Changing epidemiology of infections due to extended spectrum beta-lactamase producing bacteria

Microbiological etiology and current resistance patterns in acute calculous cholecystitis

INTRODUCTION

The current treatment for acute calculous cholecystitis (ACC) is early laparoscopic cholecystectomy, in association with appropriate empiric antibiotic therapy. In our country, the evolution of the prevalence of the germs involved and their resistance patterns have been scarcely described. The aim of the study was to analyze the bacterial etiology and the antibiotic resistance patterns in ACC.

METHODS

We conducted a single-center, retrospective, observational study of consecutive patients diagnosed with ACC between 01/2012 and 09/2019. Patients with a concomitant diagnosis of pancreatitis, cholangitis, postoperative cholecystitis, histology of chronic cholecystitis or carcinoma were excluded. Demographic, clinical, therapeutic and microbiological variables were collected, including preoperative blood cultures, bile and peritoneal fluid cultures.

RESULTS

A total of 1104 ACC were identified, and samples were taken from 830 patients: bile in 89%, peritoneal fluid and/or blood cultures in 25%. Half of the bile cultures and less than one-third of the blood and/or peritoneum samples were positive. Escherichia coli (36%), Enterococcus spp (25%), Klebsiella spp (21%), Streptococcus spp (17%), Enterobacter spp (14%) and Citrobacter spp (7%) were isolated. Anaerobes were identified in 7% of patients and Candida spp in 1%. Nearly 37% of patients received inadequate empirical antibiotic therapy. Resistance patterns were scrutinized for each bacterial species. The main causes of inappropriateness were extended-spectrum beta-lactamase-producing bacteria (34%) and Enterococcus spp (45%), especially in patients older than 80 years.

CONCLUSIONS

Updated knowledge of microbiology and resistance patterns in our setting is essential to readjust empirical antibiotic therapy and ACC treatment protocols.

Increasing community prevalence of extended-spectrum beta-lactamase-producing Escherichia coli in urine is associated with increasing district-level antibiotic consumption

This study aimed to analyze ESBL-producing Escherichia coli prevalence in urine samples collected between 2011-2019 in Curitiba, a large city in Brazil, and relating it to antibiotic consumption and sanitary conditions. This is a longitudinal study correlating prevalence of ESBL-producing E. coli isolates from urine samples with district-level antibiotic consumption and sociodemographic data during 2011-2019. E. coli isolates were tested for antibiotic susceptibility and ESBL by an automated method. Statistical analysis applied linear regressions, pooled ordinary least squares, and fixed effects models for districts or years. The Chow and Hausman tests indicated that the fixed effects model for individual districts fitted best. Chi-square test was used for qualitative variables (statistical significance was set when P < 0.05). Among the 886 535 urine sample cultures, 9.9% of isolates were ESBL-producing E. coli. Their prevalence increased from 4.7% in 2012 to 19.3% in 2019 (P < 0.0001; R2 = 0.922). This progressive increase correlated with age (P = 0.007; R2 = 0.8725) and male gender (P < 0.001) and increased antibiotic consumption (P = 0.0386; R2 = 0.47). The fixed effects model showed that district influences ESBL prevalence and that antibiotic consumption explains 20%-30% of this variation, with an increase of one defined daily dose accounting for an increase of 0.02084 percentage points of ESBL. The increasing prevalence of ESBL-producing E. coli can, to a considerable extent, be explained by increasing antibiotic consumption.

A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia

Background

The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance.

Methods

Therefore, an inventory surveillance of the ESBL-Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated.

Results

A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The blaCTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring blaCTX-M-1 only, 27 isolates (21.3%) co-harbouring blaCTX-M-1 and blaTEM, and ten isolates (7.9%) co-harbouring blaCTX-M-1, blaTEM and blaSHV. A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes.

Spatial clusters of extended-spectrum beta-lactamase-producing Escherichia coli causing community-onset bacteriuria due to repeat infections: cluster analysis from a large urban medical center, San Francisco, 2014-2020

BACKGROUND

Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak.

METHODS

We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 h after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression.

RESULTS

Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001).

CONCLUSION

We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli. These findings may help better tailor clinical treatment of patients with recurrent urinary tract infections after an initial episode caused by ESBL-E. coli.

Phenotypic characterization and epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae strains from urinary tract infections in Garoua, Cameroon

Background and objectives

The emergence of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) is causing increased morbidity and mortality around the world as a result of therapeutic failures. ESBL-E are priority pathogens due to their multidrug resistance (MDR). In Northern Cameroon, ESBL-producing bacteria, particularly in urinary tract infections (UTIs), are being increasingly isolated. This study aimed to retrospectively determine the prevalence of multi-drug resistant ESBL strains isolated from UTIs in Northern Cameroon and to evaluate the effectiveness of the ATB UR Gallery of BioMérieux in diagnosing ESBL-E in clinical settings.

Methods

Standard microbiology protocols and statistical tools were utilized to identify ESBL-producing bacteria and characterize their phenotypic susceptibility and resistance profiles in the study population.

Results

Out of the 144 enterobacteria isolates successfully cultured, 59 (41%) were identified as MDR strains. The ATB UR EU gallery identified 33 (23%) multi-drug resistant ESBL-producing strains, while the double synergy test identified 35 strains without disc reconciliation and 38 strains after reconciliation. The most prevalent ESBL-E isolate was Escherichia coli, accounting for 77.1% of the isolates, followed by Klebsiella pneumoniae (20%) and Enterobacter aerogenes (2.9%). Additionally, the study revealed the emergence of Imipenem resistance (5.7%), a critical last-resort antibiotic. However, all ESBL strains were sensitive to Fosfomycin (FSF/FOS), demonstrating its potential as an effective therapeutic option. Moreover, 37% of the ESBL producers exhibited co-resistance to over 20 different antibiotics.

Conclusion

This study provides valuable insights into the prevalence and susceptibility patterns of ESBL-E associated with UTIs in Northern Cameroon. These insights emphasizes the importance of implementing appropriate treatment guidelines and antimicrobial stewardship measures to mitigate the spread and impact of MDR ESBL-producing strains on public health.

Spatial clusters of extended-spectrum beta-lactamase-producing Escherichia coli causing community-onset bacteriuria due to repeat infections: cluster analysis from a large urban medical center, San Francisco, 2014-2020

Background

Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak.

Methods

We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 hours after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression.

Results

Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001).

Conclusion

We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli.

Risk Factors for Bloodstream Infections Due to ESBL-Producing Escherichia coli, Klebsiella spp., and Proteus mirabilis

(1) Background: Risk factors for extended-spectrum beta-lactamase (ESBL) infections could vary geographically. The purpose of this study was to identify local risk factors for ESBL production in patients with Gram-negative bacteremia. (2) Methods: This retrospective observational study included adult patients admitted from January 2019 to July 2021 and had positive blood cultures for E. coli, K. pneumoniae, K. oxytoca, and P. mirabilis. Patients with ESBL infection were matched to a non-ESBL-producing infection with the same organism. (3) Results: A total of 150 patients were included: 50 in the ESBL group and 100 in the non-ESBL group. Patients in the ESBL group had a longer length of stay (11 vs. 7 days, p < 0.001), but not increased mortality (14% vs. 15%, p = 0.87) Multivariate analysis identified the receipt of >1 antibiotic in the last 90 days as a risk factor for ESBL infection (OR = 3.448, 95% CI = 1.494-7.957; p = 0.004); (4) Conclusions: Recent antimicrobial use was identified as an independent risk factors for ESBL-producing Enterobacterales infections. Knowledge of this risk may improve empirical therapy and reduce inappropriate use.

ESBL-Positive Enterobacteriaceae from Dogs of Santiago and Boa Vista Islands, Cape Verde: A Public Health Concern

Antimicrobial resistance is a public health threat with an increasing expression in low- and middle-income countries such as Cape Verde. In this country, there is an overpopulation of dogs, which may facilitate the spread of resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. To clarify the role of dogs as reservoirs for the dissemination of this bacterial group, 100 rectal swab samples were collected from confined (n = 50) and non-confined (n = 50) dogs in Santiago and Boa Vista Islands, Cape Verde. These were analyzed using conventional bacteriological techniques for the detection of ESBL-producing Enterobacteriaceae and characterization of their pathogenic and resistance profiles. Twenty-nine samples displayed ESBL-positive bacteria, from which 48 ESBL-producing isolates were obtained and mostly identified as Escherichia coli. Multiple antimicrobial resistance indexes ranged from 0.18 to 0.70 and half of the isolates were classified as multidrug-resistant. Isolates were capable of producing relevant virulence factors, including biofilm, showing virulence indexes between 0.29 and 0.71. As such, dogs in Cape Verde may act as reservoirs of resistant bacteria, including pathogenic and zoonotic species, representing a public health concern. Although further investigation is needed, this study proposes the periodical analysis of dogs’ fecal samples to monitor resistance dissemination in the country, in a One-Health perspective.

