Antimicrobial resistance and spread of multi drug resistant Escherichia coli isolates collected from nine urology services in the Euregion Meuse-Rhine

Effectiveness and safety of cefotaxime combined with avibactam for treating multidrug-resistant E coli infections: A systematic review and meta-analysis

BACKGROUND

Multidrug-resistant Escherichia coli infections are a global health challenge, notably in North America, Europe, Asia, and Africa. This systematic review and meta-analysis evaluates the effectiveness and safety of cefotaxime combined with avibactam, aiming to mitigate these infections' impact and lessen their burden on healthcare systems worldwide.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and PICO frameworks, we conducted a comprehensive literature search across 4 primary databases on May 6, 2023. Studies evaluating the efficacy and safety of cefotaxime and avibactam were included. Key outcomes included treatment success, adverse effects, and microbiological eradication. Quality assessment utilized the Cochrane Collaboration Risk of Bias instrument. Heterogeneity was analyzed using chi-square statistics and the I2 index. Both fixed- and random-effects models were applied as appropriate. Publication bias was rigorously evaluated using Egger linear regression test and funnel plot analysis, ensuring the study's integrity and reliability.

RESULTS

The clinical cure rate derived from 8 studies showed no significant difference between the treatment groups (odds ratio [OR] = 1.97, 95% CI: 0.69 to 1.36, P = .86). Analysis of the bacterial clearance rate from the 5 studies also indicated no significant difference (OR = 0.97, 95% CI: 0.42 to 2.25, P = .36). Notably, a reduced mortality rate favoring the experimental group was observed in 6 studies (OR = 0.64, 95% CI: 0.44 to 0.92, P = .012). Comprehensive sensitivity analyses and the assessment of publication bias strengthened the reliability of the results.

CONCLUSIONS

Ceftazidime combined with avibactam significantly reduced mortality among patients with multidrug-resistant Escherichia coli infections, indicating its potential as a therapeutic option, especially for carbapenem-resistant Enterobacteriaceae. However, extensive large-scale clinical trials are required to validate these findings.

Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

A guide for urogynecologic patient care utilizing telemedicine during the COVID-19 pandemic: review of existing evidence

Introduction and hypothesis

The COVID-19 pandemic and the desire to “flatten the curve” of transmission have significantly affected the way providers care for patients. Female Pelvic Medicine and Reconstructive Surgeons (FPMRS) must provide high quality of care through remote access such as telemedicine. No clear guidelines exist on the use of telemedicine in FPMRS. Using expedited literature review methodology, we provide guidance regarding management of common outpatient urogynecology scenarios during the pandemic.

Methods

We grouped FPMRS conditions into those in which virtual management differs from direct in-person visits and conditions in which treatment would emphasize behavioral and conservative counseling but not deviate from current management paradigms. We conducted expedited literature review on four topics (telemedicine in FPMRS, pessary management, urinary tract infections, urinary retention) and addressed four other topics (urinary incontinence, prolapse, fecal incontinence, defecatory dysfunction) based on existing systematic reviews and guidelines. We further compiled expert consensus regarding management of FPMRS patients in the virtual setting, scenarios when in-person visits are necessary, symptoms that should alert providers, and specific considerations for FPMRS patients with suspected or confirmed COVID-19.

Results

Behavioral, medical, and conservative management will be valuable as first-line virtual treatments. Certain situations will require different treatments in the virtual setting while others will require an in-person visit despite the risks of COVID-19 transmission.

Conclusions

We have presented guidance for treating FPMRS conditions via telemedicine based on rapid literature review and expert consensus and presented it in a format that can be actively referenced.

