A UK multicentre study of the antimicrobial susceptibility of bacterial pathogens causing urinary tract infection

Progress of Photoantibiotics in Overcoming Antibiotic Resistance

Antibiotic resistance has emerged as a global public health crisis in the 21st century, leading to treatment failures. To address this issue, the medical and pharmaceutical sectors are confronted with two challenges: i) finding potent new antimicrobial agents that would work against resistant-pathogens, and ii) developing conceptually new or unconventional strategies by which a particular antibiotic would remain effective persistently. Photopharmacology with the aid of reversibly controllable light-active antibiotics that we call "photoantibiotics" shows great promise to meet the second challenge, which has inspired many research laboratories worldwide to align their research in inventing or developing such antibiotics. In this review, we have given an overview of the progress made over the last ten years or so towards developing such photoantibiotics. Although making such antibiotics that hold high antimicrobial potency like the native drugs and subsequently maintain a significant activity difference between light-irradiated and non-irradiated states is very challenging, the progress being reported here demonstrates the feasibility of various approaches to engineer photoantibiotics. This review provides a future perspective on the use of such antibiotics in clinical practice with the identification of potential problems and their solutions.

Precision single cell analysis to characterize host dependent antimicrobial response heterogeneity in physiological medium

Antimicrobial stewardship plays an essential role in combating the global health threat posed by multidrug-resistant pathogens. Phenotypic antimicrobial susceptibility testing (AST) is the gold standard for analyzing bacterial responses to antimicrobials. However, current AST techniques, which rely on end-point bulk measurements of bacterial growth under antimicrobial treatment in a broth solution, have limitations in resembling the physiological working environment and resolving heterogeneity in response kinetics within the population. In this study, we investigate the responses of uropathogenic bacteria under antimicrobial treatment in individual urine. Our results demonstrate substantial heterogeneity in time-kill kinetics in response to antimicrobials in a host-dependent manner. We also establish a microfluidic gel encapsulation platform for single cell imaging to rapidly resolve heterogeneous subpopulations in response to antimicrobials. The platform captures both bacterial growth and killing within the gel and enables medium exchange to assess the ability of surviving cells to resume growth after antimicrobial removal. Our study lays the foundation for a new generation of precision single cell analysis for personalizing antimicrobial treatment.

Model-driven characterization of functional diversity of Pseudomonas aeruginosa clinical isolates with broadly representative phenotypes

Pseudomonas aeruginosa is a leading cause of infections in immunocompromised individuals and in healthcare settings. This study aims to understand the relationships between phenotypic diversity and the functional metabolic landscape of P. aeruginosa clinical isolates. To better understand the metabolic repertoire of P. aeruginosa in infection, we deeply profiled a representative set from a library of 971 clinical P. aeruginosa isolates with corresponding patient metadata and bacterial phenotypes. The genotypic clustering based on whole-genome sequencing of the isolates, multilocus sequence types, and the phenotypic clustering generated from a multi-parametric analysis were compared to each other to assess the genotype-phenotype correlation. Genome-scale metabolic network reconstructions were developed for each isolate through amendments to an existing PA14 network reconstruction. These network reconstructions show diverse metabolic functionalities and enhance the collective P. aeruginosa pangenome metabolic repertoire. Characterizing this rich set of clinical P. aeruginosa isolates allows for a deeper understanding of the genotypic and metabolic diversity of the pathogen in a clinical setting and lays a foundation for further investigation of the metabolic landscape of this pathogen and host-associated metabolic differences during infection.

Frequency of drug-resistant bacterial isolates among pregnant women with UTI in maternity and children's hospital, Bisha, Saudi Arabia

Urinary tract infections (UTIs) are one of the most prevalent bacterial infections affecting humans, with a higher incidence among women. Pregnant women are at an increased risk of developing UTIs, which can have detrimental consequences for both the mother and fetus. UTIs can be caused by various bacteria, and the prevalence of drug-resistant UTIs in maternity and children's hospitals is a cause for concern due to the potential for severe complications if left untreated. The primary objective of the current study was to determine the distribution of UTI-causing bacteria and investigate the antibiotic sensitivity patterns of isolated cultures obtained from pregnant women with UTIs at the Maternity and Children's Hospital, Bisha, Saudi Arabia. This cross-sectional study was conducted from October 2021 to October 2023, involving the analysis of urine samples collected from 321 participants who acquired UTIs during pregnancy. Using biochemical tests and standard cultures, the urine samples were examined for pathogenic bacteria and their anti-microbial sensitivity patterns. The study analyzed susceptibility results according to the Clinical Laboratory Standards Institute guidelines (M100, 28th Edition, 2018). Bacterial strains demonstrating resistance to three or more antibiotics were classified as multidrug-resistant (MDR). This study revealed the distribution of UTI-causing bacteria to be as follows: Escherichia coli, 57.01%; Klebsiella pneumoniae, 24.61%; Pseudomonas aeruginosa, 4.36%; Proteus mirabilis and Enterobacter cloacae, 3.74%; Streptococcus agalactiae, 3.11%; Enterococcus faecalis, 2.18%; and Staphylococcus aureus, 1.24%. Antimicrobial susceptibility testing varied among gram-positive and gram-negative bacteria. Gentamicin demonstrated the highest sensitivity among both gram-positive and gram-negative bacteria; piperacillin-tazobactam was the second most effective drug against gram-negative bacteria. The bacterial isolates showed varying susceptibility to different antibiotics, with Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa being mainly sensitive to gentamicin, piperacillin-tazobactam, and ciprofloxacin, respectively. The strategies for reducing the risk of UTIs need to be improved to limit the spread of MDR bacteria. These strategies may include promoting hygienic practices and administering appropriate antibiotics to prevent the emergence and spread of drug-resistant bacteria. Further research is required to monitor the trends in antibiotic resistance among UTI-causing bacteria and develop effective strategies for managing this public health menace.

Investigating the impact of the genetic variant CXCR1 (rs2234671) in individuals with urinary tract infections

BACKGROUND

Urinary tract infections (UTIs) are currently posing a worldwide health concern by affecting millions of people. The genetic variant rs2234671 in the CXCR1-interleukin-8 receptor is closely related to a raised UTI risk.

OBJECTIVES

In this work, the impact of CXCR1 (rs2234671) on UTI individuals was examined.

METHODS

The demographic features of 30 recurrent UTI patients and 20 controls were thoroughly investigated. Bacterial isolation and identification were performed by the implementation of cultural and biochemical methods. DNA extraction, purification of all samples from both patients and healthy people, and IL-8 rs2234671 (C/G) SNP genotyping using T-ARMS-PCR were performed. The significance of the results was evaluated by carrying out a statistical analysis.

FINDINGS

The patient's average age was 34.63 ± 11.44 years, and controls averaged 30.30 ± 8.59 years (P= 0.156). No significant gender difference existed (P= 0.804). Escherichia coli (63.3%) was predominant, followed by Proteus mirabilis (26.7%), Enterococcus faecalis (23.3%), Klebsiella pneumoniae (10.0%), and Pseudomonas aeruginosa (20.0%). No significant association was found between bacterial species frequency, age, or sex. From the CXCR1 (rs2234671) frequency comparison, a higher GG genotype incidence in UTI patients than controls was extracted (26.7% vs. 15.0%), though not statistically significant. Risk analysis revealed that GG homozygous and C/G heterozygous genotypes were not UTI risk factors (OR = 2.47 and OR = 1.85, respectively). Moreover, the allele frequencies displayed no significant difference between the patients and controls (G allele: 66.7% vs. 66.7%; C allele: 33.3% vs. 33.3%).

MAIN CONCLUSIONS

Although no significant association between CXCR1 (rs2234671) and UTI was found, the GG genotype may point to the increasing probability of UTI risk. Additional research is required to confirm and expand these conclusions.

Fluoroquinolone resistance determinants in carbapenem-resistant Escherichia coli isolated from urine clinical samples in Thailand

Background

Escherichia coli is the most common cause of urinary tract infections and has fluoroquinolone (FQ)-resistant strains, which are a worldwide concern.

Objectives

To characterize FQ-resistant determinants among 103 carbapenem-resistant E. coli (CREc) urinary isolates using WGS.

Methods

Antimicrobial susceptibility, biofilm formation, and short-read sequencing were applied to these isolates. Complete genome sequencing of five CREcs was conducted using short- and long-read platforms.

Results

ST410 (50.49%) was the predominant ST, followed by ST405 (12.62%) and ST361 (11.65%). Clermont phylogroup C (54.37%) was the most frequent. The genes NDM-5 (74.76%) and CTX-M-15 (71.84%) were the most identified. Most CREcs were resistant to ciprofloxacin (97.09%) and levofloxacin (94.17%), whereas their resistance rate to nitrofurantoin was 33.98%. Frequently, the gene aac(6')-Ib (57.28%) was found and the coexistence of aac(6')-Ib and blaCTX-M-15 was the most widely predominant. All isolates carried the gyrA mutants of S83L and D87N. In 12.62% of the isolates, the coexistence was detected of gyrA, gyrB, parC, and parE mutations. Furthermore, the five urinary CREc-complete genomes revealed that blaNDM-5 or blaNDM-3 were located on two plasmid Inc types, comprising IncFI (60%, 3/5) and IncFI/IncQ (40%, 2/5). In addition, both plasmid types carried other resistance genes, such as blaOXA-1, blaCTX-M-15, blaTEM-1B, and aac(6')-Ib. Notably, the IncFI plasmid in one isolate carried three copies of the blaNDM-5 gene.

Conclusions

This study showed FQ-resistant determinants in urinary CREc isolates that could be a warning sign to adopt efficient strategies or new control policies to prevent further spread and to help in monitoring this microorganism.

