Multidrug-Resistance and Extended Spectrum Beta-Lactamase Production in Uropathogenic E. Coli which were Isolated from Hospitalized Patients in Kolkata, India

Antibiotic Resistance and Biofilm Development of Escherichia coli on Different Surfaces

The goal of this research is on antibiotic resistance and biofilm formation of Escherichia coli on different surfaces. 37 E.coli isolates were obtained from K.A.P. Viswanatham Government Medical College, Tiruchirappalli, Tamil Nadu, India. Biochemical assays were used to re-confirm all the isolates. Ampicillin, Cefepime, Cefotaxime, Co-trimoxazole, Tetracycline and Levofloxacin showed substantial levels of resistance. Meropenem, Tigecycline, and Colistin showed the least amount of resistance. 75.6% of the E.coli strains were multidrug resistant (MDR). Biofilm formation of E.coli was higher in TSBG than in TSB in all (polystyrene, polypropylene, glass and stainless steel) surfaces. It is evident that the presence of glucose or any sugar substrate promotes biofilm development, resulting in notable antibiotic resistance. This situation is hazardous to human health.

Occurrence of Extended-spectrum Beta-lactamases and the Antibiogram Pattern of Escherichia coli Isolates from Pus and Urine Samples

Escherichia coli (E. coli) is a significant species and a common dweller in the guts of humans and animals causing urinary tract infections, wound infection, otitis media, bloodstream infections, and other complications in humans. Worldwide resistance to antimicrobials is a serious public health problem. β-lactamases production by E. coli is responsible for resistance to frequently used beta-lactam antibiotics. 1) To determine antibiotic susceptibility pattern of Escherichia coli isolated from pus and urine samples 2) To determine ESBL producing Escherichia coli and its antibiotic susceptibility pattern. Retrospective study of E. coli isolates from urine and pus samples was performed by collecting data from bacteriology registers. Gender, age details of patients, number of E. coli isolates, and their antimicrobial susceptibility profiles were collected from the records. Out of 747 samples 102 E. coli were isolated and among them 60 (59%) were ESBL producers. Male preponderance was seen i.e. 59 (57.84%) and majority 68 (66.66%) were isolated from the age group of <18 years. E. coli showed maximum sensitivity to imipenem 88 (86.27%), followed by piperacillin-tazobactam 84 (82.35%), aminoglycoside group 76 (74.5%) and maximum resistance was seen to penicillin groups 92 (90.19%), followed by cephalosporins 71 (69.6%). Urinary isolates showed maximum sensitivity to nitrofurantoin (93.67%). ESBL producers showed resistance to ciprofloxacin 47 (78%). This study helps in the periodic formulation of regional antimicrobial policies and also giving continuous information to the clinicians with respect to the sensitivity pattern along with ESBL production which can help to avert further drug resistance.

Antibiotic resistance pattern of uropathogenic Escherichia coli isolated from children with symptomatic urinary tract infection in Moscow, Russia

Background and Aim: Uropathogenic Escherichia coli (UPEC) is commonly involved in urinary tract infections (UTIs), which are generally treated with antibiotics. However, the emergence of multidrug-resistant (MDR) strains of UPEC has made the treatment difficult. There is thus a need to continuously assess their sensitivity to antibiotics. This study aimed to determine the antibiotic resistance patterns and MDR phenotypes of UPEC strains isolated from children diagnosed with UTIs at the Russian Children's Clinical Hospital in Moscow, Russia. Materials and Methods: Kirby–Bauer's disc diffusion method was used to study the sensitivity to antibiotics of 106 UPEC isolates from urine specimens from children (aged from 9 months to 18 years old) diagnosed with UTIs. The results were interpreted in accordance with the Clinical and Laboratory Standards Institute guidelines and the correlations of variables with the degree to which each antibiotic inhibited the UPEC strains in terms of diameter on the disc were determined using Spearman's rank correlation test. A t-test and principal component analysis were performed to visualize the correlations of the susceptibility of UPEC to antibiotics with the age and sex of the patients. Statistical significance was set at p≤0.05. Results: Among the 106 UPEC strains tested, none (0%) showed resistance to fosfomycin (FO), while 84 (79.2%) were resistant (R) to at least one antibiotic. The highest rates of resistance were observed to amoxicillin (69.8%), ampicillin (62.3%), cefazolin (39.6%), trimethoprim (TR) (37.7%), ceftriaxone (34.9%), and tetracycline (33.0%). Interestingly, 22 (20.8%) strains were R to imipenem. UPEC isolates from males aged 1-6 years were more R to antibiotics than those from the other groups, with the exception of TR, to which UPEC isolates from females aged 13-18 years old were less sensitive (S). The multidrug-resistance (MDR) index ranged between 0.00 and 0.75 and we found that more than a quarter of UPEC (31/106) had an MDR index ≥0.5 and only 22 (20.7%) strains were S to all antibiotics tested (MDR index=0). Finally, Spearman's rank correlation test showed that, with the exception of FO, there were correlations between the inhibition diameters of all other antibiotics. Conclusion: FO is the only antibiotic to which all UPECs were S and may be suggested as the first line of treatment for UPEC. Further research is needed to continue monitoring antibiotic resistance and to investigate the genetic features associated with such resistance observed in this study.

