In vitro biofilm formation by uropathogenic Escherichia coli and their antimicrobial susceptibility pattern

Sustainable nanophytosome-based therapies against multidrug-resistant Escherichia coli in urinary tract infections: an in Vitro and in vivo study

BACKGROUND

Urinary tract infection (UTI) is a prevalent bacterial infection impacting a significant number of individuals globally. The rise in multidrug-resistant (MDR) E. coli strains as the predominant cause of UTIs presents a substantial public health concern and poses a challenge to existing antibiotic treatments. This study introduces an innovative and sustainable therapeutic approach utilizing rosemary oil nanophytosomes as a targeted drug delivery system to address biofilms in UTIs induced by MDR E. coli.

METHOD

Seventy clinically identified E. coli isolates from UTI patients were used for this study. Nanophytosomes were formulated with chitosan (CS) and nanostructured lipid carriers. CS-nanophytosomes were lyophilized to evaluate the storage stability. In vivo study included 40 female Wistar rats with daily treatment over seven days. For all the statistical tests, differences were considered significant at p < 0.01 and highly significant at p < 0.001.

RESULTS

CS-nanophytosomes demonstrated a particle size of 176.70 ± 12.30 nm with a substantial antibiofilm efficacy against MDR E. coli. High entrapment efficiency was ascertained with 93.12 ± 1.05%. The drug release study showed that the pure rosemary oil exhibited a notably lower release of 35.4 ± 2.36% over 48 h. In contrast, the CS-nanophytosomes and lyophilized CS-nanophytosomes displayed significantly higher release percentages of 58.6 ± 3.69% and 56.9 ± 5.01%, respectively, compared to the pure rosemary oil of 35.4 ± 2.36% over 48 h. The in vivo study indicated that nanophytosomes successfully reduced the bacterial load in the urine, bladder, and kidney tissues of mice infected with MDR E. coli, while also lowering the levels of inflammatory cytokines and oxidative stress markers in serum and urine samples. Additionally, the nanophytosomes improved histopathological changes in bladder and kidney tissues caused by UTI without causing any toxicity or adverse effects on kidney function or hematological parameters.

CONCLUSION

Our research introduces a cost-effective and innovative approach to addressing UTIs caused by MDR E. coli by the use of rosemary oil, a natural antimicrobial agent encapsulated in nanophytosomes. This strategy not only demonstrates proven therapeutic efficacy in UTI animal models but also promotes the adoption of sustainable medical approaches. CS-nanophytosomes provides a sustainable alternative therapeutic option to combat MDR UTIs.

Analysis of phylogroups, biofilm formation, virulence factors, antibiotic resistance and molecular typing of uropathogenic Escherichia coli strains isolated from patients with recurrent and non-recurrent urinary tract infections

BACKGROUND

Uropathogenic Escherichia coli (UPEC) is the predominant cause of urinary tract infections (UTIs), and the recurrence of these infections poses significant treatment challenges.

OBJECTIVE

This study aimed to compare the phylogroups, biofilm formation, virulence factors, and antibiotic resistance of UPEC strains in patients with recurrent versus non-recurrent UTIs in Hamadan City, Western Iran.

MATERIALS AND METHODS

A total of 110 E. coli isolates were collected from urine cultures across three major hospitals and laboratories. The isolates were confirmed through biochemical tests, and their antibiotic resistance profiles were evaluated using the disk diffusion method. Biofilm production was assessed using the microtiter plate method, while virulence genes and phylogroup determination were analyzed via PCR. Real-time PCR was employed to compare the expression levels of the pap and fimH virulence genes.

RESULTS

The results indicated that 73% of isolates were from non-recurrent UTI patients, with a higher incidence in females and children under 10 years. A significant difference was detected in the underlying diseases and the expression of the pap between the recurrent and non-recurrent groups. Antibiotic resistance was notably significant, particularly against Ampicillin-sulbactam, Trimethoprim-Sulfamethoxazole, Nalidixic acid, and Ciprofloxacin, with 77% of strains classified as multi-drug resistant (MDR). Despite differences in the rates of ESBL production between recurrent (53%) and non-recurrent (42.5%) strains, no significant differences were observed in antibiotic resistance, biofilm formation, virulence factors, or phylogroups between the two groups. Phylogenetic analysis revealed a predominance of phylogroups B2 and D, with high genetic diversity among the isolates.

CONCLUSION

The study highlights the traits of UPEC strains in recurrent and non-recurrent UTIs, showing high antibiotic resistance and genetic diversity among isolates. The study found notable differences in underlying diseases and the expression of the pap gene between recurrent and non-recurrent groups, suggesting that these factors may play a crucial role in the recurrence of infections. Further investigation into these differences could enhance our understanding and management of recurrent UTIs.

Differential Expression of fimH, ihf, upaB, and upaH Genes in Biofilms- and Suspension-Grown Bacteria From Samples of Different Uropathogenic Strains of Escherichia coli

Uropathogenic Escherichia coli (UPEC) strains are the main bacteria that cause urinary tract infections (UTIs). UPEC are a significant public health hazard due to their high proliferation, antibiotic resistance, and infection recurrence. The ability to form biofilms is a mechanism of antibiotic resistance, which requires the expression of different genes such as fimH, ihf, upaB, and upaH. Despite the relevance of biofilm formation in bacterial pathogenicity, differences in the expression level of these genes among bacterial growth conditions have been little studied. Here, we have characterized the expression of fimH, ihf, upaB, and upaH genes in biofilms and suspension-grown bacteria of different E. coli strains. These included the UPEC CFT073, the multidrug-resistant strain CDC-AR-0346, and clinical isolates obtained from UTI patients. The expression of fimH, ihf, upaB, and upaH was markedly heterogeneous in clinical isolates, both in terms of transcript levels and response to suspension or biofilm conditions. That expression pattern was distinct from the one in UPEC CFT073, where upaB and upaH were upregulated and ihf and fimH were slightly downregulated in biofilm. In conclusion, the data presented here show that the pattern of biofilm-associated genes in the clinical isolates from UTI patients is not fully related to the reference strain of UPEC CFT073. However, analysis of a larger number of samples is required.

Biofilm-producing antibiotic-resistant bacteria in Indian patients: a comprehensive review

For the past few years, microbial biofilms have been emerging as a significant threat to the modern healthcare system, and their prevalence and antibiotic resistance threat gradually increase daily among the human population. The biofilm has a remarkable impact in the field of infectious diseases, in particular healthcare-associated infections related to indwelling devices such as catheters, implants, artificial heart valves, and prosthetic joints. Bacterial biofilm potentially adheres to any biotic or abiotic surfaces that give specific shelter to the microbial community, making them less susceptible to many antimicrobial agents and even resistant to the immune cells of animal hosts. Around thirty clinical research reports available in PUBMED have been considered to establish the occurrence of biofilm-forming bacteria showing resistance against several regular antibiotics prescribed against infection by clinicians among Indian patients. After the extensive literature review, our observation exhibits a high predominance of biofilm formation among bacteria such as Escherichia sp., Streptococcus sp., Staphylococcus sp., and Pseudomonas sp., those are the most common biofilm-producing antibiotic-resistant bacteria among Indian patients with urinary tract infections and/or catheter-related infections, respiratory tract infections, dental infections, skin infections, and implant-associated infections. This review demonstrates that biofilm-associated bacterial infections constantly elevate in several pathological conditions along with the enhancement of the multi-drug resistance phenomenon.

Biofilm-forming ability, antibiotic resistance and phylogeny of Escherichia coli isolated from extra intestinal infections of humans, dogs, and chickens

Escherichia coli (E. coli) causes various infections in humans and animals. The biofilm-forming ability of E. coli has increased antimicrobial resistance and capacity to cause recurrent and chronic infections. This study determined the biofilm-forming ability of E. coli isolated from extraintestinal infections of humans, chickens, and dogs in relation to the phylogroup, type of infection, and antibiotic resistance. Isolates from chickens showed significantly higher biofilm-forming ability compared to those causing urinary tract infections in humans (p = 0.0001). Further, isolates belonging to phylogroup B1 displayed a higher likelihood to form biofilms. Resistance to ciprofloxacin and trimethoprim-sulfamethoxazole was positively correlated with biofilm-forming ability. Harbouring plasmid-mediated quinolone resistance gene, qnrS was also positively correlated with biofilm formation. This study provides insight into factors such as phylogroup and the type of infections that could enhance biofilm formation, as well as genotypic and phenotypic antibiotic resistance that could correlate with the ability to form biofilms.

