scholarly journals Bacterial Profile of Urinary Tract Infections: Evaluation of Biofilm Formation and Antibiotic Resistance Pattern of Uropathogenic Escherichia coli

2020 ◽  
Vol 14 (4) ◽  
pp. 2577-2584
Author(s):  
Tariq Ahmad Shah ◽  
P. Preethishree ◽  
Ashwini ◽  
Vidya Pai

Urinary tract infection (UTI) is one of the most common complaints in the outpatient clinic and a major health problem owing to the emergence of antibiotic resistance and biofilm formation. The objective of this study was to isolate and identify the causative bacterial agent of UTI and detect in vitro biofilm formation by Escherichia coli and investigate its correlation with antibiotic resistance. Urine samples from 519 patients with suspected UTIs were collected and processed by conventional microbiological procedures. Antimicrobial susceptibility testing for E. coli isolates was performed on Mueller Hinton agar (MHA) plates using the Kirby-Bauer disk diffusion method. Biofilm production was evaluated using the tissue culture plate method. Of 519 urine samples, 115 (22.1%) showed significant bacteriuria. The most common isolate was E. coli (n=57, 49.6%), followed by Klebsiella spp. (n=23, 20%). All E. coli isolates were evaluated for their ability to form biofilms in vitro. Of 57 isolates, 50 (87.7%) were biofilm producers and 7 (12.3%) were non-biofilm producers. Antibiogram of E. coli isolates revealed the highest resistance to ampicillin (96.5%) and nitrofurantoin (91.2%), followed by amoxyclav (82.5%), ceftazidime (73.7%), cefepime (71.9%), and tetracycline (71.9%). A significant association (p<0.05) was observed between biofilm formation and resistance to amoxyclav, ceftazidime, cefepime, imipenem, and nitrofurantoin. A significant correlation was noted between biofilm production and antibiotic resistance. Hence, screening of all isolates of uropathogenic E. coli for biofilm production and studying their antibiogram would allow appropriate choice of antibiotic therapy.

Author(s):  
Rachana Kanaujia ◽  
Amit Kumar ◽  
Malay Bajpai

Background: Urinary tract infections (UTIs) are one of the most common infections. For treatment of UTIs, there are limited antibiotics due to increased resistance among uropathogens. Two older antibiotics; Nitrofurantoin and Fosfomycin have become novel oral therapeutic options against uropathogens. Aim of the study was to identify UTI causing micro-organisms and evaluate in-vitro activity of nitrofurantoin and fosfomycin against most common isolated organism (E. coli).Methods: Results of urine samples culture and susceptibility testing over a period of 1 year were analysed and included in this study.Results: Micro-organisms were isolated from 568 urine samples. Most commonly isolated organism was Escherichia coli (40.50%), followed by Klebsiella spp. (20.07%) and Staphylococcus spp. (17.07%). Susceptibility of E. coli to nitrofurantoin and fosfomycin was 91.74% and 65.65% respectively. Conclusion: Good activity of nitrofurantoin and fosfomycin against E. coli indicates that these two drugs are potential therapeutic alternatives for urinary tract infections.


Diseases ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 17 ◽  
Author(s):  
Payam Behzadi ◽  
Edit Urbán ◽  
Márió Gajdács

Urinary tract infections (UTIs) are among the most common infections requiring medical attention worldwide. The production of biofilms is an important step in UTIs, not only from a mechanistic point of view, but this may also confer additional resistance, distinct from other aspects of multidrug resistance (MDR). A total of two hundred and fifty (n = 250) Escherichia coli isolates, originating from clean-catch urine samples, were included in this study. The isolates were classified into five groups: wild-type, ciprofloxacin-resistant, fosfomycin-resistant, trimethoprim-sulfamethoxazole-resistant and extended spectrum β-lactamase (ESBL)-producing strains. The bacterial specimens were cultured using eosine methylene blue agar and the colony morphology of isolates were recorded. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method and E-tests. Biofilm-formation of the isolates was carried out with the crystal violet tube-adherence method. n = 76 isolates (30.4%) produced large colonies (>3 mm), mucoid variant colonies were produced in n = 135 cases (54.0%), and n = 119 (47.6%) were positive for biofilm formation. The agreement (i.e., predictive value) of mucoid variant colonies in regard to biofilm production in the tube-adherence assay was 0.881 overall. Significant variation was seen in the case of the group of ESBL-producers in the ratio of biofilm-producing isolates. The relationship between biofilm-production and other resistance determinants has been extensively studied. However, no definite conclusion can be reached from the currently available data.


