Uropathogenic Escherichia Coli Strains Research Articles

The RyfA small RNA regulates oxidative and osmotic stress responses and virulence in uropathogenic Escherichia coli.

Urinary tract infections (UTIs) are a common bacterial infectious disease in humans, and strains of uropathogenic Escherichia coli (UPEC) are the most frequent cause of UTIs. During infection, UPEC must cope with a variety of stressful conditions in the urinary tract. Here, we demonstrate that the small RNA (sRNA) RyfA of UPEC strains is required for resistance to oxidative and osmotic stresses. Transcriptomic analysis of the ryfA mutant showed changes in expression of genes associated with general stress responses, metabolism, biofilm formation and genes coding for cell surface proteins. Inactivation of ryfA in UPEC strain CFT073 decreased urinary tract colonization in mice and the ryfA mutant also had reduced production of type 1 and P fimbriae (pili), adhesins which are known to be important for UTI. Furthermore, loss of ryfA also reduced UPEC survival in human macrophages. Thus, ryfA plays a key regulatory role in UPEC adaptation to stress, which contributes to UTI and survival in macrophages.

Virulence genes and phylogenetic groups of uropathogenic Escherichia coli isolates from patients with urinary tract infection and uninfected control subjects: a case-control study

BackgroundUrinary Tract Infection (UTI) is one of the most common bacterial infectious diseases which causes considerable morbidity and costly health problems. Uropathogenic Escherichia coli (UPEC), the most common pathogen causing UTI, is a highly heterogeneous group of extraintestinal pathogenic E. coli (ExPEC) which may carry a variety of virulence factors and belonging to different phylogenetic backgrounds. The current study aimed to investigate the frequency and association between various virulence factors (VFs) and phylogenetic groups of UPEC and commensal isolates.MethodsUPEC and commensal E. coli strains isolated from UTI and feces of healthy humans were compared for the presence of VFs and phylogenetic groups. Association between virulence genes was investigated and cluster analysis was employed.ResultsAccording to the results, among a 30 virulence markers tested, the pathogenicity-associated island (PAI), papAH, papEF, fimH, fyuA, and traT genes prevalence were statistically significant in UPEC isolates. A strong association was found between the B2 and D phylogenetic groups and clinical isolates of UPEC; while, commensal isolates were mostly associated with phylogenetic group A. The aggregated VFs scores were more than twice higher in the UPEC isolates in comparison with the commensal isolates. Interestingly, the B2 group in both UPEC and commensal isolates had the highest VF scores. A strong positive association was found between several virulence genes. The clustering results demonstrated that UPEC or commensal E. coli isolates were highly heterogeneous due to different composition of their virulence gene pool and pathogenicity islands.ConclusionGenetic structure and VFs of UPEC strains vary from region to region; therefore, to control the UTI, the epidemiological aspects and characterization of the UPEC isolates need to be investigated in different regions. Since UPEC isolates are generally originate from the commensal strains, it may be feasible to reduce the UTI burden by interfering the intestinal colonization, particularly in the highly pathogenic clonal lineages such as B2.

Frequency and Diversity of Hybrid Escherichia coli Strains Isolated from Urinary Tract Infections.

(1) Background: Hybrid uropathogenic Escherichia coli (UPEC) strains carry virulence markers of the diarrheagenic E. coli (DEC) pathotypes, which may increase their virulence potential. This study analyzed the frequency and virulence potential of hybrid strains among 452 UPEC strains. (2) Methods: Strains were tested for the DEC virulence diagnostic genes’ presence by polymerase chain reaction (PCR). Those carrying at least one gene were classified as hybrid and further tested for 10 UPEC and extraintestinal pathogenic E. coli (ExPEC) virulence genes and phylogenetic classification. Also, their ability to produce hemolysis, adhere to HeLa and renal HEK 293T cells, form a biofilm, and antimicrobial susceptibility were evaluated. (3) Results: Nine (2%) hybrid strains were detected; seven of them carried aggR and two, eae, and were classified as UPEC/EAEC (enteroaggregative E. coli) and UPEC/aEPEC (atypical enteropathogenic E. coli), respectively. They belonged to phylogroups A (five strains), B1 (three), and D (one), and adhered to both cell lineages tested. Only the UPEC/EAEC strains were hemolytic (five strains) and produced biofilm. One UPEC/aEPEC strain was resistant to third-generation cephalosporins and carried blaCTX-M-15. (4) Conclusions: Our findings contribute to understanding the occurrence and pathogenicity of hybrid UPEC strains, which may cause more severe infections.