Prevalence of extended spectrum beta lactamase and molecular detection of blaTEM, blaSHV and blaCTX-M genotypes among Gram negative bacilli isolates from pediatric patient population in Gaza strip

BACKGROUND

Extended-spectrum β lactamases (ESBLs), have the ability to hydrolyze and cause resistance to various types of the β-lactam antibiotics, including the extended-spectrum (or third-generation) cephalosporins (e.g., cefotaxime, ceftriaxone, ceftazidime) and monobactams (e.g., aztreonam). ESBL-producing Gram negative bacteria is still posing significant therapeutic challenges.

OBJECTIVES

To assess the prevalence and molecular characteristics of ESBL producing Gram negative bacilli, isolated from a cohort of pediatric patients in Gaza hospitals.

METHODS

A total of 322 isolates of Gram-negative bacilli were collected from four referral pediatric hospitals in Gaza, namely: Al-Nasr, Al-Rantisi, Al-Durra and Beit Hanoun hospitals. These isolates were tested for ESBL production using the double disk synergy and CHROMagar phenotypic methods. Molecular characterization of the ESBL producing strains was performed using PCR targeting the CTX-M, TEM and SHV genes. Antibiotic profile was done using Kirby Bauer method according to Clinical and Laboratory Standard Institute.

RESULTS

Out of 322 isolates tested by phenotypic methods, 166 (51.6%) were ESBL positive. The prevalence of ESBL production in Al-Nasr, Al-Rantisi, Al-Durra and Beit Hanoun hospitals was 54%, 52.5%, 45.5% and 52.8% respectively. The prevalence of ESBL production among Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp., Proteus mirabilis, Enterobacter spp., Citrobacter spp., and Serratia marcescens is 55.3%, 63.4%, 17.8%, 57.1%, 33.3%, 28.5%, 38.4%, and 4% respectively. ESBL production among urine, pus, blood, CSF and sputum was 53.3%, 55.2%, 47.4%, 33.3%, and 25% respectively. Out of the 322 isolates, 144 were screened for CTX-M, TEM and SHV production. Using PCR, 85 (59%) had at least one gene. The prevalence rate of CTX-M, TEM and SHV genes was 60%, 57.6%, and 38.3% respectively. Meropenem and amikacin were highest rates of susceptibility antibiotics against ESBLs producers (83.1% and 82.5% respectively), while the least effective antibiotics were amoxicillin (3.1%) and cephalexin (13.9%). Moreover, ESBLs producers showed high resistance rate to cefotaxime, ceftriaxone and ceftazidime (79.5%, 78.9% and 79.5% respectively).

CONCLUSION

Our results show high prevalence of ESBL production among Gram negative bacilli isolated from children in different pediatric hospitals in Gaza strip. A substantial level of resistance to first and second generation cephalosporins was also observed. This ascertains the need for a rational antibiotic prescription and consumption policy.

Risk factors for community acquired pediatric urinary tract infection with extended-spectrum-β-lactamase Escherichia coli - A case-control study

INTRODUCTION

Community-acquired (CA) infections caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli urinary tract infections (UTI) have become increasingly prevalent, posing a serious threat to public health. Risk factors for ESBL UTI have not been extensively studied in the pediatric population. We report findings from a case control study to identify risk factors for CA ESBL-producing E. coli UTI in children.

MATERIALS AND METHOD

A cohort of children with CA ESBL Escherichia coli UTI evaluated at a tertiary referral hospital from January 2014 through April 2021, were matched 1:3 with control group of non-ESBL CA E. coli UTI based on age at first episode of non-ESBL UTI. To identify potential risk factors for ESBL E. coli UTI, conditional logistic regression model was utilized accounting for age matching. Univariate models were fitted for each clinical risk factor. Factors found to be significantly associated with ESBL UTI were simultaneously included in a single model to check for associations adjusted for all other factors.

RESULTS

On conditional multivariate analyses for univariate testing, male sex (P = 0.021), history of Urology care (P = 0.001), and antibiotic treatment within 30 days prior to positive culture (P = 0.004) were identified as independent risk factors for CA ESBL E. coli UTI. Comorbidity scores were assigned to each patient according to pediatric comorbidity index (PCI); children with ESBL UTI were more likely to have higher morbidity risk than non-ESBL UTI children (P < 0.001). From the logistic model, the higher the morbidity scores, the more likely children will have CA ESBL UTI (P < 0.001).

DISCUSSION

Identifying risk factors for ESBL-producing E. coli UTI in children is important because of limited therapeutic options. This knowledge is essential for clinical decision making and to develop intervention strategies to reduce disease burden. Our study found that although females have an increased predisposition to UTIs, we observed that the male sex is an independent risk factor for ESBL E. coli UTI. This finding warrants further investigation to determine underlying cause. Because of the retrospective design of the study, collection of data from a single center, and differences in characteristics between patient populations, treatments, and prescribing patterns in the community, this study may not be generalizable.

CONCLUSIONS

Findings from our case-control study suggest that the male sex, history of Urology care, and previous antibiotic exposure are independent risk factors for CA ESBL-GNB UTI. Children with ESBL E. coli UTI are more likely to have longer admission duration and higher comorbidity index.

Antimicrobial Susceptibility and Genetic Prevalence of Extended-Spectrum β-Lactamases in Gram-Negative Rods Isolated from Clinical Specimens in Pakistan

The prevalence of extended-spectrum β-lactamase (ESBL) genes has increased remarkably, resulting in multidrug-resistant gram-negative rods (GNRs) in clinical specimens. This cross-sectional study aimed to determine the antimicrobial susceptibility of ESBL-producing GNRs and its correlation with corresponding genes. Two hundred and seventy-two (n = 272) samples were evaluated for the molecular identification of ESBL genes by polymerase chain reaction after confirmation with the modified double-disc synergy test. E. coli 64.0% (n = 174) was the most prevalent ESBL producer, followed by Klebsiella species 27.2% (n = seventy-four), Acinetobacter species 6.6% (n = eighteen) and others 2.2% (n = six). These ESBL-producing isolates showed resistance to β-lactam antibiotics, i.e., sulbactam/cefoperazone (41.5%), piperacillin/tazobactam (39.3%), meropenem (36.0%), imipenem (34.2%) and non- β-lactam antibiotics, i.e., nalidixic acid (89.0%), co-trimoxazole (84.9%), ciprofloxacin (82.4%), gentamicin (46.3%), nitrofurantoin (24.6%), amikacin (19.9%) and fosfomycin (19.9%). The incidences of the ESBLs-producing genes bla_CTX-M, bla_TEM, bla_OXA and bla_SHV were 91.2%, 61.8%, 39.3% and 17.6%, respectively. Among nine multiple-gene combinations, bla_CTX-M + bla_TEM (30.5%) was the most prevalent combination, followed by bla_CTX-M + bla_OXA + bla_TEM (14.0%), bla_CTX-M + bla_OXA (13.6%), bla_CTX-M + bla_TEM + bla_SHV (7.0%), bla_CTX-M + bla_SHV (2.2%), bla_CTX-M + bla_OXA + bla_SHV (2.2%) and bla_OXA + bla_TEM (1.8%). ESBLs producing GNRs carrying bla_CTX-M, bla_TEM, bla_OXA and bla_SHV showed resistances to β-lactam antibiotics, i.e., ampicillin, amoxillin-clavulanic acid, cefotaxime and ceftazidime but were susceptible to carbapenems (meropenem and imipenem), β-lactam-β-lactamase inhibitor combination (piperacillin/tazobactam) and non-β-lactam antibiotics i.e., aminoglycoside (amikacin and gentamicin), nitrofurantoin and fosfomycin. These antibiotics that demonstrated activity may be used to treat infections in clinical settings.