Biofilm Formation by Escherichia coli Isolated from Urinary Tract Infections from Aguascalientes, Mexico

Uropathogenic Escherichia coli (UPEC) strains are among the leading causes of urinary tract infections (UTIs) worldwide. They can colonize the urinary tract and form biofilms that allow bacteria to survive and persist, causing relapses of infections and life-threatening sequelae. Here, we analyzed biofilm production, antimicrobial susceptibility, virulence factors, and phylogenetic groups in 74 E. coli isolated from diagnosed patients with UTIs to describe their microbiological features and ascertain their relationship with biofilm capabilities. High levels of ceftazidime resistance are present in hospital-acquired UTIs. Isolates of multidrug resistance strains (p = 0.0017) and the yfcV gene (p = 0.0193) were higher in male patients. All the strains tested were able to form biofilms. Significant differences were found among higher optical densities (ODs) and antibiotic resistance to cefazolin (p = 0.0395), ceftazidime (p = 0.0302), and cefepime (p = 0.0420). Overall, the presence of fimH and papC coincided with strong biofilm formation by UPEC. Type 1 fimbriae (p = 0.0349), curli (p = 0.0477), and cellulose (p = 0.0253) production was significantly higher among strong biofilm formation. Our results indicated that high antibiotic resistance may be related to male infections as well as strong and moderate biofilm production. The ability of E. coli strains to produce biofilm is important for controlling urinary tract infections.

Quinolone resistance and biofilm formation capability of uropathogenic Escherichia coli isolates from an Iranian inpatients' population

BACKGROUND

Uropathogenic Escherichia coli (UPEC) is a major pathogen of the urinary tract infection (UTI), and biofilm formation is crucial as it facilitates the colonization in the urinary tract. We aimed to investigate the antibiotic susceptibility pattern, biofilm formation capability, distribution of quinolone resistance genes, and phylogenetic groups among UPEC isolates from an Iranian inpatients' community.

METHODS AND RESULTS

A collection of 126 UPEC obtained from hospitalized patients with symptomatic UTI at 3 teaching hospitals during 2016 were included. Antibiogram of all isolates against quinolone and fluoroquinolones was performed using the disk diffusion method. Phylogenetic groups and qnr A, B, and S genes were assessed by PCR. Susceptibility pattern showed that more than 50% and 81% of the isolates were resistant to fluoroquinolones and quinolones, correspondingly. The frequency of qnrS and qnrB genes was 22% and 13.5%, correspondingly. Our result indicated no significant association between the presence of fluoroquinolone genes and antibiotic resistance to them. The frequent common phylogroup was B2 (84.1%), followed by D (10.3%), A (3.2%) and B1 (2.4%) groups. Indeed, 80.2% of the isolates were biofilm producers, so that 42.1%, 16.7% and 21.4% of them were classified as weak, moderate and strong producers, respectively.

CONCLUSIONS

Our results showed considerable fluoroquinolone and quinolone resistance among UPEC along with a remarkable rate of biofilm-producing isolates from symptomatic hospitalized patients, making them a serious health concern in the region. This survey highlights the need for awareness on quinolone resistance and careful prescription of them by physicians.

Evaluation of the Ability to Form Biofilms in KPC-Producing and ESBL-Producing Klebsiella pneumoniae Isolated from Clinical Samples

The appearance of Klebsiella pneumoniae strains producing extended-spectrum β-lactamase (ESBL), and carbapenemase (KPC) has turned into a significant public health issue. ESBL- and KPC-producing K. pneumoniae's ability to form biofilms is a significant concern as it can promote the spread of antibiotic resistance and prolong infections in healthcare facilities. A total of 45 K. pneumoniae strains were isolated from human infections. Antibiograms were performed for 17 antibiotics, ESBL production was tested by Etest ESBL PM/PML, a rapid test was used to detect KPC carbapenemases, and resistance genes were detected by PCR. Biofilm production was detected by the microtiter plate method. A total of 73% of multidrug resistance was found, with the highest resistance rates to ampicillin, trimethoprim-sulfamethoxazole, cefotaxime, amoxicillin-clavulanic acid, and aztreonam. Simultaneously, the most effective antibiotics were tetracycline and amikacin. bla_CTX-M, bla_TEM, bla_SHV, aac(3)-II, aadA1, tetA, cmlA, catA, gyrA, gyrB, parC, sul1, sul2, sul3, bla_KPC, bla_OXA, and bla_PER genes were detected. Biofilm production showed that 80% of K. pneumoniae strains were biofilm producers. Most ESBL- and KPC-producing isolates were weak biofilm producers (40.0% and 60.0%, respectively). There was no correlation between the ability to form stronger biofilms and the presence of ESBL and KPC enzymes in K. pneumoniae isolates.

Characterization of unconventional pathogenic Escherichia coli isolated from bloodstream infection: virulence beyond the opportunism

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of urinary tract infection worldwide and a critical bloodstream infection agent. There are more than 50 virulence factors (VFs) related to ExPEC pathogenesis; however, many strains isolated from extraintestinal infections are devoid of these factors. Since opportunistic infections may occur in immunocompromised patients, E. coli strains that lack recognized VFs are considered opportunist, and their virulence potential is neglected. We assessed eleven E. coli strains isolated from bloodstream infections and devoid of the most common ExPEC VFs to understand their pathogenic potential. The strains were evaluated according to their capacity to interact in vitro with human eukaryotic cell lineages (Caco-2, T24, HEK293T, and A549 cells), produce type 1 fimbriae and biofilm in diverse media, resist to human sera, and be lethal to Galleria mellonella. One strain displaying all phenotypic traits was sequenced and evaluated. Ten strains adhered to Caco-2 (colon), eight to T24 (bladder), five to HEK-293 T (kidney), and four to A549 (lung) cells. Eight strains produced type 1 fimbriae, ten adhered to abiotic surfaces, nine were serum resistant, and seven were virulent in the G. mellonella model. Six of the eleven E. coli strains displayed traits compatible with pathogens, five of which were isolated from an immune-competent host. The genome of the EC175 strain, isolated from a patient with urosepsis, reveals that the strain belonged to ST504-A, and serotype O11:H11; harbors thirteen VFs genes, including genes encoding UpaG and yersiniabactin as the only ExPEC VFs identified. Together, our results suggest that the ExPEC pathotype includes pathogens from phylogroups A and B1, which harbor VFs that remain to be uncovered.

Antibiotic Resistance, Biofilm Formation and Sub-Inhibitory Hydrogen Peroxide Stimulation in Uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is the most prevalent cause of urinary tract infections (UTIs). Biofilm formation and antibiotic resistance could be high among the causative agent. The purpose of this study was to determine antibiotic resistance, biofilm production, and biofilm-associated genes, bcsA and csgD, and sub-inhibitory hydrogen peroxide (H2O2) stimulation in UPEC for biofilm formation. A total of 71 UPEC were collected from a tertiary care hospital in Kathmandu and subjected to identify antibiotic susceptibility using Kirby-Bauer disk diffusion. The biofilm formation was assessed using microtiter culture plate method while pellicle formation was tested by a tube method. In representative 15 isolates based on biofilm-forming ability, bcsA and csgD were screened by conventional polymerase chain reaction, and treated with sub-lethal H2O2. The UPEC were found the most susceptible to meropenem (90.2%), and the least to ampicillin (11.3%) in vitro and 90.1% of them were multi-drug resistant (MDR). Most UPEC harbored biofilm-producing ability (97.2%), and could form pellicle at 37°C. Among representative 15 isolates, csgD was detected only among 10 isolates (66.67%) while bcsA gene was present in 13 isolates (86.67%). This study revealed that level of biofilm production elevated after sub-lethal H2O2 treatment (P = .041). These findings suggested that the pathogens are emerging as MDR. The biofilm production is high and the majority of selected strains contained bcsA and csgD genes. Pellicle formation test was suggestive to be an alternative qualitative method to screen biofilm production in UPEC. The sub-inhibitory concentration of H2O2 may contribute in increasing biofilm formation in UPEC.