Antibiotic Resistance Among Uropathogenic Escherichia coli

Urinary tract infections (UTIs) belong to the most common community-acquired and nosocomial infections. A main etiological factor of UTIs is uropathogenic Escherichia coli (UPEC). This review describes the current state of knowledge on the resistance of UPEC to antibiotics recommended for the treatment of UTIs based on the available literature data. Nitrofurantoin and fosfomycin are recommended as first-line therapy in the treatment of uncomplicated cystitis, and the resistance to these antimicrobial agents remains low between UPEC. Recently, in many countries, the increasing resistance is observed to trimethoprim-sulfamethoxazole, which is widely used as the first-line antimicrobial in the treatment of uncomplicated UTIs. In European countries, the resistance of UPEC to this antimicrobial agent ranges from 14.6% to 60%. The widespread use of fluoroquinolones (FQs), especially ciprofloxacin, in the outpatients is the cause of a continuous increase in resistance to these drugs. The resistance of UPEC to FQs is significantly higher in developing countries (55.5–85.5%) than in developed countries (5.1–32.0%). Amoxicillin-clavulanic acid is recommended as first line-therapy for pyelonephritis or complicated UTI. Resistance rates of UPEC to amoxicillin-clavulanic acid are regionally variable. In European countries the level of resistance to this antimicrobial ranges from 5.3% (Germany) to 37.6% (France). Increasing rates of UPEC resistance to antimicrobials indicate that careful monitoring of their use for UTI treatment is necessary.

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.

Antibiotic resistance of Escherichia coli isolated from uncomplicated UTI in general practice patients over a 10-year period

Recommendations of first choice antibiotic therapy need to be based on actual antibiotic susceptibility data. We determined the antibiotic susceptibility of E. coli in uncomplicated UTI among women and compared the results with 2004 and 2009. In 30 sentinel general practitioner practices of Nivel Primary Care database, urine samples were collected from women with symptoms of uncomplicated UTI. Patient characteristics, E. coli susceptibility, and ESBL production were analyzed. Six hundred eighty-nine urine samples were collected; E. coli was the most isolated uropathogen (83%). Antibiotic susceptibility was stable over time except for ciprofloxacin (96% in 2004, 97% in 2009, and 94% in 2014; P < 0.05). The susceptibility to co-amoxiclav was 88%, 87%, and 92% in 2004, 2009, and 2014, respectively. The prevalence of ESBL-producing E. coli increased from 0.1% in 2004 to 2.2% in 2014 (P < 0.05). Regional differences in antibiotic susceptibility for co-trimoxazole were found being the highest in the west (88%) and the lowest in the north (72%, P = 0.021). Ciprofloxacin susceptibility was related to antibiotic use in the past 3 months (97% no use versus 90% use, P = 0.002) and age > 70 years (P = 0.005). In 2014, prescription of fosfomycin increased compared to 2009 (14.3% versus 5.6%) at the expense of co-amoxiclav, co-trimoxazole, and fluoroquinolones (P < 0.05). The susceptibility percentages to most antimicrobial agents tested were stable over 10 years’ period although the prevalence of E. coli and ESBLs significantly increased. Performance of a survey with regular intervals is warranted.

Clinical Impact of Sequence Type 131 in Adults with Community-Onset Monomicrobial Escherichia Coli Bacteremia

Background: The clinical impact of ST (sequence type) 131 in adults with community-onset Escherichia coli bacteremia remains controversial. Methods: Clinical data of 843 adults presenting with community-onset monomicrobial E. coli bacteremia at a medical center between 2008 and 2013 were collected. E. coli isolates were genotyped by a multiplex polymerase chain reaction to detect ST131 and non-ST131 clones. Results: Of 843 isolates from 843 patients with a mean age of 69 years, there were 102 (12.1%) isolates of ST131. The ST131 clone was more likely to be found in the elderly (76.5% vs. 64.0%; p = 0.01) and in nursing-home residents (12.7% vs. 3.8%; p < 0.001) than non-ST131 clones. Furthermore, the ST131 clone was associated with a longer time to appropriate antibiotic therapy (2.6 vs. 0.8 days; p = 0.004) and a higher 28-day mortality rate (14.7% vs. 6.5%, p = 0.003). In the Cox regression analysis with an adjustment of independent predictors, the ST131 clone exhibited a significant adverse impact on 28-day mortality (adjusted odds ratio (aOR), 2.18; p = 0.02). The different impact of the ST131 clone on 28-day mortality was disclosed in the non-ESBL (aOR 1.27; p = 0.70) and ESBL (aOR 10.19; p = 0.048) subgroups. Conclusions: Among adults with community-onset E. coli bacteremia, the ST131 clone was associated with higher 28-day mortality, particularly in those infected by ESBL producers.

Incidence of single-drug resistant, multidrug-resistant and extensively drug-resistant Escherichia coli urinary tract infections: An Australian laboratory-based retrospective study

OBJECTIVES

The aim of this study was to evaluate the incidence of single-drug resistant, multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) Escherichia coli urinary tract infections (UTIs) in a sample of Australian Capital Territory (ACT) residents.