Extended-Spectrum Beta-Lactamases Producing Enterobacteriaceae in the USA Dairy Cattle Farms and Implications for Public Health

Antimicrobial resistance (AMR) is one of the top global health threats of the 21th century. Recent studies are increasingly reporting the rise in extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBLs-Ent) in dairy cattle and humans in the USA. The causes of the increased prevalence of ESBLs-Ent infections in humans and commensal ESBLs-Ent in dairy cattle farms are mostly unknown. However, the extensive use of beta-lactam antibiotics, especially third-generation cephalosporins (3GCs) in dairy farms and human health, can be implicated as a major driver for the rise in ESBLs-Ent. The rise in ESBLs-Ent, particularly ESBLs-Escherichia coli and ESBLs-Klebsiella species in the USA dairy cattle is not only an animal health issue but also a serious public health concern. The ESBLs-E. coli and -Klebsiella spp. can be transmitted to humans through direct contact with carrier animals or indirectly through the food chain or via the environment. The USA Centers for Disease Control and Prevention reports also showed continuous increase in community-associated human infections caused by ESBLs-Ent. Some studies attributed the elevated prevalence of ESBLs-Ent infections in humans to the frequent use of 3GCs in dairy farms. However, the status of ESBLs-Ent in dairy cattle and their contribution to human infections caused by ESBLs-producing enteric bacteria in the USA is the subject of further study. The aims of this review are to give in-depth insights into the status of ESBL-Ent in the USA dairy farms and its implication for public health and to highlight some critical research gaps that need to be addressed.

Sources and Drivers of ARGs in Urban Streams in Atlanta, Georgia, USA

The spread of antibiotic resistance genes (ARGs) in the aquatic environment is an emerging concern in the interest of protecting public health. Stemming the environmental dissemination of ARGs will require a better understanding of the sources and drivers of ARGs in the water environment. In this study, we used direct measurement of sewage-associated molecular markers, the class 1 integron gene, standard water quality parameters, and watershed characteristics to evaluate the sources and drivers of ARGs in an urban watershed impacted by a gradient of human activities. Quantitative polymerase chain reaction (qPCR) was used to quantify the abundance of the sewage-associated HF183, the E. coli fecal indicator, class 1 integron gene (int1), and the ARGs sulI, sulII, tetW, tetM, ampC, and blaSHV in stream water samples collected from the Proctor Creek watershed in Atlanta, Georgia. Our findings show that ARGs were widely distributed, with detection frequencies of 96% (sulI and sulII), 82% (tetW and tetM), and 49% (ampC and blaSHV). All the ARGs were positively and significantly correlated (r > 0.5) with the HF183 and E. coli markers. Non-linear machine learning models developed using generalized boosting show that more than 70% of the variation in ARG loads in the watershed could be explained by fecal source loading, with other factors such as class 1 integron, which is associated with acquired antibiotic resistance, and environmental factors contributing < 30% to ARG variation. These results suggest that input from fecal sources is a more critical driver of ARG dissemination than environmental stressors or horizontal gene transfer in aquatic environments highly impacted by anthropogenic pollution. Finally, our results provide local watershed managers and stakeholders with information to mitigate the burden of ARGs and fecal bacteria in urban streams.

Retrospective analysis of a large single cohort of Enterobacteriaceae producing extended-spectrum B-lactamase (E-ESBL) patients: incidence, microbiology, and mortality

We conducted a retrospective study from 2005 to 2019 to describe the epidemiology and mortality of enterobacterial producing extended-spectrum β-lactamase (E-ESBL) infections in our university hospital over a 17-year period of time. Clinical and microbiological data were extracted from different software used for continuous surveillance. Stool samples from systematic screening for E-ESBL colonization were excluded from the study. The incidence rate of infected patient was calculated by E-ESBL species and by year. A comparison of mortality rate in patients with bloodstream infections versus other types of infections was conducted using a Kaplan-Meier method survival curves. A log rank test (with a risk of 5%) was carried out. A total of 3324 patients with E-ESBL infection were included with an increased incidence density per 1000 days of hospitalization from 0.03 in 2005 to 0.47 in 2019. Escherichia coli was the most frequently isolated pathogen (64%). Global mortality rate was significantly higher with E. coli than with Klebsiella spp. and Enterobacter spp. (p < 0.001). Mortality was higher in patients with E-ESBL bloodstream infection than in patients with other type of E-ESBL infection (p < 0.001). Our study showed a significant increase of the E-ESBL incidence density over a 17-year period survey with a higher mortality in patients with E-ESBL bacteremia. This highlights the need to continue efforts to control the spread of these multi-resistant bacteria in our institution.

Antibiotic resistance in the invasive bacteria Escherichia coli

OBJECTIVES

The beta-lactamases with extended spectrum of activity (ESBL) are medically one of the most important group of enzymes. Another group of beta-lactamases representing of Enterobacteriaceae is group of the AmpC-type cephalosporinases. The presented study provides identification and determination of the spectrum of resistance against different and clinically used antimicrobial drugs in the clinical isolates of Escherichia coli.

METHODS

These isolates had origin in different departments of the L. Pasteur University Hospital in Košice. The goal was the detection of beta-lactamase production with extended-spectrum effect and testing of AmpC-type cephalosporinases by several phenotypic tests in clinical isolates. MALDI-TOF MS analysis was performed on a Microflex MALDI Biotyper. Samples were positively tested for ESBL with the use of the disc diffusion method. PCR were performed with a series of primers designed for the detection of Ambler class A, B and C beta-lactamase genes.

RESULTS

For all 485 isolates, we determined the production of ESBL, which we detected in 166 E. coli isolates, which represents a 34.2% prevalence of ESBL production. It is clear from the results that the prevalence of ESBL-producing E. coli out of the total number of E. coli investigated reached 34.2%. In the monitored period, we confirmed at least one resistance gene from 485 E. coli in 188 positive isolates.

CONCLUSIONS

We describe a complex ESBL epidemiology. The study revealed a high rate of ESBL-producing E. coli isolates; bla_TEM and bla_SHV enzymes dominated in ESBL-positive E. coli isolates in the L. Pasteur University Hospital in Košice.

Evaluation of Tebipenem Hydrolysis by β-Lactamases Prevalent in Complicated Urinary Tract Infections

Tebipenem pivoxil is the first orally available carbapenem antibiotic and has been approved in Japan for treating ear, nose, and throat and respiratory infections in pediatric patients. Its active moiety, tebipenem, has shown potent antimicrobial activity in vitro against clinical isolates of Enterobacterales species from patients with urinary tract infections (UTIs), including those producing extended-spectrum β-lactamases (ESBLs) and/or AmpC β-lactamase. In the present study, tebipenem was tested for stability to hydrolysis by a set of clinically relevant β-lactamases, including TEM-1, AmpC, CTX-M, OXA-48, KPC, and NDM-1 enzymes. In addition, hydrolysis rates of other carbapenems, including imipenem, meropenem, and ertapenem, were determined for comparison. It was found that, similar to other carbapenems, tebipenem was resistant to hydrolysis by TEM-1, CTX-M, and AmpC β-lactamases but was susceptible to hydrolysis by KPC, OXA-48, and NDM-1 enzymes with catalytic efficiency values (k_cat/K_m) ranging from 0.1 to 2 × 10⁶ M^-1s^-1. This supports the reported results of antimicrobial activity of tebipenem against ESBL- and AmpC-producing but not carbapenemase-producing Enterobacterales isolates. Considering that CTX-M and AmpC β-lactamases represent the primary determinants of multidrug-resistant complicated UTIs (cUTIs), the stability of tebipenem to hydrolysis by these enzymes supports the utility of its prodrug tebipenem, tebipenem pivoxil hydrobromide (TBP-PI-HBr), as an oral therapy for adult cUTIs.

Antibiotic exposure and acquisition of antibiotic-resistant gram-negative bacteria among outpatients at a US Veterans Affairs medical center

Objectives:

To assess the prevalence of antibiotic-resistant gram-negative bacteria (R-GNB) among patients without recent hospitalization and to examine the influence of outpatient antibiotic exposure on the risk of acquiring R-GNB in this population.

Design:

2-year retrospective cohort study.

Setting:

Regional Veterans Affairs healthcare system.

Patients:

Outpatients at 13 community-based clinics.

Methods:

We examined the rate of acquisition of R-GNB within 90 days following an outpatient visit from 2018 to 2019. We used clinical and administrative databases to determine and summarize prescriptions for systemic antibiotics, associated infectious diagnoses, and subsequent R-GNB acquisition among patients without recent hospitalizations. We also calculated the odds ratio of R-GNB acquisition following antibiotic exposure.