Candida albicans Promotes the Antimicrobial Tolerance of Escherichia coli in a Cross-Kingdom Dual-Species Biofilm

Cross-kingdom multi-species biofilms consisting of fungi and bacteria are often resistant to antimicrobial treatment, leading to persistent infections. We evaluated whether the presence of Candida albicans affects the antibacterial tolerance of Escherichia coli in dual-species biofilms and explored the underlying mechanism. We found that the survival of E. coli in the presence of antibacterial drugs was higher in dual-species biofilms compared to single-species biofilms. This tolerance-inducing effect was observed in E. coli biofilms that were treated with a C. albicans culture supernatant. To explore the antibacterial tolerance-inducing factor contained in the culture supernatant and identify the tolerance mechanism, a heated supernatant, a supernatant treated with lyticase, DNase, and proteinase K, or a supernatant added to a drug efflux pump inhibitor were used. However, the tolerance-inducing activity was not lost, indicating the existence of some other mechanisms. Ultrafiltration revealed that the material responsible for tolerance-inducing activity was <10 kDa in size. This factor has not yet been identified and needs further studies to understand the mechanisms of action of this small molecule precisely. Nevertheless, we provide experimental evidence that Candida culture supernatant induces E. coli antibacterial tolerance in biofilms. These findings will guide the development of new treatments for dual-species biofilm infections.

Genetic Diversity and Virulence Profiling of Multi-Drug Resistant Escherichia coli of Human, Animal, and Environmental Origins

Rapid urbanization has increased human-animal interaction and consequently enhanced the chances to acquire zoonotic diseases. The current investigation is focused to uncover the genetic diversity of multidrug-resistant E. coli strains between different ecologies (i.e., humans, livestock, and environment) at the molecular level by employing antimicrobial resistance profiling, virulence genes profiling, and microbial typing approach using ERIC PCR. Based on multiple antibiotic resistance, overall, 19 antibiotic resistance patterns (R1–R19) were observed. Most of the strains (49/60) were detected to have the combinations of stx, eaeA, and hlyA genes and considered STEC/EPEC/EHEC. A total of 18 unique genetic profiles were identified based on ERIC-PCR fingerprints and most of the strains (13) belong to P1 whereas the least number of strains were showing profiles P7 and P8-P11 (one member each profile). The calculated values for Shannon index (H) for human, animal, and environment are 1.70, 1.82, and 1.78, respectively revealing the highest genetic diversity among the E. coli strains of animal origin. The study revealed that drug-resistant pathogenic E. coli strains could be transmitted bidirectionally among the environment, humans, and animals.

Targeting Microbial Bio-film: an Update on MDR Gram-Negative Bio-film Producers Causing Catheter-Associated Urinary Tract Infections

In every age group, urinary tract infection (UTI) is found as a major recurrence infectious disorder. Bio-films produced by bacteria perform a vital role in causing infection in the tract of the urinary system, leading to recurrences and relapses. The purpose of this review is to present the role and mechanism of bio-film producing MDR Gram-negative bacteria causing UTI, their significance, additionally the challenges for remedy and prevention of catheter-associated UTI. This work appreciates a new understanding of bio-film producers which are having multi-drug resistance capability and focuses on the effect and control of bio-film producing uropathogenic bacteria related to catheterization. We have tried to analyze approaches to target bio-film and reported phytochemicals with anti-bio-film activity also updated on anti-bio-film therapy.

Molecular Epidemiology and Presence of Hybrid Pathogenic Escherichia coli among Isolates from Community-Acquired Urinary Tract Infection

Urinary tract infections (UTI) affect community and healthcare patients worldwide and may have different clinical outcomes. We assessed the phylogenetic origin, the presence of 43 virulence factors (VFs) of diarrheagenic and extraintestinal pathogenic Escherichia coli, and the occurrence of hybrid strains among E. coli isolates from 172 outpatients with different types of UTI. Isolates from phylogroup B2 (46%) prevailed, followed by phylogroups A (15.7%) and B1 (12.2%), with similar phylogenetic distribution in symptomatic and asymptomatic patients. The most frequent VFs according to their functional category were fimA (94.8%), ompA (83.1%), ompT (63.3%), chuA (57.6%), and vat (22%). Using published molecular criteria, 34.3% and 18.0% of the isolates showed intrinsic virulence and uropathogenic potential, respectively. Two strains carried the eae and escV genes and one the aggR gene, which classified them as hybrid strains. These hybrid strains interacted with renal and bladder cells, reinforcing their uropathogenic potential. The frequency of UPEC strains bearing a more pathogenic potential in the outpatients studied was smaller than reported in other regions. Our data contribute to deepening current knowledge about the mechanisms involved in UTI pathogenesis, especially among hybrid UPEC strains, as these could colonize the host’s intestine, leading to intestinal infections followed by UTI.

Characterization of virulence determinants and phylogenetic background of multiple and extensively drug resistant Escherichia coli isolated from different clinical sources in Egypt

Abstract

Escherichia coli is a multifaceted microbe since some are commensals, normally inhabiting the gut of both humans and animals while others are pathogenic responsible for a wide range of intestinal and extra-intestinal infections. It is one of the leading causes of septicemia, neonatal meningitis, urinary tract infections (UTIs), cystitis, pyelonephritis, and traveler’s diarrhea. The present study aims to survey the distribution and unravel the association of phylotypes, virulence determinants, and antimicrobial resistance of E. coli isolated from different clinical sources in Mansoura hospitals, Egypt. One hundred and fifty E. coli isolates were collected from different clinical sources. Antimicrobial resistance profile, virulence determinants, and virulence encoding genes were detected. Moreover, phylogenetic and molecular typing using ERIC-PCR analysis was performed. Our results have revealed that phylogroup B2 (26.67%) with the greatest content in virulence traits was the most prevalent phylogenetic group. Different virulence profiles and varying incidence of virulence determinants were detected among tested isolates. High rates of resistance to different categories of antimicrobial agents, dramatic increase of MDR (92.67%), and emergence of XDR (4%) were detected. ERIC-PCR analysis revealed great diversity among tested isolates. There was no clustering of isolates according to resistance, virulence patterns, or phylotypes. Our research has demonstrated significant phylogenetic diversity of E. coli isolated from different clinical sources in Mansoura hospitals, Dakahlia governorate, Egypt. E. coli isolates are equipped with various virulence factors which contribute to their pathogenesis in human. The elevated rates of antimicrobial resistance and emergence of MDR and XDR mirror the trend detected globally in recent years.

Key points

• Clinical E. coli isolates exhibited substantial molecular and phylogenetic diversity.

• Elevated rates of antimicrobial resistance and emergence of XDR in pathogenic E. coli.

• B2 Phylogroup with the highest VS was the most prevalent among pathogenic E. coli.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-021-11740-x.

A global systematic review and meta-analysis on correlation between Biofilm producers and Non-biofilm producers with antibiotic resistance in Uropathogenic Escherichiacoli

Escherichia coli accounts for nearly 80% of community-acquired and 50% of hospital-acquired urinary tract infections (UTI). This study aimed to evaluate the correlation between biofilm producers and Non-biofilm producers with antibiotic resistance in Uropathogenic Escherichia coli (UPEC) isolated from patients with UTI globally. The search was conducted between 1st 2000 to 30^th October 2021 in various databases (PubMed, Scopus, Web of sciences, and Google Scholar) with suitable MeSH terms, and text words. Then, after applying the appropriate inclusion and exclusion criteria on the studies for their selection, the data were analyzed by CMA software. Thirty-seven studies met the eligibility criteria to include. The pooled prevalence of ESBL and MDR isolates were reported 37.9%, and 65.8%, respectively. Biofilm formation varied between 13.3% and 99% all over the world. A total of 74.4% of all isolates were biofilm producers, out of which 28.6%, 35.2%, and 38.6% showed strong, moderate, and weak biofilm. The highest and lowest resistance was against Amoxicillin and Meropenem with the prevalence of 80.8%, and 13%, respectively. Fourteen out of 17(82.35%) studies reported a positive correlation between biofilm and antibiotic resistance. Findings showed high numbers of isolates were able to form biofilm, which is one of the factors of antibiotic resistance, and this has been confirmed by the positive significant correlation between biofilm formation and antibiotic resistance that has been reported by studies included. Therefore, due to the importance of biofilm in the etiology of UTI caused by UPEC, it should be prevented; consequently, bacterial resistance can be reduced and controlled.