A Study on Prevalence of Extended Spectrum Beta-lactamases Gene (CTX-M, TEM & SHV) Producing Enterobacteriaceae Members Isolated from Different Clinical Specimens at Tertiary Care Hospital, Uttarakhand

Extended spectrum b-lactamases (ESBLs) are one of the major enzymes responsible for antimicrobial drug resistance in bacterial isolates. The objective of this study was to find out the ESBL genes (blaTEM, blaSHV and blaCTX-M) in Enterobacteriaceae. This study was conducted from November 2013 to October 2015. The identification of Enterobacteriaceae isolates & antimicrobial drug resistance was done by conventional standard microbial methods. Further genotypic detection of ESBL was done by multiplex PCR. Results: Among 942 Enterobacteriaceae isolates, 332 (35.24%) isolates was ESBL producers. We observed high prevalence of ESBL enzyme in Klebsiella pneumonia (59.09%). These isolate revealed high resistance to co-trimoxazole, fluoroquinolones and aminoglycosides. Out of 48 randomly selected isolates, ESBL genes were identified in 45 isolates which were found resistant to third generation cephalosporins. Single CTX-M gene noticed in 29 strains of Escherichia coli (E. coli), 02 strains of Klebsiella pneumoniae, and 01 strain of Proteus mirabilis. Occurrence of Combination of the genes e.g., (blaTEM+blaCTX-M), (blaSHV+blaCTX-M), (blaTEM+blaSHV+blaCTX-M) was detected in 08, 01 and 04 isolates respectively. Multiplex PCR in CTX-M carrying isolates revealed the presence of blaCTX-M group-1. The most common blaCTX-M group-1 was observed in all isolates of family Enterobacteriaceae. Antimicrobial drug resistance is a major problem of concern now a day. Studies like this will be helpful to knowing the burden of multi drug resistance as well as formulating antibiotics policy for a particular region.

Selenomethionine Suppressed TLR4/NF-κB Pathway by Activating Selenoprotein S to Alleviate ESBL Escherichia coli-Induced Inflammation in Bovine Mammary Epithelial Cells and Macrophages

Inflammation is the hallmark of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli-induced bovine mastitis. Organic selenium can activate pivotal proteins in immune responses and regulate the immune system. The present study aimed to investigate whether selenomethionine (SeMet) attenuates ESBL E. coli-induced inflammation in bovine mammary epithelial cells (bMECs) and macrophages. Cells were treated with 0, 5/10, 10/20, 20/40, or 40/60 μM SeMet for 12 h and/or inoculated with ESBL-E. coli [multiplicity of infection (MOI) = 5] for 4/6 h, respectively. We assessed inflammatory responses, including selenoprotein S (SeS), Toll-like receptor 4 (TLR4), Ikappa-B (IκB), phospho-NF-κB p65 (Ser536), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and lactate dehydrogenase (LDH) activities. Treatment with 40/60 μM SeMet promoted cell viability and inhibited LDH activities in both bMECs and macrophages. Inoculation with ESBL-E. coli reduced cell viability, which was attenuated by SeMet treatment in bMECs and macrophages. SeMet increased ESBL E. coli-induced downregulation of SeS and decreased LDH activities, TLR4, IκB, phospho-NF-κB p65 (Ser536), IL-1β, and TNF-α protein expressions in bMECs and macrophages. In addition, knockdown of SeS promoted protein expression of TLR4-mediated nuclear factor-kappa (NF-κB) pathway and BAY 11-708 inhibited TNF-α and IL-1β protein levels in bMECs and macrophages after ESBL-E. coli treatment. Moreover, ESBL-E. coli inoculation increased monocyte chemoattractant protein 1 (MCP-1), C-C motif ligand 3 (CCL-3), and CCL-5 mRNA expressions in bMECs. In conclusion, ESBL-E. coli induced expression of MCP-1, CCL-3, and CCL-5 in bMECs and then recruited and activated macrophages, whereas SeMet attenuated ESBL E. coli-induced inflammation through activated SeS-mediated TLR4/NF-κB signaling pathway in bMECs and macrophages.

