Urinary tract infections owing to ESBL-producing bacteria: microorganisms change--clinical pattern does not

Molecular detection of plasmid mediated blaTEM, blaCTX-M,and blaSHV genes in Extended Spectrum β-Lactamase (ESBL) Escherichia coli from clinical samples

BACKGROUND

Extended spectrum β-lactamases (ESBLs) are a group of beta-lactamase enzymes that confer resistance to the oxyimino-cephalosporins and monobactams. The emergence of ESBL - producing genes possesses a serious threat for treating infections since it is associated with multi-drug resistance. This study was focused to identify the ESBLs producing genes from Escherichia coli isolates from clinical samples from a referral-level tertiary care hospital in Lalitpur.

METHODS

This was a cross-sectional study conducted from September 2018 to April 2020 at the Microbiology Laboratory of Nepal Mediciti Hospital. Clinical samples were processed, and culture isolates were identified and characterized following standard microbiological techniques. An antibiotic susceptibility test was performed by a modified Kirby-Bauer disc diffusion method as recommended by Clinical and Laboratory Standard Institute guidelines.Extended -spectrum beta-lactamases were phenotypically confirmed by the combined disc method. The ESBL-producing genes bla_TEM, bla_CTX-M and bla_SHV were confirmed by PCR.

RESULTS

Of the 1449 total E. coli isolates, 22.29% (323/1449) isolates were multi-drug resistant (MDR). Among the total MDR E. coli isolates, 66.56% (215/323) were ESBL producers. The maximum number of ESBL E. coli was isolated from urine 90.23% (194) followed by sputum 5.58% (12), swab 2.32% (5), pus 0.93% (2), and blood 0.93% (2). The antibiotic susceptibility pattern of ESBL E. coli producers showed the highest sensitivity toward tigecycline (100%) followed by polymyxin b, colistin and meropenem. Out of 215 phenotypically confirmed ESBL E. coli, only 86.51% (186) isolates were found to be positive by PCR for either bla_TEM or bla_CTX-M genes. Among the ESBL genotypes, the most common were bla_TEM 63.4% (118) followed by bla_CTX-M 36.6% (68).

CONCLUSION

The emergence of MDR and ESBL - producing E. coli isolates with high antibiotic - resistant rates to commonly used antibiotics and increased predominance of major gene types bla_TEM is a serious concern to the clinicians and microbiologists. Periodic monitoring of antibiotic susceptibility and associated genes would help guide the rationale use of antibiotics for treating the predominant pathogen E. coli in the hospitals and healthcare facilities of the communities.

Evolution of the Antimicrobial resistance of Bacteria causing Urinary Tract Infections

BACKGROUND

The bacteria, Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae), are the main reasons for urinary tract infections (UTIs). This research aimed to investigate the isolation of etiologic agents from patients with UTI; it also investigates the antibiotic resistance activities and incidence of ESBL genes between different clinical separates of uropathogenic E. coli, determining their association with ESBL genes.

METHODS

The study enrolled 1000 positive growth isolates. The predominant pathogen associated with urinary tract infection, Gram-negative, were the main isolates from UTI patients, including E. coli, K. pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus and Enterococcus faecalis.

RESULTS

Among suspicious cases of urinary tract infection, we showed that 15.2% of the patients had UTI, and female patients in the childbearing age group were more affected. 644 E. coli (64.4%) and 322 (32.2%) K. pneumoniae were more isolated. Among 936 (93.6%) ESBL producing bacteria, 614 (61.4 %) E. coli showedhigh resistance to the antibiotics, Cefotaxime (85.7 %), Cefepime (85.7 %), Ciprofloxacin (83.1 %) and Kanamycin (77.9 %). Most ESBL-producing K. pneumoniae were multidrug-resistant (MDR). Nitrofurantoin, gentamycin, and imipenem were the most effective antibiotics for ESBL-producing E. coli isolates.