Gut microbiology of UK care home residents: a cross-sectional analysis from a randomised controlled trial

OBJECTIVE

To describe the prevalence of potentially clinically relevant gut pathogens and associations with the carriage of resistant organisms in UK care home residents.

METHODS

Stool samples were collected pre-randomisation from care home residents participating in a randomised placebo-controlled trial. Cultivable clinically relevant bacteria were analysed. Antimicrobial susceptibility testing was performed by agar dilution (amoxicillin, co-amoxiclav, gentamicin, trimethoprim, nitrofurantoin, and ciprofloxacin). We also aimed to detect resistance to third-generation cephalosporins, carbapenems, and vancomycin.

RESULTS

Stool samples were available for 159/310 residents participating in the trial (51%) from 23 care homes between 2016 and 2018. In total, 402 bacterial isolates were cultured from 158 stool samples and 29 different species were cultured. The five most common species were Escherichia coli (155/158, 98%), Pseudomonas aeruginosa (40/158, 25%), Enterococcus faecalis (35/158, 22%), Enterococcus faecium (30/158, 19%), and Proteus mirabilis (25/158, 16%). Enterobacterales isolates were cultured from 157 samples (99%), and resistance to at least one of the tested antimicrobials was found in 119 of these (76%). There were high levels of variation in outcomes by care home.

DISCUSSION

We demonstrated that care home residents harbour significant levels of antimicrobial-resistant organisms in their stool. This work emphasises the importance of both enhanced infection control practices and antimicrobial stewardship programmes to support the appropriate use of antimicrobials in this setting.

Model-driven characterization of functional diversity of Pseudomonas aeruginosa clinical isolates with broadly representative phenotypes

Pseudomonas aeruginosa is a leading cause of infections in immunocompromised individuals and in healthcare settings. This study aims to understand the relationships between phenotypic diversity and the functional metabolic landscape of P. aeruginosa clinical isolates. To better understand the metabolic repertoire of P. aeruginosa in infection, we deeply profiled a representative set from a library of 971 clinical P. aeruginosa isolates with corresponding patient metadata and bacterial phenotypes. The genotypic clustering based on whole-genome sequencing of the isolates, multi-locus sequence types, and the phenotypic clustering generated from a multi-parametric analysis were compared to each other to assess the genotype-phenotype correlation. Genome-scale metabolic network reconstructions were developed for each isolate through amendments to an existing PA14 network reconstruction. These network reconstructions show diverse metabolic functionalities and enhance the collective P. aeruginosa pangenome metabolic repertoire. Characterizing this rich set of clinical P. aeruginosa isolates allows for a deeper understanding of the genotypic and metabolic diversity of the pathogen in a clinical setting and lays a foundation for further investigation of the metabolic landscape of this pathogen and host-associated metabolic differences during infection.

Allele distribution and phenotypic resistance to ciprofloxacin and gentamicin among extended-spectrum β-lactamase-producing Escherichia coli isolated from the urine, stool, animals, and environments of patients with presumptive urinary tract infection in Tanzania

Background

Additional antimicrobial resistance to extended-spectrum β-lactamase (ESBL)-producing E. coli exhausts treatment options. We investigated allele distribution and resistance to ciprofloxacin and gentamicin among ESBL-producing E. coli isolates from the urine, stool, animals, and environments of presumptive urinary tract infection (UTI) patients, in order to gain a crucial insight toward devising prevention and control measures and treatment guidelines.

Methods

Archived ESBL-producing E. coli isolates from the urine, stool, animals, and surrounding environments of presumptive UTI patients were retrieved. Antimicrobial susceptibility profiles for ciprofloxacin and gentamicin were done followed by multiplex Polymerase chain reaction (PCR) for blaCTX-M , blaTEM , and blaSHV , to determine ESBL allele distribution. Data were analyzed using STATA version 17.

Results

A total of 472 confirmed ESBL-producing E. coli isolates from Mwanza 243 (51.5%), Kilimanjaro 143 (30.3%), and Mbeya 86 (18.2%) were analyzed. Of these, 75 (15.9%) were from urine, 199 (42.2%) from stool, 58 (12.3%) from rectal/cloaca swabs of animals, and 140 (29.7%) from surrounding environments. Out of the 472 ESBL-producing E. coli, 98.9% (467) had at least one ESBL allele. The most frequent allele was blaCTX-M , which was detected in 88.1% (416/472) of isolates, followed by the blaTEM allele, which was detected in 51.5% (243/472) of isolates. A total of 40.7% (192/472) of isolates harbored dual blaCTX-M  + blaTEM alleles and only 0.2% (1/472) of isolates had dual blaCTX-M  + blaSHV alleles, whereas 2.3% (11/472) of isolates had a combination of all three alleles (blaCTX-M  + blaTEM  + blaSHV ). None of the isolates harbored a combination of blaTEM  + blaSHV only. Resistance to ciprofloxacin and gentamicin was observed in 70.8% (334/472) and 46.0% (217/472) of isolates, respectively. There was a significant difference in the distribution of resistance to ciprofloxacin as well as gentamicin among ESBL-producing E. coli isolated from various sources (p-value < 0.001 and 0.002, respectively).

Conclusion

Almost all ESBL-producing E. coli isolates carry blaCTX-M , blaTEM , and blaSHV either alone or in combination, with the most common allele being blaCTX-M. The resistance to ciprofloxacin and gentamicin, which are frontline antibiotics for UTIs among ESBL-producing E. coli, is high. This implies the need to continually revise the local guidelines used for optimal empirical therapy for UTIs, and for continual research and surveillance using one health approach.

Effective antimicrobial therapies of urinary tract infections among children in low- and middle-income countries: A systematic review

Importance

Urinary tract infection (UTI) is one of the most common infections encountered in infancy and childhood. Despite the emerging problem of antibiotic resistance in recent years, the use of antibiotics for better management of UTIs is inevitable.

Objective

This study aims to explore the efficacy and adverse effects of the available antimicrobial agents that are used in pediatric UTIs in low- and middle-income countries (LMICs).

Methods

Five electronic databases were searched to identify relevant articles. Two reviewers independently performed screening, data extraction, and quality assessment of the available literature. Randomized controlled trials providing antimicrobial interventions in both male and female participants within the age range of 3 months to 17 years in LMICs were included.

Results

Six randomized controlled trials from 13 LMICs were included in this review (four trials explored the efficacy). Due to high heterogeneity across the studies, a meta-analysis was not performed. Other than attrition and reporting bias, the risk of bias was moderate to high due to poor study designs. The differences in the efficacy and adverse events of different antimicrobials were not found to be statistically significant.

Interpretation

This review indicates the necessity for additional clinical trials on children from LMICs with more significant sample numbers, adequate intervention periods, and study design.

Topical and Oral Oestrogen for Recurrent Urinary Tract Infection-Evidence-based Review of Literature, Treatment Recommendations, and Correlation with the European Association of Urology Guidelines on Urological Infections

CONTEXT

Urinary tract infection (UTI) represents a significant disease for women, with 20-40% suffering from recurrent UTIs (rUTIs) across their lifetime.

OBJECTIVE

This review aims to provide evidence for current European Association of Urology (EAU) guidance that topical, but not oral, oestrogen is a worthwhile preventative therapy for rUTIs in postmenopausal women. We also aim to establish whether a relationship exists between oestrogen dosage and treatment efficacy.

EVIDENCE ACQUISITION

A literature search was performed across databases for this review. All studies that included oral or topical oestrogen in females with urinary tract infections were selected. Studies were inspected to establish treatment and follow-up duration, average weekly oestrogen dosage, efficacy of treatment, and reasons for dropout.

EVIDENCE SYNTHESIS

Clinical resolution and reduction of UTIs were evaluated. Six studies (seven treatment groups) using topical oestrogen as a treatment arm (258 patients total) and four studies using oral oestrogen as the treatment arm were included (1376 patients total). Topical oestrogen was administered as creams, pessaries, or per-vaginal tablets with follow-up spanning 2-12 mo. Of the patients, 51-100% remained UTI free throughout the duration of follow-up with minimal dropouts. Patients enrolled and treated with oral oestrogen were generally given higher weekly doses and had follow-up between 3 mo and 4.1 yr. All included studies agreed that topical oestrogen is an effective prophylaxis for rUTIs in women, with higher efficacy associated with weekly doses of ≥850 µg. Conversely, only one study arrived at the same conclusion for oral oestrogen.

CONCLUSIONS

Our review concurs with current EAU guidance that topical but not oral oestrogen therapy can be a valid treatment for women suffering from rUTIs. Administration weekly topical doses of ≥850 µg is associated with the best outcomes.

PATIENT SUMMARY

In this study, we look at the role of oral and topical oestrogens for the treatment of urinary tract infections and their adherence to European Association of Urology guidelines. We found that administration of weekly topical doses of ≥850 µg is associated with the best outcomes.

Antibiotic Antibiogram in Patients With Complicated Urinary Tract Infections in Nephrology Unit of South Waziristan

Objectives

To evaluate the antibiotic antibiogram in patients with complicated urinary tract infections (cUTIs) presenting to a Nephrology unit of South Waziristan.

Methods

A cross-sectional study was conducted at the Department of Nephrology, Sholam, South Waziristan. The study included all patients who presented with cUTIs and the symptoms included urinary urgency, hematuria, dysuria, suprapubic discomfort, and increased frequency. Those patients with clinical manifestations but are on antibiotics within the past five days were excluded.

Results

A total of 158 patients were included in the study with 113 (71.5%) females and 45 (28.5%) males. A total of 95 (60%) cases had gram-negative microbes, 47 (30%) had gram-positive cocci, and 16 (10%) had candida infection. In our study, the highly prevalent uropathogenic gram-positive bacteria showed the highest sensitivity to Linezolid, Rifampicin, and Vancomycin. Methicillin-resistant staph aureus was detected in 25% of isolates. All isolates of candida were sensitive to fluconazole. Gram-negative bacteria were highly resistant to ceftazidime, cefepime, ceftriaxone, and ciprofloxacin.