Multiple Drug Resistance Patterns in Various Phylogenetic Groups of Hospital-Acquired Uropathogenic E. coli Isolated from Cancer Patients

Cancer patients are more susceptible to several bacterial infections, particularly urinary tract infections caused by uropathogenic E. coli (UPEC). The objective of this work was detection and the phylogenetic characterization of hospital-acquired isolates of uropathogenic E. coli in cancer patients and the determination of its relation with antibiotic resistance. A total of 110 uropathogenic E. coli responsible for hospital-acquired urinary tract infections in cancer patients were included in this study. A triplex PCR was employed to segregate different isolates into four different phylogenetic groups (A, B1, B2 and D). Drug resistance was evaluated by the disc diffusion method. All of the isolates were multiple drug-resistant (MDR) and 38.18% of all UPEC isolates were extended-spectrum beta-lactamase (ESBL) producers from which 52% were positive for the blaCTX-M gene, 40% for the blaTEM gene, and 17% for the blaSHVgene. Among 42 ESBL-producing uropathogenic E. coli isolates, the majority belonged to phylogenetic group B2 (43%), followed by group D (36%), group A (19%) and group B1 (2%). Our results have shown the emergence of MDR isolates among uropathogenic E. coli with the dominance of phylogenetic group B2. Groups A and B1 were relatively less common. The most effective drug in all phylogenetic groups was imipenem.

Prevalence of plasmid-mediated resistance genes among multidrug-resistant uropathogens in Egypt

Background

The emergence of multidrug-resistant (MDR) uropathogens has become a public health threat and current knowledge of the genotypic basis of bacterial resistance is essential for selecting appropriate treatment options.

Objectives

To determine the prevalence of antimicrobial resistance among MDR uropathogens and to elucidate the molecular bases of plasmid-mediated resistance.

Methods

Bacterial isolates were recovered from urine specimens of 150 out-patients with signs and symptoms of urinary tract infections (UTIs) at El-Demerdash Hospital, Cairo, Egypt. Standard methods were used for identification, antimicrobial susceptibility testing was performed according to CLSI guidelines.

Results

Among the recovered isolates, 22.7% and 77.3% were Gram-positive, and negative, respectively. Of which; 43.3% were MDR with 60% harboring plasmids. Extended spectrum β-lactamase (ESBL) genes ^blaCTX-M, ^blaSHV, and ^blaTEM were detected on plasmids of 89.7%, 41%, and 84.6% of the tested isolates, respectively. The aminoglycoside resistance gene aac6′-Ib/aac-6′-Ib-cr was found on plasmids of 92.3% of the tested isolates followed by qnrS (92.3%), qnrB (46.2%), and qnrA (7.7%). The most prevalent quinolone efflux pump gene was oqxB (38.5%), followed by oqxA (20.5%), then qepA (10.3%).

Conclusion

High levels of resistance to nitrofurans, β-lactam/β-lactamase inhibitor, cephalosporins, aminoglycosides, and fluoroquinolones were detected, and their use as empirical treatment for UTIs has become questionable.

Prevalence and antibiotic resistance pattern of extended-spectrum beta-lactamase-producing Escherichia coli in clinical specimens

Background

Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae seem to have an extended antibiotic resistance, but have different resistance patterns throughout different sites and regions. This study aimed to evaluate the antibiotic resistance pattern of ESBL-producing Escherichia coli.

Materials and Methods

One hundred swab samples from patients hospitalized due to a clinical suspicion of any kind of infection (with manifestations such as fever, leukocytosis, and an active urinalysis result) were processed in Alzahra Microbiology Laboratory, Isfahan, Iran. Isolated E. coli were cultured on Mueller-Hinton agar and antibiotic susceptibility was tested by Kirby-Bauer disk diffusion method following the Clinical and Laboratory Standard Institute 2017 guidelines.

Results

ESBL-producing samples had higher antibiotic resistance rates than ESBL-non-producing samples: ceftriaxone (58.8% vs. 27.3%), cefotaxime (73.5% vs. 30.3%), ceftizoxime (76.5% vs. 33.3%), cefixime (79.4% vs. 40.9%), and cefpodoxime (73.5% vs. 53%), except for carbenicillin (29.4% vs. 48.5%). Imipenem and meropenem were the least resisted antibiotics in ESBL-producing samples (5.9% and 11.8%).

Conclusion

ESBL-producing Enterobacteriaceae have a high resistance rate to third-generation cephalosporins and high susceptibility to imipenem and meropenem.

The relationship between phylogenetic groups and antibiotic susceptibility patterns of Escherichia coli strains isolated from feces and urine of patients with acute or recurrent urinary tract infection

BACKGROUND AND OBJECTIVES

B2 and D have been mentioned as the most common phylogenetic groups among uropathogenic Escherichia coli. However, there is still controversy about the importance of these phylo-groups. This study was conducted to investigate the probable relation between these groups and antibiotic resistance patterns of E. coli isolates derived from urine and feces of the patients with acute or recurrent UTI.