Elucidating the resistance repertoire, biofilm production, and phylogenetic characteristics of multidrug-resistant Escherichia coli isolated from community ponds: A study from West Bengal, India

This study details about the phenotypic and molecular characteristics of multidrug-resistant (MDR) Escherichia coli in the fresh community pond water (n = 257) collected from three districts of West Bengal, India. In total, 57 isolates were MDR of which 38 emerged as extended spectrum and 7 as AmpC-type β-lactamase producers in phenotypic assay. Among β-lactamase genes, blaCTXM-1was predominant (87.71%) followed by blaAmpC (77.2%) and blaTEM-1 (22.8%). Six MDR strains carried metallo-β-lactamase (MBL, blaNDM-1) gene. Tissue culture plate assay confirmed strong biofilm (SP) production in four MDR and one non-MDR isolates. In PCR-based replicon typing (PBRT), multiple plasmids of diverse replicon types (Frep, FIB, I1, FIA, K/B, HI1, and Y) were identified. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)-based phylogenetic analysis revealed a high degree of genetic divergence among the MDR isolates. Multiplex PCR-based phylogrouping categorized 11 isolates as virulent (B2/D/F), which carried blaCTXM-1 gene and three had blaNDM-1 gene. Relative transcriptional activity of AcrAB efflux pump was significantly elevated among the SP and MBL producers. The presence of MDR E. coli isolates, particularly those resistant to carbapenem, in pond water used for daily domestic and household work, is a cause of concern as these pathogens may sneak into human food chain causing life-threatening infections. PRACTITIONER POINTS: Multidrug-resistant biofilm producing E. coli isolated from community pond water. A few of them were carbapenem-resistant and belonged to virulent (B2/D) types. Expression of AcrAB efflux pumps was found significantly elevated among biofilm producers and carbapenem-resistant population.

Evaluation of Biofilm Formation and Virulence Genes and Association with Antibiotic Resistance Patterns of Uropathogenic Escherichia coli Strains in Southwestern Iran

Background: Uropathogenic Escherichia coli (UPEC) strains, encoding superficial and secretory virulence factors, can lead to colonization and facilitation of bacterial growth in the host urinary tract, causing Urinary Tract Infection (UTI). Objectives: This study determined the ability of biofilm formation by the Congo red agar method, the presence of virulence genes using the multiplex polymerase chain reaction (PCR) method, and the relationship between biofilm formation and antibiotic resistance patterns and virulence genes in E. coli clinical isolates in Yasuj. Methods: This cross-sectional study was performed on 144 UPEC isolates collected in 2017. Biofilm formation was detected by the Congo red agar phenotypic assay and virulence factors by the multiplex PCR method. Antibiotic resistance tests were performed by the Kirby-Bauer method. Results: Out of 144 isolates of E. coli, 22 (19.4%) isolates showed to be strong biofilm producers, 27 (23.8%) moderate biofilm producers, and 64 (56.3%) weak biofilm producers. A significant relationship was observed between biofilm-producing strains and resistance to ampicillin (P = 0.020) and cotrimoxazole (P = 0.038). The virulence genes in strong biofilm producers included iutA (95%), FimH (93%), ompT (90%), PAI (90%), and TraT (81%) genes. The phylogroup B2 carried the most virulence genes. A significant correlation was observed between E. coli phylogenetic groups and aer (P = 0.019), iroN (P = 0.042), and ompT (P = 0.032) virulence genes. Conclusions: The results of this study showed a high prevalence of virulence genes, and antibiotic-resistant E. coli strains capable of biofilm formation. The results of this study may help elucidate the pathogenesis of UPEC and facilitate better treatment strategies for patients with UTIs in this geographic area.

Genetic and Virulence Characteristics of a Hybrid Atypical Enteropathogenic and Uropathogenic Escherichia coli (aEPEC/UPEC) Strain

Hybrid strains of Escherichia coli combine virulence traits of diarrheagenic (DEC) and extraintestinal pathogenic E. coli (ExPEC), but it is poorly understood whether these combined features improve the virulence potential of such strains. We have previously identified a uropathogenic E. coli (UPEC) strain (UPEC 252) harboring the eae gene that encodes the adhesin intimin and is located in the locus of enterocyte effacement (LEE) pathogenicity island. The LEE-encoded proteins allow enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) to form attaching and effacing (A/E) lesions in enterocytes. We sought to characterize UPEC 252 through whole-genome sequencing and phenotypic virulence assays. Genome analysis unveiled that this strain harbors a complete LEE region, with more than 97% of identity comparing to E2348/69 (EPEC) and O157:H7 Sakai (EHEC) prototype strains, which was functional, since UPEC 252 expressed the LEE-encoded proteins EspB and intimin and induced actin accumulation foci in HeLa cells. Phylogenetic analysis performed comparing 1,000 single-copy shared genes clustered UPEC 252 with atypical EPEC strains that belong to the sequence type 10, phylogroup A. Additionally, UPEC 252 was resistant to the bactericidal power of human serum and colonized cells of the urinary (T24 and HEK293-T) and intestinal (Caco-2 and LS174T) tracts. Our findings suggest that UPEC 252 is an atypical EPEC strain that emerges as a hybrid strain (aEPEC/UPEC), which could colonize new niches and potentially cause intestinal and extraintestinal infections.

In-vitro Investigation of Antibiotics Efficacy Against Uropathogenic Escherichia coli Biofilms and Antibiotic Induced Biofilm Formation at Sub-Minimum Inhibitory Concentration of Ciprofloxacin

BACKGROUND

Community-acquired urinary tract infections are associated with significant morbidity, and uropathogenic Escherichia coli (UPEC) alone causes 90% of urinary tract infections. This bacterium retains a diverse armament of virulence factors including fimbria, hemolysins, and siderophores production. In a post invasion scenario, formation of intracellular communities mimic biofilm-like characteristics and are linked to recurrent urinary tract infections. We investigated the effects of different frontline antibiotics on the formation, inhibition, and eradication of biofilms of virulent UPEC strains.

MATERIALS AND METHODS

A total of 155 UPEC strains were scrutinized for various virulence factors including gelatinase, cell surface hydrophobicity, hemagglutination, and serum bactericidal activity. Biofilm formation was confirmed by three different methods: Congo red agar, test tube, and tissue culture plate method. Biofilm inhibition and eradication assays were performed according to the standard protocols. Topographical analysis of biofilms was done by scanning electronic microscopy (SEM).

RESULTS

Out of 155 strains, 113 (73%) were strong biofilm formesr, while 37 (24%) produced biofilms at moderate level. Significant differences were observed between MICs of planktonic cells (MIC-p) and MICs of UPEC biofilms (MIC-b). Among tested frontline antibiotics, levofloxacin successfully inhibited biofilms at a concentration of 32 µg/mL, while trimethoprim eradicated biofilms at higher concentrations (512-1024 µg/mL). Ciprofloxacin treatment at sub-MIC level significantly enhanced biofilm formation (P<0.05).

CONCLUSION

The majority of UPEC strains are strong biofilm formers and show higher tolerance towards frontline antibiotics in biofilm form. We observed significant inhibitory effects of levofloxacin (32 µg/mL) on UPEC biofilms, while treatment with sub-minimal concentrations of ciprofloxacin significantly enhanced biofilm formation. Out of all tested antibiotics, trimethoprim (512-1024 µg/mL) eradicated UPEC biofilms.