Conclusion

The development of bacterial resistance against multiple antibiotics is a global crisis that restricts the drug of choice for the treatment of cUTIs. In our study, we showed that overall, E.coli (gram negative) and S. Aureus (gram-positive) showed variable resistance to many antibiotics including ceftazidime, cefepime, piperacillin-tazobactam, ceftriaxone, and clindamycin.

Epidemiologic, microbiologic and imaging characteristics of urinary tract infections in hospitalized children < 2 years of age diagnosed with anatomic abnormalities of the urinary tract

BACKGROUND

To compare the epidemiologic, microbiologic and imaging characteristics of urinary tract infections (UTI) in children <2 years of age with and without anatomic urinary tract abnormalities (AA).

METHODS

All children hospitalized with UTI during 1.1.2005-31.12.2018 were included. The study group (patients with AA) included 76 patients. The control group (99 patients) included patients without AA.

RESULTS

1163 children were hospitalized. Age at diagnosis was younger in the study group vs. controls (5.2 ± 6.0 vs. 7.9 ± 7.5 months, P = 0.038). Uropathogens distribution was different (P = 0.007), with lower Escherichia coli (Ec) and Proteus mirabilis (Pm) percentages in the study group and higher percentages of Enterococcus spp. (Ent) in controls. In the study group, Ec nonsusceptibility rates to ampicillin, amoxicillin/clavulanic acid, cefazolin, cefuroxime, TMP/SMX and ceftriaxone were 58%, 40%, 14%, 14%, 12% and 10%, respectively, with no differences vs. controls. Ultrasound (US) was performed in 69/76 (98%) patients with AA (84.1%, abnormal); bilateral (39.7%) and unilateral (32.7%) ureteral dilatation were the most frequent findings. Voiding cystourethrography was performed in 46 patients (pathologic in 35, 76%); 31 (81.6%) patients had vesicoureteral reflux (VUR) (bilateral in 11, 35.5%; grade 4/5 in 7 patients). Uropathogens distribution in VUR patients differed between study and control groups, with lower Ec and Pm in the first group and higher Pseudomonas aeruginosa and Ent percentages in the control group.

CONCLUSION

Age at diagnosis was lower and pathogen distribution was different in patients with AA. Antibiotic susceptibility patterns of the main uropathogens were similar between patients with or without AA.

Epidemiology of Antibiotic Resistant Pathogens in Pediatric Urinary Tract Infections as a Tool to Develop a Prediction Model for Early Detection of Drug-Specific Resistance

Antibiotic resistance is an increasing problem, especially in children with urinary tract infections. Rates of drug-specific resistant pathogens were reported, and an easy prediction model to guide the clinical decision-making process for antibiotic treatment was proposed. Data on microbiological isolation from urinoculture, between January 2007−December 2018 at Istituto Gaslini, Italy, in patients aged <19 years were extracted. Logistic regression-based prediction scores were calculated. Discrimination was determined by the area under the receiver operating characteristic curve; calibration was assessed by the Hosmer and Lemeshow test and the Spiegelhalterz test. A total of 9449 bacterial strains were isolated in 6207 patients; 27.2% were <6 months old at the first episode. Enterobacteriales (Escherichia coli and other Enterobacteriales) accounted for 80.4% of all isolates. Amoxicillin-clavulanate (AMC) and cefixime (CFI) Enterobacteriales resistance was 32.8% and 13.7%, respectively, and remained quite stable among the different age groups. On the contrary, resistance to ciprofloxacin (CIP) (overall 9.6%) and cotrimoxazole (SXT) (overall 28%) increased with age. After multivariable analysis, resistance to AMC/CFI could be predicted by the following: sex; age at sampling; department of admission; previous number of bacterial pathogens isolated. Resistance to CIP/SXT could be predicted by the same factors, excluding sex. The models achieved very good calibration but moderate discrimination performance. Specific antibiotic resistance among Enterobacteriales could be predicted using the proposed scoring system to guide empirical antibiotic choice. Further studies are needed to validate this tool.

Antimicrobial resistance in urinary pathogens and culture-independent detection of trimethoprim resistance in urine from patients with urinary tract infection

Background

Although urinary tract infections (UTIs) are extremely common, isolation of causative uropathogens is not always routinely performed, with antibiotics frequently prescribed empirically. This study determined the susceptibility of urinary isolates from two Health and Social Care Trusts (HSCTs) in Northern Ireland to a range of antibiotics commonly used in the treatment of UTIs. Furthermore, we determined if detection of trimethoprim resistance genes (dfrA) could be used as a potential biomarker for rapid detection of phenotypic trimethoprim resistance in urinary pathogens and from urine without culture.

Methods

Susceptibility of E. coli and Klebsiella spp. isolates (n = 124) to trimethoprim, amoxicillin, ceftazidime, ciprofloxacin, co-amoxiclav and nitrofurantoin in addition to susceptibility of Proteus mirabilis (n = 61) and Staphylococcus saprophyticus (n = 17) to trimethoprim was determined by ETEST® and interpreted according to EUCAST breakpoints. PCR was used to detect dfrA genes in bacterial isolates (n = 202) and urine samples(n = 94).

Results

Resistance to trimethoprim was observed in 37/124 (29.8%) E. coli and Klebsiella spp. isolates with an MIC₉₀ > 32 mg/L. DfrA genes were detected in 29/37 (78.4%) trimethoprim-resistant isolates. Detection of dfrA was highly sensitive (93.6%) and specific (91.4%) in predicting phenotypic trimethoprim resistance among E. coli and Klebsiella spp. isolates. The dfrA genes analysed were detected using a culture-independent PCR method in 16/94 (17%) urine samples. Phenotypic trimethoprim resistance was apparent in isolates cultured from 15/16 (94%) dfrA-positive urine samples. There was a significant association (P < 0.0001) between the presence of dfrA and trimethoprim resistance in urine samples containing Gram-negative bacteria (Sensitivity = 75%; Specificity = 96.9%; PPV = 93.8%; NPV = 86.1%).

Conclusions

This study demonstrates that molecular detection of dfrA genes is a good indicator of trimethoprim resistance without the need for culture and susceptibility testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02551-9.

A Cross-Sectional Study to Evaluate Antimicrobial Susceptibility of Uropathogens from South Punjab, Pakistan

Background

Urinary tract infections (UTIs) are a common infection caused by uropathogenic bacteria. Drug resistance against common antibiotics is a leading cause of treatment failure in UTIs.

Objective

This study was conducted to check the prevalence of antimicrobial susceptibility against uropathogens and identify the best treatment option against UTIs.

Methods

In this cross-sectional study, urine samples (n = 1000) were collected and cultured for pure bacterial growth by using cysteine-lactose-electrolyte-deficient (CLED) media. After physical and biochemical characterization, antibacterial susceptibility was performed by the Kirby-Bauer disk diffusion method.

Results

Uropathogenic bacteria were successfully isolated in 57% (n = 572) of total tested samples (n = 1000). Escherichia coli 51.2% (n = 293/572), Klebsiella species 15.4% (n = 88/572), Enterococcus species 15.4% (n = 88/572), Pseudomonas species 9.4% (n = 54/572), Staphylococcus aureus 3.2% (n = 18/572), coagulase-negative Staphylococci (CoNS) 3.0% (n = 17/572) and Proteus species 2.4% (n = 14/572) were the most prevalent organism in UTIs. Prevalence of Gram-negative rods (GNRs) was 78.5% (n = 449/572) among UTI patients as compared to Gram-positive cocci (GPCs) 21.5% (n = 123/572). Escherichia coli 65.3% (n = 293/449), Klebsiella species 19.6% (n = 88/449), Pseudomonas species 12.0% (54/449) and Proteus species 3.1% (n = 14/449) were the most prevalent GNRs in UTIs, while Enterococcus species 71.5% (n = 88/123), Staphylococcus aureus 14.6% (n = 18/123) and coagulase-negative Staphylococci (CoNS) 13.8% (17/123) were the most prevalent GPCs in UTIs. The majority of isolated uropathogens showed resistance against routinely used antibiotics. However, teicoplanin and linezolid were the most effective drugs against GPCs and piperacillin/tazobactam, meropenem and imipenem were the most effective drugs against GNRs. Nitrofurantoin and fosfomycin were shown to be most effective against both GNRs and GPCs.

Conclusion

In conclusion, Escherichia coli (GNRs) and Enterococcus species (GPCs) are the most prevalent organisms among UTIs patients, which are shown to be antibiotic-resistant to the most commonly used antibiotics. However, nitrofurantoin and fosfomycin are the most effective drugs against uropathogens in UTIs.

Effective antimicrobial therapies of urinary tract infection among children in low-income and middle-income countries: protocol for a systematic review and meta-analysis

INTRODUCTION

Urinary tract infection (UTI) is a frequently diagnosed infection in women and children. Treatments are often initiated with broad-spectrum antibiotics without performing any culture and sensitivity test. Inappropriate and empirical antimicrobial regimens and poor adherence to the drugs lead to the recurrence of the disease. Moreover, resistance against antibiotics in the urinary tract bacteria due to inadequate therapies is a more significant cause of concern. This systematic review will explore the different antimicrobial options for treating UTIs in children and compare their effectiveness.

METHODS AND ANALYSIS

Four electronic databases MEDLINE, Cochrane Central Register of Controlled Trials, Scopus and Web of Science will be searched in February 2022 to find relevant studies. After the initial screening by two independent review authors, the selected articles will go through the full-text evaluation to filter the inclusion criteria. Using an appropriate tool, the risk of bias will also be assessed by two independent review authors. The review results showing the treatment effects of different antimicrobials will be presented as a narrative synthesis, and a meta-analysis will be conducted if applicable. Assessment of heterogeneity between studies, assessment of publication bias, and sensitivity analysis will also be performed.