MATERIALS AND METHODS

10 isolates were recovered from urine and feces samples of patients with different phases of UTI in whom E. coli was causative pathogen. Biochemical fingerprinting was performed to classify the isolates and select their appropriate representatives. Phylogenetic grouping was performed using multiplex PCR, and antibiotic resistance was determined by disk diffusion method.

RESULTS

Five-hundred-sixty E. coli isolates were derived from 56 UTI patients (27 acute, 29 recurrent). Among them, 261 isolates were selected using biochemical fingerprinting. All the isolates were sensitive to imipenem and nitrofurantoin. Compared to other phylo-groups, the isolates in group D showed considerably different frequencies in acute vs. recurrent phase of UTI, in urine vs. stool samples, in males vs. females, and in- vs. out-patients. They were more resistant to the antibiotics (except norfloxacin), and in contrast to others, this was seen more in acute UTI, especially in urine samples. Multi-drug resistance pattern was also meaningfully higher in group D.

CONCLUSION

Although phylo-groups B2 and D of E. coli bacteria are more responsible for UTI, group D isolates seem to be more resistant and probably more virulent, even than the ones from group B2.

Determination of the frequency of β-lactamase genes (bla SHV, bla TEM, bla CTX-M) and phylogenetic groups among ESBL-producing uropathogenic Escherichia coli isolated from outpatients

Background

Escherichia coli accounts for 70–95% of community-acquired urinary tract infections (UTIs). Recently, there has been an increase in the prevalence of extended-spectrum β-lactamase (ESBL) in the community which required an accurate identification for better management. Therefore, the current study was performed to determine the antimicrobial resistance pattern, investigate ESBL phenotypes and genotypes (blaCTX-M, bla TEM and bla SHV genes) and determine the phylogenetic groups among ESBL-positive isolates from outpatients.

Methods

One hundred and eighty-three positive urine samples were collected from 4450 outpatient clinic attendees. Antibiotic susceptibility was determined and ESBL phenotype screening was carried out using disk diffusion agar and combination disk techniques, respectively. The assessment of the presence of the blaCTX-M, bla TEM and blaSHV genes and phylogenetic grouping were performed using the polymerase chain reaction (PCR) method.

Results

Out of 183 E. coli isolates, 59 (32.2%) showed a positive ESBL phenotype. The prevalence of ESBL-producing E. coli was higher in males (57.4%). Fifty-seven of the ESBL-producing strains carried at least one of the β-lactamase genes (bla CTX-M, bla TEM, bla SHV). Phylotyping of multi-drug resistant isolates indicated that the isolates belonged to B2, A and D phylogroups. Analysis of resistance patterns among these phylogroups revealed that 74.4%, 55.3% and 29.7% of the isolates in the B2 group were resistant to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Most of the strains in the phylogroup B2 carried the bla CTX-M gene.

Conclusions

All the ESBL-producing isolates were placed in one of the four phylogenetic groups. The presence of CTX-M and resistance to quinolones were more frequent in B2 strains than in non-B2 strains.

Pattern of Antibacterial Resistance in Urinary Tract Infections: A Systematic Review and Meta-analysis

Background

Urinary tract infection (UTI) is one of the most common infectious diseases ranking next to upper respiratory tract infections. UTIs are often significantly associated with morbidity and mortality. The inappropriate administration of antibiotics to treat these infections increased infection resistance to antibiotics. The aim of this study is to determine the frequency of antibiotic resistance pattern in UTIs.

Methods

We searched several databases including PubMed, Web of Science, Scopus, Google Scholar, Iran Medex, Magiran, IranDoc, MedLib, and Scientific Information Database to identify the studies addressing antibacterial resistance patterns of the most common uropathogenic bacteria in UTIs in Iran. A total of 90 reports published from different regions of Iran from 1992 to May 2015 were involved in this study.

Results

It is shown that the most common pathogen causing UTIs is Escherichia coli with 62%. The resistance among the isolates of E. coli was as follows: ampicillin (86%), amoxicillin (76%), tetracycline (71%), trimethoprim-sulfamethoxazole (64%), cephalexin (61%), and cefalothin (60%). The highest sensitivity among isolates of E. coli was as follows: imipenem (86%), nitrofurantoin (82%), amikacin (79%), chloramphenicol (72%), and ciprofloxacin (72%).

Conclusions

The results of this study showed that the most common resistance are antibiotics that are commonly used. The most effective antibiotics for E. coli were imipenem, nitrofurantoin, amikacin, chloramphenicol, and ciprofloxacin. Considering this study, it had better, use less gentamicin, second-generation cephalosporins, and nalidixic acid in the initial treatment of infections caused by E. coli, and no use penicillins, tetracyclines, cotrimoxazole, and first-generation cephalosporins.