METHODS

Laboratory-based retrospective data from all ACT residents whose urine samples were processed from January 2009 to December 2013 at ACT Pathology were utilised. Multivariate logistic regression models were constructed to determine the associations of age, sex, urine sample source and socioeconomic status with risk of resistant infections.

RESULTS

A total of 146 915 urine samples from 57 837 ACT residents were identified over 5 years. The mean±standard deviation age of residents at first sample submitted was 48±26years, and 64.4% were female. The 5-year incidence of single-drug resistant E. coli UTI was high for ampicillin, trimethoprim and cefazolin (6.8%, 3.5% and 1.9%, respectively). No PDR E. coli UTI was detected. Five-year incidences of MDR and XDR E. coli UTIs were 1.9% and 0.2%, respectively, which is low in comparison with international rates. Female sex and age ≥38 years were significantly associated with single-drug and multidrug resistance. The risk of single-drug resistance was significantly higher in samples from after-hours general practice (GP) clinics compared with hospitals, office-hours GP clinics, and community and specialist health services (adjusted odds ratio=2.6, 95% confidence interval 2.2-3.1).

CONCLUSIONS

These findings have significant implications for antimicrobial prescribing given the identified risk factors for the detection of resistance, especially in patients attending after-hours GP clinics.

Determination of antimicrobial resistance to extended-spectrum cephalosporin, quinolones, and vancomycin in selected human enteric pathogens from Prince Edward Island, Canada

The aim of this study was to determine the frequency of fecal carriage of vancomycin-resistant Enterococcus spp. and Escherichia coli with reduced susceptibilities to extended-spectrum cephalosporins (ESCs) and quinolones in humans on Prince Edward Island, Canada. Convenience fecal samples from individuals on Prince Edward Island were screened phenotypically using selective culture and genotypically using multiplex polymerase chain reactions to detect E. coli and Enterococcus spp. resistant to critically important antimicrobials. Twenty-six (5.3%) of 489 individuals had E. coli with reduced susceptibility to ESCs. Twenty-five (96.2%) of the 26 isolates harbored blaTEM, 18 (69.2%) harbored blaCMY-2, 16 (61.5%) harbored blaCTX-M groups, 2 (7.7%) harbored blaSHV genes. None of the ESC-resistant E. coli was positive for carbapenem resistance. Twenty-one (8.3%) of 253 individuals had E. coli isolates with reduced quinolone susceptibility. All 21 isolates were positive for at least 1 qnr gene, with 3 (14.3%) isolates positive for qnrB, 5 (23.8%) positive for qnrS, and 13 (61.9%) positive for both qnrB and qnrS genes. All the enterococci isolates were vancomycin-susceptible. Higher susceptibility to the critically important antimicrobials was found in this study. This study can serve as a baseline for future antimicrobial resistance surveillance within this region.

Multiple drug resistance and biocide resistance in Escherichia coli environmental isolates from hospital and household settings

Background

Antibiotic resistance of environmental Escherichia coli in hospitals could be increased due to extensive use of biocides resulting in serious infections. In this study, the prevalence of antibiotic resistance of environmental isolates of E. coli from hospitals and household settings were evaluated and compared. In addition, the association between biocide minimum inhibitory concentration (MIC) and multiple drug resistance (MDR) was investigated.

Methods

Environmental samples were collected from different homes and hospitals in Amman, Jordan. The isolates were identified phenotypically and by PCR. Antibiotic susceptibility tests and MIC of selected biocides were performed on the isolates. Screening for blaCTX-M group 1 was also performed.

Results

Of 21 E. coli strains isolated, 47.6% were MDR and 67.9% were phenotypically identified as extended spectrum beta-lactamase (ESBL) producers. The occurrence of these ESBL isolates was comparable between household and hospital settings (P > 0.05). The MIC values of the biocides tested against all isolates were well below the in-use concentration of biocides. Moreover, the MICs of biocides were comparable between isolates from households and those from hospitals (P > 0.05). No association was found between MDR and biocide MIC (P > 0.05). Most of ESBL isolates harboured blaCTX-M 1.

Conclusions

The extensive use of biocides in hospitals is not associated with MDR nor does it affect the MIC of biocides against E.coli.