ETHICS AND DISSEMINATION

The study protocol of this systematic review has been approved by the institutional review board of North South University. The dissemination of the results will be conducted in the form of scientific publication in a peer-reviewed journal and presentations in different regional and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42021260415.

Phylogenicity and Virulence Profiles of Clinical Escherichia coli Isolates in the Ho Teaching Hospital of Ghana

Background. Escherichia coli bacteria are Gram-negative, non-spore-forming aerobes or facultative anaerobic rods. Some strains are pathogenic in men while others are commensals in the gut. The pathogenic strains cause a wide array of diseases by virtue of virulence factors. The commensal strains are generally categorized into phylogenetic groups A and B1. The aim of this study was to determine the association between phylogeny of E. coli isolates and virulence and sociodemographic characteristics of the study subjects. Method. This study was a cross-sectional study carried out from July 2018 to June 2019. E. coli isolates obtained from different clinical specimens were subjected to polymerase chain reaction to determine their phylogenetic groupings and virulence. Results. The majority of the isolates belonged to phylogroup A 101 (74.8%), and the predominant virulent gene was fimA (88.9%). There was no significant correlation between phylogenicity and virulence, except for chuA which was found in all isolates that belonged to phylogroups clade I and D. None of the 101 isolates that belonged to group A had the chuA virulence gene. There was a significant association between patient age category and phylogenetic groups B1 and D. Conclusions. This study assessed the relationship between the phylogenetic distribution and the virulence profile of clinical isolates of E. coli. The virulence of isolates belonging to phylogroup A, which are generally considered as commensals, is alarming. Measures must therefore be put in place to control the spread of these virulent E. coli.

Prevalence and Resistance Patterns of Pediatric Urinary Tract Infections in Bahrain

Background

Urinary tract infections (UTI) are a commonly encountered infection in the pediatric age group. Knowledge of the causative pathogens and their antimicrobial resistance patterns in specific geographical locations is important to provide optimum care. The aim of this study is to describe the prevalence and the antimicrobial resistance patterns of the pathogens causing UTI in the pediatric age group in one tertiary inpatient Pediatric unit in Bahrain.

Methods

This is a retrospective cross-sectional study, conducted at King Hamad University Hospital (KHUH), Bahrain. The inclusion criteria consisted of patients ≤ 14 years of age admitted to the Pediatrics department at KHUH with bacteriologically proven UTI between the months of January 2018 and May 2021. Patients who were identified to have chronic urinary tract conditions or neurodevelopmental problems involving the urinary tract were excluded from the study. Electronic medical records were used to collect data regarding the isolated pathogens and sensitivity testing results.

Results

A total of 242 cases with positive culture were included. The most common bacteria causing UTI in this sample were successively Escherichia coli (68.60%), Klebsiella pneumoniae (10.30%), Proteus mirabilis (4.69%) and Pseudomonas aeruginosa (3.31%) (p<0.01). E. coli was most resistant to cefazolin (94%), followed by ampicillin (62.68%), whilst it was most sensitive to nitrofurantoin (98.96%) followed by amikacin (98.43%) (p<0.01). K. pneumoniae showed the highest rate of resistance to ampicillin (95.24%) followed by cefazolin (83.33%), meanwhile having the highest sensitivity rate to amikacin (95.24%), followed by ciprofloxacin (90.48%). P. mirabilis had the highest resistance to cefazolin (100%) followed by nitrofurantoin (87.50%), while having the highest sensitivity to piperacillin/tazobactam (100%).

Conclusion

E. coli is the most common cause of UTI in the pediatric population and it was found to be most sensitive to nitrofurantoin and amikacin whilst being relatively resistant to cefazolin and ampicillin. Similarities between our study and previous studies around the world were found when comparing the antibiotics resistance patterns. Nevertheless, it is our recommendation that empirical antibiotic selection should be tailored to the local data collected from the region.

Resistance Trend Estimation Using Regression Analysis to Enhance Antimicrobial Surveillance: A Multi-Centre Study in London 2009-2016

In the last years, there has been an increase of antimicrobial resistance rates around the world with the misuse and overuse of antimicrobials as one of the main leading drivers. In response to this threat, a variety of initiatives have arisen to promote the efficient use of antimicrobials. These initiatives rely on antimicrobial surveillance systems to promote appropriate prescription practices and are provided by national or global health care institutions with limited consideration of the variations within hospitals. As a consequence, physicians' adherence to these generic guidelines is still limited. To fill this gap, this work presents an automated approach to performing local antimicrobial surveillance from microbiology data. Moreover, in addition to the commonly reported resistance rates, this work estimates secular resistance trends through regression analysis to provide a single value that effectively communicates the resistance trend to a wider audience. The methods considered for trend estimation were ordinary least squares regression, weighted least squares regression with weights inversely proportional to the number of microbiology records available and autoregressive integrated moving average. Among these, weighted least squares regression was found to be the most robust against changes in the granularity of the time series and presented the best performance. To validate the results, three case studies have been thoroughly compared with the existing literature: (i) Escherichia coli in urine cultures; (ii) Escherichia coli in blood cultures; and (iii) Staphylococcus aureus in wound cultures. The benefits of providing local rather than general antimicrobial surveillance data of a higher quality is two fold. Firstly, it has the potential to stimulate engagement among physicians to strengthen their knowledge and awareness on antimicrobial resistance which might encourage prescribers to change their prescription habits more willingly. Moreover, it provides fundamental knowledge to the wide range of stakeholders to revise and potentially tailor existing guidelines to the specific needs of each hospital.

Preoperative polymicrobial urine culture: An analysis of the risk of perioperative urinary tract infection

PURPOSE

To report our management of preoperative polymicrobial urine culture and to determine its correlation with the risk of postoperative urinary tract infection (UTI).

PATIENTS AND METHODS

We retrospectively identified all patients with preoperative polymicrobial urine culture in our center between January 2017 and October 2019. Preoperative urine cultures were collected 5 to 8 days before the surgery. No antibiotic prophylaxis was administered preoperatively in the absence of pyuria. Patients with pyuria (≥10 leukocytes/mm³) were treated preoperatively with Ceftriaxone. In case of beta-lactam allergy, the choice between other antibiotic therapies was left to the surgeon's discretion. A second urine culture was collected the day before surgery. The primary endpoint was the occurrence of UTI within 15 days following surgery.

RESULTS

In all, 690 patients were included in the study. In line with our protocol, patients had Ceftriaxone, Fluoroquinolones, another antibiotic or no antibiotic prophylaxis in 492 cases (71.3%), 22 cases (3.2%), 31 cases (4.5%), and 145 cases (21%), respectively. The overall sterilization rate of 40.4% was similar between each treatment arm (P=0.54). Postoperative UTI occurred in 68 cases (10.5%). In multivariate analysis, a sterile urine culture the day before surgery was the only factor decreasing the risk of postoperative UTI (OR 0.39, 95%CI, 0.17-0.84; P=0.022).

CONCLUSIONS

Our findings suggest that empirical antibiotic therapy for the treatment of preoperative polymicrobial urine culture is no longer adequate. Further evaluation of organisms isolated may provide the necessary antibiograms for initiation of susceptibility based antibiotic therapy that could decrease postoperative UTI rates.

LEVEL OF EVIDENCE

3.

Multidimensional Clinical Surveillance of Pseudomonas aeruginosa Reveals Complex Relationships between Isolate Source, Morphology, and Antimicrobial Resistance

Antimicrobial susceptibility in Pseudomonas aeruginosa is dependent on a complex combination of host and pathogen-specific factors. Through the profiling of 971 clinical P. aeruginosa isolates from 590 patients and collection of paired patient metadata, we show that antimicrobial resistance is associated with not only patient-centric factors (e.g., cystic fibrosis and antipseudomonal prescription history) but also microbe-specific phenotypes (e.g., mucoid colony morphology). Additionally, isolates from different sources (e.g., respiratory tract, urinary tract) displayed rates of antimicrobial resistance that were correlated with source-specific antimicrobial prescription strategies. Furthermore, isolates from the same patient often displayed a high degree of heterogeneity, highlighting a key challenge facing personalized treatment of infectious diseases. Our findings support novel relationships between isolate and patient-level data sets, providing a potential guide for future antimicrobial treatment strategies. IMPORTANCE P. aeruginosa is a leading cause of nosocomial infection and infection in patients with cystic fibrosis. While P. aeruginosa infection and treatment can be complicated by a variety of antimicrobial resistance and virulence mechanisms, pathogen virulence is rarely recorded in a clinical setting. In this study, we discovered novel relationships between antimicrobial resistance, virulence-linked morphologies, and isolate source in a large and variable collection of clinical P. aeruginosa isolates. Our work motivates the clinical surveillance of virulence-linked P. aeruginosa morphologies as well as the tracking of source-specific antimicrobial prescription and resistance patterns.

Prevalence of bacterial uropathogens and their antimicrobial susceptibility patterns among pregnant women in Eastern Ethiopia: hospital-based cross-sectional study

BACKGROUND

Urinary tract infection (UTI) is the commonest bacterial infections during pregnancy, leading to significant maternal and prenatal morbidity and mortality.