GENOTYPIC DETECTION OF THE VIRULENCE FACTORS OF UROPATHOGENIC ESCHERICHIA COLI (UPEC) STRAINS ISOLATED FROM PREGNANT FEMALES AND THEIR CORRELATION WITH ANTIBIOTIC RESISTANCE PATTERN

Urinary Tract Infections (UTIs) during pregnancy are among the most common infections worldwide and can lead to poor perinatal and maternal outcomes, especially in developing countries and requires medical treatment as soon as it is detected. Virulent and resistant strains of Escherichia coli are the most important causative agents for UTIs. The present investigation aimed to detect virulence factors of Uropathogenic Escherichia coli (UPEC), including pap, fim, sfa, aer and hly genes in isolates collected from symptomatic and asymptomatic pregnant females by multiplex polymerase chain reaction (PCR) assay and determine their correlation with antibiotic resistance patterns. Two hundred urine samples collected from pregnant females with or without symptoms of UTI were admitted to antenatal clinic at Obstetrics and Gynecology Department of Al- Zahraa University Hospital in Cairo. Out of 200 cultured urine samples, the cultures that showed ≥ 105 CFU/ml were identified to have significant growth. Found significant bacteriuria was detected in 61 samples and these samples selected for further analysis in this study, the overall prevalence of UTI among pregnant females was (30.5%). Symptomatic pregnant females with UTI were (48.5%) more than asymptomatic (11.3%). The most frequently isolated species was S. saprophyticus (35.0%),followed by E. coli (26.2%),S .aureus (19.4%), C .albicans (5.8%),S. epidermidis (2.9%) and each of K. pneumonia, K .oxytoca, P .vulgaris, E.fecalis, Bacillus spp were(1.9%),while P. auroginosa had the least percentage of isolation (1.0%). Antimicrobial susceptibility pattern was done for 27 UPECisolates showed the highest level of resistance (100%) against β-lactams as (Ampicillin, Penicillin and Ceftriaxone), nitrofurantoin, and ampicillin/sulbactam, while the lowest level of resistance (66.7%) against Cotrimoxazole. Multiple drug resistance (resistance to two or more drugs) was observed in (100%) of the UPEC isolates. The higher level of resistance to antibiotics was observed in symptomatic bacteriuria more than asymptomatic. Among two predominant uropathogens, E. coli showed complete resistance up to 5 different antibiotics of total 11 antibiotics (45.5%) while S. saprophyticus showed complete resistance (18.2%), so E. coli showed higher virulence and resistance than S. saprophyticus to cause UTI, so subjected to Multiplex PCR to detect its virulence factors, which included pap, fim, sfa, aer and hly genes Theadhesive fimH gene was the most frequent in UPEC isolates (92.6%) . These virulence genes detected from total UPEC isolates of symptomatic cases were higher than asymptomatic. On the other hand, UPEC strains carrying the virulence genes were more resistant to the antibiotics used, so these observations confirm the important role of virulence genes of UPEC in in existence of symptoms of UTI and the drug resistance.