CONCLUSION

This study shows that the high rates of MDR Escherichia coli infection in our hospital were frequentative reasons for UTI. Nitrofurantoin and aminoglycosides were the most beneficial first-line drugs to be applied in the cases of UTI. It is recommended to conduct regular investigations on the drug resistance of all isolates and formulate helpful antibiotic treatment policies in China. It is important to determine the prevalence of ESBL in urine E. coli and K. pneumoniae isolates because it has a great influence on the selection of suitable antibacterial agents. In short, more than half of ESBL producers have multiple drug resistance (MDR).

Extended-spectrum beta-lactamase Escherichia coli and Klebsiella pneumoniae urinary tract infections

The prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae urinary tract infections (UTIs) is increasing worldwide. We investigated the prevalence, clinical findings, impact and risk factors of ESBL E. coli/K. pneumoniae UTI through a retrospective review of the medical records of children with UTI aged <15 years admitted to Prince of Songkla University Hospital, Thailand over 10 years (2004–2013). Thirty-seven boys and 46 girls had ESBL-positive isolates in 102 UTI episodes, compared with 85 boys and 103 girls with non-ESBL isolates in 222 UTI episodes. The age of presentation and gender were not significantly different between the two groups. The prevalence of ESBL rose between 2004 and 2008 before plateauing at around 30–40% per year, with a significant difference between first and recurrent UTI episodes of 27.3% and 46.5%, respectively (P = 0.003). Fever prior to UTI diagnosis was found in 78.4% of episodes in the non-ESBL group and 61.8% of episodes in the ESBL group (P = 0.003). Multivariate analysis indicated that children without fever (odds ratio (OR) 2.14, 95% confidence interval (CI) 1.23–3.74) and those with recurrent UTI (OR 2.67, 95% CI 1.37–5.19) were more likely to yield ESBL on culture. Congenital anomalies of the kidney and urinary tract were not linked to the presence of ESBL UTI. In conclusion, ESBL producers represented one-third of E. coli/K. pneumoniae UTI episodes but neither clinical condition nor imaging studies were predictive of ESBL infections. Recurrent UTI was the sole independent risk factor identified.

Third-generation cephalosporin-resistant urinary tract infections in children presenting to the paediatric emergency department

Background

The incidence of antibiotic-resistant urinary tract infections (UTIs) in children is increasing. The purpose of this study was to describe the incidence, clinical characteristics, and risk factors for third-generation cephalosporin-resistant UTIs presenting to the paediatric emergency department (ED).

Methods

This was a retrospective cohort study conducted at British Columbia Children's Hospital. Children aged 0 to 18 years old presenting to the ED between July 1, 2013 and June 30, 2014 and were found to have UTI due to Enterobacteriaceae and Pseudomonas species were included. Patient demographics, clinical features, laboratory findings, and outcomes were compared using standard statistical analyses. Risk factors for resistant UTIs were analyzed using multiple logistic regression analysis.

Results

There were 294 eligible patients. The median age was 27.4 months. A third-generation cephalosporin-resistant organism was identified in 36 patients (12%). Patients with resistant UTI had lower rates of appropriate empiric antibiotic therapy (25% versus 95.3%, P<0.05), higher rates of hospitalization (38.9% versus 21.3%, P<0.05), higher rates of undergoing a voiding cystourethrogram (19.4% versus 5.0%, P<0.05), and higher rates of UTI recurrence within 30 days (13.9% versus 4.7%, P<0.05). In multivariate analysis, recent hospitalization (odds ratio [OR] 4.3, confidence interval [CI] 1.2 to 16) and antibiotic therapy (OR 3.5, CI 1.5 to 8.5) within the previous 30 days were risk factors for resistant UTI.

Conclusions

Third-generation cephalosporin-resistant organisms account for a significant proportion of community-acquired paediatric UTIs. Recent hospitalization and antibiotic use are associated with increased risk of resistant UTI.

Urinary tract infection caused by community-acquired extended-spectrum β-lactamase-producing bacteria in infants

OBJECTIVE

Urinary tract infection (UTI) caused by resistant strains of bacteria is increasingly prevalent in children. The aim of this study was to investigate the clinical characteristics and risk factors for UTI caused by community-acquired extended-spectrum β-lactamase (CA-ESBL)-producing bacteria in infants.