2019 ◽  
Vol 11 (01) ◽  
pp. 017-022 ◽  
Author(s):  
Rashmi M. Karigoudar ◽  
Mahesh H. Karigoudar ◽  
Sanjay M. Wavare ◽  
Smita S. Mangalgi

Abstract BACKGROUND: Escherichia coli accounts for 70%–95% of urinary tract infections (UTIs). UTI is a serious health problem with respect to antibiotic resistance and biofilms formation being the prime cause for the antibiotic resistance. Biofilm can restrict the diffusion of substances and binding of antimicrobials. In this context, the present study is aimed to perform in vitro detection of biofilm formation among E. coli strains isolated from urine and to correlate their susceptibility pattern with biofilm formation. MATERIALS AND METHODS: A total of 100 E. coli strains isolated from patients suffering from UTI were included in the study. The identification of E. coli was performed by colony morphology, Gram staining, and standard biochemical tests. The detection of biofilm was carried out by Congo Red Agar (CRA) method, tube method (TM), and tissue culture plate (TCP) method. Antimicrobial sensitivity testing was performed by Kirby–Bauer disc diffusion method on Muller–Hinton agar plate. RESULTS: Of the 100 E. coli strains, 49 (49%) and 51 (51%) were from catheterized and noncatheterized patients, respectively. Biofilm production was positive by CRA, TM, and TCP method were 49 (49%), 55 (55%), and 69 (69%), respectively. Biofilm producers showed maximum resistance to co-trimoxazole (73.9%), gentamicin (94.2%), and imipenem (11.6%) when compared to nonbiofilm producers. Significant association was seen between resistance to antibiotic and biofilm formation with a P = 0.01 (<0.05). CONCLUSION: A greater understanding of biofilm detection in E. coli will help in the development of newer and more effective treatment. The detection of biofilm formation and antibiotic susceptibility pattern helps in choosing the correct antibiotic therapy.


2017 ◽  
Vol 66 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Sarah M. Abdelhamid ◽  
Rania R. Abozahra

Escherichia coli is one of the most frequent causes of urinary tract infections. Efflux system overexpression is reported to contribute to E. coli resistance to several antibiotics. Our aim in this study was to investigate the relation between antibiotic resistance and the expression of the efflux pump genes acrA and mdfA in E. coli by real-time reverse transcription-PCR. We tested the in vitro susceptibilities to 12 antibiotics in 28 clinical isolates of E. coli obtained from urine samples. We also determined the minimum inhibitory concentrations of levofloxacin to these samples. We then revealed significant correlations between the overexpression of both mdfA and acrA and MICs of levofloxacin. In conclusion, we demonstrated that the increased expression of efflux pump genes such as mdfA and acrA can lead to levofloxacin resistance in E. coli. These findings contribute to further understanding of the molecular mechanisms of efflux pump systems and how they contribute to antibiotic resistance.


2013 ◽  
Vol 32 (3) ◽  
pp. 233-238 ◽  
Author(s):  
Basudha Shrestha ◽  
Rajesh Lal Gurubacharya ◽  
Basanta Maharjan ◽  
Sanjit Shrestha

Introduction: Antibiotic resistance of urinary tract pathogens has increased globally. Updated knowledge of the antibiotic resistance patterns of uropathogens in the health institutes is important for the selection of an appropriate empirical antimicrobial therapy. The aim of this study was to evaluate the multi drug resistant urinary isolates in the children from 1 to15 years and evaluate the options for empiric antibiotic therapy. Materials and Methods: The study was conducted from December 2011 to May 2012 in the Bacteriology laboratory, Kathmandu Model Hospital. Urine samples received in the laboratory were processed for routine, culture and its sensitivity. The antimicrobial susceptibility of bacterial isolates was determined following Clinical and Laboratory Standard Institute (CLSI) recommended Kirby-Bauer Disc Diffusion method. Results: Of the total 372 urine samples received in the laboratory, 60 (16.13%) showed significant growth; of which 55.0 % (33/60) were MDR isolates. Escherichia coli were the predominant isolate from urine sample. Out of 49 Escherichia coli isolates, 27 (45.0%) were Multi drug resistant. Enterococcus faecalis (N=3) was the most predominant Gram positive isolate and 66.67 % (2/3) of this organism were multi drug resistant. Among the first line drugs used against gram negative isolates, nitrofurantoin was the most effective drug followed by quinolones, while among the second line drugs; meropenem was the most effective drug followed by chloramphenicol and amikacin, whereas; nitrofurantoin (100%) was the most effective drug for Gram positive isolates followed by norfloxacin and cefotaxime. Conclusion: High percentages of multi drug resistant uropathogens were revealed in children. Nitrofurantoin was found to be the most effective drug for gram positive, gram negative and multi drug resistant isolates. DOI: http://dx.doi.org/10.3126/jnps.v32i3.6771 J. Nepal Paediatr. SocVol.32(3) 2012 233-238