DNA adenine methylation is involved in persister formation in E. coli

Uropathogenic Escherichia coli (UPEC) is a major cause of urinary tract infections (UTI). UPEC persister bacteria play crucial roles in clinical treatment failure and relapse. Although DNA methylation is known to regulate gene expression, its role in persister formation has not been investigated. Here, we show that Δdam (adenine methylase) mutant from UPEC strain UTI89 had significant defect in persister formation and complementation of the Δdam mutant restored this defect. Using PacBio sequencing of methylome and RNA sequencing of Δdam, we defined, for the first time, the role of Dam in persister formation. We found that Δdam mutation had an overwhelming effect on demethylation of the genome and the demethylation sites affected expression of genes involved in broad transcriptional and metabolic processes. Using comparative COG analysis of methylome and transcriptome, we demonstrate that Dam mediates persister formation through transcriptional control, cell motility, DNA repair and metabolite transport processes. These findings provide the first evidence and molecular basis for DNA methylation mediated persister formation and implicate Dam DNA methylation as a potential drug target for persister bacteria.

HIGH PREVALENCE OF CLASS I AND CLASS II INTEGRONS IN UROPATHOGENIC E. COLI STRAINS (UPECs) AND THEIR RELATIONSHIP WITH ANTIBIOTIC RESISTANCE, PHYLOGENY AND VIRULENCE

Objective: Integrons, which are highly effective in capturing, integrating and expressing gene cassettes, play an important role in the dissemination of multiple antibiotic resistances. This study investigated the correlations of integrons in uropathogenic E. coli (UPEC) with antibiotic resistance, virulence and phylogeny and also the relationships of phylogroups with virulence and antibiotic resistance. Material and Methods: Fifty UPECs isolated from uncomplicated cystitis and uncomplicated pyelonephritis were investigated to detect the presence of class I, II and III integrons and phylogenetic grouping by the PCR method. Their statistical relationship with antibiotic resistance and virulence genes were investigated using our previous findings. Results: Among 50 UPEC strains, 37 (74%), 22 (44%) and only one (2%) strain was shown to harbor class I, class II and class III integrons, respectively. Twenty one (42%) strains were found to carry both class I and class II integrons. The majority of the strains were grouped as phylogroup B2 (38%) and phylogroup E (38%). The presence of integrons was in association with only ampicillin resistance (p=0.014). Integrons was found to be related neither to virulence genes nor phylogroups; however, the presence of PAI (p<0.001), ompT (p=0.035), and usp (p<0.001) genes was found to be significantly related to phylogroup B2. Phylogroup E was found to be statistically significantly correlated with co-trimoxazole resistance (p=0.043). Conclusion: Consistent with previous studies, our results have proven that there is a strong association between antibiotic resistance and the presence of integrons (especially class I) in UPEC strains, and it has been shown that integrons became very prevalent globally.

HIGH PREVALENCE OF CLASS I AND CLASS II INTEGRONS IN UROPATHOGENIC E. COLI STRAINS (UPECs) AND THEIR RELATIONSHIP WITH ANTIBIOTIC RESISTANCE, PHYLOGENY AND VIRULENCE

Objective: Integrons, which are highly effective in capturing, integrating and expressing gene cassettes, play an important role in the dissemination of multiple antibiotic resistances. This study investigated the correlations of integrons in uropathogenic E. coli (UPEC) with antibiotic resistance, virulence and phylogeny and also the relationships of phylogroups with virulence and antibiotic resistance. Material and Methods: Fifty UPECs isolated from uncomplicated cystitis and uncomplicated pyelonephritis were investigated to detect the presence of class I, II and III integrons and phylogenetic grouping by the PCR method. Their statistical relationship with antibiotic resistance and virulence genes were investigated using our previous findings. Results: Among 50 UPEC strains, 37 (74%), 22 (44%) and only one (2%) strain was shown to harbor class I, class II and class III integrons, respectively. Twenty one (42%) strains were found to carry both class I and class II integrons. The majority of the strains were grouped as phylogroup B2 (38%) and phylogroup E (38%). The presence of integrons was in association with only ampicillin resistance (p=0.014). Integrons was found to be related neither to virulence genes nor phylogroups; however, the presence of PAI (p<0.001), ompT (p=0.035), and usp (p<0.001) genes was found to be significantly related to phylogroup B2. Phylogroup E was found to be statistically significantly correlated with co-trimoxazole resistance (p=0.043). Conclusion: Consistent with previous studies, our results have proven that there is a strong association between antibiotic resistance and the presence of integrons (especially class I) in UPEC strains, and it has been shown that integrons became very prevalent globally.