Results:

During the 2-year study period, 7,215 patients had outpatient visits with microbiological cultures obtained within 90 days. Of these patients, 206 (2.9%) acquired an R-GNB. Among patients receiving antibiotics at the visit, 4.6% acquired a R-GNB compared to 2.7% among patients who did not receive antibiotics, yielding an unadjusted odds ratio of 1.75 (95% confidence interval, 1.18–2.52) for a R-GNB following an outpatient visit with versus without an antibiotic exposure. Regardless of R-GNB occurrence, >50% of antibiotic prescriptions were issued at visits without an infectious disease diagnosis or issued without documentation of an in-person or telehealth clinical encounter.

Conclusions:

Although the rate of R-GNBs was low (2.9%), the 1.75-fold increased odds of acquiring a R-GNB following an outpatient antibiotic highlights the importance of antimicrobial stewardship efforts in outpatient settings. Specific opportunities include reducing antibiotics prescribed without an infectious diagnosis or a clinical visit.

Changes of antibiotic resistance over time among Escherichia coli peritonitis in Southern China

Escherichia coli (E. coli) is the main cause of Gram-negative bacterial peritonitis among peritoneal dialysis patients. According to the 2016 update of the International Society for Peritoneal Dialysis Peritonitis Recommendations, drug susceptibilities of specific organisms should be regularly monitored. The aim of this study was to examine the evolution of antimicrobial resistance of E. coli peritonitis from 2006 to 2018. Two hundred and fifty-three episodes of E. coli peritonitis were enrolled in our study, corresponding to a rate of 0.024 episodes per patient-year. According to drug sensitivity test results, isolates were most sensitive to carbapenems, followed by cefmetazole, piperacillin/tazobactam, cefotetan and amikacin, with an overall rate of more than 90% in both cohorts. Cefazolin and ciprofloxacin resistance increased significantly from 2006-2011 to 2012-2018. Conversely, cefepime and ceftazidime resistance decreased significantly. The extended-spectrum β-lactamase (ESBL) rate fluctuated from 34.7% in 2006-2011 to 46.8% in 2012-2018. Compared with the ESBL-negative strains, ESBL-producing E. coli were more likely be resistant to ampicillin, ampicillin/sulbactam, cephalosporins, quinolones, aminoglycosides, furadantin and sulfamethoxazole and accounted for over 50% of the drug resistance. In the correlation analysis, E. coli displayed significantly increased resistance to cefazolin and ciprofloxacin, a finding correlated with ESBL production (r = 0.883 and 0.276 respectively, p < 0.001 and p = 0.003). In conclusion, the rate of E. coli peritonitis declined stably in recent years, but the resistance to antimicrobial was high.

Trends in prevalence of extended-spectrum beta-lactamase-producing Escherichia coli isolated from patients with community- and healthcare-associated bacteriuria: results from 2014 to 2020 in an urban safety-net healthcare system

BACKGROUND

The prevalence of infections caused by extended-spectrum beta-lactamase producing Escherichia coli (ESBL-E. coli) is increasing worldwide, but the setting in which this increase is occurring is not well defined. We compared trends and risk factors for ESBL-E. coli bacteriuria in community vs healthcare settings.

METHODS

We collected electronic health record data on all patients with E. coli isolated from urine cultures in a safety-net public healthcare system from January 2014 to March 2020. All analyses were stratified by healthcare-onset/associated (bacteriuria diagnosed > 48 h after hospital admission or in an individual hospitalized in the past 90 days or in a skilled nursing facility resident, N = 1277) or community-onset bacteriuria (bacteriuria diagnosed < 48 h after hospital admission or in an individual seen in outpatient clinical settings without a hospitalization in the past 90 days, N = 7751). We estimated marginal trends from logistic regressions to evaluate annual change in prevalence of ESBL-E. coli bacteriuria among all bacteriuria. We evaluated risk factors using logistic regression models.

RESULTS

ESBL-E. coli prevalence increased in both community-onset (0.91% per year, 95% CI 0.56%, 1.26%) and healthcare-onset/associated (2.31% per year, CI 1.01%, 3.62%) bacteriuria. In multivariate analyses, age > 65 (RR 1.88, CI 1.17, 3.05), male gender (RR 2.12, CI 1.65, 2.73), and Latinx race/ethnicity (RR 1.52, CI 0.99, 2.33) were associated with community-onset ESBL-E. coli. Only male gender (RR 1.53, CI 1.03, 2.26) was associated with healthcare-onset/associated ESBL-E. coli.

CONCLUSIONS

ESBL-E. coli bacteriuria frequency increased at a faster rate in healthcare-associated settings than in the community between 2014 and 2020. Male gender was associated with ESBL-E. coli bacteriuria in both settings, but additional risks-age > 65 and Latinx race/ethnicity-were observed only in the community.

A Retrospective Analysis of Risk Factors and Patient Outcomes of Bloodstream Infection with Extended-Spectrum β-Lactamase-Producing Escherichia coli in a Chinese Tertiary Hospital

Objective

The present study assessed risk factors and patient outcomes of bloodstream infection (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli).

Methods

A retrospective study was performed to analyze risk factors and patient outcomes of BSI caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) in one Chinese tertiary hospital over a 7.5-year period. The clinical characteristics of patients infected with ESBL-producing and non-ESBL-producing E. coli were compared. Predictors of 30-day mortality in patients with E. coli BSI were also identified in our study.

Results

The results of drug sensitivity showed that quinolones, aminoglycosides, β-lactam/β-lactamase inhibitor combinations (BLICs) and trimethoprim/sulfamethoxazole exhibited significant differences between the ESBL and non-ESBL groups. Of the 963 patients with E. coli BSI, 57.6% developed ESBL-EC. Multivariate analysis showed that biliary tract infection (BTI) [P<0.001,OR (95% CI):1.798 (1.334–2.425)], urinary tract obstructive disease [P=0.001,OR (95% CI):2.106 (1.366–3.248)], surgery within 3 months [P=0.002,OR (95% CI):1.591 (1.178–2.147)], hospitalization within 3 months [P<0.001,OR (95% CI):2.075 (1.579–2.725)], ICU admission [P=0.011,OR (95% CI):1.684 (1.124–2.522)] and history of cephalosporin use [P=0.006,OR (95% CI):3.097 (1.392–6.891)] were statistically significant. In mortality analysis, aCCI>2 [P=0.016,OR (95% CI): 2.453 (1.179–5.103)], gastrointestinal catheterization [P=0.004, OR (95% CI): 2.525 (1.333–4.782)] were significantly associated with 30-day mortality. According to Kaplan-Meier survival analysis, we found that in SOFA<2 group and SOFA≥2 group, the mortality rate of patients treated with BLICs were lower than that of carbapenems(P<0.05).

Conclusion

This study showed that BTI, urinary tract obstructive disease, surgery within 3 months, hospitalization within 3 months, ICU admission and cephalosporin exposure were independent risk factors for the emergence of ESBL-EC BSI. Analysis of risk factors for 30-day mortality revealed that the factors independently associated with a higher risk of mortality were aCCI>2, gastrointestinal catheterization. Compared to carbapenems, the BLICs had preferable effect to treat patients with ESBL-EC BSI. Notably, patients with severe illness were inlcined to use carbapenems, which affected the analysis results. Therefore, we suggest that BLICs could be recommended to treat mild patients with ESBL-EC bacteremia.

Microbiological quality of kitchens sponges used in university student dormitories

Background

Kitchen sponges are a major source of cross-contamination as they can transfer foodborne pathogens, infectious agents and spoilage causing microorganisms to food contact surfaces. Several studies have revealed that university students adopt poor practices regarding food safety, hygiene, and the handling of kitchen cleaning equipment.

Methods

A total of fifty kitchen sponges were collected along with a questionnaire addressing social demographics and kitchen sponge usage by students living at the University of Sharjah dormitories. The effect of storage (3 and 10 days) on the microbial population of kitchen sponges at room temperature (21 °C) was assessed. Enterobacteriaceae isolated from sponges were identified and their antibiotic resistance determined.