Empirical treatment of lower urinary tract infections in the face of spreading multidrug resistance: in vitro study on the effectiveness of nitroxoline

The spread of antimicrobial resistance challenges the empirical treatment of urinary tract infections (UTIs). Among others, nitrofurantoin is recommended for first-line treatment, but acceptance among clinicians is limited due to chronic nitrofurantoin-induced lung toxicity and insufficient coverage of Enterobacteriaceae other than Escherichia coli. Nitroxoline appears to be an alternative to nitrofurantoin owing to its favourable safety profile, however data on its current in vitro susceptibility are sparse. In this study, susceptibility to nitroxoline was tested against 3012 urinary clinical isolates (including multidrug-resistant bacteria and Candida spp.) by disk diffusion test and/or broth microdilution. At least 91% of all Gram-negatives (n = 2000), Gram-positives (n = 403) and yeasts (n = 132) had inhibition zone diameters for nitroxoline ≥18 mm. Except for Pseudomonas aeruginosa, nitroxoline MIC₉₀ values were ≤16 mg/L and were 2- to >16-fold lower compared with nitrofurantoin. In extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA), MIC₉₀ values of nitroxoline were two-fold higher compared with non-ESBL-producing enterobacteria and methicillin-susceptible S. aureus (MSSA). The in vitro efficacies of nitroxoline and nitrofurantoin against ATCC strains of E. coli, Enterococcus faecalis and Proteus mirabilis were compared by time-kill curves in Mueller-Hinton broth and artificial urine. Nitroxoline was non-inferior against E. coli, P. mirabilis and E. faecalis in artificial urine. In conclusion, nitroxoline showed a broad antimicrobial spectrum, with inhibition zone diameters and MICs of nitroxoline well below the EUCAST breakpoint for E. coli for most organisms, and thus may also be a target for therapy of uncomplicated UTIs.

Metagenomic analysis reveals wastewater treatment plants as hotspots of antibiotic resistance genes and mobile genetic elements

The intensive use of antibiotics results in their continuous release into the environment and the subsequent widespread occurrence of antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs). This study used Illumina high-throughput sequencing to investigate the broad-spectrum profiles of both ARGs and MGEs in activated sludge and anaerobically digested sludge from a full-scale wastewater treatment plant. A pipeline for identifying antibiotic resistance determinants was developed that consisted of four categories: gene transfer potential, ARG potential, ARGs pathway and ARGs phylogenetic origin. The metagenomic analysis showed that the activated sludge and the digested sludge exhibited different microbial communities and changes in the types and occurrence of ARGs and MGEs. In total, 42 ARGs subtypes were identified in the activated sludge, while 51 ARG subtypes were detected in the digested sludge. Additionally, MGEs including plasmids, transposons, integrons (intI1) and insertion sequences (e.g. ISSsp4, ISMsa21 and ISMba16) were abundant in the two sludge samples. The co-occurrence pattern between ARGs and microbial taxa revealed by network analysis indicated that some environmental bacteria (e.g. Clostridium and Nitrosomonas) might be potential hosts of multiple ARGs. The findings increase our understanding of WWTPs as hotspots of ARGs and MGEs, and contribute towards preventing their release into the downstream environment.

Clinical Management of an Increasing Threat: Outpatient Urinary Tract Infections Due to Multidrug-Resistant Uropathogens

Urinary tract infections (UTIs) are among the most commonly treated bacterial infections. Over the past decade, antimicrobial resistance has become an increasingly common factor in the management of outpatient UTIs. As treatment options for multidrug-resistant (MDR) uropathogens are limited, clinicians need to be aware of specific clinical and epidemiological risk factors for these infections. Based on available literature, the activity of fosfomycin and nitrofurantoin remain high for most cases of MDR Escherichia coli UTIs. Trimethoprim-sulfamethoxazole retains clinical efficacy, but resistance rates are increasing internationally. Beta-lactam agents have the highest rates of resistance and lowest rates of clinical success. Fluoroquinolones have high resistance rates among MDR uropathogens and are being strongly discouraged as first-line agents for UTIs. In addition to accounting for local resistance rates, consideration of patient risk factors for resistance and pharmacological principles will help guide optimal empiric treatment of outpatient UTIs.

Susceptibility of Multidrug-Resistant Gram-Negative Urine Isolates to Oral Antibiotics

Increasing resistance among Gram-negative uropathogens limits treatment options, and susceptibility data for multidrug-resistant isolates are limited. We assessed the activity of five oral agents against 91 multidrug-resistant Gram-negative urine isolates that were collected from emergency department/hospitalized patients. Fosfomycin and nitrofurantoin were most active (>75% susceptibility). Susceptibilities to sulfamethoxazole-trimethoprim, ciprofloxacin, and ampicillin were ≤40%; empirical use of these agents likely provides inadequate coverage in areas with a high prevalence of multidrug-resistant uropathogens.