Genomic Characterization of Multidrug-Resistant Escherichia coli BH100 Sub-strains.

The rapid emergence of multidrug-resistant (MDR) bacteria is a global health problem. Mobile genetic elements like conjugative plasmids, transposons, and integrons are the major players in spreading resistance genes in uropathogenic Escherichia coli (UPEC) pathotype. The E. coli BH100 strain was isolated from the urinary tract of a Brazilian woman in 1974. This strain presents two plasmids carrying MDR cassettes, pBH100, and pAp, with conjugative and mobilization properties, respectively. However, its transposable elements have not been characterized. In this study, we attempted to unravel the factors involved in the mobilization of virulence and drug-resistance genes by assessing genomic rearrangements in four BH100 sub-strains (BH100 MG2014, BH100 MG2017, BH100L MG2017, and BH100N MG2017). Therefore, the complete genomes of the BH100 sub-strains were achieved through Next Generation Sequencing and submitted to comparative genomic analyses. Our data shows recombination events between the two plasmids in the sub-strain BH100 MG2017 and between pBH100 and the chromosome in BH100L MG2017. In both cases, IS3 and IS21 elements were detected upstream of Tn21 family transposons associated with MDR genes at the recombined region. These results integrated with Genomic island analysis suggest pBH100 might be involved in the spreading of drug resistance through the formation of resistance islands. Regarding pathogenicity, our results reveal that BH100 strain is closely related to UPEC strains and contains many IS3 and IS21-transposase-enriched genomic islands associated with virulence. This study concludes that those IS elements are vital for the evolution and adaptation of BH100 strain.

Study of Virulence Factors and Antimicrobial Susceptibility Pattern of Uropathogenic Escherichia Coli in a Tertiary Care Hospital

Introduction: Urinary tract infections are the most commonly encountered bacterial infections both in community and health care settings. Uropathogenic Escherichia coli (UPEC) is the single most common pathogen, accounting for 70-75% of all cases of Urinary Tract Infections (UTIs). The aim of the present study is to isolate UPEC from urine samples from UTI patients, to evaluate the virulence factors and antimicrobial susceptibility pattern. Material and methods: A total of 100 E.coli isolates out of 292 urine samples collected from clinically suspected UTI were taken for the study and detection of virulence factors such as haemolysin production, haemagglutination and cell surface hydrophobicity were done. Antibiotic susceptibility test was done by Kirby Baur disc diffusion method as per the CLSI guidelines. Results: The incidence of UTI was more in females 52% and haemolysis was seen in 32%, haemagglutination in 40%, and cell surface hydrophobicity in 24% of strains. The UPEC strains were more resistant to Ampicillin (52%) followed by Cotrimoxazole (46%), Norfloxacin (42%) and Ceftriaxone(40%). Most of the strains were sensitive to Meropenem (80%) followed by Amikacin(78%) and Nitrofurantoin (72%). Conclusion: As there is a significant association between the virulence and antimicrobial resistance of UPEC, a routine testing of these factors is recommended and further studies at molecular level are necessary.