Results

Student responses revealed that kitchen sponges used to clean food contact surfaces were also used to clean the oven (32%), sink (26%), refrigerator (10%), and to clean spills on the floor (4%). Kitchen sponges contained high counts of mesophilic aerobic bacteria (7.9 log₁₀/cm³), coliform (7.2 log₁₀/cm³), Enterobacteriaceae (7.3 log₁₀/cm³) and yeasts and molds (7.0 log₁₀/cm³). After storage of the sponges at room temperature (21 °C) for 3 and 10 days, the number of mesophilic aerobic bacteria, coliform, Enterobacteriaceae and yeasts and molds decreased by 0.4 and 1.3 log₁₀/cm³, 0.7 and 1.4 log₁₀/cm³, 0.4 and 1.1 log₁₀/cm³, and 0.6 and 1.3 log₁₀/cm³, respectively. The most frequently isolated Enterobacteriaceae were Enterobacter cloacae (56%) and Klebsiella oxytoca (16%). All E. cloacae isolates were resistant to amoxicillin, cefalotin, cefoxitin and cefuroxime axetil.

Conclusions

This study showed that students living in dormitories lacked good hygienic practices and were at increased risk of food poisoning. Kitchen sponges were highly contaminated with potentially pathogenic bacteria which could be transferred from the general kitchen environment to food contact surfaces and consequently lead to food contamination.

Differential Trends in Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Infections in Four Health Care Facilities in a Single Metropolitan Area: A Retrospective Analysis

Background: Prevalence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) is increasing worldwide, but greatly varies geographically. We compared the prevalence of ESBL-E. coli infections at four distinct health care facilities in San Francisco, California. Methods: Antimicrobial susceptibility reports were obtained for E. coli isolates from (1) a county hospital, (2) a public skilled nursing facility, (3) a university hospital, and (4) a Veterans Affairs (VA) Medical Center. We compared change in frequency of ESBL-E. coli and antimicrobial resistance to trimethoprim-sulfamethoxazole between 2012 and 2018. Results: From 2012 to 2018, frequency of ESBL-E. coli increased in urine and nonurine isolates from the county hospital (urine: 1.1% per year, 95% confidence interval [CI]: 0.5-1.6, p < 0.01; nonurine: 1.9% per year, 95% CI: 0.9-2.9, p < 0.01) and in urine isolates from the VA hospital (0.9% per year, 95% CI: 0.3-1.4, p < 0.01). The frequency of trimethoprim-sulfamethoxazole resistance fluctuated in all facilities. Conclusions: At the skilled nursing facility, the prevalence of ESBL-E. coli was highest, but remained stable over time, while the prevalence of ESBL-E. coli increased among urine and nonurine isolates at the county hospital and urine isolates at the VA hospital. The temporal trend of ESBL-E. coli infections, even within one city, varied by health care facility.

Incidence of community-onset extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae infections: an 11-year population-based study in Denmark

Background: Data elucidating trends of community-onset extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae infections remain sparse in low prevalence areas. We conducted a population-based study to determine the incidence, temporal trends and co-resistance of community-onset ESBL infections.Methods: We identified all recorded episodes of E. coli and K. pneumoniae bacteraemia and urinary tract infections in adult patients (>15 years) in the North Denmark Region between 2007-2017. Using population-based registries, we obtained information on demographics and place of acquisition, and investigated the standardized incidence rates and temporal trends of community-onset ESBL infections and the associated patterns of co-resistance.Results: A total of 3741 episodes of community-onset ESBL E. coli or K. pneumoniae infections were observed during the study period, with the annual standardized incidence rate increasing from 7.5 to 105 per 100,000 person-years between 2007-2017. The increase was conveyed primarily by a rise in E. coli urinary tract infections shifting from being mainly healthcare-associated to community-acquired. ESBL-producing isolates increased from 0.5 to 4.0% with considerable co-resistance.Conclusion: The proportion of E. coli and K. pneumoniae isolates producing ESBL have increased considerably in the North Denmark Region. The increasing incidence and frequent co-resistance should raise awareness among physicians responsible for empirical antibiotic treatment.

Imipenemase-producing carbapenem-resistant Enterobacteriaceae transmission in a long-term-care facility during a community-wide multidrug resistant organism outbreak-North Carolina, 2017

We describe an outbreak of imipenemase metallo-β-lactamase-producing organisms in a long-term-care facility (LTCF) amid a larger community outbreak of extended-spectrum β-lactamase-producing organisms. Transmission was propagated by inadequate infection prevention practices. We provided infection prevention recommendations and education, facilitated colonization screening, and increased interfacility communication. This outbreak demonstrates the unmet need for infection prevention education in long-term-care facilities and the importance of prompt public health response to ensure appropriate identification, containment, and prevention of emerging resistance.

β-lactam resistance genes in bacteriophage and bacterial DNA from wastewater, river water, and irrigation water in Washington State

Our objective was to determine whether β-lactamase genes are carried within bacteriophage capsids, as a first step towards exploring the possible role of bacteriophages as vehicles for dispersal of antimicrobial resistance genes through an agricultural region of Washington State. Water samples (n = 178) from municipal wastewater treatment plants, river and irrigation canals were collected over a period of eight months. The occurrence of four β-lactam resistance gene groups (bla_TEM, bla_CTX-M, bla_PSE and bla_CMY-2) and three carbapenem resistance genes (bla_KPC, bla_OXA-48-like, and bla_NDM) in bacterial and phage fractions of water samples was evaluated by PCR. All of the seven targeted resistance genes were detected both in wastewater and river water samples. Relatively high proportions of samples (7.3%-64.9%) positive for resistance genes were found in bacteriophage fractions of water samples compared to the bacterial fractions (5.4%-36.8%). bla_OXA-48-like (57.3%) and bla_TEM (64.0%) were the most prevalent antimicrobial resistance genes detected at all the sampling points. Resistance genes are commonly present in treated wastewater flowing through municipal and agricultural environments, indicating a plausible role for this water in the dissemination of antimicrobial resistance traits, including bla_CTX-M.

Pharmacodynamics of Tebipenem: New Options for Oral Treatment of Multidrug-Resistant Gram-Negative Infections

Tebipenem pivoxil HBr (TBPM-PI-HBr) is a novel orally bioavailable carbapenem. The active moiety is tebipenem. Tebipenem pivoxil is licensed for use in Japan in children with ear, nose, and throat infections and respiratory infections. The HBr salt was designed to improve drug substance and drug product properties, including stability. TBPM-PI-HBr is now being developed as an agent for the treatment of complicated urinary tract infections (cUTI) in adults. The pharmacokinetics-pharmacodynamics of tebipenem were studied in a well-characterized neutropenic murine thigh infection model. Plasma drug concentrations were measured using liquid chromatography-tandem mass spectrometry. Dose fractionation experiments were performed after establishing dose-response relationships. The magnitude of drug exposure required for stasis was established using 11 strains of Enterobacteriaceae (Escherichia coli, n = 6; Klebsiella pneumoniae, n = 5) with a variety of resistance mechanisms. The relationship between drug exposure and the emergence of resistance was established in a hollow-fiber infection model (HFIM). Tebipenem exhibited time-dependent pharmacodynamics that were best described by the free drug area under the concentration-time curve (fAUC_0-24)/MIC corrected for the length of the dosing interval (fAUC_0-24/MIC · 1/tau). The pharmacodynamics of tebipenem versus E. coli and K. pneumoniae were comparable, as was the response of strains possessing extended-spectrum β-lactamases versus the wild type. The median fAUC_0-24/MIC · 1/tau value for the achievement of stasis in the 11 strains was 23. Progressively more fractionated regimens in the HFIM resulted in the suppression of resistance. An fAUC_0-24/MIC · 1/tau value of 34.58 to 51.87 resulted in logarithmic killing and the suppression of resistance. These data and analyses will be used to define the regimen for a phase III study of adult patients with cUTI.

Recent Advances in Investigation, Prevention, and Management of Healthcare-Associated Infections (HAIs): Resistant Multidrug Strain Colonization and Its Risk Factors in an Intensive Care Unit of a University Hospital

Active screening for resistant multidrug strain carriers remains an important component of infection control policy in any healthcare setting indifferent of financial and logistical costs. The objective of our study was to determine the spectrum of bacterial colonization individually among intensive care unit patients. A retrospective observational study was performed in the Intensive Care Unit of Emergency Clinical County Hospital of Oradea during 2017. Medical records of the patients were used for evaluation of source of ICU admission, previous antibiotic therapy, comorbidities, and length of hospital stay. Nasal and groin swabs for MRSA detection and rectal swabs for ESBL, VRE, and CRE detection were collected upon ICU admission of all patients in the first 24 hours and after 7 days. Swab samples were processed for isolation and identification of these resistant multidrug strains. Bacterial colonization on admission was detected in a quarter of patients included in the study. Carbapenemase-producing bacteria were the most common colonizers (21.16%). On admission, 12.06% of patients have been colonized by ESBL-producing members of the family Enterobacterales. Risk factors for colonization on admission to the ICU were chronic liver diseases and chronic renal failure for ESBL infection and chronic liver disease for CRE in male patients. Evaluation of Carmeli's score for male patients showed association only with CRE colonization. Chronic renal failure was found as risk factor for ESBL colonization in female patients. The prevalence of MRSA was 5.23% and less than 1% for VRE. There was no association between any risk factors studied and the presence of S. aureus or VRE upon admission. The 7-day ICU stay also proved to be an increased risk for ESBL and CRE infection.