METHOD

This hospital-based cross-sectional study during November 2017 to January 2018 was aimed to determine hospital-based antibacterial susceptibility patterns of bacterial uropathogens among 200 pregnant women in Eastern Ethiopia. ~ 10-20 ml clean-catch midstream urine samples were collected by the study participants. The well-mixed urine samples standardized to 1 µl have inoculated onto Cystine Lactose Electrolyte-Deficient and MacConkey agar. The inoculum was cultured at 37 °C under aerobic conditions for 18-48 h and examined macroscopically to evaluate the colony appearance and size of colonies. The isolate on the plates with pure growth and colonies ≥ 105 CFU/ml were further subjected to biochemical identification and susceptibility testing according to the standard procedures explained in the Clinical and Laboratory Standards Institute guideline. SPSS version 25 was used for data analysis. Descriptive statistics such as frequency, percentage, and cross-tabulation were used to present the findings in the form of graphs and tables.

RESULTS

The response rate for this study was 98.04%. Thirty-one bacteria were isolated among the 200 urine samples processed, which gave the overall UTI prevalence of 15.5%. The majority (90.3%) of the isolates were Gram-negative. Escherichia coli (45.2%) was the most frequent isolated uropathogen which followed by Proteus spp. (22.6%), Klebsiella pneumoniae (16.1%), Staphylococcus aureus (9.7%), and Pseudomonas aeruginosa (6.5%). Among the isolates, 96.4% of them were susceptible to amikacin and followed by nitrofurantoin (90.3%), and gentamicin (83.9%). However, high rates of resistance to ampicillin (58.1%), amoxicillin-clavulanate (51.6%), and cotrimoxazole (51.6%) were observed. Overall, 16(51.6%) of the bacterial isolates had developed multiple drug resistance to the selected antimicrobials.

CONCLUSION

In general, the overall prevalence of UTI was high, 15.5%. Most of isolated bacterial uropathogens were Gram-negative bacteria, and Escherichia coli was the most frequent isolate. The majority of the isolates were susceptible to amikacin, nitrofurantoin, and gentamicin. However, a high rate of resistance was observed to ampicillin, amoxicillin-clavulanate, and cotrimoxazole. More than half of the isolated bacteria had multiple drug-resistant features. Therefore, periodic and continuous urine culture for screening and diagnosis is mandatory to reduce the consequence of UTI and multidrug resistance bacteria in pregnancy.

Clinical manifestations, laboratory markers, and renal ultrasonographic examinations in 1-month to 12-year-old Iranian children with pyelonephritis: a six-year cross-sectional retrospective study

BACKGROUND

Upper urinary tract infection (UTI) or pyelonephritis may increase the pathogenesis rate and risk of severe complications in children due to kidney atrophy.

OBJECTIVE

A set of clinical symptoms, laboratory markers, and ultrasound findings were assessed to achieve the early diagnosis and prognosis of pyelonephritis in hospitalized pediatrics.

METHODS

A cross-sectional study with 104 Iranian children (95 girls and 9 boys) aged 1 month to 12 years with acute pyelonephritis during 2012-2018 was conducted. The ultrasound examination of kidneys and urinary tract during hospitalization, the incidence of clinical symptoms, and laboratory markers in blood and urine were monitored to identify the best predictive factors of early diagnosis of this bacterial infection.

RESULTS

Three-fourth of the patients had one of the four clinical symptoms of abdominal pain, constipation, dysuria, and vomiting, while others were asymptomatic. A much frequency of pyuria (88.46%), Escherichia coli in urine (92.31%), leukocytosis (81.73%), and high ESR (> 10 mm/h, 92.30%) and CRP (> 10 mg/L, 82.82%) was observed. The kidney and urinary tract ultrasonography only in 32.7% of children revealed findings in favor of pyelonephritis (cystitis, ureteral stones, and hydronephrosis).

CONCLUSION

There was a high frequency of clinical signs and laboratory markers associated with pyelonephritis. Ultrasound alone was not an efficient tool to track febrile UTI as most patients presented normal sonography.

First UTI episode in life in infants <1 year of age: Epidemiologic, clinical, microbiologic and disease recurrence characteristics

BACKGROUND

To examine the epidemiologic and microbiologic characteristics of first and recurrent UTI in young infants.

METHODS

A retrospective study of all infants <1 year hospitalized during 2014-2017 with their first UTI and followed during their first year of life.

RESULTS

191 infants were enrolled; 69 (36.12%) patients were <2 months and 32 (16.8%) developed R-UTI during the follow-up. The five most common uropathogens were Escherichia coli, Klebsiella spp., Enterococcus spp., Proteus mirabilis and Staphylococcus aureus. High resistance rates were recorded for ampicillin, amoxicillin/clavulanic acid, TMP/SMX, cefuroxime, ceftriaxone, piperacillin/tazobactam and gentamicin among E. coli and Klebsiella spp.; 29.15% E. coli and 42.9% Klebsiella spp. were ESBL-positive. 53.2% of recurrent UTI (R-UTI) episodes were diagnosed within 2 months after the initial UTI episode. E. coli (40.6%) and Klebsiella spp. (37.55) were the most frequent R-UTI pathogens. Twenty-five (78.1%) R-UTIs were caused by recurrent uropathogens representing new infections. Antibiotic resistance rates at recurrence were similar to those at initial UTI, except for a significant increase in E. coli and Klebsiella spp. resistance to piperacillin/tazobactam.

CONCLUSION

We reported high antibiotic resistance rates to major antibiotic classes used in UTI treatment. Most R-UTI episodes were caused by uropathogens different than those isolated at the initial UTI episode and were caused by highly-resistant organisms. Our findings require frequent monitoring and possible modification of the empiric and prophylactic antibiotic therapy protocols in use. As a result of our findings, the protocol for initial empiric treatment of infants with suspicion of UTI was modified by changing gentamicin to amikacin in the treatment of infants <2 months of life and amikacin monotherapy (intravenous or intramuscular) was introduced as first-line therapy for infants >2 months of life.

Comparing the Bacteriostatic Effects of Different Metal Nanoparticles Against Proteus vulgaris

For many years, researchers were looking for new antibacterial substances to deal with hospital infections and especially resistant infections. Nanoparticles attracted much attentions because of their very small size that increases the surface to capacity ratio and consequently increase chemical activity. In this study, the antibacterial effects of silver, copper oxide, nickel oxide, and titanium dioxide nanoparticles were studied on Proteus vulgaris, as a bacterium involved in the resistant hospital infections. The capability of nanoparticles to inhibit the growth of bacteria was assessed via 9 different methods including cylinder, disk, and well-diffusion, spot test, MBC, MIC, liquid inhibitory action test, diffusion, and assessing the effects of nanoparticles on a 24-h culture. Based on the results, copper oxide and silver nanoparticles had high antibacterial effects on P. vulgaris in both liquid and solid cultures, respectively. However, nickel oxide and titanium dioxide nanoparticles only had a weak effect on the inhibition of bacterial growth in the liquid culture. CuO and Ag NPs could release ions and consequently produce free radicals, disturb the equilibrium of electrons between electron donor groups and inactivate enzymes and DNA of the organisms. Moreover, they triggered holes in the bacterial membrane to disturb cellular ion equilibrium. So, they can be used to inhibit the growth of pathogens. Besides, further studies have shown that they could be used as a supplementary treatment and/or in combination with other drugs to cure infections caused by P. vulgaris.

Urinary tract infections in children < 2 years of age hospitalized in a tertiary medical center in Southern Israel: epidemiologic, imaging, and microbiologic characteristics of first episode in life

The objectives of the study were to describe the epidemiologic, microbiologic, and imaging characteristics of first 44 UTI episode in hospitalized infants and children < 2 years of age. A UTI episode was diagnosed based on suprapubic aspiration or urinary catheterization and report of a significant bacterial growth of true uropathogens. Two thousand two hundred ninety-four UTI episodes were recorded during 2009-2013 in 1694 patients; 1350 (79.7%), 223 (13.2%), and 66 (3.9%) had one, two, and three episodes, respectively. Of 1955 pathogens isolated, the most frequent were E. coli, Klebsiella spp., and Enterococcus spp. (56.9%, 14.1%, and 11%, respectively). E. coli percentages increased with increase in patient age while Klebsiella spp. and Enterococcus spp. decreased with decrease in age. 136/344 (39.5%) renal ultrasound examinations performed were reported abnormal. The percentages of abnormal ultrasound examinations in Enterococcus spp.-UTI were higher than in E. coli and Klebsiella spp.-UTI (P < 0.001 and P = 0.007, respectively). The E. coli nonsusceptibility to ampicillin, TMP/SMX, ceftriaxone, amoxicillin/clavulanic acid, cefuroxime, and gentamicin was 71%, 31%, 14.9%, 14.7%, 7%, and 4.4%, respectively. Nonsusceptibility of Klebsiella spp. to ampicillin, amoxicillin/clavulanic acid, TMP/SMX, ceftriaxone, gentamicin, and cefuroxime was 98.7%, 10.4%, 9.5%, 8.4%, 4.8%, and 4.3%, respectively. E. coli nonsusceptibility to amoxicillin/clavulanate, TMP/SMX, and ciprofloxacin decreased during the study period. E. coli percentages increased and those of Klebsiella spp. and Enterococcus spp. decreased with increase in patient age. Enterococcus. spp.-UTI was associated with older age and more severe findings on renal ultrasound. E. coli and Klebsiella spp. nonsusceptibility to amoxicillin/clavulanate, TMP/SMX, cefuroxime, and ceftriaxone was low.

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.

Occurrence of Multidrug-resistant Uropathogens Implicated in Asymptomatic Bacteriuria in Adults with Sickle Cell Disease in Ile-Ife, Southwest Nigeria

OBJECTIVES

We sought to determine the prevalence of asymptomatic bacteriuria (ASB) in patients with sickle cell disease (SCD), the susceptibility profile of its agents and their extended-spectrum β-lactamase (ESBL) production.

METHODS

Fifty-nine patients with SCD and 116 healthy controls were investigated. Urine samples were collected and cultured by standard techniques. We used the disc diffusion technique to determine antibiotic susceptibility. ESBL was detected by the combination disc method and detection of bla SHV, bla TEM, and bla CTX-M genes by multiplex-polymerase chain reaction.