In silico screening of some phytochemicals for treating urinary tract infection (UTI) targeting fimH gene

Introduction: UPEC (Uropathogenic Escherichia coli) strains were evaluated to know the prevalence rate of virulence genes, antimicrobial activities of Cd-L1, Ni-L1 and Cu-L1 transition metal complexes, in silico screening of selected phytochemicals and their molecular docking. Methods: 140 urine samples were collected to assess the virulence properties of fimH, gafD and bmaE genes by polymerase chain reaction (PCR). In vitro antibacterial screening activities of ligand, HL and complexes against UPEC bacterial strains was evaluated by inhibition zone method using well diffusion assay. The fimH was docked with the phytochemicals using software FlexX defining the active sites of amino acids and residues with radius showing 10A were included. Results: Presence of urinary tract infection (UTI) infection in 124 (88%) samples of which 61.29% among females and 38.71% among males with overall incidence of UPEC were confirmed in 42 isolates (33.8%). PCR amplification of 16S rRNA gene revealed presence of adhesion genes with its highest prevalence in fimH gene (80.9%) while gafD and bmaE were reported to be negative. In vitro antibacterial activities of Cd-L1, Ni-L1 and Cu-L1 complexes and molecular docking performed by registered docking software FlexX revealed best scores over –20. Highest zone of diameter was observed to be 13 mm by Ni-L1- Complex and all the three complexes were reported as good antimicrobial compounds. Conclusion: Our findings hold efficient prospects in preventing and formulating new UTI strategies as significant epidemiological research tool in Silchar, India.

Nitrofurantoin Combined With Amikacin: A Promising Alternative Strategy for Combating MDR Uropathogenic Escherichia coli.

Urinary tract infections (UTI) are common infections that can be mild to life threatening. However, increased bacterial resistance and poor patient compliance rates have limited the effectiveness of conventional antibiotic therapies. Here, we investigated the relationship between nitrofurantoin and amikacin against 12 clinical MDR uropathogenic Escherichia coli (UPEC) strains both in vitro and in an experimental Galleria mellonella model. In vitro synergistic effects were observed in all 12 test strains by standard checkerboard and time-kill assays. Importantly, amikacin or nitrofurantoin at half of the clinical doses were not effective in the treatment of UPEC infections in the G. mellonella model but the combination therapy significantly increased G. mellonella survival from infections caused by all 12 study UPEC strains. Taken together, these results demonstrated synergy effects between nitrofurantoin and amikacin against MDR UPEC.

Distribution of phylogenetic groups, adhesin genes, biofilm formation, and antimicrobial resistance of uropathogenic Escherichia coli isolated from hospitalized patients in Thailand.

BackgroundUrinary tract infections (UTIs) are the most common bacterial infections and are often caused by uropathogenic Escherichia coli (UPEC). We investigated the distribution of phylogenetic groups, adhesin genes, antimicrobial resistance, and biofilm formation in E. coli isolated from patients with UTIs.MethodsIn the present study, 208 UPEC isolated from Thai patients were classified into phylogenetic groups and adhesin genes were detected using multiplex PCR. Antimicrobial susceptibility testing was performed using agar disk diffusion. The Congo red agar method was used to determine the ability of the UPEC to form biofilm.ResultsThe most prevalent UPEC strains in this study belonged to phylogenetic group B2 (58.7%), followed by group C (12.5%), group E (12.0%), and the other groups (16.8%). Among adhesin genes, the prevalence of fimH (91.8%) was highest, followed by pap (79.3%), sfa (12.0%), and afa (7.7%). The rates of resistance to fluoroquinolones, trimethoprim-sulfamethoxazole, and amoxicillin-clavulanate were 65%, 54.3%, and 36.5%, respectively. The presence of adhesin genes and antibiotic resistance were more frequent in groups B2 and C compared to the other groups. Of the 129 multidrug-resistant UPEC strains, 54% were biofilm producers. Our findings further indicated that biofilm production was significantly correlated with the pap adhesin gene (p ≤ 0.05).ConclusionThese findings provide molecular epidemiologic data, antibiotic resistance profiles, and the potential for biofilm formation among UPEC strains that can inform further development of the appropriate prevention and control strategies for UTIs in this region.