Risk factors and molecular features of extended-spectrum beta-lactamase producing bacteria at southwest of Saudi Arabia

Objectives:

To explore the risk factors, the prevalence rate, and gene types of extended-spectrum beta-lactamase (ESBL)-producing bacteria as the causative agents of infection at King Abdulaziz Specialist Hospital (KAASH), Taif, Kingdom of Saudi Arabia.

Methods:

This was a retrospective study conducted during the period between February 2017 and January 2018. All samples obtained from the KAASH were analyzed. The MicroScan Walkaway System, bacteriological examination and double disk synergy tests were used to detect ESBL-producing bacteria. To identify ESBL genes, the polymerase chain reaction (PCR) technique was used.

Results:

The ESBL phenotype was detected in 351 of 1151 isolates (30.5%); Escherichia coli (E. coli) (62.7%) and Klebsiella pneumoniae (K. pneumoniae) (23.6%) were the most prevalent. The highest proportion of ESBL specimens was found in urine (62%.5), and these organisms were mainly isolated from the female medical ward (20.2%). Based on the statistical analysis, lung diseases, renal diseases, diabetes and heart diseases contributed to the spread of ESBL infections. Amikacin, imipenem, meropenem and tigecycline were found to be effective in overcoming ESBL infections; however, these antibiotics may be inappropriate for new strains of K.pneumoniae. The distribution of the blaCTX-M gene was high (87%), compared with blaTEM (74.9%) and blaSHV (29.4%).

Conclusion:

These data provide new epidemiological information about the prevalence of ESBL-producing organisms among patients in KAASH, Taif, Saudi Arabia. In addition, this study identified the clonal nature of isolated E.coli and K.pneumoniae.

Prevalence and antibiotic susceptibility pattern of CTX-M type extended-spectrum β-lactamases among clinical isolates of gram-negative bacilli in Jimma, Ethiopia

Background

The prevalence of extended-spectrum β-lactamases (ESBLs) have been reported in clinical isolates obtained from various hospitals in Ethiopia. However, there is no data on the prevalence and antibiotic susceptibility patterns of CTX-M type ESBL produced by Gram-negative bacilli. The aim of this study was to determine the frequency and distribution of the bla_CTX-M genes and the susceptibility patterns in ESBL producing clinical isolates of Gram-negative bacilli in Jimma University Specialized Hospital (JUSH), southwest Ethiopia.

Methods

A total of 224 non-duplicate and pure isolates obtained from clinically apparent infections, were included in the study. Identification of the isolates was performed by MALDI-TOF mass spectrometry. Susceptibility testing and ESBL detection was performed using VITEK® 2, according to EUCAST v4.0 guidelines. Genotypic analysis was performed using Check-MDR CT103 Microarrays.

Results

Of the total 112 (50.0%) isolates screen positive for ESBLs, 63.4% (71/112) tested positive for ESBL encoding genes by Check-MDR array, which corresponds to 91.8% (67/73) of the total Enterobacteriaceae and 10.3% (4/39) of nonfermenting Gram-negative bacilli. Among the total ESBL gene positive isolates, 95.8% (68/71) carried bla_CTX-M genes with CTX-M group 1 type15 being predominant (66/68; 97.1% of CTX-M genes). The bla_CTX-M carrying Enterobacteriaceae (n = 64) isolates showed no resistance against imipenem and meropenem and a moderate resistance rate against tigecycline (14.1%), fosfomycin (10.9%) and amikacin (1.6%) suggesting the effectiveness of these antibiotics against most isolates. On the other hand, all the bla_CTX-M positive Enterobacteriaceae showed a multidrug resistant (MDR) phenotype with remarkable co-resistances (non-susceptibility rates) to aminoglycosides (92.2%), fluoroquinolones (78.1%) and trimethoprim/sulfamethoxazol (92.2%).

Conclusions

This study demonstrates a remarkably high prevalence of bla_CTX-M genes among ESBL-producing isolates. The high level of resistance to β-lactam and non-β-lactam antibiotics as well as the trend to a MDR profile associated with the bla_CTX-M genes are alarming and emphasize the need for routine diagnostic antimicrobial susceptibility testing for appropriate choice of antimicrobial therapy.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3436-7) contains supplementary material, which is available to authorized users.

Extended-spectrum β-lactamase prevalence and virulence factor characterization of enterotoxigenic Escherichia coli responsible for acute diarrhea in Nepal from 2001 to 2016

Background

Multidrug-resistant (MDR) Gram-negative bacterial species are an increasingly dangerous public health threat, and are now endemic in many areas of South Asia. However, there are a lack of comprehensive data from many countries in this region determining historic and current MDR prevalence. Enterotoxigenic Escherichia coli (ETEC) is a leading cause of both acute infant diarrhea and traveler’s diarrhea in Nepal. The MDR prevalence and associated resistance mechanisms of ETEC isolates responsible for enteric infections in Nepal are largely unknown.

Methods

A total of 265 ETEC isolates were obtained from acute diarrheal samples (263/265) or patient control samples (2/265) at traveler’s clinics or regional hospitals in Nepal from 2001 to 2016. Isolates were screened for antibiotic resistance, to include extended spectrum beta-lactamase (ESBL) production, via the Microscan Automated Microbiology System. ETEC virulence factors, specifically enterotoxins and colonization factors (CFs), were detected using multiplex PCR, and prevalence in the total isolate population was compared to ESBL-positive isolates. ESBL-positive isolates were assessed using multiplex PCR for genetic markers potentially responsible for observed resistance.

Results

A total of 118/265 (44.5%) ETEC isolates demonstrated resistance to ≥2 antibiotics. ESBL-positive phenotypes were detected in 40/265 isolates, with isolates from 2008, 2013, 2014, and 2016 demonstrating ESBL prevalence rates of 1.5, 34.5, 31.2, and 35.0% respectively. No difference was observed in overall enterotoxin characterization between the total ETEC and ESBL-positive populations. The CFs CS2 (13.6%), CS3 (25.3%), CS6 (30.2%), and CS21 (62.6%) were the most prevalent in the total ETEC population. The ESBL-positive ETEC isolates exhibited a higher association trend with the CFs CS2 (37.5%), CS3 (35%), CS6 (42.5%), and CS21 (67.5%). The primary ESBL gene identified was bla_CTX-M-15 (80%), followed by bla_SHV-12 (20%) and bla_CTX-M-14 (2.5%). The beta-lactamase genes bla_TEM-1 (40%) and bla_CMY-2 (2.5%) were also identified. It was determined that 42.5% of the ESBL-positive isolates carried multiple resistance genes.

Conclusion

Over 30% of ETEC isolates collected post-2013 and evaluated in this study demonstrated ESBL resistance. Persistent surveillance and characterization of enteric ETEC isolates are vital for tracking the community presence of MDR bacterial species in order to recommend effective treatment strategies and help mitigate the spread of resistant pathogens.

Outbreak epidemiologically linked with a composite product of beef, mechanically separated chicken and textured vegetable protein contaminated with multiple serotypes of Salmonella enterica including multidrug-resistant Infantis, California 2016

A salmonellosis outbreak occurred at a California prison in April and May 2016. In a cohort study of 371 inmates, persons who consumed dishes from the prison kitchen made from ground meat had a higher attack rate (15%) than those who did not (4%) (risk ratio 3.4, 95% CI 1.1–10.6). The ground meat product was composed exclusively of beef, mechanically separated chicken (MSC) and textured vegetable protein; eight of eight lots of the product collected from the prison and processing facility were contaminated with Salmonella enterica of eight serotypes and 17 distinct PFGE patterns, including multidrug-resistant S. Infantis. Either the MSC or the beef could have been the source of the particular strains of S. enterica isolated from patients or the product. The microbiological evidence is most consistent with MSC as the source of the high levels of S. enterica in the epidemiologically linked meat product. Our findings contribute to the growing body of evidence about the hazard posed by the use of products containing raw mechanically separated poultry in kitchens in institutions.