2021 ◽  
Vol 10 (7) ◽  
pp. 414-418
Author(s):  
Greeshma Hareendranath

BACKGROUND Escherichia coli is one of the most important causes of urinary tract infections (UTIs). Increased antibiotic resistance may limit the therapeutic options for the treatment of these infections. Fosfomycin trometamol is a phosphonic acid derivative, which acts primarily by interfering with bacterial peptidoglycan synthesis with broad spectrum of activity against agents causing urinary tract infection with good antibiofilm activity and limited reports of resistance and hence is increasingly called upon for the treatment of multi drug resistant (MDR) organisms causing UTI. There are limited studies from India regarding the efficacy of this drug; so, the study was conducted to determine the in vitro efficacy of fosfomycin against uropathogenic MDR E. coli. METHODS This was a prospective study done in the Department of Microbiology, Government T.D. Medical College, Alappuzha, over a period of 1 year from April 2018 to March 2019. A total of 150 MDR urine samples were processed by routine microbiological methods and after identification of E. coli urinary isolates, antibiotic susceptibility testing was performed and results were interpreted following the Clinical and Laboratory Standards Institute guidelines (CLSI). Fosfomycin sensitivity was tested by the Kirby-Bauer disc diffusion method. RESULTS Among the 150 MDR urinary E. coli isolates, 148 (98 %) were sensitive to fosfomycin in our study. The susceptibility rate of fosfomycin was clearly higher than other commonly used drugs for UTI. All extended-spectrum beta-lactamases (ESBL) producing E. coli were sensitive to this drug. The susceptibility for nitrofurantoin was fair, whereas for ampicillin, norfloxacin, cefotaxime and trimethoprim / sulphamethoxazole was found poor. Relatively better rates of resistance were observed for parenteral antibiotics. CONCLUSIONS With an enormous increase in the bacterial pathogens resistant to first-line antibiotics, there has been a revival in the use of fosfomycin. The convenience of a single dose regimen, a good activity proven invitro, and minimal propensity for development of resistance pathogens makes fosfomycin an attractive regimen for the treatment of uncomplicated community and hospital acquired UTIs. In this regard, with the existing limited options for treating MDR organisms, fosfomycin finds its utility acting as an effective and promising option in the treatment of UTIs due to MDR pathogens in the future.


Author(s):  
Somayeh Bakhtiari ◽  
Hassan Mahmoudi ◽  
Sara Khosravi Seftjani ◽  
Mohammad Ali Amirzargar ◽  
Sima Ghiasvand ◽  
...  

Background and Objectives: Escherichia coli is the most common causative agent of urinary tract infections (UTIs) in 90-80% of patients in all age groups. Phylogenetic groups of these bacteria are variable and the most known groups are A, B1, B2 and D. The present study aimed to evaluate the phylogenetic groups of E. coli samples obtained from UTIs and their relation with antibiotic resistance patterns of isolates. Materials and Methods: In this study 113 E. coli isolates were isolated from distinct patients with UTIs referred to Hamadan hospitals. After biochemical and molecular identification of the isolates, typing and phylogenetic grouping of E. coli strains were performed using multiplex PCR targeting chu, yjaA and TSPE4.C2 genes. The anti-microbial susceptibility of the isolates to amikacin, ampicillin, trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, ciprofloxacin, cefotaxime, imipenem, aztreonam, gentamicin, meropenem, nitrofurantoin, nalidixic acid and cefazolin was determined using disk diffusion method. Results: Of 113 isolates, 50 (44.2%), 35 (31%), 23 (20.4%) and 5 (4.4%) of samples belonged to group B2, group D, group A and group B1 phylogenetic groups respectively. All isolates were susceptible to meropenem, imipenem (100%), followed by amikacin (99.1%). The highest resistance rates were observed against ampicillin (74.3%) and nalidixic acid (70.8%). Correlation between phylogenetic groups and antibiotic susceptibilities was significant only with co-amoxiclav (P = 0.006), which had the highest resistance in phylogenetic group A. Conclusion: Prevalence of different phylogroup and resistance associated with them in E. coli samples could be variable in each region. Therefore, investigating of these items in E. coli infections, could be more helpful in selecting the appropriate antibiotic treatment and epidemiological studies.


2014 ◽  
Vol 60 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Amy Huei Teen Teh ◽  
Yi Wang ◽  
Gary A. Dykes