Activation of NLRP3 by uropathogenic Escherichia coli is associated with IL-1\u03b2 release and regulation of antimicrobial properties in human neutrophils

The NLRP3 inflammasome and IL-1β have recently been linked to the severity of uropathogenic Escherichia coli (UPEC)-mediated urinary tract infection (UTI). However, not much is known about the contribution of NLRP3 to the antimicrobial properties of neutrophils and the release of IL-1β during UPEC infection. The purpose of this study was to elucidate the mechanisms behind UPEC-induced IL-1β release from human neutrophils, and to investigate the contribution of the NLRP3 inflammasome in neutrophil-mediated inhibition of UPEC growth. We found that the UPEC strain CFT073 increased the expression of NLRP3 and increased caspase-1 activation and IL-1β release from human neutrophils. The IL-1β release was mediated by the NLRP3 inflammasome and by serine proteases in an NF-κB-and cathepsin B-dependent manner. The UPEC virulence factors α-hemolysin, type-1 fimbriae and p-fimbriae were all shown to contribute to UPEC mediated IL-1β release from neutrophils. Furthermore, inhibition of caspase-1 and NLRP3 activation increased neutrophil ROS-production, phagocytosis and the ability of neutrophils to suppress UPEC growth. In conclusion, this study demonstrates that UPEC can induce NLRP3 and serine protease-dependent release of IL-1β from human neutrophils and that NLRP3 and caspase-1 can regulate the antimicrobial activity of human neutrophils against UPEC.

Antibiotic-Resistant Uropathogenic <i>Escherichia coli</i> Isolated from Children with Congenital Abnormalities of the Kidneys and Urinary Tract

Uropathogenic Escherichia coli (UPEC) is a serious health problem worldwide. UPEC's multiple drug resistance combined with virulence factors is a cause of serious concern. In childhood, urinary tract infections are of particular importance, since they can occur against the background of long-term unrecognized congenital anomalies of the kidneys and urinary tract. Of the 106 UPEC clinical isolates, 63.2% of cultures were isolated from girls' urine samples and 36.8% from boys' urine samples, which corresponds to a 1.7: 1 ratio. The antibiotic resistance of the isolated UPEC cultures was assessed in relation to 12 antimicrobial drugs. Among the tested cultures, 49% were multidrug-resistant and 20.75% were found to be resistant to imipenem. Phenotypic analysis of antibiotic susceptibility spectrum of uropathogenic E.coli (n=106) indicates a high percentage of occurrence of multi-resistant UPEC strains (49%) and imipenem-resistant UPEC strains (20.75%) among children of all age groups.

Phylogenetic Group B2 Expressed Significant Biofilm Formation among Drug Resistant Uropathogenic Escherichia coli

ABSTRACT Biofilm is an important virulent marker attributed to the development of urinary tract infections (UTIs) by uropathogenic E. coli (UPEC). Drug-resistant and biofilm-producing UPEC are highly problematic causing catheter-associated or recurrent UTIs with significant morbidity and mortality. The aim of the current study was to investigate the prevalence of biofilm formation and phylogenetic groups in drug-resistant UPEC to predict their ability to cause disease. This prospective study was conducted at the Department of Microbiology, University of Karachi from January to June 2019. A total of 50 highly drug-resistant UPEC were selected for this study. UPEC isolates were screened to form biofilm by Congo-red agar (CRA) and microtiter plate (MTP) technique. The representative biofilm-producing isolates were analysed by scanning electron microscopy (SEM) monitoring. Phylogenetic analysis was done by PCR method based on two preserved genes; chuA, yjaA and TspE4-C2 DNA fragment. On CRA 34 (68%) UPEC were slime producers, while on MTP 20 (40%) were strong biofilm producers, 19 (38%) moderate and 11 (22%) were low to negligible biofilm producers. Molecular typing confirmed that phylogenetic group B2 was prevalent in drug resistant UPEC strains. Pathogenic strains belonged to phylogenetic group B2 and D were found to have greater biofilm forming ability as compare to non-pathogenic commensal strains that belonged to phylogenetic group A. Our results indicate that biofilm formation vary in drug resistant UPEC belonged to different phylogenetic groups. This study indicates possible link between in vitro biofilm formation and phylogenetic groups of UPEC, therefore this knowledge might be helpful to predict the pathogenic potential of UPEC and help design strategies for controlling UTIs.