Clinical Risk Score for Prediction of Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Bloodstream Isolates

OBJECTIVE

To develop a risk score to predict probability of bloodstream infections (BSIs) due to extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBLE).

DESIGN

Retrospective case-control study.

SETTING

Two large community hospitals.

PATIENTS

Hospitalized adults with Enterobacteriaceae BSI between January 1, 2010, and June 30, 2015.

METHODS

Multivariate logistic regression was used to identify independent risk factors for ESBLE BSI. Point allocation in extended-spectrum β-lactamase prediction score (ESBL-PS) was based on regression coefficients.

RESULTS

Among 910 patients with Enterobacteriaceae BSI, 42 (4.6%) had ESBLE bloodstream isolates. Most ESBLE BSIs were community onset (33 of 42; 79%), and 25 (60%) were due to Escherichia coli. Independent risk factors for ESBLE BSI and point allocation in ESBL-PS included outpatient procedures within 1 month (adjusted odds ratio [aOR], 8.7; 95% confidence interval [CI], 3.1–22.9; 1 point), prior infections or colonization with ESBLE within 12 months (aOR, 26.8; 95% CI, 7.0–108.2; 4 points), and number of prior courses of β-lactams and/or fluoroquinolones used within 3 months of BSI: 1 course (aOR, 6.3; 95% CI, 2.7–14.7; 1 point), ≥2 courses (aOR, 22.0; 95% CI, 8.6–57.1; 3 points). The area under the receiver operating characteristic curve for the ESBL-PS model was 0.86. Patients with ESBL-PSs of 0, 1, 3, and 4 had estimated probabilities of ESBLE BSI of 0.7%, 5%, 24%, and 44%, respectively. Using ESBL-PS ≥3 to indicate high risk provided a negative predictive value of 97%.

CONCLUSIONS

ESBL-PS estimated patient-specific risk of ESBLE BSI with high discrimination. Incorporation of ESBL-PS with acute severity of illness may improve adequacy of empirical antimicrobial therapy and reduce carbapenem utilization.

Infect Control Hosp Epidemiol 2017;38:266–272

High Prevalence of ESBL-Producing Klebsiella pneumoniae Causing Community-Onset Infections in China

The aim of this work was to investigate the epidemiological and genetic characteristics of ESBL-producing Klebsiella pneumoniae (ESBL-Kp) causing community-onset infections. K. pneumoniae isolates were collected from 31 Chinese secondary hospitals between August 2010 and 2011. Genes encoding ESBL and AmpC beta-lactamases were detected by PCR. The isolates were assigned to sequence types (STs) using multi-locus sequence typing (MLST). Eleven ESBL-Kp strains were selected for whole-genome sequencing (WGS) for investigating the genetic environment and plasmids encoding ESBL genes. A total of 578 K. pneumoniae isolates were collected, and 184 (31.8%) carried ESBL genes. The prevalence of ESBL-Kp varied from different geographical areas of China (10.2–50.3%). The three most prevalent ESBL genes were bla_CTX-M-14 (n = 74), bla_CTX-M-15 (n = 60), and bla_CTX-M-3 (n = 40). MLST assigned 127 CTX-M-14 and CTX-M-15 producers to 54 STs, and CC17 was the most prevalent population (12.6%). STs (23, 37, and 86) that were known frequently associated with hypervirulent K. pneumoniae (hvKP) account for 14.1% (18/127). Phylogenetic analysis by concatenating the seven loci of MLST revealed the existence of ESBL-producing K. quasipneumoniae (two strains) and K. varricola (one strain), which was further confirmed by WGS. This study highlights the challenge of community-onset infections caused by ESBL-Kp in China. The prevalence of STs frequently associating with hvKP should be of concern. Surveillance of ESBL-KP causing community-onset infections now appears imperative.

Prevalence of ESBL in Escherichia coli Isolates Among ICU Patients in a Tertiary Care Hospital

INTRODUCTION

Resistance to common antibiotics is a matter of grave concern in treating infections in hospital settings especially in Intensive Care Units (ICUs). One of the most commonly used and effective group of antibiotics, cephalosporins, exhibit resistance due to production of Extended Spectrum Beta- Lactamases (ESBLs). The prevalence of ESBL producing Escherichia coli (E.coli) has increased throughout the world and is a major cause of treatment failure in ICUs. As per our knowledge studies were not available on the prevalence of ESBL producing E.coli in ICUs of this region.

AIM

To determine the prevalence of ESBLs among Escherichia coli isolates in ICUs of a tertiary care hospital.

MATERIALS AND METHODS

A cross sectional study was conducted over a period of 4 years (Sept 2011 to Sept 2015) in the Department of Microbiology, Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar. Consecutive non-duplicate isolates of E.coli recovered from 6800 clinical samples of patients admitted to different Intensive Care Units (ICUs) were subjected to ESBL screening test and then to CLSI recommended Phenotypic Confirmatory Disc Diffusion Tests (PCDDT) for ESBL production determination.

RESULTS

Out of 6800 samples, 1038 were E.coli isolates and 452(44%) were resistant to third generation cephalosporins. ESBL producing Escherichia coli among them were 276 (61.1%). Paediatric ICU showed the highest prevalence of ESBL E.coli at 80.9%. The highest prevalence of ESBL E.coli was in urine samples (82.6%) followed by pus (9.8%). The most effective antibiotic for ESBL producers was imipenem (96.7% sensitive), followed by amikacin (88.4%) and piperacillin- tazobactum (87%).

CONCLUSION

This study has highlighted the high prevalence of ESBL producing E.coli in the ICUs of our hospital. An in depth analysis of their antibiogram will be helpful in formulating the antibiotic policy and prevent spread of ESBL strains. It is recommended that ESBL testing should be done routinely to curtail antibiotic resistance and to effectively implement infection control measures.

Increasing Incidence of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Community Hospitals throughout the Southeastern United States

OBJECTIVE To describe the epidemiology of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) and Klebsiella pneumoniae (ESBL-KP) infections DESIGN Retrospective cohort SETTING Inpatient care at community hospitals PATIENTS All patients with ESBL-EC or ESBL-KP infections METHODS ESBL-EC and ESBL-KP infections from 26 community hospitals were prospectively entered into a centralized database from January 2009 to December 2014. RESULTS A total of 925 infections caused by ESBL-EC (10.5 infections per 100,000 patient days) and 463 infections caused by ESBL-KP (5.3 infections per 100,000 patient days) were identified during 8,791,243 patient days of surveillance. The incidence of ESBL-EC infections increased from 5.28 to 10.5 patients per 100,000 patient days during the study period (P=.006). The number of community hospitals with ESBL-EC infections increased from 17 (65%) in 2009 to 20 (77%) in 2014. The median ESBL-EC infection rates among individual hospitals with ≥1 ESBL-EC infection increased from 11.1 infections/100,000 patient days (range, 2.2-33.9 days) in 2009 to 22.1 infections per 100,000 patient days (range, 0.66-134 days) in 2014 (P=.05). The incidence of ESBL-KP infections remained constant over the study period (P=.14). Community-associated and healthcare-associated ESBL-EC infections trended upward (P=.006 and P=.02, respectively), while hospital-onset infections remained stable (P=.07). ESBL-EC infections were more common in females (54% vs 44%, P<.001) and Caucasians (50% vs 40%, P<.0001), and were more likely to be isolated from the urinary tract (61% vs 52%, P<.0001) than ESBL-KP infections. CONCLUSIONS The incidence of ESBL-EC infection has increased in community hospitals throughout the southeastern United States, while the incidence of ESBL-KP infection has remained stable. Community- and healthcare-associated ESBL-EC infections are driving the upward trend. Infect. Control Hosp. Epidemiol. 2015;37(1):49-54.