METHODS

This was a retrospective study performed over 5 years in a single Korean center. Hospitalized infants with febrile UTI were enrolled and divided into two groups (CA-ESBL vs. CA non-ESBL UTI). The yearly prevalence was calculated. Baseline characteristics and clinical course such as fever duration, laboratory and radiological findings were compared between the two groups. Risk factors associated with the CA-ESBL UTI were investigated.

RESULTS

Among the enrolled infants (n=185), 31 (17%) had CA-ESBL UTI. The yearly prevalence of ESBL of CA-ESBL UTI increased during the study (0% in 2010, 22.2% in 2015). Infants with CA-ESBL UTI had a longer duration of fever after initiating antibiotics (2.0±1.1 vs. 1.5±0.6 days, p=0.020). Cortical defects on renal scan and early treatment failure were more frequent in CA-ESBL (64.5 vs. 42.2%, p=0.023; 22.6 vs. 4.5%, p=0.001). A logistic regression analysis revealed that urinary tract abnormalities and previous UTI were independent risk factors for CA-EBSL UTI (odds ratio, 2.7; p=0.025; 10.3; p=0.022).

CONCLUSION

The incidence of UTI caused by ESBL-producing bacteria has increased in Korean infants. Recognition of the clinical course and risk factors for ESLB-producing UTI may help to determine appropriate guidelines for its management.

Childhood urinary tract infection caused by extended-spectrum β-lactamase-producing bacteria: Risk factors and empiric therapy

BACKGROUND

This study investigated risk factors of childhood urinary tract infection (UTI) associated with extended-spectrum β-lactamase (ESBL)-producing bacteria (ESBL-positive UTI) and evaluated antimicrobial resistance as well as empiric treatment of childhood UTI.

METHODS

The records of children with positive urine culture between 1 January 2008 and 31 December 2012 were evaluated. Patients with positive urine culture for ESBL-producing bacteria were defined as the ESBL-positive group, whereas patients of the same gender and similar age with positive urine culture for non-ESBL-producing bacteria were defined as the ESBL-negative group. Each ESBL-positive patient was matched with two ESBL-negative patients.

RESULTS

The ESBL-positive and negative groups consisted of 154 and 308 patients, respectively. Potential risk factors for ESBL-positive UTI were identified as presence of underlying disease, clean intermittent catheterization (CIC), hospitalization, use of any antibiotic and history of infection in the last 3 months (P < 0.05). On logistic regression analysis, CIC, hospitalization and history of infection in the last 3 months were identified as independent risk factors. In the present study, 324 of 462 patients had empiric therapy. Empiric therapy was inappropriate in 90.3% of the ESBL-positive group and in 4.5% of the ESBL-negative group. Resistance to nitrofurantoin was similar between groups (5.1% vs 1.2%, P = 0.072); resistance to amikacin was low in the ESBL-positive group (2.6%) and there was no resistance in the ESBL-negative group.

CONCLUSIONS

Clean intermittent catheterization, hospitalization and history of infection in the last 3 months should be considered as risk factors for ESBL-positive UTI. The combination of ampicillin plus amikacin should be taken into consideration for empiric therapy in patients with acute pyelonephritis who have the risk factors for ESBL-positive UTI. Nitrofurantoin seems to be a logical choice for the empiric therapy of cystitis.

Causative pathogens and antibiotic resistance in children hospitalized for urinary tract infection

BACKGROUND

Urinary tract infections (UTI) are one of the most common bacterial infections in children and a major cause of hospitalization. In this study we investigated the clinical characteristics, causative uropathogens; their antibiotic susceptibility and resistance patterns, treatment modalities and efficacy in children hospitalized for UTI in a tertiary care setting.

METHODS

Patients hospitalized for an upper UTI between March 2009 and July 2014 were enrolled. The urine culture-antibiogram results and accompanying urinary tract abnormalities were recorded retrospectively.

