Marked increase in incidence for bloodstream infections due to Escherichia coli, a side effect of previous antibiotic therapy in the elderly

Changing epidemiology and antimicrobial susceptibility of bloodstream infections at a Vietnamese infectious diseases hospital (2010-2020)

Bloodstream infection (BSI) poses a global health problem, with diverse organisms and rising antimicrobial resistance (AMR). Here, we characterized trends in BSI prevalence, AMR, and antibiotic use at a Vietnamese infectious diseases hospital from 2010 to 2020. Among 108,303 cultured blood samples, 8.8% were positive, yielding 7995 pathogens. Of 7553 BSI cases, 86.4% were community-acquired. BSI prevalence varied from 17 to 35 cases/1000 admissions/year, highest in HIV/hepatitis wards and patients >60. The in-hospital mortality or hospice discharge outcome was 21.3%. The top three pathogens, E. coli (24%), K. pneumoniae (8.7%) and S. aureus (8.5%) exhibited increasing prevalence and multidrug resistance. Pathogens like Cryptococcus neoformans (8.4%), Talaromyces marneffei (6.7%), and Salmonella enterica (6.5%) declined. E. coli and K. pneumoniae were prevalent in older adults with community-acquired BSIs. Antibiotic use reached 842.6 DOT/1000 PD and significantly reduced after an antibiotic control policy. Enhanced surveillance and antimicrobial stewardship are crucial for managing BSIs in Vietnam.

A randomized phase 1/2a trial of ExPEC10V vaccine in adults with a history of UTI

The safety, reactogenicity, and immunogenicity of 3 doses of ExPEC10V (VAC52416), a vaccine candidate to prevent invasive Escherichia coli disease, were assessed in a phase 1/2a study (NCT03819049). In Cohort 1, ExPEC10V was well tolerated; the high dose was selected as optimal and further characterized in Cohort 2. Cohort 2 comprised a maximum 28-day screening, vaccination (Day 1), double-blind 181-day follow-up, and open-label long-term follow-up until Year 1. Healthy participants (≥60 years) with a history of urinary tract infection (UTI) within 5 years were randomized to receive ExPEC10V or placebo. The primary endpoint evaluated the safety and reactogenicity of ExPEC10V (solicited local and systemic AEs [until Day 15]; unsolicited AEs [until Day 30], SAEs [until Day 181], and immunogenicity [Day 30]) via multiplex electrochemiluminescent (ECL) and multiplex opsonophagocytic assay (MOPA). 416 participants (ExPEC10V, n = 278; placebo, n = 138) were included (mean age [SD], 68.8 [6.52] years; female, 79.6%; White, 96.1%). The incidence of solicited AEs was higher with ExPEC10V (local, 50.0% [n = 139]; systemic, 50.0% [n = 139]) than placebo (15.9% [n = 22]; 38.4% [n = 53]); rates of unsolicited AEs were comparable (ExPEC10V, 28.4% [n = 79]; placebo, 26.1% [n = 36]). No vaccine-related SAEs or deaths were reported. ExPEC10V elicited a robust antibody-mediated immunogenic response across all serotypes with ECL (Day 30 geometric mean fold increase, 2.33-8.18) and demonstrated functional opsonophagocytic killing activity across all measured serotypes (Day 30 geometric mean fold increase, 1.81-9.68). ExPEC10V exhibited an acceptable safety profile and a robust vaccine-induced functional immunogenic response in participants with a history of UTI. Clinical trial registration details: https://clinicaltrials.gov/study/NCT03819049 .

Clinical presentation and antimicrobial resistance of invasive Escherichia coli disease in hospitalized older adults: a prospective multinational observational study

BACKGROUND

Clinical data characterizing invasive Escherichia coli disease (IED) are limited. We assessed the clinical presentation of IED and antimicrobial resistance (AMR) patterns of causative E. coli isolates in older adults.

METHODS

EXPECT-2 (NCT04117113) was a prospective, observational, multinational, hospital-based study conducted in patients with IED aged ≥ 60 years. IED was determined by the microbiological confirmation of E. coli from blood; or by the microbiological confirmation of E. coli from urine or an otherwise sterile body site in the presence of requisite criteria of systemic inflammatory response syndrome (SIRS), Sequential Organ Failure Assessment (SOFA), or quick SOFA (qSOFA). The primary outcomes were the clinical presentation of IED and AMR rates of E. coli isolates to clinically relevant antibiotics. Complications and in-hospital mortality were assessed through 28 days following IED diagnosis.

RESULTS

Of 240 enrolled patients, 80.4% had bacteremic and 19.6% had non-bacteremic IED. One-half of infections (50.4%) were community-acquired. The most common source of infection was the urinary tract (62.9%). Of 240 patients, 65.8% fulfilled ≥ 2 SIRS criteria, and 60.4% had a total SOFA score of ≥ 2. Investigator-diagnosed sepsis and septic shock were reported in 72.1% and 10.0% of patients, respectively. The most common complication was kidney dysfunction (12.9%). The overall in-hospital mortality was 4.6%. Of 299 E. coli isolates tested, the resistance rates were: 30.4% for trimethoprim-sulfamethoxazole, 24.1% for ciprofloxacin, 22.1% for levofloxacin, 16.4% for ceftriaxone, 5.7% for cefepime, and 4.3% for ceftazidime.

CONCLUSIONS

The clinical profile of identified IED cases was characterized by high rates of sepsis. IED was associated with high rates of AMR to clinically relevant antibiotics. The identification of IED can be optimized by using a combination of clinical criteria (SIRS, SOFA, or qSOFA) and culture results.