Reciprocal Cooperation of Type A Procyanidin and Nitrofurantoin Against Multi-Drug Resistant (MDR) UPEC: A pH-Dependent Study

Uropathogenic Escherichia coli (UPEC) accounts for the majority of complicated and uncomplicated urinary tract infections. The use of phytomolecules in the treatment of UTI is fast gaining attention. The current report identifies a multidrug-resistant strain (QSLUPEC7), which is a strong biofilm producer, among the considered clinical isolates. The antimicrobial and antibiofilm activity was evaluated for the phytomolecule, Type A procyanidin (TAP) from Cinnamomum zeylanicum against QSLUPEC7. TAP treatment did not affect the growth of the MDR strain but affected the biofilm formation (~70% inhibition). The confocal microscopic examination reveals the biofilm inhibition and the live cells in the biofilm corroborates the antimicrobial results. Further, the synergy studies of TAP and nitrofurantoin (NIT) were carried out at different pH. TAP acts synergistically with nitrofurantoin at different pH considered. A closer look in the results reveals that at pH 5.8, maximum growth inhibition is recorded. The gene expression analysis shows that TAP alone and in combination with NIT downregulates the major fimbriae adhesins of UPEC. The results conclude that the TAP has an antibiofilm activity against the multidrug-resistant strain of UPEC, without affecting the growth. Also, TAP reciprocally cooperates with nitrofurantoin at different pH by downregulating the adhesins of UPEC.

The Frequency of PAI, aer and traT Genes in Escherichia coli Commensal and Urinary Pathogenic E. coli Isolates in Shahrekord and the Relationship Between the Two Groups by Multiplex PCR

Background: Nosocomial infections are acquired during hospital treatment or in a hospital environment. One such infecting agent is uropathogenic Escherichia coli and many virulence genes enable it to become pathogenic, thereby causing damage to the host. Objectives: This study aimed to identify aer, traT, and PAI genes in E. coli isolates collected from fecal and urinary tract infection (UTI) specimens and determine the relationship between them in both populations studied in a center in Iran by multiplex polymerase chain reaction (PCR) assay. Methods: Seventy-five isolates of E. coli from the urine of inpatients and 75 isolates from commensal fecal without UTI and diarrhea were collected. The E. coli bacteria were detected and isolated, using biochemical techniques and supplementary tests in the Microbiology Laboratory of Shahrekord University of Medical Sciences. Antibiotic susceptibility pattern for 14 antibiotics was done utilizing the disc diffusion method. The existence of aer, traT, and PAI virulence genes among all isolates was investigated by multiplex PCR. Results: Among the urinary pathogenic E. coli isolates, the highest antibiotic resistance was observed in cefazolin, ampicillin, and cotrimoxazole antibiotics. The prevalence rates of aer, traT, and PAI genes in the fecal isolates were 92%, 90.6%, and 46.6%, respectively. Further, their prevalence rates in urine isolates were 96%, 97.3%, and 41.3%, in that order. Conclusions: The presence of the high frequency of pathogenic islands (PAIs), especially in fecal samples, is important because these genes are easily transmitted and convert a commensal bacterium into a pathogen. Because only the genome of pathogenic bacteria has been unwrapped, little attention has been paid to PAIs in commensal bacteria.

Biofilm formation, antimicrobial susceptibility and virulence genes of Uropathogenic Escherichia coli isolated from clinical isolates in Uganda

INTRODUCTION

Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the biofilm forming capability, presence of virulence genes and antimicrobial susceptibility pattern of Uropathogenic E. coli isolates in Uganda.

METHODS

This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (> 105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers.

RESULTS

In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant (MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%).

CONCLUSIONS

We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.

A systematic review and meta-analysis of antibiotic resistance patterns, and the correlation between biofilm formation with virulence factors in uropathogenic E. coli isolated from urinary tract infections

Urinary tract infection (UTI) is caused by the invasion of the pathogen in the urinary system that can manifest as symptomatic or asymptomatic bacteriuria. This study was conducted to investigate antibiotic resistance patterns, and the correlation between biofilm formations with virulence factors in uropathogenic E. coli isolates retrieved from UTI. We searched Scopus and Google Scholar, PubMed, Web of sciences for studies published in the English language between 1st 2005 to 31st December 2019. The Mesh terms and text words included "biofilms", OR "biofilm formation", AND "antibiotic resistance", OR "drug-resistance", OR "antimicrobial drug resistance", AND "urinary tract infections", OR "UTI", AND "biofilm related-genes", AND "virulence factors" AND "correlation", AND "Uropathogenic Escherichia coli", OR "Uropathogenic E. coli" AND "prevalence" AND "Iran". Data analyzed using Comprehensive Meta-Analysis (CMA) software. The random-effects model was used to calculate the pooled prevalence with 95% confidence interval (CI). The combined rates of biofilm formation in Uropathogenic E. coli (UPEC) isolates were achieved as 84.6% (95% CI: 72.7-91.9). Also, 24.8%, 26.1% and 44.6% of UPEC isolates were able to create strong, moderate and weak biofilm, respectively. The highest pooled antibiotic resistance was against Ampicillin followed by Tetracycline with resistance rates of 74.6% and 64.9%, respectively. Accordingly, some studies reported that biofilm production was significantly associated with antibiotic resistance and virulence genes (p < 0.05). This study showed a high tendency among UPEC isolates to form biofilm (more than 84%), also, most studies included in the present review reported a significant correlation between biofilm formation with antibiotic resistance and virulence factors.

Detection of biofilm among uropathogenic Escherichia coli and its correlation with antibiotic resistance pattern

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.

Correlation between biofilm formation and antimicrobial susceptibility pattern toward extended spectrum β-lactamase (ESBL)- and non-ESBL-producing uropathogenic bacteria

BACKGROUND

Urinary tract infections (UTIs) are the most common bacterial infection encountered worldwide and are associated with significant morbidity and mortality.

METHODS

The present study was undertaken to investigate the biofilm-forming ability, antibiotic susceptibility patterns and extended spectrum β-lactamase (ESBL) production of seven uropathogenic isolates comprising both Escherichia coli and Klebsiella pneumoniae. The morphological, cultural and biochemical tests for the identification of the isolates, antibiotic susceptibility test, detection of ESBL production, biofilm formation on 96-well microtiter plate and Congo red agar (CRA) media are performed.

RESULTS

The antimicrobial susceptibility profiles obtained in this study showed that the most active drugs gentamicin, amikacin and imipenem (100% sensitivity) were followed by amoxicillin-clavulanic acid (85% sensitivity), co-trimoxazole, ciprofloxacin (57% sensitivity) ceftazidime and kanamycin (50% sensitivity). All the isolates showed resistance to amoxicillin followed by ceftriaxone and cefotaxime (71% resistance), and the scenario gets more complicated because of the production of ESBL by five isolates (three E. coli isolates and two K. pneumoniae). The strains were also able to form biofilm as tested on CRA medium and by microtiter plate assay. The correlation between ESBL, non-ESBL and biofilm-producing E. coli and K. pneumonia was determined along with the multiple drug resistance patterns of E. coli and K. pneumonia.

CONCLUSIONS

The findings of the study indicate that the emergence and rapid spread of such multidrug-resistant pathogens are of great concern. Early detection of ESBL-producing pathogen is of paramount clinical importance; therefore, strict infection control practices as well as therapeutic guidance for confirmed infection can be rapidly initiated.

Extended spectrum β-lactamase producing uropathogenic Escherichia coli and the correlation of biofilm with antibiotics resistance in Nepal

BACKGROUND

Urinary tract infection (UTI) is one of the frequently diagnosed infectious diseases which is caused mainly by Escherichia coli. E. coli confers resistance against the two major classes of antibiotics due to the production of extended spectrum β-lactamase enzymes (ESBL), biofilm, etc. Biofilm produced by uropathogenic E. coli (UPEC) protects from host immune system and prevent entry of antimicrobial compounds. The main objective of this cross-sectional study was to determine the correlation of biofilm production and antibiotic resistance as well as to characterize the pgaA and pgaC genes responsible for biofilm formation among uropathogenic ESBL producing E. coli.