Developments in Mannose-Based Treatments for Uropathogenic Escherichia coli-Induced Urinary Tract Infections.

During their lifetime almost half of women will experience a symptomatic urinary tract infection (UTI) with a further half experiencing a relapse within six months. Currently UTIs are treated with antibiotics, but increasing antibiotic resistance rates highlight the need for new treatments. Uropathogenic Escherichia coli (UPEC) is responsible for the majority of symptomatic UTI cases and thus has become a key pathological target. Adhesion of type one pilus subunit FimH at the surface of UPEC strains to mannose‐saturated oligosaccharides located on the urothelium is critical to pathogenesis. Since the identification of FimH as a therapeutic target in the late 1980s, a substantial body of research has been generated focusing on the development of FimH‐targeting mannose‐based anti‐adhesion therapies. In this review we will discuss the design of different classes of these mannose‐based compounds and their utility and potential as UPEC therapeutics.

Uropathogenic Escherichia coli in the high vaginal swab samples of fertile and infertile women: virulence factors, O-serogroups, and phenotyping and genotyping characterization of antibiotic resistance

Transmission of urinary tract infections into the reproductive system is unavoidable. The present research was performed to assess the distribution of virulence genes, O-serogroups and antibiotic resistance properties of uropathogenic Escherichia coli (UPEC) strains isolated from the high vaginal swab samples of fertile and infertile women. A total of 460 high vaginal swab samples were taken from fertile and infertile women. Distribution of virulence factors and serogroups and antibiotic resistance properties of the E. coli isolates were assessed. Sixty-five out of 460 (14.13%) swab samples were positive for E. coli. Prevalences of E. coli in samples taken from fertile and infertile women were 13.63% and 14.58%, respectively. O1 (7.69%), O2 (6.15%) and O6 (6.15%) were the most frequently detected serogroups. The most frequently detected virulence genes were sfa (72.72%), afa (72.72%), cnf1 (72.72%) and fim (72.72%). The most commonly detected antibiotic-resistance genes were tetA (95.45%), CITM (88.63%), aac(3)-IV (86.36%) and sul1 (72.72%). UPEC strains harboured the highest prevalence of resistance against tetracycline (88.63%), ampicillin (79.54%), gentamicin (77.27%) and enrofloxacin (52.27%). Seventeen out of 26 (65.38%) UPEC strains isolated from infertile women were resistant toward more than ten antibiotic agents. Infertile women with a history of urinary tract infections had the higher prevalence of UPEC strains and also the other characters. High prevalence of the virulent and resistant UPEC strains in the high vaginal part of the infertile women with a history of urinary tract infections may show an important role of these pathogens as causes of female infertility. However, further research is required to confirm this hypothesis.

In Vitro and In Vivo Biological Activity of Berberine Chloride against Uropathogenic E. coli Strains Using Galleria mellonella as a Host Model.