Mortality and length of hospital stay after bloodstream infections caused by ESBL-producing compared to non-ESBL-producing E. coli

OBJECTIVE

To compare mortality and length of hospital stay between patients with ESBL-producing E. coli bloodstream infections (BSIs) and patients with non-ESBL E. coli BSIs. We also aimed at describing risk factors for ESBL-producing E. coli BSIs and time to effective antibiotic treatment for the two groups.

METHODS

A retrospective case-control study among adults admitted between 2014 and 2021 to a Norwegian University Hospital.

RESULTS

A total of 468 E. coli BSI episodes from 441 patients were included (234 BSIs each in the ESBL- and non-ESBL group). Among the ESBL-producing E. coli BSIs, 10.9% (25/230) deaths occurred within 30 days compared to 9.0% (21/234) in the non-ESBL group. The adjusted 30-day mortality OR was 1.6 (95% CI 0.7-3.7, p = 0.248). Effective antibiotic treatment was administered within 24 hours to 55.2% (129/234) in the ESBL-group compared to 86.8% (203/234) in the non-ESBL group. Among BSIs of urinary tract origin (n = 317), the median length of hospital stay increased by two days in the ESBL group (six versus four days, p < 0.001). No significant difference in the length of hospital stay was found for other sources of infection (n = 151), with a median of seven versus six days (p = 0.550) in the ESBL- and non-ESBL groups, respectively.

CONCLUSION

There was no statistically significant difference in 30-day mortality in ESBL-producing E. coli compared to non-ESBL E. coli BSI, despite a delay in the administration of an effective antibiotic in the former group. ESBL-production was associated with an increased length of stay in BSIs of urinary tract origin.

E. coli Common pili promote the fitness and virulence of a hybrid aEPEC/ExPEC strain within diverse host environments

Pathogenic subsets of Escherichia coli include diarrheagenic (DEC) strains that cause disease within the gut and extraintestinal pathogenic E. coli (ExPEC) strains that are linked with urinary tract infections, bacteremia, and other infections outside of intestinal tract. Among DEC strains is an emergent pathotype known as atypical enteropathogenic E. coli (aEPEC), which can cause severe diarrhea. Recent sequencing efforts revealed that some E. coli strains possess genetic features that are characteristic of both DEC and ExPEC isolates. BA1250 is a newly reclassified hybrid strain with characteristics of aEPEC and ExPEC. This strain was isolated from a child with diarrhea, but its genetic features indicate that it might have the capacity to cause disease at extraintestinal sites. The spectrum of adhesins encoded by hybrid strains like BA1250 are expected to be especially important in facilitating colonization of diverse niches. E. coli common pilus (ECP) is an adhesin expressed by many E. coli pathogens, but how it impacts hybrid strains has not been ascertained. Here, using zebrafish larvae as surrogate hosts to model both gut colonization and extraintestinal infections, we found that ECP can act as a multi-niche colonization and virulence factor for BA1250. Furthermore, our results indicate that ECP-related changes in activation of envelope stress response pathways may alter the fitness of BA1250. Using an in silico approach, we also delineated the broader repertoire of adhesins that are encoded by BA1250, and provide evidence that the expression of at least a few of these varies in the absence of functional ECP.

Multicenter surveillance of in vitro activities of cefepime-zidebactam, cefepime-enmetazobactam, omadacycline, eravacycline, and comparator antibiotics against Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii complex causing bloodstream infection in Taiwan, 2020

OBJECTIVES

: To determine the in vitro activities of novel and comparator antibiotics against gram-negative bacteria (GNB) in Taiwan.

METHODS

: Isolates of Escherichia coli (n = 335), Klebsiella pneumoniae (n = 316; 144 isolates with hyperviscosity characteristics), Pseudomonas aeruginosa (n = 271), Acinetobacter baumannii complex species (n = 187), and non-typhoidal Salmonella species (n = 226), Shigella species (n = 13) from miscellaneous culture sources were collected in 2020 in Taiwan. The MICs of the isolates to test antibiotics were determined using the broth microdilution method. GeneXpert was used to detect genes encoding carbapenemases among the carbapenem-non-susceptible (NS) Enterobacterales isolates.

RESULTS

: The MIC values of the cefepime-enmetazobactam combination against extended-spectrum β-lactamase-producing E. coli and K. pneumoniae isolates (MIC₉₀ ≤ 0.5 mg/L), bla_KPC-harboring E. coli isolates (0.25 mg/L; n = 2), and 80% of bla_OXA-48-like gene-harboring K. pneumoniae isolates (≤2 mg/L) were low. The MIC ranges of the cefepime-zidebactam against carbapenemase-producing Enterobacterales isolates (irrespective of the carbapenemase type [MIC₉₀ ≤ 4 mg/L]) and carbapenem-NS or ceftolozane-tazobactam-NS P. aeruginosa isolates (MIC₉₀ value, 8 mg/L) were significantly lower than those of the cefepime-enmetazobactam.

CONCLUSIONS

: The efficacy of novel antibiotics against important drug-resistant GNB must be monitored and validated during the clinical treatment of patients.

Exploring temporal trends and risk factors for resistance in Escherichia coli-causing bacteraemia in England between 2013 and 2018: an ecological study

BACKGROUND

Escherichia coli are Gram-negative bacteria associated with an increasing burden of antimicrobial resistance (AMR) in England.

OBJECTIVES

To create a comprehensive epidemiological picture of E. coli bacteraemia resistance trends and risk factors in England by linking national microbiology data sources and performing a longitudinal analysis of rates.

METHODS

A retrospective observational study was conducted on all national records for antimicrobial susceptibility testing on E. coli bacteraemia in England from 1 January 2013 to 31 December 2018 from the UK Health Security Agency (UKHSA) and the BSAC Resistance Surveillance Programme (BSAC-RSP). Trends in AMR and MDR were estimated using iterative sequential regression. Logistic regression analyses were performed on UKHSA data to estimate the relationship between risk factors and AMR or MDR in E. coli bacteraemia isolates.