Epidemiology of Multidrug Resistant Uropathogenic Escherichia coli in Iran: a Systematic Review and Meta-Analysis

Urinary tract infection (UTI) is one of the most common infections in humans. It is primarily caused by uropathogenic Escherichia coli (UPEC), which has a high multidrug resistance (MDR). In consideration of the prevalence of MDR-UPEC strains, the aims of the present study were to systematically review the published data about the prevalence rate of MDR-UPEC from different parts of Iran and to establish the overall relative frequency (RF) of these strains in Iran. We searched several databases including PubMed, ISI Web of Science, Scopus, Google Scholar, IranMedex, and Iranian Scientific Information Database by using the following keywords: "Escherichia coli", "multidrug resistant", "MDR", "urinary tract infections", "UTI", "uropathogenic". and "Iran". Articles or abstracts that reported the prevalence of MDR-UPEC were included in this review. We found 15 articles suitable for inclusion in this study. A pooled estimation of 10,247 UPEC strains showed that 49.4% (95% confidence interval = 48.0-50.7%) of the stranis were MDR positive. The RF of MDR-UPEC in different studies varied from 10.5% to 79.2% in the Kashan and Hamedan provinces, respectively. According to the results of the present study, the RF of MDR-UPEC in Iran is high. Thus, measures should be taken to keep the emergence and transmission of these strains to a minimum.

Epidemic potential of Escherichia coli ST131 and Klebsiella pneumoniae ST258: a systematic review and meta-analysis

OBJECTIVES

Observational studies have suggested that Escherichia coli sequence type (ST) 131 and Klebsiella pneumoniae ST258 have hyperendemic properties. This would be obvious from continuously high incidence and/or prevalence of carriage or infection with these bacteria in specific patient populations. Hyperendemicity could result from increased transmissibility, longer duration of infectiousness, and/or higher pathogenic potential as compared with other lineages of the same species. The aim of our research is to quantitatively estimate these critical parameters for E. coli ST131 and K. pneumoniae ST258, in order to investigate whether E. coli ST131 and K. pneumoniae ST258 are truly hyperendemic clones.

PRIMARY OUTCOME MEASURES

A systematic literature search was performed to assess the evidence of transmissibility, duration of infectiousness, and pathogenicity for E. coli ST131 and K. pneumoniae ST258. Meta-regression was performed to quantify these characteristics.

RESULTS

The systematic literature search yielded 639 articles, of which 19 data sources provided information on transmissibility (E. coli ST131 n=9; K. pneumoniae ST258 n=10)), 2 on duration of infectiousness (E. coli ST131 n=2), and 324 on pathogenicity (E. coli ST131 n=285; K. pneumoniae ST258 n=39). Available data on duration of carriage and on transmissibility were insufficient for quantitative assessment. In multivariable meta-regression E. coli isolates causing infection were associated with ST131, compared to isolates only causing colonisation, suggesting that E. coli ST131 can be considered more pathogenic than non-ST131 isolates. Date of isolation, location and resistance mechanism also influenced the prevalence of ST131. E. coli ST131 was 3.2 (95% CI 2.0 to 5.0) times more pathogenic than non-ST131. For K. pneumoniae ST258 there were not enough data for meta-regression assessing the influence of colonisation versus infection on ST258 prevalence.

CONCLUSIONS

With the currently available data, it cannot be confirmed nor rejected, that E. coli ST131 or K. pneumoniae ST258 are hyperendemic clones.

