iminosugars were studied either at an early stage of biofilm formation or later on when the mature biofilm of Pseudomonas aeruginosa was already formed. A series of diverse iminosugar structures significantly inhibited biofilm formation, whereas they showed no influence on already formed biofilm. This indicates a possible mechanism of their action based on inhibition of exopolysaccharide backbone synthesis in the early stages of biofilm formation. Moreover, iminosugar derivatives did not show significant effect on the viable bacterial numbers in both early and mature biofilm forms. Importantly, they were not cytotoxic against human Caco-2 cells in vitro, which may be to their advantage in case of their medical application in preventing P. aeruginosa biofilm formation.