RESULTS

An increase in resistance rates was observed in community- and hospital-onset bacteraemia for third-generation cephalosporins, co-amoxiclav, gentamicin and ciprofloxacin. Among community-acquired cases, and after adjustment for other factors, patients aged >65 years were more likely to be infected by E. coli isolates resistant to at least one of 11 antibiotics than those aged 18-64 years (OR: 1.21, 95% CI: 1.18-1.25; P < 0.05). In hospital-onset cases, E. coli isolates from those aged 1-17 years were more likely to be resistant than those aged 18-64 years (OR: 1.33, 95% CI: 1.02-1.73; P < 0.05).

CONCLUSIONS

Antibiotic resistance rates in E. coli-causing bacteraemia increased between 2013 and 2018 in England for key antimicrobial agents. Findings of this study have implications for guiding future policies on a prescribing of antimicrobial agents, for specific patient populations in particular.

A TTP-incorporated scoring model for predicting mortality of solid tumor patients with bloodstream infection caused by Escherichia coli

Background

Few mortality-scoring models are available for solid tumor patients who are predisposed to develop Escherichia coli–caused bloodstream infection (ECBSI). We aimed to develop a mortality-scoring model by using information from blood culture time to positivity (TTP) and other clinical variables.

Methods

A cohort of solid tumor patients who were admitted to hospital with ECBSI and received empirical antimicrobial therapy was enrolled. Survivors and non-survivors were compared to identify the risk factors of in-hospital mortality. Univariable and multivariable regression analyses were adopted to identify the mortality-associated predictors. Risk scores were assigned by weighting the regression coefficients with corresponding natural logarithm of the odds ratio for each predictor.

Results

Solid tumor patients with ECBSI were distributed in the development and validation groups, respectively. Six mortality-associated predictors were identified and included in the scoring model: acute respiratory distress (ARDS), TTP ≤ 8 h, inappropriate antibiotic therapy, blood transfusion, fever ≥ 39 °C, and metastasis. Prognostic scores were categorized into three groups that predicted mortality: low risk (< 10% mortality, 0–1 points), medium risk (10–20% mortality, 2 points), and high risk (> 20% mortality, ≥ 3 points). The TTP-incorporated scoring model showed excellent discrimination and calibration for both groups, with AUC being 0.833 vs 0.844, respectively, and no significant difference in the Hosmer–Lemeshow test (6.709, P = 0.48) and the chi-square test (6.993, P = 0.46). Youden index showed the best cutoff value of ≥ 3 with 76.11% sensitivity and 79.29% specificity. TTP-incorporated scoring model had higher AUC than no TTP-incorporated model (0.837 vs 0.817, P < 0.01).

Conclusions

Our TTP-incorporated scoring model was associated with improving capability in predicting ECBSI-related mortality. It can be a practical tool for clinicians to identify and manage bacteremic solid tumor patients with high risk of mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06442-z.

Mortality in Escherichia coli bloodstream infections: antibiotic resistance still does not make it

BACKGROUND

Escherichia coli bloodstream infections (BSIs) account for high mortality rates (5%-30%). Determinants of death are unclear, especially since the emergence of ESBL producers.

OBJECTIVES

To determine the relative weight of host characteristics, bacterial virulence and antibiotic resistance in the outcome of patients suffering from E. coli BSI.

METHODS

All consecutive patients suffering from E. coli BSI in seven teaching hospitals around Paris were prospectively included for 10 months. E. coli isolates were sequenced using Illumina NextSeq technology to determine the phylogroup, ST/ST complex (STc), virulence and antimicrobial resistance gene content. Risk factors associated with death at discharge or Day 28 were determined.

RESULTS

Overall, 545 patients (mean ± SD age 68.5 ± 16.5 years; 52.5% male) were included. Mean Charlson comorbidity index (CCI) was 5.6 (± 3.1); 19.6% and 12.8% presented with sepsis and septic shock, respectively. Portals of entry were mainly urinary (51.9%), digestive (41.9%) and pulmonary (3.5%); 98/545 isolates (18%) were third-generation cephalosporin resistant (3GC-R), including 86 ESBL producers. In-hospital death (or at Day 28) was 52/545 (9.5%). Factors independently associated with death were a pulmonary portal of entry [adjusted OR (aOR) 6.54, 95% CI 2.23-19.2, P = 0.0006], the iha_17 virulence gene (aOR 4.41, 95% CI 1.23-15.74, P = 0.022), the STc88 (aOR 3.62, 95% CI 1.30-10.09, P = 0.014), healthcare-associated infections (aOR 1.98, 95% CI 1.04-3.76, P = 0.036) and high CCI (aOR 1.14, 95% CI 1.04-1.26, P = 0.006), but not ESBL/3GC-R.

CONCLUSIONS

Host factors, portal of entry and bacterial characteristics remain major determinants associated with mortality in E. coli BSIs. Despite a high prevalence of ESBL producers, antibiotic resistance did not impact mortality. (ClinicalTrials.gov identifier: NCT02890901.).

A prospective study of Escherichia coli bloodstream infection among adolescents and adults in northern Tanzania

Background

Characterization of the epidemiology of Escherichia coli bloodstream infection (BSI) in sub-Saharan Africa is lacking. We studied patients with E. coli BSI in northern Tanzania to describe host risk factors for infection and to describe the antimicrobial susceptibility of isolates.

Methods

Within 24 h of admission, patients presenting with a fever at two hospitals in Moshi, Tanzania, were screened and enrolled. Cases were patients with at least one blood culture yielding E. coli and controls were those without E. coli isolated from any blood culture. Logistic regression was used to identify host risk factors for E. coli BSI.