Drug Resistance Reversal Potential of Ursolic Acid Derivatives against Nalidixic Acid- and Multidrug-resistant Escherichia coli

As a part of our drug discovery program, ursolic acid was chemically transformed into six semi-synthetic derivatives, which were evaluated for their antibacterial and drug resistance reversal potential in combination with conventional antibiotic nalidixic acid against the nalidixic acid-sensitive and nalidixic acid-resistant strains of Escherichia coli. Although ursolic acid and its all semi-synthetic derivatives did not show antibacterial activity of their own, but in combination, they significantly reduced the minimum inhibitory concentration of nalidixic acid up to eightfold. The 3-O-acetyl-urs-12-en-28-isopropyl ester (UA-4) and 3-O-acetyl-urs-12-en-28-n-butyl ester (UA-5) derivatives of ursolic acid reduced the minimum inhibitory concentration of nalidixic acid by eightfold against nalidixic acid-resistant and four and eightfold against nalidixic acid-sensitive, respectively. The UA-4 and UA-5 were further evaluated for their synergy potential with another antibiotic tetracycline against the multidrug-resistant clinical isolate of Escherichia coli-KG4. The results showed that both these derivatives in combination with tetracycline reduced the cell viability in concentration-dependent manner by significantly inhibiting efflux pump. This was further supported by the in silico binding affinity of UA-4 and UA-5 with efflux pump proteins. These ursolic acid derivatives may find their potential use as synergistic agents in the treatment of multidrug-resistant Gram-negative infections.

Antimicrobial activity and molecular analysis of azoderivatives of β-diketones

The emergence and increase in the number of multidrug resistant microorganisms have highly increased the need of therapeutic trials, necessitating a deep exploration on novel antimicrobial response tactics. This study is intended to screen and analyze the activity of a novel set of azoderivatives of β-diketones and their known analogs for antimicrobial properties. The compounds were analyzed to determine their minimum inhibitory concentration. Hit compounds 5-(2-(2-hydroxyphenyl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (C5), 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (C8), 2-(2-carboxyphenylhydrazo)malononitrile (C11) were then considered in evaluating their effect on transcription, translation and cellular oxidation impact. All three compounds were found to have in vitro inhibitory action on E.coli cell growth. The study also revealed that those compounds have a notable impact on cellular activities. It is determined that the newly synthesized azoderivative of barbituric acid (C8) have maximum growth inhibitory activity among the three compounds considered, characterized by a MIC50 of 0.42mg/ml. The MS2 reporter system was used to detect the transcriptional response of the bacteria to the treatment with the selected drugs. All three compounds are found to down regulate the transcriptional pathway. The novel compound, C8, showed maximum inhibition of transcription mechanism, followed by C5 and C11. The effect of the compounds on translation was analyzed using a Yellow Fluorescent protein reporter system. All the compounds displayed reductive impact on translation of which C8 was found to the best, exhibiting 8.5-fold repression followed by C5 and C11, respectively. Fluctuations of the Reactive Oxygen Species (ROS) concentrations were investigated upon incubation in hit compounds using ROS sensor protein. All the three compounds were found to contribute to oxidative pathway. C8 is found to have the best oxidative effect than C5 and C11. All experiments were repeated at least twice, the results being verified to be significant using statistical analysis.

Prevalence and antibiotic resistance pattern of urinary tract bacterial infections in Dessie area, North-East Ethiopia

BACKGROUND

Different studies have indicated that urinary tract infections frequently occur in both community and hospital environments and are of the most common bacterial infections in humans. the outcomes of urinary tract infections are increased hospitalization, increased direct patient costs and mortality. In Dessie, the prevalence of the commmon pathogens and antibiotic susceptibility pattern is not well studied sofar. Thus, the aim of this study is to address these gaps in the study area.

METHODS

Retrospective study was conducted in Dessie regional health reseacrh laboratory from January 1-March 31, 2012. All culture and antibiotic susceptibility test results of patients' diagnosed with UTI from September 2002 to September 2011 G.C were included in the study. Data were abstracted using structured questionnaires and finally, entered into SPSS Windows version 16.0, and descriptive statistics was generated to meet the study objective.

RESULTS

During the last ten years 680 (27.35%) bacteria were isolated in the regional laboratory. The most commonly isolated were E. coli 410 (60.29%), Pseudomonas species 59 (8.68%), Proteus species 53 (7.79%), S. aurous 50 (7.35%) and Klebsiella species 40 (5.88%). The E.coli were susceptible to Nitrofurantoin 43 (89.6%), furantoin 124 (87.3%), Nalidixic acid 91 (86.7%), kanamycin 116 (80%) & ciprofloxacin 66 (71.7%) but were almost resistant to Ampicillin, tetracycline, & trimethoprim-sulfamethoxazole. Similarly Pseudomonas and proteus species were resistant to almost all antibiotics except Gentamycin.