RESULTS

The prevalence of ASB was higher among patients with SCD (8.6%) than controls (0.9%) (p = 0.016), predominantly among females. Coagulase-negative staphylococci (n = 2; 33.3%) predominated among the isolates. Other uropathogens included Stenotrophomonas maltophilia, Acinetobacter baumannii, and Enterobacter cloacae. All isolates were sensitive to meropenem but were resistant to ceftazidime, ampicillin, and tetracycline. bla SHV, bla TEM, and bla CTX-M-15 were detected in Enterobacter cloacae.

CONCLUSIONS

The prevalence of ASB is high in patients with SCD predominantly among females. Rare multidrug-resistant uropathogens were implicated. We posit a need for resistance surveillance programs and antibiotic stewardship to prevent treatment failure and reduce drug resistance.

The burden of antimicrobial resistance among urinary tract isolates of Escherichia coli in the United States in 2017

Urinary tract infections (UTIs) caused by Escherichia coli have been historically managed with oral antibiotics including the cephalosporins, fluoroquinolones and trimethoprim-sulfamethoxazole. The use of these agents is being compromised by the increase in extended spectrum β-lactamase (ESBL)-producing organisms, mostly caused by the emergence and clonal expansion of E. coli multilocus sequence typing (ST) 131. In addition, ESBL isolates show co-resistance to many of oral agents. Management of UTIs caused by ESBL and fluoroquinolone-resistant organisms is becoming increasingly challenging to treat outside of the hospital setting with clinicians having to resort to intravenous agents. The aim of this study was to assess the prevalence of ESBL phenotypes and genotypes among UTI isolates of E. coli collected in the US during 2017 as well as the impact of co-resistance to oral agents such as the fluoroquinolones and trimethoprim-sulfamethoxazole. The national prevalence of ESBL phenotypes of E. coli was 15.7% and was geographically distributed across all nine Census regions. Levofloxacin and trimethoprim-sulfamethoxazole-resistance rates were ≥ 24% among all isolates and this co-resistance phenotype was considerably higher among isolates showing an ESBL phenotype (≥ 59.2%) and carrying bla_CTX-M-15 (≥ 69.5%). The agents with the highest potency against UTI isolates of E. coli, including ESBL isolates showing cross-resistance across oral agents, were the intravenous carbapenems. The results of this study indicate that new oral options with the spectrum and potency similar to the intravenous carbapenems would address a significant unmet need for the treatment of UTIs in an era of emergence and clonal expansion of ESBL isolates resistant to several classes of antimicrobial agents, including oral options.

Antimicrobial resistance patterns of Uropathogens isolated from adult women with acute uncomplicated cystitis

Background

To evaluate the antibiotic resistance patterns of uropathogens isolated from adult women with acute community-acquired (CA) uncomplicated cystitis.

Results

Over a one-year period (May 2015–April 2016), the results of susceptibility testing of outpatient midstream urine samples from 5 different laboratories were prospectively evaluated. The study included only adult women with uncomplicated cystitis. The susceptibility testing in all laboratories was performed using the disk diffusion method with the VITEK-2 Compact system. The isolated uropathogens and their resistance to the tested antibiotics were evaluated. Out of 317 adult women with CA uncomplicated cystitis, 179 had a positive culture. The most commonly isolated organism was Escherichia coli (E. coli) (70.4%), followed by Klebsiella (21.2%). The overall resistance rate was highest for ampicillin (85.6%), followed by cefalotin (56.3%), trimethoprim/sulfamethoxazole (54.7%), pipracillin (51.9%), nitrofurantoin (48.8%) and aztreonam (47.4%). Isolated E. coli strains were commonly resistant to ampicillin (80.5%), trimethoprim/sulfamethoxazole (72.2%) and aztreonam (71.4%), followed by cefalotin (55.9%). The overall ciprofloxacin resistance rate was 17.9%, and the resistent was found only with E. coli (25.4%).

Conclusions

Our results may aid in the selection of proper empiric antibiotic therapy for adult women with acute CA uncomplicated cystitis.

Antimicrobial susceptibility among urinary Escherichia coli isolates from female outpatients: age-related differences

OBJECTIVES

Urinary tract infections (UTIs) are common problems in women, and important reason for visiting primary care physicians, resulting in substantial financial burden to community. The aim of this study was to determine the resistance rates of E. coli to commonly prescribed antimicrobial drugs for community-acquired UTIs in women and to establish the association between age and resistance to antibiotics among isolates of E. coli from urine.

METHODS

The study was designed as a retrospective cross-sectional study during the 5-years period. It was conducted on a sample of urinary tract isolates of E. coli taken from women with community-acquired UTIs. After prevalence of E. coli resistance to antibiotics was established, the analysis of risk factors for emergence of resistance was conducted.

RESULTS

There were 10,734 isolates of E. coli, comprising 70.62% of all samples analyzed. E. coli was the most frequently resistant to ampicillin (54.68%), followed by trimethoprim-sulphamethoxazole (37.46%), first and second generation cephalosporins (cephalexin and cefaclor) (29.53% both), and ciprofloxacin (23.80%). Less than 50% of E. coli isolates was sensitive to all three tested antibiotics, and nearly 13% acquired triple-resistance. Prevalence of isolates resistant to two or three agents was higher in the subgroup of women older than 65 years.

CONCLUSIONS

Empirical choice of antimicrobial agent for community-acquired non-complicated UTIs in women should be individualized on the basis of the patient's age, prevalence of resistance in the local community, and compliance history of the patient.

Emerging Antibiotic Resistance to Bacterial Isolates from Human Urinary Tract Infections in Grenada

A urinary tract infection (UTI) in humans is one of the most common ailments in developing countries. The treatment of UTI is becoming difficult because of the increasing drug resistance against the common bacteria associated with UTI. This research aimed to determine the bacteria, and their antimicrobial drug resistance, associated with UTI in the Grenada population. A retrospective study of data (2015 through 2017) from the microbiology laboratory of the Grenada General Hospital was analyzed. Bacteria were isolated from 1289 (33.3%) urine cultures of 3867 UTI suspected urine samples. Both Gram-positive (Staphylococcus aureus 5.0%; Enterococci group D 43.2%) and Gram-negative bacteria (Escherichia coli 51%; Klebsiella pneumoniae20.0%; Proteus mirabilis 10.0%; Acinetobacter spp. 20.0%) were isolated. Bacterial isolates were tested for their resistance to nine antibacterial drugs (ampicillin, gentamicin, norfloxacin, cefuroxime, ceftazidime, Bactrim, imipenem, augmentin, and ciprofloxacin). Gram-negative bacteria showed higher antimicrobial drug resistance.

The use of nitrofurantoin for children with acute cystitis caused by extended-spectrum Β-lactamase-producing Escherichia coli

BACKGROUND

Acute cystitis in children caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) is on the rise. Treatment of these is usually parenteral treatment. The aim of this study was to investigate the clinical and microbiological efficacy of oral nitrofurantoin treatment in children with lower urinary tract infection (UTI) caused by ESBL-producing E. coli.

METHODS

Fifty children with lower UTI due to ESBL-producing E. coli were prospectively studied. Demographic data, clinical condition, laboratory values, treatment regimens, and complications of the patients were recorded. Urine samples were obtained by transurethral catheterization or clean catch; urine bags were not used for specimen collection for culture. Patients with lower UTI due to ESBL-producing E. coli and found to be susceptible to nitrofurantoin were given oral nitrofurantoin. Patients were re-evaluated 3-4 days after the end of treatment. Renal scintigraphy was performed 1-3 months after the end of treatment.

RESULTS

A total of 50 pediatric patients (48 females and 2 males) were enrolled into study. The mean age was 7.5 ± 3.96 years (range, 1-17 years). The duration of nitrofurantoin treatment was 10 days. Bacteriological response was observed in 49 of 50 patients (98%). No patient had symptoms after treatment. No significant side-effect was observed in any of the patients. All patients had normal serum creatinine values. Renal scintigraphic study, which was performed in all patients 1-3 months after completion of treatment, demonstrated the non-scarring in 48 of 50 patients (96%).

CONCLUSIONS

UTIs due to ESBL-producing E. coli are a serious problem because of the bacteria's multidrug antibiotic resistance pattern. This study suggests that oral nitrofurantoin treatment could be a good alternative for lower UTI caused by ESBL-producing E. coli in pediatric patients.

Personal clinical history predicts antibiotic resistance of urinary tract infections

Antibiotic resistance is prevalent among the bacterial pathogens causing urinary tract infections. However, antimicrobial treatment is often prescribed “empirically”, in the absence of antibiotic susceptibility testing, risking mismatched and therefore ineffective treatment. Here, linking a 10-year longitudinal dataset of over 700,000 community-acquired UTIs with over 5,000,000 individually-resolved records of antibiotic purchases, we identify strong associations of antibiotic resistance with the demographics, records of past urine cultures and history of drug purchases of the patients. When combined together, these associations allow for machine learning-based personalized drug-specific predictions of antibiotic resistance, thereby enabling drug-prescribing algorithms that match antibiotic treatment recommendation to the expected resistance of each sample. Applying these algorithms retrospectively, over a one-year test period, we find that they much reduce the risk of mismatched treatment compared to the current standard-of-care. The clinical application of such algorithms may help improve the effectiveness of antimicrobial treatments.

Determination of antibiotic resistance genes and virulence factors in Escherichia coli isolated from Turkish patients with urinary tract infection

INTRODUCTION

: Escherichia coli ranks among the most common sources of urinary tract infections (UTI).

METHODS

Between November 2015 and August 2016, 90 isolates of E. coli were isolated from patients at Rize Education and Research Hospital in Turkey. Antibiotic susceptibility was determined for all isolates using the Kirby-Bauer disk diffusion method. These E. coli isolates were also screened for virulence genes, β-lactamase coding genes, quinolone resistance genes, and class 1 integrons by PCR.