Changing antibiotic susceptibility pattern in uropathogenic Escherichia coli over a period of 5 years in a tertiary care center

Objective: To assess the changing antibiotic sensitivity pattern in Uropathogenic E. coli over a period of time (2013–2017) with a special emphasis on ESBL-producing E. coli.

Methods: This retrospective study was carried out in the Department of Microbiology, Kasturba Medical College, Ambedkar Circle, Mangalore. A retrospective time bound analysis of 500 samples/year was performed. The urine samples received from the suspected cases of urinary tract infection (UTI) were processed. Wet mount examinations of urine samples were done. The urine culture was done by a semi-quantitative method on Mac Conkey’s agar, Cysteine Lactose Electrolyte Deficient (CLED) medium, and UTI Chrome agar. Culture plates were incubated for 18–24 hours at 37°C. Urine samples with a colony count of ≥10⁵ CFU/ml were considered significant. The uropathogens were identified by their biochemical reactions. The antibiotic susceptibility testing (AST) was carried out using a Vitek Compact 2 system and Modified Kirby Bauer disc diffusion method.

Results: Antibiotic resistance of Uropathogenic E.coli to cephalosporins increased from 51 to 58%, Cotrimoxazole: 52 to 59%, Piperacillin tazobactam 9.4 to 23%, Carbapenems 0 to 5.9%. Antibiotic resistance to netilmicin has reduced from 8 to 6.5%, and norfloxacin 59 to 48%. The rates of ESBL production have increased from 45.2 to 59.6% in the 5 years.

Conclusion: The increasing antibiotic resistance trends in UTI patients indicate that it is vitally important to use them conservatively. Proper guidelines, management of antibiotic usage, and constant information to the clinicians regarding the sensitivity pattern can help to prevent drug resistance.

In Vitro Synergism of Silver Nanoparticles with Antibiotics as an Alternative Treatment in Multiresistant Uropathogens

The increase in the prevalence of bacterial resistance to antibiotics has become one of the main health problems worldwide, thus threatening the era of antibiotics most frequently used in the treatment of infections. The need to develop new therapeutic strategies against multidrug resistant microorganisms, such as the combination of selected antimicrobials, can be considered as a suitable alternative. The in vitro activities of two groups of conventional antimicrobial agents alone and in combination with silver nanoparticles (AgNPs) were investigated against a set of ten multidrug resistant clinical isolate and two references strains by MIC assays and checkerboard testing, as well as their cytotoxicity, which was evaluated on human fibroblasts by MTT assay at the same concentration of the antimicrobial agents alone and in combination. Interesting results were achieved when the AgNPs and their combinations were characterized by Dynamic Light Scattering (DLS), Zeta Potential, Transmission Electron Microscopy (TEM), UV⁻visible spectroscopy and Fourier Transforms Infrared (FTIR) spectroscopy. The in vitro activities of ampicillin, in combination with AgNPs, against the 12 microorganisms showed one Synergy, seven Partial Synergy and four Additive effects, while the results with amikacin and AgNPs showed three Synergy, eight Partial Synergy and one Additive effects. The cytotoxic effect at these concentrations presented a statistically significant decrease of their cytotoxicity (p < 0.05). These results indicate that infections caused by multidrug resistant microorganisms could be treated using a synergistic combination of antimicrobial drugs and AgNPs. Further studies are necessary to evaluate the specific mechanisms of action, which could help predict undesirable off-target interactions, suggest ways of regulating a drug&rsquo;s activity, and identify novel therapeutic agents in this health problem.

A retrospective study of the changing trends of antimicrobial resistance of Klebsiella pneumoniae isolated from urine samples over last 3 years (2012-2014)

Background:

In our country, the problem of antibiotic resistance is compounding because of overuse and misuse of antibiotics. There is no systematic national surveillance of antibiotic resistance and insufficient data are available to quantify the problem.

Objectives:

To study the changing pattern of antimicrobial resistance of Klebsiella pneumoniae isolates from patients of urinary tract infections over last 3 years.

Materials and Methods:

A retrospective, record-based study carried out based on the records culture sensitivity reports of indoor patients, during past 3 years (2012-2014). The type of organisms most common in urine sample was noted, and the drugs still effective for the particular organism were noted.