METHODS

A total of 1977 mid-stream urine samples were examined and cultured for bacterial strain identification. ESBL was detected by combined disc method following CLSI whereas biofilm formation was analyzed by semi-quantitative method. Furthermore, the pgaA and pgaC genes responsible for biofilm formation in UPEC were detected by multiplex PCR. All the statistical analyses were done via IBM SPSS Statistics 21 where Pearson's correlation test were used to determine correlation (-1 ≥ r ≤ 1).

RESULTS

E. coli was the predominant causative agent, which accounted 159 (59.3%) of the Gram-negative bacteria, where 81 (50.9%) E. coli strains were found to be ESBL producers. In addition, 86 (54.1%) E. coli strains were found to be biofilm producers. Both the pgaA and pgaC genes were detected in 45 (93.7%) the UPEC isolates, which were both biofilm and ESBL producers. Moreover, there was a positive correlation between biofilm and ESBL production.

CONCLUSION

The analyses presented weak positive correlation between biofilm and ESBL production in which biofilm producing UPEC harbors both pgaA and pgaC genes responsible for biofilm formation.

Identification phenotypic and genotypic characterization of biofilm formation in Escherichia coli isolated from urinary tract infections and their antibiotics resistance

Objective

Urinary tract infections (UTIs) are the most common infectious diseases, and Escherichia coli is the most common pathogen isolated from patients with UTIs. The products of sfa, afa and foc genes are important for binding of the bacterium to urinary tract epithelium. Our aim was to investigate these genes in E. colis isolated from patients with UTIS. The frequencies of the genes were determined using PCR. Biofilm formation and antibiotic resistance rates were determined using microtiter plate and disk diffusion methods, respectively. The P < 0.05 was considered statistically significant.

Results

The frequencies of sfa, afa and foc were 75.3%, 17.5% and 22.5%, respectively showing a significantly higher prevalence of the sfa gene. The most effective antibiotics against the E. colis were nitrofurantoin and amikacin. The highest microbial resistance rates were also observed against amoxicillin and ampicillin. Furthermore, 12.7%, 6.3%, 74.7% and 6.3% of the isolates showed strong, moderate, weak capacities and no connections to form biofilms, respectively. The expression of the sfa gene was significantly associated with forming strong biofilms. Regarding the variabilities in the characteristics of E. coli strains associated with UTIs, it seems reasonable to adjust diagnostic and therapeutic methods according to the regional microbial characteristics.

Association Between Kinetics of Early Biofilm Formation and Clonal Lineage in Escherichia coli

Background

Escherichia coli biofilm formation has mostly been assessed in specific pathogenic E. coli groups. Here, we assessed the early biofilm formation (EBF), i.e., adhesion stage, using the BioFilm Ring Test^® on 394 E. coli clinical isolates (EC) [196 consecutively isolated (CEC) in 2016 and 198 ESBL-producing E. coli (ESBLEC) isolated in 2015]. Then, biofilm-forming ability was contrasted with phylogroups, clonotypes (fumC-fimH), and sequence types (STs), all being used to define clones, virulence factors (VF), and FimB.

Result

According to both biofilm production levels at 2, 3, and 5 h, and EBF kinetics over 5 h, CEC and ESBLEC isolates segregated into three EBF groups: strong (G1), moderate (G2), and weak (G3) producers. At 2 h, strong producers were more frequent among CEC (n = 28; 14.3%) than among ESBLEC (n = 8; 4%) (P = 0.0004). As CEC and ESBLEC isolates showed similar individual EBF kinetics in each group, a comparison of isolate features between each group was applied to gathered CEC and ESBLEC isolates after 2 h of incubation, 2 h being the most representative time point of the CEC and ESBLEC isolate segregation into the three groups. Phylogroup B2 displayed by 51.3% of the 394 isolates was more frequent in G1 (77.8%) than in G3 (47.6%) (P = 0.0006). The 394 isolates displayed 153 clones, of which 31 included at least three isolates. B2-CH14-2-ST127, B2-CH40-22-ST131, B2-CH52-5/14-ST141, and E-CH100-96-ST362 clones were associated with G1 (P < 0.03) and accounted for 41.7% of G1 isolates. B2-CH40-30-ST131 clone was associated with G3 (P < 0.0001) and accounted for 25.5% of G3 isolates. VF mean was higher among G1 than among G3 isolates (P < 0.001). FimB-P2 variant was associated with G1 (P = 0.0011) and FimB-P1 variant was associated with G3 (P = 0.0023). Clone, some VF, and FimB were associated with EBF, with clonal lineage being able to explain 72% of the variability of EBF.

Conclusion

Among our 394 isolates, <10% are able to quickly and persistently produce high biofilm levels over 5 h. These isolates belong to a few clones previously described in various studies as dominant gut colonizers in mammalians and birds and comprised the B2-CH40-22-ST131 clone, i.e., the ancestor of the globally disseminated B2-CH40-30-ST131 clone that is the dominant clone among the weak biofilm producers.

Magnitude of Biofilm Formation and Antimicrobial Resistance Pattern of Bacteria Isolated from Urinary Catheterized Inpatients of Jimma University Medical Center, Southwest Ethiopia

Biofilm formation is one of the features of most bacteria. Catheterization in medicine is a source of highly resistant bacterial infections, and those bacteria respond poorly to antimicrobial therapy. Bacterial biofilm features were not described from catheterized inpatients in Ethiopia as its formation is known to afford antimicrobial resistance and challenge patient management. The aim of this study was to isolate catheter-associated urinary bacterial pathogens, their biofilm formation, and antimicrobial susceptibility pattern among inpatients of Jimma University Medical Center (JUMC) in Southwest Ethiopia. A prospective cross-sectional study was conducted among urinary catheterized inpatients of JUMC from February to August 2016. A total of 143 study participants were enrolled consecutively in this study. Urine samples were collected from catheterized patients and processed using a standard bacteriological protocol for isolation and identification. Evaluation of in vitro biofilm formation and antimicrobial susceptibility pattern of uropathogenic bacteria was done using microtiter plates and disk diffusion method, respectively. Data were cleaned, coded, and entered into SPSS version 20 for analysis. All statistical test values of p < 0.05 were considered statistically significant. From all study participants, mean age was 44 years. Sixty bacterial strains were recovered from 57 urinary catheterized inpatients among which 54 of them were monomicrobial (94.7%). The remaining six bacterial strains were recovered from three study participants each with two bacterial isolates. The predominant bacterial isolates were Gram-negative bacteria with E. coli turning out first. About 80% of bacterial isolates were biofilm formers. The majority of the bacteria were resistant to commonly prescribed antimicrobial agents. In conclusion, the majority of bacterial uropathogen isolates were Gram-negative, biofilm formers, and resistant to commonly prescribed antimicrobial agents. Relatively ciprofloxacin, nitrofurantoin, and amikacin were highly effective against most isolated bacteria.

Catheter-Associated Urinary Tract Infection and Obstinate Biofilm Producers

Background

Biofilms, or colonies of uropathogen growing on the surface of indwelling medical devices, can inflict obstinate or recurring infection, thought-provoking antimicrobial therapy.

Methods

This prospective analysis included 105 urine samples from catheterized patients receiving intensive care. Ensuing phenotypic identification, antibiotic sensitivity test was performed by modified Kirby-Bauer disc diffusion method following CLSI guidelines; MDR isolates were identified according to the combined guidelines of the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC). Biofilm-forming uropathogens were detected by the tissue culture plate (TCA) method.