Results

We analyzed data from 33 cases and 1615 controls enrolled from 2007 through 2018. The median (IQR) age of cases was 47 (34–57) y and 24 (72.7%) were female. E. coli BSI was associated with (adjusted OR [aOR], 95% CI) increasing years of age (1.03, 1.01 to 1.05), female gender (2.20, 1.01 to 4.80), abdominal tenderness (2.24, 1.06 to 4.72) and urinary tract infection as a discharge diagnosis (3.71, 1.61 to 8.52). Of 31 isolates with antimicrobial susceptibility results, the prevalence of resistance was ampicillin 29 (93.6%), ceftriaxone three (9.7%), ciprofloxacin five (16.1%), gentamicin seven (22.6%) and trimethoprim-sulfamethoxazole 31 (100.0%).

Conclusions

In Tanzania, host risk factors for E. coli BSI were similar to those reported in high-resource settings and resistance to key antimicrobials was common.

Bloodstream infections in the elderly: what is the real goal?

Bloodstream infections (BSI) represent a serious bacterial infection with substantial morbidity and mortality. Population-based studies demonstrate an increased incidence, especially among elderly patients. Controversy exists regarding whether presentation of BSI are different in older patients compared to younger patients; our narrative review of the literature suggests that BSI in elderly patients would probably include one or more of the traditional symptoms/signs of fever, severe sepsis or septic shock, acute kidney injury, and/or leukocytosis. Sources of BSI in older adults are most commonly the urinary tract (more so than in younger adults) and the respiratory tract. Gram-negative bacteria are the most common isolates in the old (~ 40-60% of BSI); isolates from the elderly patient population show higher antibiotic resistance rates, with long-term care facilities serving as reservoirs for multidrug-resistant bacteria. BSI entail significantly higher rates of mortality in older age, both short and long term. Some of the risk factors for mortality are modifiable, such as the appropriateness of empirical antibiotic therapy and nosocomial acquisition of infection. Health-related quality of life issues regarding the elderly patient with BSI are not well addressed in the literature. Utilization of comprehensive geriatric assessment and comprehensive geriatric discharge planning need to be investigated further in this setting and might serve as key for improved results in this population. In this review, we address all these aspects of BSI in old patients with emphasis on future goals for management and research.

National database study of trends in bacteraemia aetiology among children and adults in Japan: a longitudinal observational study

OBJECTIVES

Domestic epidemiological studies are needed to ascertain the disease burden of bacteraemia in individual countries. This study aimed to evaluate the domestic trends in paediatric and adult bacteraemia in Japan.

SETTING

Laboratory-based surveillance was used to obtain data from 592 hospitals located throughout Japan.

PARTICIPANTS

The study was conducted using the results of 827 780 and 3 512 524 blood culture tests obtained from children and adults, respectively, between January 2010 and December 2016.

OUTCOME MEASURES

We analysed the temporal trends in specific bacterial species (Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Haemophilus influenzae, Listeria monocytogenes and Neisseria meningitidis) detected from the blood cultures of children and adults. For children aged ≤2 years, the data were analysed for each year of age. The proportions of bacteraemia-positive results among the patients were also evaluated.

RESULTS

The number of bacteraemia-positive samples over the study period was 47,125/827,855 (5.7%) in children and 959,765/3,513,885 (27.3%) in adults. S. pneumoniae was the most frequent cause of bacteraemia in children in 2010. However, after 2011, S. aureus bacteraemia was the most frequent, followed by S. pneumoniae and E. coli. E. coli bacteraemia showed significant increases in both children and adults. In children, S. pneumoniae and H. influenzae bacteraemia decreased from 2010 to 2013. However, S. pneumoniae bacteraemia case numbers stabilised from 2013, whereas H. influenzae bacteraemia cases continued to decrease until 2016.

CONCLUSION

The results suggest that the introduction of the 13-valent pneumococcal conjugate vaccine did not substantially affect disease occurrence. In contrast to the decreasing trends in H. influenzae and S. pneumoniae bacteraemia, S. aureus, E. coli and S. agalactiae bacteraemia showed increasing trends. These findings shed light on recent temporal trends in bacteraemia in both children and adults in Japan.

Bloodstream infections in older population: epidemiology, outcome, and impact of multidrug resistance

Bloodstream infections (BSIs) among older patients are frequent with high rate of mortality. Infections with multidrug-resistant organisms (MDRO) are associated with higher mortality than with susceptible microorganisms. We aimed to evaluate the prevalence of MDRO infection during BSI in older population and the factors associated with unfavorable outcome. This study is a retrospective cohort of all BSI episodes occurring among older patients (> 65yo), from April 1, 2010, to December 31, 2016, in a French university hospital for geriatric medicine. A total of 255 BSI episodes were analyzed. Mean age was 86.3±6.5 years, and sex ratio (M/F) was 0.96. Main comorbidities were orthopedic device (26.7%), active neoplasia (24.3%), and diabetes mellitus (18.4%). Main primary sites of infection were urinary tract infections (56.9%), respiratory tract infections (10.6%), intra-abdominal infections (7.1%), and skin and soft tissue infections (4.7%). Main bacteria identified were Escherichia coli (45.1%), Staphylococcus aureus (14.1%), enterococci (10.7%), coagulase-negative staphylococci (CoNS) (5.5%), and streptococci (5.1%). MDROs were involved in 17.2% of BSI (gram-negative bacilli: 9.0%; CoNS: 4.3%; and methicillin-resistant S. aureus (MRSA): 3.9%). The main factor associated with MDRO BSI was colonization with MDRO (OR=6.29; 95%CI=2.9-14.32). Total mortality was 18.4% and significantly higher in case of initial severity (OR=3.83; 95%CI=1.75-8.38), healthcare-associated infection (OR=5.29; 95%CI=1.11-25.30), and MRSA BSI (OR=9.16; 95%CI=1.67-50.16). BSI due to MDRO is frequent in older population and is strongly associated with carriage of MDRO. Healthcare-associated BSI, severe episodes, and BSI due to MRSA are associated with unfavorable outcome. In these cases, a broad-spectrum antibiotic should be promptly initiated.