Results:

Klebsiella was the second most frequent isolate throughout the 3 years (14%) of the total isolates). Analysis of the results year wise indicated that the lowest percentage of resistance was manifested against imipenem between 11.94% (2012) and 13.75% (2014). Over the successive years, resistance to ceftriaxone tends to increase from 74.95 % (2012) to 81% (2014). Klebsiella showed very high resistance 90.78% (2012) and 95.63% (2012) to co-trimoxazole and tetracycline, respectively with increasing trend to absolute resistance to both groups over the 3 years period. On an average over the 3 years Klebsiella showed a high amount of resistances to fluoroquinolones (72.71%) and aminoglycosides (76.22%). While multi-drug resistant Klebsiella range between 65% (2012) and 67% (2014).

Conclusion:

The antimicrobial resistance patterns are constantly evolving and vary from region to region it has become a necessity to do constant antimicrobial sensitivity surveillance. This will help clinicians to provide safe and effective empirical therapies.

Antibiotic Resistance, RAPD- PCR Typing of Multiple Drug Resistant Strains of Escherichia Coli From Urinary Tract Infection (UTI)

INTRODUCTION

Global spreading of multidrug resistant strains of Escherichia coli is responsible for Urinary Tract Infection (UTI) which is a major health problem in of concern. Among the gram negative bacteria, the major contributors for UTI belongs to the family Enterobacteriaceae, which includes E. coli, Klebsiella, Citrobacter and Proteus. However, E. coli accounts for the major cause of Urinary tract infections (UTIs) and accounts for 75% to 90% of UTI isolates.

AIM

The main aim of this study is to analyse the phylogenetic grouping of clinical isolates of UTI E. coli.

MATERIALS AND METHODS

In this study nearly 58 E. coli strains were isolated and confirmed through microbiological, biochemical characterization. The urine samples were collected from outpatients having symptoms of UTI, irrespective of age and sex in Tamil Nadu, India. The isolates were subjected to analyse for ESBL and AmpC β-lactamase production. To understand its genetic correlation, molecular typing was carried out using RAPD-PCR method.

RESULTS

Here we noted phenotypically twenty seven isolates were positive for ESBL and seven for AmpC β-lactamase production. However, among the ESBL isolates higher sensitivity was noted for Nitrofurantoin and Cefoxitin. It is worth to note that the prevalence of UTIs was more common among female and elderly male. Phylogenetic grouping revealed the presence of 24 isolates belonged to B2 group followed by 19 isolates to group A, eight isolates to group B1 and Seven isolates to group D.

CONCLUSION

Phenotypically most of the strains were positive for ESBL and showed high sensitivity for Nitrofurantoin and cefoxitin.

A Comparative Analysis of the Mechanism of Toll-Like Receptor-Disruption by TIR-Containing Protein C from Uropathogenic Escherichia coli

The TIR-containing protein C (TcpC) of uropathogenic Escherichia coli strains is a powerful virulence factor by impairing the signaling cascade of Toll-like receptors (TLRs). Several other bacterial pathogens like Salmonella, Yersinia, Staphylococcus aureus but also non-pathogens express similar proteins. We discuss here the pathogenic potential of TcpC and its interaction with TLRs and TLR-adapter proteins on the molecular level and compare its activity with the activity of other bacterial TIR-containing proteins. Finally, we analyze and compare the structure of bacterial TIR-domains with the TIR-domains of TLRs and TLR-adapters.

Extended-spectrum ß-Lactamase-producing Enterobacteriaceae as a Common Cause of Urinary Tract Infections in Sri Lanka

Background

Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) are increasingly reported as pathogens in urinary tract infections (UTIs). However, in Sri Lanka, the clinical and molecular epidemiology of ESBL-PE implicated in UTIs has not been well described.

Materials and Methods

We conducted prospective, laboratory-based surveillance from October to December 2013 at a tertiary care hospital in southern Sri Lanka and enrolled patients ≥1 year of age with clinically relevant UTIs due to ESBL-PE. Isolate identity, antimicrobial drug susceptibility, and ESBL production were determined. Presence of ß-lactamase genes, bla_SHV, bla_TEM, and bla_CTX-M, was identified by polymerase chain reaction.

Results

During the study period, Enterobacteriaceae were detected in 184 urine samples, with 74 (40.2%) being ESBL producers. Among 47 patients with ESBL-PE who had medical records available, 38 (80.9%) had clinically significant UTIs. Most UTIs (63.2%) were community acquired and 34.2% were in patients with diabetes. Among 36 cultured ESBL-PE isolates, significant susceptibility (>80%) was only retained to amikacin and the carbapenems. The group 1 bla_CTX-M gene was present in 90.0% of Escherichia coli isolates and all Klebsiella pneumoniae and Enterobacter cloacae isolates. The bla_SHV and bla_TEM genes were more common in K. pneumoniae (75% and 50%) and E. cloacae (50% and 50%) isolates than in E. coli (10% and 20%) isolates, respectively.