RESULTS

With respect to the antibiotic resistance profile, imipenem and meropenem were effective against 98% and 90% of isolates, respectively. A high percentage of the isolates showed resistance against β lactam/β lactamase inhibitor combinations, quinolones, and cephalosporins. PCR results revealed that 63% (57/90) of the strains carried class 1 integrons. In addition, a high predominance of extended-spectrum β-lactamases (ESBLs) was observed. The qnrA, qnrB, and qnrS genes were found in 24 (26.6%), 6 (6.6%), and 3 (3.3%), isolates, respectively. The most common virulence gene was fim (82.2%).The afa, hly, and cnf1 genes were detected in 16.6%, 16.6%, and 3.3% of isolates, respectively. Moreover, we observed eleven different virulence patterns in the 90 E. coli isolates. The most prevalent pattern was fım, while hly-fım, afa-aer-cnf-fım, aer-cnf, afa-aer, and afa-cnf-fım patterns were less common.

CONCLUSIONS

Most of the E. coli virulence genes investigated in this study were observed in E. coli isolates from UTI patients. Virulence genes are very important for the establishment and maintenance of infection.

Common microbial causes of significant bacteriuria and their antibiotic resistance pattern in the Isfahan Province of Iran

Urinary tract infections (UTIs) are considered the most common community-acquired infections worldwide, which have possible complications along with significant economic impact on national healthcare systems. The aim of this study was to identify the most common causes of significant bacteriuria and to assess their antimicrobial resistance pattern in the Isfahan province of Iran. In this cross-sectional study, 11,678 urine samples of the patients referred to Mahdieh Medical Diagnostic Centre Charity were examined over a period of 10 months (from September 2015 to June 2016). Among the cases, 6.85% were positive for bacteriuria (F/M = 11.3). Escherichia coli (62%) was the most frequently isolated bacteria, followed by Staphylococcus epidermidis (13.9%) and Staphylococcus aureus (6.8%). E. coli was more prevalent among patients with diabetes mellitus. E. coli isolates showed the highest resistance to nalidixic acid, Trimethoprim/Sulfamethoxazole and Cefixime. Our results revealed that broad-spectrum antibiotic resistance is frequent among isolated uropathogens in Isfahan, Iran.

High Prevalence of Multidrug-Resistant Escherichia coli in Urine Samples from Inpatients and Outpatients at a Tertiary Care Hospital in Sétif, Algeria

The worldwide dissemination of multidrug-resistant (MDR) Enterobacteriaceae is a major public health issue. The aim of this study was to investigate the prevalence of MDR Escherichia coli (MDR-EC) isolates, in inpatients/outpatients with urinary tract infections at Sétif University Hospital (Algeria). Bacterial cultures were obtained from 426 of the 3,944 urine samples collected from January 2015 to February 2017. Among these cultures, 215 E. coli isolates were identified by mass spectrometry, and 38 (17.7%) were MDR-EC (disk diffusion method): 36 produced only extended-spectrum β-lactamases (ESBL), one ESBL and a carbapenemase, and one only a cephalosporinase (double-disk synergy test). Multiplex PCR and sequencing analyses showed that 37 ESBL-producing isolates harbored genes encoding CTX-M enzymes (CTX-M-15 in 33 isolates, 89.19%; and CTX-M-14 group in four isolates, 10.81%). One CTX-M-15-producing isolate co-expressed also an OXA-48-like carbapenemase. Phylogenetic group analysis of the 37 ESBL-producing and 178 non-ESBL-producing isolates indicated that the most common phylogenetic group was B2 (54.05% of ESBL-producing and 48.31% of non-ESBL-producing isolates), followed by A and D for ESBL-, and by B1, A, and F for non-ESBL-producing isolates. This is the first report highlighting the presence of MDR-EC isolates that produce both CTX-M and OXA-48-like enzymes in Sétif, Algeria.

Prevalence of vancomycin resistance among isolates of enterococci in Iran: a systematic review and meta-analysis

Introduction

Enterococcus is responsible for 10% of hospital-acquired infections. The purpose of this review was to evaluate the prevalence of vancomycin-resistant Enterococcus (VRE) isolates in Iran using a meta-analysis method.

Materials and methods

Iranian databases, including Magiran and IranDoc, and international databases, including PubMed and MedLib, were examined carefully, and a total of 20 articles published between 2000 and 2011 were extracted. The data were subjected to meta-analysis and random-effects models. In addition, heterogeneous studies were assessed using the I ² index. Finally, the data were analyzed using R and STATA software.

Results

The results showed that the strain of Enterococcus faecalis had been more common than Enterococcus faecium in clinical infection (69% vs 28%). However, resistance to vancomycin was higher among strains of E. faecium compared with strains of E. faecalis (33% vs 3%). The complete resistance, intermediate resistance, and sensitivity to vancomycin among Enterococcus isolates were 14% (95% CI: 11, 18), 14% (95% CI: 5, 23), and 74% (95% CI: 65, 83), respectively. The resistance patterns, depending on the sample type, did not show a significant difference. In addition, the resistance of isolated strains to vancomycin in outpatients was significantly higher than that in inpatients (16% vs 1%). Moreover, 80%-86% of resistant strains were genotype van A and 14%-20% of resistant strains were genotype van B.

Conclusion

The findings of the present review show that there is a high frequency of resistant Enterococcus in Iran. Therefore, consideration of the prevalence and frequency of subjected resistant strains can be helpful for decision makers to implement proper health policies in this direction.

Prevalence of Multidrug Resistance and Extended-Spectrum β-Lactamase Carriage of Clinical Uropathogenic Escherichia coli Isolates in Riyadh, Saudi Arabia

The prevalence of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-producing E. coli) has recently increased worldwide. This study aims at determining the antimicrobial susceptibility patterns of a collection of clinical E. coli urine isolates and evaluating the ESBL carriage of these isolates at phenotypic and genotypic levels. A total of 100 E. coli urine isolates were collected at a tertiary healthcare centre in Riyadh from January 2018 to March 2018. Antimicrobial susceptibility testing was carried out for all isolates. ESBL production was characterized at phenotypic and genotypic levels using double-disc synergy test and polymerase chain reaction, respectively. Detection of different ESBL variants was performed using DNA sequencing. Of 100 E. coli isolates, 67 were associated with multidrug resistance (MDR) phenotype. All isolates showed variable resistance levels to all antibiotics used here expect to imipenem, where they were all imipenem-sensitive. 33 out of 100 E. coli isolates were positive for ESBLs by phenotypic and genotypic methods. Among all ESBL-positive E. coli isolates, the CTX-M was the most prevalent ESBL type (31/33 isolates; 93.94%). CTX-M-15 variant was detected in all isolates associated with CTX-M carriage. Multiple ESBL gene carriage was detected in 15/33 isolates (45.45%), where 11 (33.33%) isolates produced two different ESBL types while 4 isolates (12.12%) associated with carrying three different ESBL types. Our study documented the high antimicrobial resistance of ESBL-producing E. coli to many front-line antibiotics currently used to treat UTI patients, and this implies the need to continuously revise the local guidelines used for optimal empirical therapy for UTI patients. It also showed the high prevalence of ESBL carriage in E. coli urine isolates, with CTX-M-15 being the most predominant CTX-M variant.

Physiologically Based Pharmacokinetic Modeling of Renally Cleared Drugs in Pregnant Women

BACKGROUND

Since pregnant women are considerably underrepresented in clinical trials, information on optimal dosing in pregnancy is widely lacking. Physiologically based pharmacokinetic (PBPK) modeling may provide a method for predicting pharmacokinetic changes in pregnancy to guide subsequent in vivo pharmacokinetic trials in pregnant women, minimizing associated risks.

OBJECTIVES

The goal of this study was to build and verify a population PBPK model that predicts the maternal pharmacokinetics of three predominantly renally cleared drugs (namely cefazolin, cefuroxime, and cefradine) at different stages of pregnancy. It was further evaluated whether the fraction unbound (f _u) could be estimated in pregnant women using a proposed scaling approach.

METHODS

Based on a recent literature review on anatomical and physiological changes during pregnancy, a pregnancy population PBPK model was built using the software PK-Sim^®/MoBi^®. This model comprised 27 compartments, including nine pregnancy-specific compartments. The PBPK model was verified by comparing the predicted maternal pharmacokinetics of cefazolin, cefuroxime, and cefradine with observed in vivo data taken from the literature. The proposed scaling approach for estimating the f _u in pregnancy was evaluated by comparing the predicted f _u with experimentally observed f _u values of 32 drugs taken from the literature.

RESULTS

The pregnancy population PBPK model successfully predicted the pharmacokinetics of cefazolin, cefuroxime, and cefradine at all tested stages of pregnancy. All predicted plasma concentrations fell within a 2-fold error range and 85% of the predicted concentrations within a 1.25-fold error range. The f _u in pregnancy could be adequately predicted using the proposed scaling approach, although a slight underestimation was evident in case of drugs bound to α₁-acidic glycoprotein.

CONCLUSION

Pregnancy population PBPK models can provide a valuable tool to predict a priori the pharmacokinetics of predominantly renally cleared drugs in pregnant women. These models can ultimately support informed decision making regarding optimal dosing regimens in this vulnerable special population.

Global research output in antimicrobial resistance among uropathogens: A bibliometric analysis (2002-2016)

OBJECTIVES

Antimicrobial resistance (AMR) among uropathogens contributes to treatment failure. Research in AMR among uropathogens is important to establish treatment options. This study assessed global research trends in AMR among uropathogens.