Results

The predominant uropathogen in catheter-associated UTIs (CAUTIs) was Escherichia coli 57%, followed by Klebsiella pneumonia 15%, Pseudomonas aeruginosa 12%, Staphylococcus aureus 8%, Enterobacter spp. 3%, Enterococcus faecalis, Acinetobacter spp., and Proteus mirabilis 1.5%, of which 46% isolates were biofilm producers. Prime biofilm producers were Escherichia coli 33%, followed by Klebsiella pneumoniae 30%, Pseudomonas aeruginosa 20%, Staphylococcus aureus 10%, Acinetobacter, and Enterobacter 3.33%. Multidrug resistance associated with biofilm producers were greater than biofilm nonproducers. The Gram-negative biofilm producers found 96.15%, 80.76%, 73.07%, 53.84%, 53.84%, 46.15%, 19.23%, and 11.5% resistant to amoxyclave, ceftazidime, tetracycline, gentamicin, meropenem, nitrofurantoin, amikacin, imipenem, and fosfomycin, respectively. Gram-positive biofilm producers, however, were found 100% resistant to tetracycline, cloxacillin, and amoxyclave: 66.67% resistant to ampicillin while 33.33% resistant to gentamicin, ciprofloxacin, and nitrofurantoin.

Conclusion

High antimicrobial resistance was observed in biofilm producers than non-biofilm producers. Of recommended antimicrobial therapies for CAUTIs, ampicillin and amoxicillin-clavulanate were the least active antibiotics, whereas piperacillin/tazobactam and imipenem were found as the most effectual for gram-negative biofilm producer. Likewise, amoxicillin-clavulanate and tetracycline were the least active antibiotics, whereas vancomycin, fosfomycin, piperacillin-tazobactam, and meropenem were found as the most effective antibiotic for Gram-positive biofilm producer. In the limelight, the activity fosfomycin was commendable against both Gram-positive and Gram-negative biofilm producers.

Phylogenetic analysis, biofilm production, and antimicrobial resistance profile of Escherichia coli isolated from slaughtered pigs

ABSTRACT Enteric diseases of bacterial origin are frequent in the pig industry, of particular notoriety are the colibacillosis that mainly affect piglets and cause great damage to the swine industry worldwide. The aim of the study was to analyze phylogenetics, to detect biofilm production, and to determine antimicrobial resistance profile in 126 strains of Escherichia coli isolated from swabs obtained from fragments of the small intestines of 235 healthy pigs killed in slaughterhouses in Pernambuco (Brazil) using polymerase chain reaction (PCR), adherence to microplates test and disc diffusion technique. Of the analyzed samples, 88.10% (111/126) were classified in phylogenetic group B1; 4.76% (6/126) in group D; 3.97% (5/126) in group B2 and, 3.17% (4/126) in group A. Antimicrobial resistance rates observed were: lincomycin 100% (126/126), erythromycin 100% (126/126), chlortetracycline 94.44% (119/126), cephalothin 51.59% (65/126), ampicillin 38.89% (49/126), sulfamethoxazole + trimethoprim 37.3% (47/126), ciprofloxacin 19.84% (25/126), norfloxacin 14.29% (18/126), gentamicin 8.73% (11/126) and, chloramphenicol 5.55% (7/126). Multiple antibiotic resistance (MAR) ranged from 0.2 to 0.9. Of the strains tested 46.03% (58/126) produced biofilm, and 99.21% (125/126) of the strains exhibited multi-resistance. Further studies are required to elucidate the importance of each phylogenetic group in pigs and to prevent the propagation of multi-resistant E. coli strains.

Biofilm Formation in Nonmultidrug-resistant Escherichia coli Isolated from Patients with Urinary Tract Infection in Isfahan, Iran

Background:

Escherichia coli is a Gram-negative, opportunistic human pathogen in which increasing antibiotic resistance is a great concern for continued human survival. Although biofilm formation is a mechanism that helps E. coli to survive in unfavorable conditions, according to the importance of biofilm formation in developing the antibiotic resistance here, we studied the relation between antibiotic resistance and in vitro qualitative rating method biofilm formation in E. coli isolated from patients with urinary tract infection (UTI).

Materials and Methods:

The clinical isolates of E. coli (n = 100) were collected from urine of patients with UTI attending Isfahan Alzahra hospital. The strains were confirmed as E. coli using biochemical tests and molecular method. The Kirby-Bauer disk diffusion tests were done according to the Clinical and Laboratory Standards Institute protocol, and the biofilm synthesis was performed by microplate method. The binary logistic test was applied and P < 0.05 was considered statistically significant.

Results:

Our results showed a high outbreak of multidrug-resistant (MDR) E. coli strains (73%) and the highest resistance was observed toward ampicillin. The prevalence of biofilm producer isolates was 80% that 29% produced strong biofilm. The distribution of non-MDR isolates was high among strong biofilm producers, which shows a significant negative correlation between biofilm production and MDR pattern (P < 0.001).

Conclusions:

We found a negative correlation between MDR phenotype and biofilm formation capacity. This transmits the concept that more antibiotic susceptibility of strong biofilm producers may be due to the reduced exposure to multiple antibiotics.

Bacterial biofilm-based catheter-associated urinary tract infections: Causative pathogens and antibiotic resistance

BACKGROUND

We sought to determine the incidence of bacterial biofilm-based catheter-associated urinary tract infections, identify variables affecting biofilm formation, and identify etiologic bacterial pathogens and antibiotic-resistance patterns associated with biofilm-based catheter-associated urinary tract infections (CAUTIs) in our setup.

METHODS

Patients who developed at least 2 symptoms of urinary tract infection after at least 2 days of indwelling urinary catheters were included. Urine was collected aseptically from catheter tubing and processed per standard microbiologic practices. Bacterial pathogens were identified on the basis of gram staining, colony morphology, and biochemical reactions. The detection of the biofilm was done using the tube adherence method. Drug susceptibility testing was done using the Kirby-Bauer disc diffusion method.

FINDINGS

Biofilm was detected in 73.4% isolates, whereas 26.6% of isolates were nonbiofilm producers. Mean duration of catheterization after which biofilm was detected was 5.01 ± 1.31 days. A latex catheter was used in 69.5% of patients, whereas a silicone catheter was used in 30.4% of patients. Escherichia coli was found to be the most common pathogen isolated (52.3%), whereas Enterobacter cloacae exhibited the highest biofilm production (87.5%) among isolated pathogens. Among biofilm producers, the highest resistance was observed with ampicillin (100%). Fosfomycin exhibited the lowest resistance (17.2%). Significant association with biofilm was detected for gender, duration of catheterization, and type of catheter.

CONCLUSION

Biofilm-based CAUTI is an emerging problem. E coli was the most frequent isolate. High antibiotic resistance was observed in biofilm-producing strains. Using the variables affecting biofilm formation, tailored intervention strategies can be implemented to reduce biofilm-based CAUTIs.

Drug treatments for prosthetic joint infections in the era of multidrug resistance

INTRODUCTION

Despite many advances, the management of prosthetic joint infection is still a complex issue. Moreover, in recent years the problem of antimicrobial resistance has emerged as an important challenge.

AREAS COVERED

We analysed recent advances in different aspects of prosthetic joint infections. The importance of biofilms needs to be considered for antibiotic selection because, when embedded in these structures, bacteria acquire resistant behaviour. Moreover, the presence of resistance mechanisms in some species of organisms increases the difficulty of management. In this sense, the growing importance of methicillin-resistant staphylococci, multidrug-resistant Enterobacteriaceae or Pseudomonas aeruginosa is of increasing concern. Together with these organisms, others with constitutive resistance against most antibiotics (like Enterococcus sp., mycobacteria or fungi) represent a similar problem for selection of therapy. Research into new materials that can be used as drug carriers opens a new field for management of these infections and will likely come to the front line in the coming years.

EXPERT OPINION

Individualised therapies should carefully consider the aetiology, pathogenesis and antimicrobial susceptibility. Satisfactory clinical outcome could be further fostered by enhancing the multidisciplinary approach, with better collaboration in the antibiotic selection and the surgical management.

Biofilm formation, antimicrobial susceptibility, serogroups and virulence genes of uropathogenic E. coli isolated from clinical samples in Iran

BACKGROUND

Uropathogenic Escherichia coli O- Serogroups with their virulence factors are the most prevalent causes of UTIs. The present research performed to track common uropathogenic E.coli serogroups, antibiotic resistance pattern of strains and prevalence of virulence genes in isolations having the ability to constitute biofilm.