Conclusion

The majority of UTIs caused by ESBL-PE were acquired in the community and due to organisms carrying the group 1 CTX-M ß-lactamase. Further epidemiologic studies of infections due to ESBL-PE are urgently needed to better prevent and treat these infections in South Asia.

EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI

BACKGROUND

Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli.

MATERIALS AND METHODS

A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out.

RESULTS

The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue).

CONCLUSION

It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases.

Multidrug resistant Enterobacteriaceae and extended spectrum β-lactamase producing Escherichia coli: a cross-sectional study in National Kidney Center, Nepal

Background

Emergence of antibacterial resistance and production of Extended spectrum β-lactamases (ESBLs) are responsible for the frequently observed empirical therapy failures. Most countries have experienced rapid dissemination of ESBLs producing Enterobacteriaceae isolates, particularly E. coli and Klebsiella pneumoniae. ESBLs are clinically significant and when detected, indicate the need for the use of appropriate antibacterial agents. But antibacterial choice is often complicated by multi-resistance.

Methods

This study was carried from June to November 2014 to study the multidrug resistant (MDR) Enterobacteriaceae and ESBL producing E. coli among urine isolates in hospital setting. Isolates from urine samples were primarily screened for possible ESBL production followed by phenotypic confirmation. Antibiotic susceptibility testing (AST) was done by Kirby Bauer disk diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines.

Results

Out of 450 urine samples processed, 141 significant growths were obtained including 95 Enterobacteriaceae isolates with 67 E. coli. Among Enterobacteriaceae, 92 (96.84 %) were recorded as MDR and 18 (26.87 %) E. coli were confirmed as ESBLs producers.

Conclusions

Using the phenotypic confirmatory test forwarded by the CLSI, relatively significant E. coli isolates tested were ESBL producers. Also high numbers of MDR organisms were isolated among Enterobacteriaceae. Isolates showed significant resistance to the commonly prescribed drugs. These findings suggest for further study in this field including the consequences of colonization with MDR and ESBL-producing bacteria both in the community and in the hospital setting.

Virulence Genes and Antimicrobial Resistance Pattern in Uropathogenic Escherichia coli Isolated From Hospitalized Patients in Kashan, Iran

Background:

Urinary tract infection (UTI) is one of the most prevalent infectious diseases. Uropathogenic Escherichia coli (UPEC), as the most important cause of UTI, are associated with a number of virulence factors.

Objectives:

The current study aimed to investigate the virulence associated determinants as well as their patterns of antibiotic resistance in UPEC isolated from hospitalized patients with UTI.

Materials and Methods:

A total of 150 E. coli isolates were collected from patients with UTI from December 2012 to June 2013 in Kashan, Iran. Antimicrobial susceptibility screening of 12 antibiotics was determined using disk diffusion method. Polymerase Chain Reaction (PCR) assay was used to detect virulence-related genes in UPEC strains. The purified PCR products were sequenced.

Results:

Of the total 150 UPEC isolates, 111 (74%) were multidrug-resistant. High resistance was observed against ampicillin (81.3%), nalidixic acid (71.3%), cotrimoxazole (64.7%) and ciprofloxacin (61.3%), respectively. Eighty-four out of the 150 isolates showed resistance against the extended spectrum cephalosporins. Totally, virulence genes were detected in 126 (84%) UPEC isolates .The PCR results identified the traT gene in (74%), PAIs markers in (61.3%) and the pap gene in (16.6%) of the isolates.

Conclusions:

The traT gene and PAI markers were highly prevalent among UPEC strains isolated from patients in Kashan, Iran; therefore these determinants could be used as targets for prophylactic interventions. Also there was a high level of resistance against the antibiotics commonly used for urinary tract infection treatment. To reach better therapeutic outcomes, treatment regimens have to be modified.

Understanding the patterns of antibiotic susceptibility of bacteria causing urinary tract infection in West Bengal, India

Urinary tract infection (UTI) is one of the most common infectious diseases at the community level. In order to assess the adequacy of empirical therapy, the susceptibility of antibiotics and resistance pattern of bacteria responsible for UTI in West Bengal, India, were evaluated throughout the period of 2008-2013. The infection reports belonging to all age groups and both sexes were considered. Escherichia coli was the most abundant uropathogen with a prevalence rate of 67.1%, followed by Klebsiella spp. (22%) and Pseudomonas spp. (6%). Penicillin was least effective against UTI-causing E. coli and maximum susceptibility was recorded for the drugs belonging to fourth generation cephalosporins. Other abundant uropathogens, Klebsiella spp., were maximally resistant to broad-spectrum penicillin, followed by aminoglycosides and third generation cephalosporin. The antibiotic resistance pattern of two principal UTI pathogens, E. coli and Klebsiella spp. in West Bengal, appears in general to be similar to that found in other parts of the Globe. Higher than 50% resistance were observed for broad-spectrum penicillin. Fourth generation cephalosporin and macrolides seems to be the choice of drug in treating UTIs in Eastern India. Furthermore, improved maintenance of infection incident logs is needed in Eastern Indian hospitals in order to facilitate regular surveillance of the occurrence of antibiotic resistance patterns, since such levels continue to change.