CONCLUSION

The E.coli, pseudomonas and proteus species were the commonly isolated bacteria in the regional health research laboratory. A majority of isolated bacterial microbes were resistant to antibiotics commonly used in clinical practices and generally available in the local economy without prescription. Culture results are necessary before initiating antibiotics.

The epidemic of extended-spectrum-β-lactamase-producing Escherichia coli ST131 is driven by a single highly pathogenic subclone, H30-Rx

The Escherichia coli sequence type 131 (ST131) clone is notorious for extraintestinal infections, fluoroquinolone resistance, and extended-spectrum beta-lactamase (ESBL) production, attributable to a CTX-M-15-encoding mobile element. Here, we applied pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing to reconstruct the evolutionary history of the ST131 clone. PFGE-based cluster analyses suggested that both fluoroquinolone resistance and ESBL production had been acquired by multiple ST131 sublineages through independent genetic events. In contrast, the more robust whole-genome-sequence-based phylogenomic analysis revealed that fluoroquinolone resistance was confined almost entirely to a single, rapidly expanding ST131 subclone, designated H30-R. Strikingly, 91% of the CTX-M-15-producing isolates also belonged to a single, well-defined clade nested within H30-R, which was named H30-Rx due to its more extensive resistance. Despite its tight clonal relationship with H30Rx, the CTX-M-15 mobile element was inserted variably in plasmid and chromosomal locations within the H30-Rx genome. Screening of a large collection of recent clinical E. coli isolates both confirmed the global clonal expansion of H30-Rx and revealed its disproportionate association with sepsis (relative risk, 7.5; P < 0.001). Together, these results suggest that the high prevalence of CTX-M-15 production among ST131 isolates is due primarily to the expansion of a single, highly virulent subclone, H30-Rx.

We applied an advanced genomic approach to study the recent evolutionary history of one of the most important Escherichia coli strains in circulation today. This strain, called sequence type 131 (ST131), causes multidrug-resistant bladder, kidney, and bloodstream infections around the world. The rising prevalence of antibiotic resistance in E. coli is making these infections more difficult to treat and is leading to increased mortality. Past studies suggested that many different ST131 strains gained resistance to extended-spectrum cephalosporins independently. In contrast, our research indicates that most extended-spectrum-cephalosporin-resistant ST131 strains belong to a single highly pathogenic subclone, called H30-Rx. The clonal nature of H30-Rx may provide opportunities for vaccine or transmission prevention-based control strategies, which could gain importance as H30-Rx and other extraintestinal pathogenic E. coli subclones become resistant to our best antibiotics.

Prevalence of extended spectrum beta lactamase producing Escherichia coli and Klebsiella pneumoniae urinary isolates in a tertiary care hospital in Kathmandu, Nepal

BACKGROUND

Escherichia coli and Klebsiella pneumoniae are the major bacterial pathogens being isolated and reported from mid stream urine (MSU) specimens, globally. These uropathogens are mostly implicated as the major extended spectrum beta-lactamase (ESBL) producers, severely limiting the therapeutic management in cases of urinary tract infections. Limited studies had been reported from Nepal investigating the ESBL producers among uropathogens. This study was designed to assess the prevalence of ESBL producing E.coli and K. pneumoniae in urinary isolates at a centrally located major tertiary care hospital in Kathmandu valley, Nepal.

METHODS

Between September 2011 and May 2012, during the nine months period, 6308 MSU specimens were collected aseptically from the same number of clinically suspected patients of urinary tract infections. The samples were cultured on MacConkey agar and blood agar. The isolates with significant bacteriuria (105 CFU / ml) were identified based on standard laboratory procedures. Antimicrobial susceptibility tests were carried out using various antimicrobial discs alongwith ceftriaxone on E.coli and K. pneumoniae isolates by Kirby Bauer disc diffusion method as per the recommendations of CLSI. On initial screening with ceftriaxone (30 μg) disc showing resistance was then confirmed for ESBL production by phenotypic confirmatory disc diffusion test (PCDDT) using ceftazidime (30 ug) and ceftazidime + clavulanic acid (30 μg + 10ug) disc as per guidelines of CLSI (2011).