National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored bla _KPC (n = 17), bla _OXA-48 (n = 2), and bla _VIM (n = 1) genes.

Clonal Structure, Virulence Factor-encoding Genes and Antibiotic Resistance of Escherichia coli, Causing Urinary Tract Infections and Other Extraintestinal Infections in Humans in Spain and France during 2016

Escherichia coli is the main pathogen responsible for extraintestinal infections. A total of 196 clinical E. coli consecutively isolated during 2016 in Spain (100 from Lucus Augusti hospital in Lugo) and France (96 from Beaujon hospital in Clichy) were characterized. Phylogroups, clonotypes, sequence types (STs), O:H serotypes, virulence factor (VF)-encoding genes and antibiotic resistance were determined. Approximately 10% of the infections were caused by ST131 isolates in both hospitals and approximately 60% of these infections were caused by isolates belonging to only 10 STs (ST10, ST12, ST58, ST69, ST73, ST88, ST95, ST127, ST131, ST141). ST88 isolates were frequent, especially in Spain, while ST141 isolates significantly predominated in France. The 23 ST131 isolates displayed four clonotypes: CH40-30, CH40-41, CH40-22 and CH40-298. Only 13 (6.6%) isolates were carriers of extended-spectrum beta-lactamase (ESBL) enzymes. However, 37.2% of the isolates were multidrug-resistant (MDR). Approximately 40% of the MDR isolates belonged to only four of the dominant clones (B2-CH40-30-ST131, B2-CH40-41-ST131, C-CH4-39-ST88 and D-CH35-27-ST69). Among the remaining MDR isolates, two isolates belonged to B2-CH14-64-ST1193, i.e., the new global emergent MDR clone. Moreover, a hybrid extraintestinal pathogenic E.coli (ExPEC)/enteroaggregative isolate belonging to the A-CH11-54-ST10 clone was identified.

Low incidence of antibiotic-resistant bacteria in south-east Sweden: An epidemiologic study on 9268 cases of bloodstream infection

Objectives

The aim of this study was to investigate the epidemiology of bloodstream infections (BSI) in a Swedish setting, with focus on risk factors for BSI-associated mortality.

Methods

A 9-year (2008–2016) retrospective cohort study from electronic records of episodes of bacteremia amongst hospitalized patients in the county of Östergötland, Sweden was conducted. Data on episodes of BSI including microorganisms, antibiotic susceptibility, gender, age, hospital admissions, comorbidity, mortality and aggregated antimicrobial consumption (DDD /1,000 inhabitants/day) were collected and analyzed. Multidrug resistance (MDR) was defined as resistance to at least three groups of antibiotics. MDR bacteria and MRSA, ESBL-producing Enterobacteriaceae, vancomycin-resistant enterococci not fulfilling the MDR criteria were all defined as antimicrobial-resistant (AMR) bacteria and included in the statistical analysis of risk factors for mortality

Results

In all, 9,268 cases of BSI were found. The overall 30-day all-cause mortality in the group of patients with BSI was 13%. The incidence of BSI and associated 30-day all-cause mortality per 100,000 hospital admissions increased by 66% and 17% respectively during the nine-year study period. The most common species were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae and Enterococcus faecalis. Independent risk factors for 30-day mortality were age (RR: 1.02 (CI: 1.02–1.03)) and 1, 2 or ≥3 comorbidities RR: 2.06 (CI: 1.68–2.52), 2.79 (CI: 2.27–3.42) and 2.82 (CI: 2.31–3.45) respectively. Almost 3% (n = 245) of all BSIs were caused by AMR bacteria increasing from 12 to 47 per 100,000 hospital admissions 2008–2016 (p = 0.01), but this was not associated with a corresponding increase in mortality risk (RR: 0.89 (CI: 0.81–0.97)).

Conclusion

Comorbidity was the predominant risk factor for 30-day all-cause mortality associated with BSI in this study. The burden of AMR was low and not associated with increased mortality. Patients with BSIs caused by AMR bacteria (MDR, MRSA, ESBL and VRE) were younger, had fewer comorbidities, and the 30-day all-cause mortality was lower in this group.

Clinical characteristics of peripheral venous catheter-associated gram-negative bloodstream infection among patients with malignancy

PURPOSE

Previous studies have suggested that peripheral venous catheter is a significant source of gram-negative bacteraemia in patients with malignancy. We aimed to identify risk factors and develop a clinical prediction rule for the involvement of gram-negative organisms in peripheral venous catheter-associated bloodstream infections (PVC-BSIs) among patients with malignancy.

METHODS

This retrospective cohort study was conducted at a 700-bed cancer hospital in Japan. Consecutive patients diagnosed with PVC-BSI based on clinical and microbiological criteria were included in this study. Based on clinical and microbiological characteristics of PVC-BSIs in cancer patients, a logistic regression model for predicting gram-negative organisms as causative organisms in PVC-BSIs was then developed.

RESULTS

Of the 99 patients included in our cohort, 60 patients (60.6%) had gram-negative PVC-BSIs. The median age of patients with PVC-BSIs was 67 years (interquartile range [IQR], 59-74 years), and the median Pitt bactearemia score was 1 (IQR, 0-3). The median duration of catherization was 5 days (IQR, 4-7 days) and 70 patients (70.7%) received peripheral parenteral nutrition that contained amino acids. On multivariable analysis, age ≥65 years (odds ratio [OR], 3.07; 95% confidence interval [CI], 1.10-8.62), showering (OR, 3.15; 95% CI, 1.07-9.26), Pitt bacteraemia score ≥2 points (OR, 6.96; 95% CI, 2.52-19.2), and use of peripheral parenteral nutrition (OR, 0.31; 95% CI, 0.10-0.98) were independent predictors for gram-negative PVC-BSIs among all PVC-BSIs. The simplified PVC-GN scores established to predict gram-negative PVC-BSIs had a optimism-corrected c-index of 0.775.