Berberine is an alkaloid of the protoberberine type used in traditional oriental medicine. Its biological activities include documented antibacterial properties against a wide variety of microorganisms; nonetheless, its use against Escherichia coli strains isolated from urinary infections has not yet been widely investigated in vivo. The emergence of antimicrobial resistance requires new therapeutic approaches to ensure the continued effectiveness of antibiotics for the treatment and prevention of urinary infections. Moreover, uropathogenic Escherichia coli (UPEC) has developed several virulence factors and resistance to routine antibiotic therapy. To this end, several in vitro and in vivo tests were conducted to assess the activity of berberine on uropathogenic E. coli strains. Galleria mellonella as an infection model was employed to confirm the in vivo translatability of in vitro data on berberine activity and its influence on adhesion and invasion proprieties of E. coli on human bladder cells. In vitro pre-treatment with berberine was able to decrease the adhesive and invasive UPEC ability. In vivo treatment increased the larvae survival infected with UPEC strains and reduced the number of circulating pathogens in larvae hemolymph. These preliminary findings demonstrated the efficacy and reliability of G. mellonella as in vivo model for pre-clinical studies of natural substances.

Characterization of Plasmid-Mediated Quinolone Resistance and Serogroup Distributions of Uropathogenic Escherichia coli among Iranian Kidney Transplant Patients.

Introduction Urinary tract infection (UTI) is one of the most frequent infections in kidney transplant patients (KTPs). This infection is mainly caused by uropathogenic Escherichia coli (UPEC). Plasmid-mediated quinolone resistance (PMQR) was also increasingly identified in UPEC. This study proposed to investigate the frequency of quinolone-resistance plasmid genes and the O-antigen serogroup among UPEC isolated from KTPs and non-KTP with UTI. Methods Totally, 114 UPEC isolates from 49 KTPs and 65 non-KTPs patients diagnosed with an UPEC-associated UTI were obtained from June 2019 to December 2019 at three laboratory centers in Isfahan, Iran. The isolates were confirmed through phenotypic and genotypic methods. Moreover, the antimicrobial susceptibility test to nalidixic acid, ciprofloxacin, norfloxacin, and ofloxacin was performed using a disk diffusion method. The presence of the qnr gene as well as the serogroup distribution was identified using the PCR method. Result According to data, the distribution of O1, O2, O4, O16, and O25 serogroups were 3.5%, 2.6, 3.5, 3.5, and 20.2%, respectively. Antibiotic susceptibility pattern revealed that the highest and lowest resistance rates were to nalidixic acid (69.3%) and norfloxacin (43.9%), respectively. Also, the frequency of qnrS and qnrB genes were 33.3% and 15.8%, respectively, while none of the isolates was found to be positive for the qnrA gene. There was no significant association between the presence of qnr genes and higher antibiotic resistance. Conclusion This study recognized that the qnrS gene, O25 serotype, and resistance to nalidixic acid had the highest frequencies in UPEC strains isolated from UTI patients.

Polysaccharides extract from Vaccaria segetalis seeds inhibits kidney infection by regulating cathelicidin expression

Ethnopharmacological relevanceAccording to the Chinese Pharmacopoeia, the seeds of Vaccaria segetalis, a traditional medicinal herb, can be used for treating urinary diseases. The polysaccharides extract from V. segetalis seeds (VSP) has been shown to prevent urinary tract infections (UTIs). Aim of the studyInvestigate the effects of VSP on treating kidney infection induced by uropathogenic Escherichia coli (UPEC) and the underlying mechanisms. Materials and methodsBoth in vivo and in vitro infection models were established with the UPEC strain CFT073. After oral administration of VSP, the levels of bacterial load, cathelicidin (CRAMP), Toll-like receptors (TLRs) in the kidney were evaluated. The expression of cathelicidin (LL-37) in human renal cell carcinoma cell line (A498) was tested after the treatment of VSP. ResultsIn the kidneys of infection models, high-titer bacteria was detected. In the kidney of rat model, the expression of CRAMP was down-regulated, no significant change was observed in the levels of TLRs. After oral administration of VSP, the bacterial load was significantly decreased in rat and mouse models, and the levels of CRAMP and TLRs were significantly up-regulated in rat model. In vitro, the expression of LL-37 was significantly inhibited by CFT073. VSP up-regulated the expression of LL-37 in A498 cells. ConclusionsThe up-regulation of cathelicidin expression may contribute to the therapeutic effects of VSP on kidney infection.