RESULTS

Out of a total of 6308 MSU specimens investigated for significant bacteriuria, E.coli isolates were 444 (7.04%) and K.pneuminiae were 145 (2.3%) making a total of 589 (9.34%). Initial screening with ceftriaxone disc revealed 155 isolates of E.coli and 70 isolates of K.pneumoniae to be resistant. Further testing by PCDDT method showed 60/444 (=13.51%) of E. coli and 24/145 (=16.55%) of K. pneumoniae isolates to be confirmed ESBL producers. These ESBL - producer uropathogens showed high degree of resistance to ceftriaxone (100.0%), amoxycillin, fluoroquinolones and co-trimoxazole.

CONCLUSION

An emerging and moderately high prevalence of ESBL-producing E. coli and K. pneumoniae was observed and confirmed in the urinary isolates investigated. It is essential to have a regular and routine monitoring of ESBL producing clinical isolates in laboratory practice.

Enterohemorrhagic Escherichia coli as causes of hemolytic uremic syndrome in the Czech Republic

BACKGROUND

Enterohemorrhagic Escherichia coli (EHEC) cause diarrhea-associated hemolytic uremic syndrome (D+ HUS) worldwide, but no systematic study of EHEC as the causative agents of HUS was performed in the Czech Republic. We analyzed stools of all patients with D+ HUS in the Czech Republic between 1998 and 2012 for evidence of EHEC infection. We determined virulence profiles, phenotypes, antimicrobial susceptibilities and phylogeny of the EHEC isolates.

METHODOLOGY/PRINCIPAL FINDINGS

Virulence loci were identified using PCR, phenotypes and antimicrobial susceptibilities were determined using standard procedures, and phylogeny was assessed using multilocus sequence typing. During the 15-year period, EHEC were isolated from stools of 39 (69.4%) of 56 patients. The strains belonged to serotypes [fliC types] O157:H7/NM[fliC(H7)] (50% of which were sorbitol-fermenting; SF), O26:H11/NM[fliC(H11)], O55:NM[fliC(H7)], O111:NM[fliC(H8)], O145:H28[fliC(H28)], O172:NM[fliC(H25)], and Orough:NM[fliC(H250]. O26:H11/NM[fliC(H11)] was the most common serotype associated with HUS (41% isolates). Five stx genotypes were identified, the most frequent being stx(2a) (71.1% isolates). Most strains contained EHEC-hlyA encoding EHEC hemolysin, and a subset (all SF O157:NM and one O157:H7) harbored cdt-V encoding cytolethal distending toxin. espPα encoding serine protease EspPα was found in EHEC O157:H7, O26:H11/NM, and O145:H28, whereas O172:NM and Orough:NM strains contained espPγ. All isolates contained eae encoding adhesin intimin, which belonged to subtypes β (O26), γ (O55, O145, O157), γ2/θ (O111), and ε (O172, Orough). Loci encoding other adhesins (efa1, lpfA(O26), lpfA(O157OI-141), lpfA(O157OI-154), iha) were usually associated with particular serotypes. Phylogenetic analysis demonstrated nine sequence types (STs) which correlated with serotypes. Of these, two STs (ST660 and ST1595) were not found in HUS-associated EHEC before.

CONCLUSIONS/SIGNIFICANCE

EHEC strains, including O157:H7 and non-O157:H7, are frequent causes of D+ HUS in the Czech Republic. Identification of unusual EHEC serotypes/STs causing HUS calls for establishment of an European collection of HUS-associated EHEC, enabling to study properties and evolution of these important pathogens.

Prevalence and spread of multidrug-resistant Escherichia coli including ST131 in different patient populations in the Euroregion Meuse–Rhine

Aim: To investigate the prevalence and genetic background of Escherichia coli collected from different patient populations in the Euroregion Meuse–Rhine. Materials & methods: Susceptibility testing was performed on 1651 E. coli isolates with broth microdilution. Their genetic background was determined using pulsed-field gel electrophoresis and multilocus sequence typing. Results: The prevalence of resistance varied significantly between the populations. Approximately 10% of the E. coli isolates were multidrug-resistant and/or a β-lactamase producer. The most prevalent extended-spectrum β-lactamase type was CTX-M-15 and ST131 was the most prevalent multilocus sequence typing type. Results from pulsed-field gel electrophoresis of the ST131 isolates indicate the spread of these isolates in the Euroregion. Conclusion: E. coli ST131 was the most prevalent sequence type in our Euroregional study. It is essential to control the spread of these resistant strains (e.g., with infection-control policies, antibiotic stewardship programs and antibiotic resistance surveillance). In this way we could observe shifts in the prevalence of resistance of the E. coli population and act accordingly.