RESULTS

A total of 142 patients (104 girls, 73.2%; 38 boys, 26.8%) were enrolled. Mean patient age was 32.6 ± 4.1 months. History of recurrent UTI was present in 45.8% (n = 65), with prior hospitalization in 12.0% (n = 17). Frequency of vesicoureteral reflux was 18.3% (n = 26). Gram-negative enteric microorganisms yielded growth in all culture-positive UTI and the most common microorganism was Escherichia coli (n = 114, 80.3%). Extended spectrum beta-lactamase-producing (ESBL (+)) bacterial strains were detected in 49.3% (n = 70), with third-generation cephalosporin resistance in all and increased duration of hospitalization.

CONCLUSIONS

The prevalence of UTI with ESBL (+) bacterial strains with multi-drug resistance is increasing in the hospitalized pediatric population, therefore rational use of antibiotics is essential.

Emergence of extended spectrum-β-lactamase-producing Escherichia coli O25b-ST131: a major community-acquired uropathogen in infants

BACKGROUND

Escherichia coli sero-group O25b-sequence type 131 (O25b-ST131), a multidrug-resistant clonal group, is a significant pathogen in adults and children. This study investigated the genotyping and role of extended spectrum β-lactamase (ESBL)-producing E. coli O25b-ST131 and non-O25b-ST131 in urinary tract infections in infants.

METHODS

Clinical and laboratory data from 111 infants less than 1 year of age, who were hospitalized for urinary tract infections caused by ESBL-producing E. coli between 2009 and 2012 were collected. Polymerase chain reactions and multi-locus sequence typing were used to identify E. coli O25-ST131 clones. The gene blaCTX-M groups 1, 2 and 9, a specific polymerase chain reaction of CTX-M 14 and 15, were also determined in ESBL-producing E. coli isolates.

RESULTS

O25b-ST131 accounted for 65% of the 111 isolates, although 92 isolates belonged to the blaCTX-M group 9, of which most were CTX-M-14. Those with O25b-ST131 clones had similar risk factors, clinical features and outcomes as those with non-O25b-ST131. The E. coli O25b-ST131 isolates were more resistant to ciprofloxacin and gentamicin, but more susceptible to cefoxitin, minocycline and trimethoprim/sulfamethoxazole than the non-O25b-ST131 isolates. Most of the infants (78%) were previously healthy with no apparent risk factors.

CONCLUSIONS

E. coli O25b-ST131 is a major community-acquired uropathogen in the infant population. Regardless of O25b-ST131 or non-O25b-ST131 clones, CTX-M-14 accounts for majority of the ESBL genotype. The O25b-ST131 clone is not associated with more severe clinical disease, but it may make the diagnosis and selection of antimicrobials for treatment more challenging.

Extended-spectrum-beta-lactamase producing bacteria related urinary tract infection in renal transplant recipients and effect on allograft function

Background

Urinary tract infection (UTI) is a well-recognized early complication in renal transplant recipients (RTR) and can have significant bearing on their outcome. The recent rise in incidence of extended spectrum beta lactamase (ESBL) producing bacteria causing UTI among RTR poses new and significant challenges in terms of management and outcome. Our aim is to analyze the effect of ESBL producing bacteria causing UTI in these patients and its impact on allograft function.

Methods

We reviewed the medical records of 147 RTR who were followed at a tertiary care hospital affiliated transplant center between January 2007 and May 2013 and noted five RTR who developed episodes of ESBL producing bacteria related UTI during follow up. Multiple patient characteristics including demographics, immunosuppression, recurrences, allograft function and outcome were analyzed.

Results

Five patients (3.4%) out of 147 had ESBL producing bacteria related UTI. We found all patients to be above 60 years of age, with three out of five being females, and all five patients had diabetes mellitus. We identified a total of 37 episodes of UTI among these five patients during this period. Two of these patients had elevated creatinine values during the episodes of UTI and three of them developed bacteremia. Of the five patients, four of them had a favorable outcome except for one patient who developed persistent allograft dysfunction.