METHODS

In this research 130 E.coli isolation from patients having UTI symptoms were collected and antimicrobial resistance pattern was performed by Kirby-Bauer method. Polymerase chain reaction was done using primer pairs to identify common serogroups of uropathogenic E.coli and studying virulence genes in isolations creating biofilm.

RESULTS

Among 130 E.coli isolates, 80 (61.53 %) were able to make biofilm that 15 isolates (18.75 %) indicated strong reaction, 20 (25 %) of medium and 45 (56.25 %) of weak biofilm reaction. Among isolations creating biofilm, the highest resistance reported to Ampicillin (87.5 %) and the lowest to Nitrofurantoin (3.75 %). The frequency of fimH, pap, sfa and afa genes in isolations having the ability to create strong biofilm reported 93.33 %, 86.66 %, 86.66 % and 66.66 %, respectively.

CONCLUSIONS

The findings indicated the importance of virulence genes in serogroups producing uropathogenic E.coli biofilm. It is recommended that strains producing biofilm before antibiotic use should be studied.

Combating Antimicrobial Resistance in Foodborne Microorganisms

This review addresses an important public health hazard affecting food safety. Antimicrobial agents are used in foods to reduce or eliminate microorganisms that cause disease. Many traditional organic compounds, novel synthetic organic agents, natural products, peptides, and proteins have been extensively studied for their effectiveness as antimicrobial agents against foodborne Campylobacter spp., Escherichia coli, Listeria spp. and Salmonella. However, antimicrobial resistance can develop in microorganisms, enhancing their ability to withstand the inhibiting or killing action of antimicrobial agents. Knowledge gaps still exist with regard to the actual chemical and microbiological mechanisms that must be identified to facilitate the search for new antimicrobial agents. Technical implementation of antimicrobial active packing films and coatings against target microorganisms must also be improved for extended product shelf life. Recent advances in antimicrobial susceptibility testing can provide researchers with new momentum to pursue their quest for a resistance panacea.

In-vitro antimicrobial activity screening of some ethnoveterinary medicinal plants traditionally used against mastitis, wound and gastrointestinal tract complication in Tigray Region, Ethiopia

OBJECTIVE

To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis, wound and gastrointestinal complications.

METHODS

Hydroalcoholic exctracts of medicinal plants namely, Achyranthes aspera (A. aspera) L. (Family Asparagaceae), Ficus caria (F. caria) (Family Moraceae), Malvi parviflora (M. parviflora) (Family Malvaceae), Vernonia species (V. species) (local name Alakit, Family Asteraceae), Solanum hastifolium (S. hastifolium) (Family Solanaceae), Calpurinia aurea (C. aurea) (Ait) Benth (Family Fabaceae), Nicotiana tabacum (N. tabacum) L. (Family Solanaceae), Ziziphus spina-christi (Z. spina-christi) (Family Rhamnaceae), Croton macrostachys (C. macrostachys) (Family Euphorbiaceae), were screened against clinical bacterial isolates of veterinary importance from October 2007 to April 2009. The antibacterial activity was tested using disc diffusion at two concentrations (200 mg/mL and 100 mg/mL) and broth dilution methods using 70% methanol macerated leaf extracts.

RESULTS

With the exception of S. hastifolium all plant extracts exhibited antibacterial activity. Among the medicinal plants tested C. aurea, C. macrostachyus, A. aspera, N. tabacum and vernonia species (Alakit) showed the most promising antimicrobial properties.

CONCLUSIONS

It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis, wound and gastrointestinal complications treatment. Further studies into their toxicity and phytochemistry is advocated.

Biofilm and multidrug resistance in uropathogenic Escherichia coli

CONTEXT

Escherichia coli is known as causative agent of urinary tract infections (UTIs) tends to form microcolonies in mucosa lining of urinary bladder known as biofilm. These biofilms make the organism to resist the host immune response, more virulent and lead to the evolution of antibacterial drug resistance by enclosing them in an extracellular biochemical matrix.

AIMS

This study was done to know the association of various virulence factors and biofilm production in uropathogenic E. coli (UPEC) and antibiotic susceptibility pattern.

SETTINGS AND DESIGN

This study was conducted in Pt. B.D. Sharma PGIMS, Rohtak, Haryana during a period of 1 year from January 2011 to December 2011.

METHODS AND MATERIAL

Biofilm was detected by microtiter plate (MTP) method, and various virulence factors like hemolysin, hemagglutination, gelatinase, siderophore production, serum resistance, and hydrophobicity were detected. The antibiotic susceptibility testing was done by modified Kirby-Bauer disk diffusion and the disk diffusion method was used to confirm the ESBL, AmpC, MBL production by the UPEC statistical analysis used: The data were analyzed by using SPSS version 17.0. A two-sided P-value of less than or equal to 0·05 was considered to be significant.

RESULTS

Biofilm production was found in 18 (13·5%) isolates, more commonly in females (two times). These isolates were found to be resistant to antibiotics common in use and were 100% MDR.

CONCLUSIONS

Biofilm production makes the organism to be more resistant to antibiotics and virulent as compared to non-biofilm producers.

Multi drug resistance in strong biofilm forming clinical isolates of Staphylococcus epidermidis

Staphylococcus epidermidis which exists in healthy human skin as a commensal inhabitant is also an important pathogen forming biofilms on many surfaces and recently, increased resistance traits were suggested to be acquired in biofilm environments. In this study; clinical Prevalences, antibiotic resistances and biofilm formations of S. epidermidis strains were determined and comparison of all these findings with each other was carried out in order to take precautions against them and figure out if high biofilm forming S. epidermidis strains display multi drug resistance. According to our results; samples of wound and blood were the most S. epidermidis isolated clinical materials (40%; 35%) and cardiothoracic surgery was the most S. epidermidis observed service unit. All of these strains were sensitive to vancomycin, however 65% of them showed resistance to all β-lactam antibiotics (Penicillin, Oxacillin, Amoxicilin/Clavulonic acid), used in this study and 60% of all S. epidermidis strains were found as multi drug resistant. When the results of strong biofilm forming S. epidermidis strains are examined; they were isolated from sample of blood and service unit of cardiovascular surgery in highest frequency and 80% of them were β-lactam resistant whereas 100% of them were multi drug resistant. One of these multi drug resistant strains which was resistant to maximum amount of different antimicrobial classes, was also observed as maximum biofilm forming strain among all the other S. epidermidis isolates. Multi drug resistance in strong biofilm forming strains shows that; biofilms play a role in antimicrobial resistance traits of S. epidermidis.

Propensity for biofilm formation by clinical isolates from urinary tract infections: developing a multifactorial predictive model to improve antibiotherapy

A group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2%) were biofilm producers. The bacterial species (P<0.001), together with patient's gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of catheterization with biofilm formation, despite being less significant (P = 0.070) than species or gender. In fact, some of the bacteria isolated were biofilm producers in all cases. With regard to resistance profile among bacterial isolates, β-lactam antibiotics presented the highest number of cases/percentages--ampicillin (32/55.2%), cephalothin (30/51.7%), amoxicillin/clavulanic acid (22/37.9%)--although the carbapenem group still represented a good therapeutic option (2/3.4%). Quinolones (nucleic acid synthesis inhibitors) also showed high resistance percentages. Furthermore, biofilm production clearly increases bacterial resistance. Almost half of the biofilm-producing bacteria showed resistance against at least three different groups of antibiotics. Bacterial resistance is often associated with catheterization. Accordingly, intrinsic (age and gender) and extrinsic (hospital unit, bacterial isolate and catheterization) factors were used to build a predictive model, by evaluating the contribution of each factor to biofilm production. In this way, it is possible to anticipate biofilm occurrence immediately after bacterial identification, allowing selection of a more effective antibiotic (among the susceptibility options suggested by the antibiogram) against biofilm-producing bacteria. This approach reduces the putative bacterial resistance during treatment, and the consequent need to adjust antibiotherapy.