CONCLUSION

Gram-negative bacteria were more commonly responsible for PVC-BSI than Gram-positive bacteria among cancer patients in this cohort. Involvement of Gram-negative bacteria in PVC-BSIs could be predicted with readily available clinical variables.

Antibiotic resistance of blood cultures in regional and tertiary hospital settings of Tyrol, Austria (2006-2015): Impacts & trends

Blood stream infections rank among the top seven causes of death of the general population. The aim of our study was to better understand the epidemiology of BSI in order to improve diagnostics and patient outcome. We used retrospective aggregated laboratory data of blood samples received from all public hospitals in Tyrol, Austria between 2006 and 2015. Microorganisms were categorized into obligatory, facultative, unusual pathogens and contaminants. The distribution, the cumulative incidence and antimicrobial susceptibility patterns were compared between the tertiary (TH) and regional peripheral hospitals (PH). Among 256,364 blood samples, 76.1% were from the TH The incidence of obligatory pathogens was 1.7 fold, and up to 3 times higher for facultative, unusual pathogens and contaminants in the TH and increased mainly due to an increase of E.coli, which was the most common isolated pathogen (n = 2,869), followed by Staphylococcus aureus (n = 1,439), Enterococcus sp. (n = 953) and Klebsiella sp. (n = 816). The distribution of obligatory pathogens differed between the hospital settings: In the TH Enterococcus sp. accounted for 40.8% and E.coli for 70.4%, respectively, whereas in the PH for 25.4% (p<0.0001) and 57.8%, respectively (p<0.0001) Antibiotic resistance of Gram negative bacteria and Staphylococcus aureus did not change during the observation period. Carbapenem resistance of Klebsiella sp. and vancomycin and linezolid resistance of Enterococcus faecium showed a non-significant increase since 2010 in the TH setting. We concluded that the incidence of BSI in TH was higher compared to PH. We observed higher contamination rates in the TH. We could not interpret the data of coagulase negative staphylococci due to lack of clinical data. We strongly recommend enhancement of training on blood culture sampling to decrease the rate of contamination. Due to differences in pathogen distribution and antimicrobial resistance between different hospital settings we recommend separate treatment guidelines for BSI by hospital setting.

Characterization of Beta-Lactamases in Bloodstream-Infection Escherichia coli: Dissemination of blaADC - 162 and blaCMY- 2 Among Bacteria via an IncF Plasmid

OBJECTIVES

To describe the molecular characteristics of beta-lactamases in bloodstream-infection Escherichia coli isolated from elderly patients, and to determine the genotypic patterns of bla CMY - 2 and bla ADC - 162.

METHODS

A total of 50 bloodstream-infection E. coli isolates were obtained from patients aged > 50 years at Shanghai Sixth People's Hospital South Campus during 2015-2018. The isolates were subjected to beta-lactamase detection using phenotypic and molecular methods. Beta-lactamase genes were verified by sequencing and the phylogenetic relationships of the isolates were analyzed by multilocus sequence typing (MLST). The transferability of plasmids carrying bla CMY- 2 and bla ADC- 162 genes was verified by conjugation experiments and plasmid replicon typing.

RESULTS

Eight beta-lactamase subtypes were detected in 50 isolates of bloodstream-infection E. coli. bla TEM- 1 (21/50) was the most common beta-lactamase gene, followed by bla CTX-M- 14 (8/50), bla OXA- 27 (5/50), bla CTX-M- 27 (3/50), bla CTX-M- 65 (1/50), bla ADC- 162 (1/50), and bla CMY- 2 (1/50). Of these, bla ADC- 162 (ST95-A), and bla CMY- 2 (ST95-B2) have not previously been reported in bloodstream-infection E. coli. In 21 isolates, beta-lactamase genes were located on conjugative plasmids belonging to incompatibility groups FrepB (n = 7), FIA (n = 1), FIC (n = 2), K (n = 8), N (n = 1), and I (n = 1), and bla CTX-M was associated with the common elements ISEcp1, IS903, and IS26, but with special sequences (region V, region Y, and region W) for ISEcp1 in 14 isolates.

CONCLUSION

To the best of our knowledge, this study provides the first molecular characterization of beta-lactamase genes in E. coli isolated from the bloodstream in elderly patients. Beta-lactamase genes were detected at a relatively high frequency in elderly patients with bloodstream E. coli infections. Plasmid replicon analysis showed that horizontal dissemination of beta-lactamase genes was mainly mediated by IncK and IncF plasmids, which could encode multidrug resistance genes. The study also provides the first report of ISAba1-bla ADC - 162-tnpA and ISEcp1-bla CTX-M- 14-IS903-bla CMY- 2-blc-sugE in E. coli, and demonstrates IncF plasmid-mediated bla ADC - 162 and bla CMY- 2 gene dissemination among bacteria.

Antimicrobial resistance trends in bloodstream infections at a large teaching hospital in China: a 20-year surveillance study (1998-2017)

Background

Bacterial bloodstream infections (BSIs) cause high morbidity and mortality worldwide in humans, but the pathogenic spectrum varies from region to region. Long-term monitoring of the pathogenic spectrum and changes in bacterial antibiotic resistance is hugely important for effective clinical therapy and infection control. This study examined the data for BSIs in Tongji Hospital, one of the largest teaching hospitals in China, in an attempt to gain better understanding of bacterial antibiotic resistance in China, focusing on central China.