Differential characteristics of healthcare-associated compared to community-acquired febrile urinary tract infections in males

The objective of this study was to analyse the characteristics of healthcare-associated febrile urinary tract infection (HCA-FUTI) compared to community-acquired FUTI (CA-FUTI) in men. An ambispective cross-sectional study in which we recorded clinical and microbiology data and outcomes from males with FUTI attended in the Emergency Department was carried out. A total of 479 males with FUTI, 162 (33.8%) HCA-FUTI and 317 (66.2%) CA-FUTI, were included. HCA-FUTI patients were older (p < 0.001), had higher Charlson scores (p < 0.001) and received previous antimicrobial treatment more frequently (p < 0.001) compared to CA-FUTI patients. HCA-FUTI was less likely caused by Escherichia coli (p < 0.001) and more frequently by Klebsiella spp. (p = 0.02), Enterobacter spp. (p < 0.001) and Pseudomonas aeruginosa (p < 0.001). Resistance to ceftriaxone (p = 0.006), gentamicin (p < 0.001), quinolones (p < 0.001), co-trimoxazole (p = 0.001) and fosfomycin (p = 0.009) was higher among E. coli strains isolated from males with HCA-FUTI and so was the prevalence of extended-spectrum beta-lactamase and AmpC E. coli and Klebsiella spp.-producing strains (p = 0.012). Inadequate antimicrobial treatment and all-cause in-hospital mortality was associated with HCA-FUTI (p < 0.001 and p = 0.004, respectively). Independent factors for mortality were severe sepsis or septic shock [odds ratio (OR) 29; 95% confidence interval (CI): 3.9-214] and cirrhosis (OR 23.7; 95% CI: 1.6-350.6). Male patients with HCA-FUTI have different clinical characteristics, outcomes and microbiological features compared to CA-FUTI patients. Previous contact with the healthcare system has to be taken into consideration when deciding the optimal antimicrobial treatment in males with FUTI.

Ongoing increasing temporal and geographical trends of the incidence of extended-spectrum beta-lactamase-producing Enterobacteriaceae infections in France, 2009 to 2013

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are a major focus of multidrug-resistant organisms (MRO) surveillance programmes in France. To describe the temporal and geographical trends of these pathogens, we conducted an epidemiological study based on data extracted from the nationwide MRO surveillance network from 2009 to 2013. During this time, the incidence of ESBL-E infections in French hospitals increased by 73%, from 0.35 to 0.60 per 1,000 patient days (PD) (p < 0.001) and ESBL-E bacteraemia by 77%, from 0.03 to 0.05 per 1,000 PD (p < 0.001). The incidence of ESBL-E infections was higher in intensive-care units (1.62 to 2.44 per 1,000 PD (p < 0.001)) than in recovery and long-term care facilities (0.20 to 0.31 per 1,000 PD (p < 0.001)). Escherichia coli was the most frequent extended-spectrum beta-lactamase-producing (ESBL) pathogen, representing 59% (26,238/44,425) of all ESBL isolates, followed by Klebsiella pneumoniae (20%; 8,856/44,425) in 2013. The most frequent infection was urinary tract infection, for all species. The incidence of ESBL-E varied by region but showed an upward trend overall. Reinforcement of control measures for halting the spread of such MRO is crucial.

Empirical therapies among adults hospitalized for community-acquired upper urinary tract infections: A decision-tree analysis of mortality, costs, and resistance

BACKGROUND

Poor outcomes occur when patients with serious infections receive antibiotics to which the organisms are resistant.

METHODS

Decision trees simulated in-hospital mortality, costs, incremental cost-effectiveness ratio per life year saved, and carbapenem resistance according to 3 empirical antibiotic strategies among adults hospitalized for community-acquired (CA) upper urinary tract infections (UTIs): ceftriaxone (CRO) plus gentamicin (GM) in the intensive care unit (ICU), imipenem (IMP), and individualized choice (IMP or CRO) based on clinical risk factors for CA- extended-spectrum β-lactamase (ESBL).

RESULTS

The estimated prevalence of CA-ESBL on admission was 5% (range, 1.3%-17.6%); 3% and 97% were admitted to the ICU and medical ward (MW), respectively. In the ICU, CRO plus GM was dominated; IMP was cost-effective (incremental cost-effectiveness ratio: €4,400 per life year saved compared with individualized choice). In the MW, IMP had no impact on mortality and was less costly (-€142 per patient vs CRO, -€38 vs individualized choice). The dominance of IMP was consistent in sensitivity analyses. Compared with CRO, colonization by carbapenem-resistant pathogens increased by an odds ratio of 4.5 in the IMP strategy.

CONCLUSION

Among the ICU patients, empirical IMP therapy reduces mortality at an acceptable cost. Among MW patients, individualized choice or CRO is preferred to limit carbapenem resistance at a reasonable cost.

Avoiding admission and facilitating early discharge through OPAT

Fifteen years ago, only a small minority of hospital inpatients were considered suitable for outpatient parenteral antimicrobial therapy (OPAT) services (Wiselka and Nicholson, 1997). Now, almost 70% of those treated with intravenous (IV) antibiotics as hospital inpatients are considered suitable (Hitchcock et al, 2009). Around 38-53% of those requiring OPAT are able to self-administer (Hills et al, 2012). The demand for IV antimicrobial therapy is increasing and the way it is being delivered is changing. The delivery of IV anti-microbial therapy in the community has the potential to make a huge difference to the way health care is delivered. It can enable people who would once have been admitted to hospital to be treated in the community. It can facilitate early hospital discharge (Nazarko, 2013a). Potentially, there are huge benefits in developing OPAT but there are also risks. People may be subjected to an invasive treatment when it is not necessary; therapy may be continued when it is no longer necessary (Nazarko, 2013b; Conant et al, 2014); and patients may be selected for OPAT who would be best treated in hospital. The key to providing safe and effective care is to work together to maximise benefits and minimise risk (Duncan et al, 2013). This article examines how acute and community services can work together to ensure appropriate selection, treatment and follow-up of patients.

Effect of ceftriaxone on the outcome of murine pyelonephritis caused by extended-spectrum-β-lactamase-producing Escherichia coli

Urinary tract infections (UTIs) due to extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in children are becoming more frequent, and they are commonly treated initially with a second- or third-generation cephalosporin. We developed a murine model of ascending UTI caused by ESBL-producing Escherichia coli. Using this model, we investigated the renal bacterial burden, interleukin-6 (IL-6) expression, and histopathological alterations caused by ESBL- and non-ESBL-producing bacteria after 1, 2, or 6 days with or without ceftriaxone therapy. The renal bacterial burden, IL-6 concentration, and histological inflammatory lesions were not significantly different between mice infected with ESBL- and non-ESBL-producing bacteria without treatment at any of the time points examined. Following ceftriaxone administration, the bacterial burden was eliminated in the kidneys of mice infected with ESBL- and non-ESBL-producing bacteria on the 6th postinfection day. The histological analysis demonstrated that among mice treated with ceftriaxone, those infected with ESBL-producing bacteria had more profound renal alterations than those infected with non-ESBL-producing bacteria on the 6th day (P < 0.001). In comparison, microbiological outcomes did not differ significantly between mice infected with ESBL- and non-ESBL-producing bacteria at any of the time points examined. The effectiveness of ceftriaxone in mice with UTIs due to ESBL-producing E. coli may have therapeutic implications; it is, however, hampered by limited activity on the histopathological lesions, a finding that needs further investigation.

Prevalence of antibiotic resistant bacteria in healthy adults, foods, food animals, and the environment in selected areas in Thailand

OBJECTIVES

The aim of this study was to determine the prevalence of antibiotic-resistant bacteria, especially extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, in samples from healthy adults, foods, food animals, and the environment in selected areas of Thailand.

METHODS

Samples were collected from stool specimens from adult food factory and food animal farm workers, fresh and cooked foods sold at markets, rectal swabs of healthy pigs and chickens, fresh pork meat from slaughterhouses, water samples from canals as well as fish and shrimp farm ponds, and stagnant water sources on pig farms. Antibiotic susceptibility was determined using the disk diffusion or agar dilution methods. Extended-spectrum beta-lactamase production was assayed using a double disk diffusion method.

RESULTS

Among 544 healthy adult food factory workers, 75·5% were positive for ESBL producing E. coli, while 77·3% of E. coli isolated from 30 healthy animal farm workers were positive. Amongst healthy food animals, ESBL producing status among E. coli isolates were more commonly detected in pigs (76·7%) than broilers (40%). Extended-spectrum beta-lactamase producing E. coli seemed to be more prevalent in fresh meat samples than in fresh vegetables, in fresh foods than in cooked foods, and in water samples collected from the animal farms than those from canals and fish and shrimp ponds.

CONCLUSIONS

Extended-spectrum beta-lactamase producing E. coli isolates are prevalent amongst healthy individuals, foods along the food production chain from farms to consumers, and in the environment in selected areas in Thailand.