METHODS

SciVerse Scopus was used to retrieve relevant documents for the period 2002-2016. Only journal articles were included in the analysis. Analysis of author keywords was carried out using VOSviewer.

RESULTS

A total of 1087 journal articles were retrieved with an h-index of 50. The number of publications increased noticeably in the past decade. Analysis of subject areas of retrieved documents showed that 275 (25.3%) articles were in molecular biology/genetics/microbiology/immunology, 197 (18.1%) were in pharmacological/therapeutic approaches for treatment of urinary tract infections and 615 (56.6%) were in epidemiology/public health. Terms such as multidrug-resistant and extended-spectrum β-lactamases (ESBLs) appeared more frequently in documents published in the period 2012-2016. The mean number of authors per article was 5.3. Most active authors in this field were from Japan. The USA ranked first with 148 documents (13.6%), followed by India (97; 8.9%) and Iran (84; 7.7%). The top productive institution was Tehran University of Medical Sciences (21 publications), followed by Kobe University in Japan (20 publications). The Journal of Antimicrobial Chemotherapy ranked first with 33 publications.

CONCLUSION

Research in AMR among uropathogens showed a noticeable increase in the past decade. Reports of increasing incidence of resistance among uropathogens were published from different parts of the world. Empirical therapy should be based on updated research in AMR.

Bladder resident macrophages: Mucosal sentinels

Macrophages are instrumental in the response to infectious and noninfectious diseases, however, their role in the bladder is poorly understood. Indeed, the bladder is a mucosal tissue frequently overlooked in research, despite the prevalence of illnesses such as urinary tract infection and bladder cancer. Notably, bladder tissue macrophages are among the most populous resident immune cells in this organ and recent studies support that resident macrophages and infiltrating monocytes play nonredundant roles in response to infection, immunotherapy, and inflammation. Advancing our understanding of macrophage behavior in the bladder is complicated by the difficulty in obtaining tissue-resident cells. Surmounting this challenge, however, for a greater understanding of macrophage ontology, impact on innate and adaptive immunity, and regulation of homeostasis, will ultimately contribute to better therapies for common afflictions of the bladder.

Metabolomics reveals immunomodulation as a possible mechanism for the antibiotic effect of Persicaria capitata (Buch.-Ham. ex D. Don) H.Gross

INTRODUCTION

In spite of advances in antibiotics, urinary tract infection (UTI) is still among the most common reasons for antibiotic medication worldwide. Persicaria capitata (Buch.-Ham. ex D. Don) H.Gross (P. capitata) is a herbal medicine used by the Miao people in China to treat UTI. However studies of its mechanism are challenging, owing to the complexity of P. capitata with multiple constituents acting on multiple metabolic pathways.

OBJECTIVE

The objective of this study was to explore the working mechanism of P. capitata on urinary tract infection.

METHODS

Relinqing® granule, which is solely made from aqueous extracts of the whole P. capitata plant, was used in this study. Urine metabolomics based on gas chromatography-mass spectroscopy was employed to assess the metabolic changes caused by administration of Relinqing® granule in a UTI mouse model. Female specific-pathogen-free Kunming mice were divided into control group (mock infection, saline treatment), model group (E.coli infection, saline treatment), Relinqing® group (E.coli infection, Relinqing® granule treatment), ciprofloxacin group (E.coli infection, ciprofloxacin treatment), and sham-Relinqing® group (no surgery, Relinqing® granule treatment).

RESULTS

The results showed that after the treatments, urine levels of itaconic acid in Relinqing® group increased by 4.9 fold and 11.3 fold compared with model and ciprofloxacin groups respectively. Itaconic acid is an endogenous antibacterial metabolite produced by macrophages, which also functions as a checkpoint for metabolic reprogramming of macrophage.

CONCLUSION

Our findings suggest that this herbal medicine can cure urinary tract infection through modulation of immune system.

Clinical Practice Guidelines for the Antibiotic Treatment of Community-Acquired Urinary Tract Infections

Urinary tract infections (UTIs) are infectious diseases that commonly occur in communities. Although several international guidelines for the management of UTIs have been available, clinical characteristics, etiology and antimicrobial susceptibility patterns may differ from country to country. This work represents an update of the 2011 Korean guideline for UTIs. The current guideline was developed by the update and adaptation method. This clinical practice guideline provides recommendations for the diagnosis and management of UTIs, including asymptomatic bacteriuria, acute uncomplicated cystitis, acute uncomplicated pyelonephritis, complicated pyelonephritis related to urinary tract obstruction, and acute bacterial prostatitis. This guideline targets community-acquired UTIs occurring among adult patients. Healthcare-associated UTIs, catheter-associated UTIs, and infections in immunocompromised patients were not included in this guideline.

Prevalence and characteristics of ST131 clone among unselected clinical Escherichia coli in a Chinese university hospital

Background

Escherichia coli clinical sequence type 131 (ST131) has emerged as an extensively antimicrobial resistant E. coli clonal group in recent years throughout the world. The aim of this study was to investigate the prevalence and molecular characteristics of ST131 among unselected E. coli clinical isolates in a Chinese university hospital.

Methods

Seven hundred consecutive E. coli isolates were collected at a Chinese university hospital between 2014 and 2015. Isolates belonging to ST131 were identified by PCR and multilocus sequence typing (MLST), and then characterized for antibiotic resistance, CTX-M-type extended-spectrum β-lactamase genes, fluoroquinolone resistance genes, O types, phylogenetic groups, virulence factors and PFGE patterns.

Results

Overall, 83 (11.6%) isolates were identified as ST131 group. The H30 lineage accounted for 53 (63.9%) of the ST131 isolates, including 13 H30-Rx and 40 H30 non-Rx. The remaining 30 isolates belonged to H41 lineage. Two O types were identified in this study: O25b (66.3%) and O16 (33.7%). Compared with O25b-B2-ST131 isolates, O16-B2-ST131 isolates harbored less virulence factors of adhesins. ST131 H30 Rx isolates had significantly higher virulence score than those of other isolates. O16-B2-ST131 isolates were shown to have a lower resistance to quinolones than O25b-B2-ST131 isolates. 5 nonsynonymous mutations (GyrA S83 L, D87N, ParC S80I, E84V and ParE I529L) were strongly associated with ST131 H30 and O25b isolates. Results of PFGE demonstrated that these isolates were classified into 68 pulsotypes and these subtypes were grouped into 23 different PFGE clusters using 70% similarity cut-off value.

Conclusions

This is the first study to reveal the prevalence and molecular characteristic of ST131 clonal group among consecutive clinical E. coli isolates in China. Our findings demonstrated that ST131 lineage accounts for a small proportion of clinical E. coli isolates in China, which included two major groups: O25b-B2-ST131 and O16-B2-ST131. Our results implies that O16-B2-ST131 subclone may be an important type of E. coli ST 131 in China, which suggests that future studies should not ignore such clone in this country.

A 6-year study of complicated urinary tract infections in southern China: prevalence, antibiotic resistance, clinical and economic outcomes

Urinary tract infections (UTIs) are common nosocomial infections. This study evaluated the prevalence, pathogens, antibiotic resistances, clinical outcomes, and hospitalization costs associated with complicated UTIs in southern China, and risk factors delaying patient discharge. We retrospectively reviewed electronic medical records of 4,284 (61.4% women) complicated UTI-related hospitalizations from 2008 to 2013. Average patient age was 61.1 years and median hospital stay was 11 days. Pathogens were isolated from 1,071 urine and 148 blood specimens. Gram-negative bacteria were the most frequent and included Escherichia coli (48.2%), Klebsiella pneumoniae (9.5%), Pseudomonas aeruginosa (4.9%), and Proteus mirabilis (4.6%), while Enterococcus spp. (14.4%) was the most common Gram-positive bacteria causing UTIs. Both E. coli and K. pneumoniae showed high resistance rates (>45%) to wide-spectrum penicillins, cephalosporins, aztreonam, and ciprofloxacin. Resistances to beta-lactamase inhibitor/beta-lactam antibiotic combination were relatively lower. Imipenem, meropenem, and amikacin had the greatest activity against E.coli and K. pneumoniae. Recurrent infection was a risk factor for mortality. Age, sex, previous surgery, diabetes, and renal insufficiency were significant risk factors for delayed discharge (P<0.01). Response to initial treatment was associated with a lower cost. Initial empiric use of antibiotics least associated with resistance may reduce costs and medical resource usage.

Species distribution and antibiotic susceptibility profile of bacterial uropathogens among patients complaining urinary tract infections

BACKGROUND

Urinary tract infection is the second most common type of infection and the problem is further compounded by the emergence of drug resistance in bacterial uropathogens. The aim of this study was to determine the spectrum of bacterial uropathogens and their drug resistant pattern.

METHODS

A single institutional cross-sectional study was carried out at Arsho Advanced Medical laboratory from September 2015 to May 2016. A total of 712 urine samples were collected, inoculated onto primary isolation culture media, incubated at 37 °C for 18-24 h, and significant bacteriuria was determined. Identification and the antimicrobial susceptibility testing of bacteria were determined by using the automated VITEK 2 compact system.

RESULTS

Out of 712 urine samples processed, 256 (36%) yielded significant bacteriuria of which 208 (81.25%) were obtained from female and 48 (18.75%) from male patients. Age group of 25-44 were more affected with the infection. Of 256 bacterial isolates recovered, Escherichia coli, was the dominant bacterium. Ampicillin and trimethoprim/sulfamethoxazole were the least effective drugs while piperacillin/tazobactam was the most effective drug against Gram-negative bacteria. Erythromycin was the least effective drug while vancomycin was the most active drug against Gram-positive bacteria.

CONCLUSIONS

Observation of many bacterial species causing UTI in this study warrants, a continuous epidemiological survey of UTI in health institutions across the country. High level of drug resistance to the commonly prescribed drugs necessitates a search for other options.