Methods

Data from Tongji Hospital for a 20-year period (1998–2017) were used for a retrospective analysis to understand the pathogenic spectrum of BSIs and the changes occurring in antimicrobial resistance in central China. The disk diffusion and E test methods were used for antimicrobial susceptibility testing according to Clinical & Laboratory Standards Institute methodologies, and the data were analyzed by WHONET 5.6 software.

Results

The isolated pathogens mainly came from hospitalized patients not treated in intensive care units (ICUs), and accounted for 81.5% of the total (9130/11200). The most common Gram-negative and Gram-positive bacterial BSI-causing pathogens were Escherichia coli and Staphylococcus aureus, respectively. The detection rate for methicillin-resistant S. aureus (MRSA) in the hospitalized non-ICU patients increased from 8.4% in 1998–2002 to 63% in 2013–2017, while the detection rate for carbapenem-resistant (CR) Klebsiella pneumoniae was below 5% in 1998–2012 but increased to 34.9% in 2013–2017. In contrast, worryingly, the detection rate for CR K. pneumoniae in ICU patients increased from 0% in 2013 to 75% in 2016. E. coli displayed the highest sensitivity rates to imipenem, meropenem and amikacin, all of which were > 90%, followed by cefoxitin at > 80%, and cefoperazone/sulbactam at > 70%. K. pneumoniae isolates were most sensitive to imipenem, meropenem and amikacin antibiotics, with sensitivity rates exceeding 60%. S. aureus isolates were most sensitive to vancomycin, teicoplanin and trimethoprim/sulfamethoxazole, with sensitivity rates exceeding 90%.

Conclusions

BSIs caused by CR K. pneumoniae clearly posed a severe challenge to infection control and treatment of ICU and non-ICU patients in this retrospective study, while MRSA was an issue for non-ICU patients.

Prevalence of and risk factor for community-onset third-generation cephalosporin-resistant Escherichia coli bacteremia at a medical center in Taiwan

Background

Increased resistance to third-generation cephalosporin (3GC) is a serious concern for community-onset Escherichia coli infection because this resistance easily delays effective treatment. This study surveyed the current antimicrobial resistance pattern among E. coli isolates that cause community-onset bacteremia, with a special focus on the prevalence of and the risk factors for 3GC resistance, and determined factors for poor outcomes among patients with community-onset E. coli bacteremia.

Methods

This retrospective study was conducted at a tertiary-care teaching hospital in Taiwan. All adult patients with community-onset E. coli bacteremia between January 1, 2015, and December 31, 2015 were enrolled and were divided into two groups depending on whether the E. coli isolate was susceptible to 3GCs. Risk factors for 3GC resistance, 14-day all-cause mortality, and length of hospital stay were analyzed.

Results

The overall rate of 3GC resistance among E. coli isolates causing community-onset bacteremia was 19.7%, whereas it was 9.6% if only isolates causing community-acquired bacteremia were considered. Independent risk factors for 3GC-resistant community-onset E. coli bacteremia were hospitalization within the past 1 year (odds ratio: 2.4, 95% confidence interval: 1.6–3.7, P < 0.001), exposure to antibiotics within the past 15 days (2.6, 1.4–4.9, P = 0.002), residence in nursing home or long-term care facility (3.6, 1.0–12.3, P = 0.044), presence of underlying genitourinary disease (1.9, 1.2–2.9, P = 0.005), and presence of indwelling implantable intravenous port (2.2, 1.1–4.1, P = 0.021). 3GC resistance was independently associated with increased length of hospital stays (P < 0.001).

Conclusion

In this study, the prevalence of 3GC resistance was high among both patients with community-onset and those with community-acquired E. coli bacteremia. 3GC resistance is a strong independent risk factor for length of hospital stay. The effectiveness of empirical antibiotic treatment would partially explain the impact of 3GC resistance, but more evidence is needed. The choice of appropriate empirical antibiotics for community-onset E. coli bacteremia might impact outcomes in terms of the length of hospital stay and need to be individualized according to the patient-specific risk for acquiring drug-resistant pathogens.

Clinical features and microbiological characteristics of hospital- and community-onset Escherichia coli bloodstream infection

PURPOSE

Escherichia coli is a leading cause of bloodstream infection (BSI) in hospitals and communities.

METHODOLOGY

We conducted a retrospective study in 2015 to evaluate the clinical features and microbiological characteristics of E. coli BSI acquired in the hospital and community.

RESULTS

A total of 100 patients with E. coli BSI were enrolled, among whom 60 % had hospital-onset (HO) BSI while 40 % had community-onset (CO) BSI. Patients with HO BSI had higher percentages of haematological disorders, immunosuppression conditions, underwent surgery within 2 weeks and had a higher 30-day mortality. The prevalences of multidrug-resistant and extended-spectrum β-lactamase-producing strains were 81 and 60 %, respectively. Resistance percentages to ampicillin, ampicillin-sulbactam, cefazolin, ceftriaxone, ciprofloxacin and levofloxacin were greater than 50 %. Of the 43 different sequence types (STs) identified, ST131 (15.3 %) was the most common. The serum agglutination rate was 52 % in which 13 O and 11 H serogroups were observed. Among the 36 detected virulence factor (VF) genes, IutA (66 %) and traT (61 %) were the most predominant. papA, papC and papEF were different between the CO and HO BSI groups. VF scores were high (mean >7) in the frequently detected ST95, ST1193 and ST131.

CONCLUSION

This study revealed that the clinical features of HO and CO E. coli BSI were different. STs and serotypes showed a great diversity in this region while VF genes of the isolates varied between clones.