Conclusion

RTR are at a higher risk for developing ESBL producing bacteria associated UTI. Early diagnosis along with appropriate and judicious use of antibiotics will ensure long term success in allograft and patient outcome.

Urinary tract infections caused by community-acquired extended-spectrum β-lactamase-producing and nonproducing bacteria: a comparative study

OBJECTIVE

To study the clinical characteristics and associated risk factors of urinary tract infections (UTIs) caused by community-acquired extended-spectrum β-lactamase (CA-ESBL)-producing Enterobacteriaceae.

STUDY DESIGN

A case-control study at a large community hospital in northern Israel, comparing children who had UTI due to CA-ESBL (n = 25) and CA non-ESBL (n = 125) in 2008-2011. Data were collected from medical charts, telephonic questionnaires administered to all participants, and groups were compared.

RESULTS

During the study period, the yearly incidence of CA-ESBL UTI increased significantly. There were no significant differences between the CA-ESBL and CA non-ESBL groups in demographics and clinical outcome. Compared with CA non-ESBL UTI, children with CA-ESBL UTI had a longer hospital stay (5.9 ± 3.3 vs 3.9 ± 2.3 days; P = .003) and higher rates of recent hospitalization (28% vs 4%; P = .001), previous UTI (40% vs 13%; P = .003), urinary tract anomalies (32% vs 5%; P < .001), UTI prophylaxis with cephalexin (32% vs 2%; P < .005), and aminoglycoside resistance. In a multivariate analysis, UTI prophylaxis (OR 12.5 [CI 2.7-58]), recent hospitalization (OR 4.8 [CI 1.1-21]), and Klebsiella spp. UTI (OR 4.7 [CI 1.3-17]), were risk factors for CA-ESBL UTI.

CONCLUSIONS

Children prescribed UTI prophylaxis (due to urinary tract anomalies or recurrent UTI) with cephalexin and those with previous hospitalizations are at increased risk for CA-ESBL UTI. Although not associated with higher rates of complications, the multidrug resistant phenotype of CA-ESBL isolates poses a challenge in choosing appropriate empiric and definitive therapy and prolongs hospital stay.

Risk factors for community-acquired urinary tract infection caused by ESBL-producing bacteria in children

BACKGROUND

The aim of the present study was to investigate the risk factors of antimicrobial resistance in children with urinary tract infection caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria.

METHODS

A total of 344 patients diagnosed with urinary tract infection (UTI) between January 2008 and December 2009 were enrolled in this retrospective study. Causative microorganisms were ESBL-producing bacteria in 148 patients and non-ESBL-producing bacteria in 196 patients. There was no difference between the two groups regarding distribution of age, sex and length of follow up.

RESULTS

The most frequent causative agent was Escherichia coli, of which 41.4% were ESBL producing. Among Klebsiella species, 53.2% were ESBL producing. The proportion of ESBL-producing bacteria that were resistant to antibiotics was 83.1% for trimethoprim/sulfamethoxazole, 18.2% for nitrofurantoin, 47.3% for quinolones, and 39.9% for aminoglycosides. For non-ESBL-producing bacteria, the resistance rate was 62.2% for trimethoprim/sulfamethoxazole, 4.6% for nitrofurantoin, 9.7% for quinolones, and 9.7% for aminoglycosides. Age <1 year, high UTI recurrence rate, long duration of prophylaxis, use of cephalosporins for prophylaxis, hospitalization within the previous 3 months and clean intermittent catheterization were found to be significant risk factors for ESBL-producing bacteria (P < 0.05). Logistic regression analysis identified age <1 year and high recurrence UTI rate to be independent risk factors, increasing the risk 1.74-fold and 2.25-fold, respectively.

CONCLUSIONS

Recognition of the risk factors for ESBL-producing bacteria may be helpful to determine new policies in the management of UTI. Recurrence of UTI should be prevented especially in the first year of life, and prophylactic cephalosporins should be avoided.