Molecular Characterization of Uropathogenic Escherichia coli: Nalidixic Acid and Ciprofloxacin Resistance, Virulent Factors and Phylogenetic Background

BACKGROUND AND OBJECTIVE

A proficient pathogen should be virulent, resistant to antibiotics, and epidemic. However, the interplay between resistance and virulence is poorly understood. Perhaps, the most commonly accepted view is that resistance to quinolones is linked to a loss of virulence factors. However, the low virulent phylogenetic groups may be more prone to acquire resistance to quinolones. The aim of this study was to identify and characterise the Nalidixic Acid (NA) and ciprofloxacin (CIP) resistant uropathogenic Escherichia coli (UPEC) isolates with respect to virulence and phylogenetic background, from hospital settings in Kolkata, an eastern region in India. Research based on these bacterial populations will help in understanding the molecular mechanisms underlying the association between resistance and virulence, that in turn, may help in managing the future disseminations of UTIs in their entirety.

MATERIAL AND METHODS

One hundred and ten E. coli isolates were screened against NA and CIP using Kirby-Bauer disk diffusion technique, following CLSI guidelines. Prevalence of virulent factor genes and distribution of phylogenetic groups amongst the isolates was determined by PCR, using gene specific primers against the different virulent factors and DNA markers (chuA, yjaA and DNA fragment, TSPE4.C2) respectively. Statistical analysis of the data was performed using SPSS software.

RESULTS

Resistance to both NA and CIP was reported in 75.5 % of the isolates which were analysed. The virulent determinants, papC, pap GII, papEF, afa, cnf1, hlyA and iroN were significantly predominant in the drug susceptible than the resistant isolates. A significant reduction of phylogroup B2 in NA (85.7% versus 64.6%, χ(2)P<0.001) and CIP (85.2 % versus 61.4%, χ(2)P<0.001) resistant UPEC isolates, followed by increase in predominance of non-B2 phylotypes (group D and group B1), were observed.

CONCLUSION

This is the first report from India that has indicated possible evidence on horizontal gene transfer from pathogenic to commensal strains and selection of the latter, on extensive usage of this group of antimicrobials in hospital settings, where these drugs were routinely prescribed for treating urinary tract infection. Therefore, this information necessitates surveillance programs and administration of effective strategies, to put an end to random prescription policies involving this group of antimicrobials.

Characteristics of urinary tract infection pathogens and their in vitro susceptibility to antimicrobial agents in China: data from a multicenter study

OBJECTIVE

This study assessed the characteristics of pathogens identified in clinical isolates from patients with urinary tract infection (UTI) and their in vitro sensitivity to commonly used antibiotics in the clinical setting in China.

DESIGN AND SETTING

Multicenter study was conducted between January and December 2011 in 12 hospitals in China.

PARTICIPANTS

Urine samples were collected from 356 symptomatic patients treated in the study hospitals for acute uncomplicated cystitis, recurrent UTI or complicated UTI.

PRIMARY AND SECONDARY OUTCOME MEASURES

Minimal inhibitory concentrations (MICs) were measured using broth microdilution according to the Clinical and Laboratory Standards Institute 2011 guidelines. Thirteen antimicrobial agents were tested: fosfomycin tromethamine, levofloxacin, moxifloxacin, cefdinir, cefixime, cefaclor, cefprozil, cefuroxime, amoxicillin/clavulanic acid, cefotaxime, azithromycin, nitrofurantoin and oxacillin. Escherichia coli isolates were screened and extended spectrum β-lactamases (ESBL) production was confirmed by a double-disk synergy test.

RESULTS

198 urine samples were culture-positive and 175 isolates were included in the final analysis. E coli was detected in 50% of cultures, followed by Staphylococcus epidermidis (9%), Enterococcus faecalis (9%) and Klebsiella pneumoniae (5%). The detection rate of ESBL-producing E coli was 53%. Resistance to levofloxacin was the most common among all the isolates. Nitrofurantoin and fosfomycin tromethamine had the greatest activity against E coli; overall, 92% and 91% of isolates were susceptible to these antimicrobials. E faecalis had the highest susceptibility rates to fosfomycin tromethamine (100%).

CONCLUSIONS

The most frequently identified pathogens in our patients were ESBL-producing E coli and E faecalis. Fosfomycin tromethamine and nitrofurantoin showed a good antimicrobial activity against UTI pathogens. They may represent good options for the empiric treatment of patients with UTI.