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli are one of the most common forms of human disease. In this study, the effect of the presence of newly acquired antibiotic resistance genes on biofilm formation of UTI-associated E. coli strains was examined. Two clinical UTI-associated E. coli strains (SMC18 and SMC20) carrying different combinations of virulence genes were transformed with pGEM-T, pGEM-T::KmΔAmp, or pGEM-T::Km to construct ampicillin-resistant (KmSAmpR), kanamycin-resistant (KmRAmpS), or ampicillin- and kanamycin-resistant (KmRAmpR) strains. Transformed and wild-type strains were characterized for biofilm formation, bacterial surface hydrophobicity, auto-aggregation, morphology, and attachment to abiotic surfaces. Transformation with a plasmid carrying an ampicillin resistance gene alone decreased (p < 0.05) biofilm formation by SMC18 (8 virulence marker genes) but increased (p < 0.05) biofilm formation by SMC20 (5 virulence marker genes). On the other hand, transformation with a plasmid carrying a kanamycin resistance gene alone or both ampicillin and kanamycin resistance genes resulted in a decrease (p < 0.05) in biofilm formation by SMC18 but did not affect (p > 0.05) the biofilm formation by SMC20. Our results suggest that transformation of UTI-associated E. coli with plasmids carrying different antibiotic resistance gene(s) had a significant impact on biofilm formation and that these effects were both strain dependent and varied between different antibiotics.


2018 ◽  
Vol 14 (30) ◽  
pp. 323
Author(s):  
Wassiyath Mousse ◽  
Haziz Sina ◽  
Mamadou Wele ◽  
Nicodeme Chabi ◽  
Durand Dah Nouvlessounon ◽  
...  

Urinary tract infections are the second common reason of medical consultations and antibiotics prescription. Escherichia coli is known to cause most urinary tract infections. The aim of this study was to characterize and determine the antibiotic resistance profile of E. coli extended-spectrum βlactamases (ESBL) producer strains isolated from urine samples. The urine samples collected came from hospitalized and non-hospitalized patient referred to Hubert Koutoukou Manga (HKM), National and University Hospital Center (Cotonou, Benin). The resistance to antibiotics was determined according to the disk diffusion method. The production of penicillinase and ESBLs was researched respectively by the acidimetric test and double disk synergy method. The presences of genes encoding βlactamases were detected by Polymerase Chain Reaction (PCR). Our data revealed that 60 % of E. coli strains (101) were isolated from female patients. Also, 69.31 % of the strains were isolated from non-hospitalized patients. The high resistance levels were recorded with amoxicillin (96.04 %) and amoxicillin + clavulanic acid (66.34 %). Twenty percent (20%) of strains were ESBLs. Among ESBLs strains, 70% comes from non-hospitalized patients. Eighty percent of E. coli strains produced penicillinase among which 25 % were ESBL producers. All the ESBL producers strains carried blaTEM gene whereas only 30 % carried the blaSHV gene. This study updates the data on the prevalence to antibiotic resistance of E. coli ESBL producers strains for better management of urinary tract infections.


1998 ◽  
Vol 66 (7) ◽  
pp. 3303-3310 ◽  
Author(s):  
Jean K. Lim ◽  
Nereus W. Gunther ◽  
Hui Zhao ◽  
David E. Johnson ◽  
Susan K. Keay ◽  
...  

ABSTRACT Type 1 fimbriae, expressed by most Escherichia colistrains, are thought to attach to human uroepithelium as an initial step in the pathogenesis of urinary tract infections (UTI). Numerous reports using both in vitro and murine models support this role for type 1 fimbriae in colonization. Unfortunately, only a limited number of studies have directly examined the expression of fimbriae in vivo. To determine whether type 1 fimbrial genes are transcribed during an acute UTI, we employed a modification of an established method. The orientation (ON or OFF) of the invertible promoter element, which drives transcription of type 1 fimbrial genes, was determined by PCR amplification using primers that flank the invertible element, followed by SnaBI digestion. The orientation of the type 1 fimbrial switch was determined under three experimental conditions. First,E. coli strains from different clinical sources (acute pyelonephritis patients, cystitis patients, and fecal controls) were tested under different in vitro culture conditions (agar versus broth; aerated versus static). The genes in the more-virulent strains (those causing acute pyelonephritis) demonstrated a resistance, in aerated broth, to switching from OFF to ON, while those in fecal strains readily switched from OFF to ON. Second, bladder and kidney tissue from CBA mice transurethrally inoculated with E. coli CFT073 (an established murine model of ascending UTI) was assayed. The switches directly amplified from infected bladder and kidney tissues were estimated to be 33 and 39% ON, respectively, by using a standard curve. Finally, bacteria present in urine samples collected from women with cystitis were tested for type 1 fimbria switch orientation. For all 11 cases, an average of only 4% of the switches in the bacteria in the urine were ON. In 7 of the 11 cases, we found that all of the visible type 1 fimbrial switches were in the OFF position (upper limit of detection of assay, 98% OFF). Strains recovered from these urine samples, however, were shown after culture in vitro to be capable of switching the fimbrial gene to the ON position and expressing mannose-sensitive hemagglutinin. The results from experimental infections and cases of cystitis in women suggest that type 1 fimbrial genes are transcribed both in the bladder and in the kidney. However, those bacteria found in the urine and not attached to the uroepithelium are not transcriptionally active for type 1 fimbrial genes.


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