Changing Antimicrobial Resistance Trends in Kathmandu, Nepal: A 23-Year Retrospective Analysis of Bacteraemia

A comprehensive longitudinal understanding of the changing epidemiology of the agents causing bacteraemia and their AMR profiles in key locations is crucial for assessing the progression and magnitude of the global AMR crisis. We performed a retrospective analysis of routine microbiological data from April 1992 to December 2014, studying the time trends of non-Salmonella associated bacteraemia at a single Kathmandu healthcare facility. The distribution of aetiological agents, their antimicrobial susceptibility profiles, and the hospital ward of isolation were assessed. Two hundred twenty-four thousand seven hundred forty-one blood cultures were performed over the study period, of which, 30,353 (13.5%) exhibited growth for non-contaminant bacteria. We observed a significant increasing trend in the proportion of MDR non-Salmonella Enterobacteriaceae (p < 0.001), other Gram-negative organisms (p = 0.006), and Gram-positive organisms (p = 0.006) over time. Additionally, there was an annual increasing trend in the proportion of MDR organisms in bacteria-positive blood cultures originating from patients attending the emergency ward (p = 0.006) and the outpatient department (p = 0.006). This unique dataset demonstrates that community acquired non-Salmonella bacteraemia has become an increasingly important cause of hospital admission in Kathmandu. An increasing burden of bacteraemia associated with MDR organisms in the community underscores the need for preventing the circulation of MDR bacteria within the local population.

Trends over time in Escherichia coli bloodstream infections, urinary tract infections, and antibiotic susceptibilities in Oxfordshire, UK, 1998-2016: a study of electronic health records

BACKGROUND

Escherichia coli bloodstream infections are increasing in the UK and internationally. The evidence base to guide interventions against this major public health concern is small. We aimed to investigate possible drivers of changes in the incidence of E coli bloodstream infection and antibiotic susceptibilities in Oxfordshire, UK, over the past two decades, while stratifying for time since hospital exposure.

METHODS

In this observational study, we used all available data on E coli bloodstream infections and E coli urinary tract infections (UTIs) from one UK region (Oxfordshire) using anonymised linked microbiological data and hospital electronic health records from the Infections in Oxfordshire Research Database (IORD). We estimated the incidence of infections across a two decade period and the annual incidence rate ratio (aIRR) in 2016. We modelled the data using negative binomial regression on the basis of microbiological, clinical, and health-care-exposure risk factors. We investigated infection severity, 30-day all-cause mortality, and community and hospital amoxicillin plus clavulanic acid (co-amoxiclav) use to estimate changes in bacterial virulence and the effect of antimicrobial resistance on incidence.

FINDINGS

From Jan 1, 1998, to Dec 31, 2016, 5706 E coli bloodstream infections occurred in 5215 patients, and 228 376 E coli UTIs occurred in 137 075 patients. 1365 (24%) E coli bloodstream infections were nosocomial (onset >48 h after hospital admission), 1132 (20%) were quasi-nosocomial (≤30 days after discharge), 1346 (24%) were quasi-community (31-365 days after discharge), and 1863 (33%) were community (>365 days after hospital discharge). The overall incidence increased year on year (aIRR 1·06, 95% CI 1·05-1·06). In 2016, 212 (41%) of 515 E coli bloodstream infections and 3921 (28%) of 13 792 E coli UTIs were co-amoxiclav resistant. Increases in E coli bloodstream infections were driven by increases in community (aIRR 1·10, 95% CI 1·07-1·13; p<0·0001) and quasi-community (aIRR 1·08, 1·07-1·10; p<0·0001) cases. 30-day mortality associated with E coli bloodstream infection decreased over time in the nosocomial (adjusted rate ratio [RR] 0·98, 95% CI 0·96-1·00; p=0·03) group, and remained stable in the quasi-nosocomial (adjusted RR 0·98, 0·95-1·00; p=0·06), quasi-community (adjusted RR 0·99, 0·96-1·01; p=0·32), and community (adjusted RR 0·99, 0·96-1·01; p=0·21) groups. Mortality was, however, substantial at 14-25% across all hospital-exposure groups. Co-amoxiclav-resistant E coli bloodstream infections increased in all groups across the study period (by 11-18% per year, significantly faster than co-amoxiclav-susceptible E coli bloodstream infections; p_{heterogeneity}<0·0001), as did co-amoxiclav-resistant E coli UTIs (by 14-29% per year; p_{heterogeneity}<0·0001). Previous year co-amoxiclav use in primary-care facilities was associated with increased subsequent year community co-amoxiclav-resistant E coli UTIs (p=0·003).

INTERPRETATION

Increases in E coli bloodstream infections in Oxfordshire are primarily community associated, with substantial co-amoxiclav resistance; nevertheless, we found little or no change in mortality. Focusing interventions on primary care facilities, particularly those with high co-amoxiclav use, could be effective in reducing the incidence of co-amoxiclav-resistant E coli bloodstream infections, in this region and more generally.

FUNDING

National Institute for Health Research.

Incidence of bloodstream infections: a nationwide surveillance of acute care hospitals in Switzerland 2008-2014

BACKGROUND

Bloodstream infections are often associated with significant mortality and morbidity. We aimed to investigate changes in the epidemiology of bloodstream infections in Switzerland between 2008 and 2014.

METHODS

Data on bloodstream infections were obtained from the Swiss antibiotic resistance surveillance system (ANRESIS).

RESULTS

The incidence of bloodstream infections increased throughout the study period, especially among elderly patients and those receiving care in emergency departments and university hospitals. Escherichia coli was the predominant pathogen, with Enterococci exhibiting the most prominent increase over the study period.

CONCLUSIONS

The described trends may impact morbidity, mortality and healthcare costs associated with bloodstream infections.

National Bloodstream Infection Surveillance in Switzerland 2008-2014: Different Patterns and Trends for University and Community Hospitals

OBJECTIVE To characterize the epidemiology of bloodstream infections in Switzerland, comparing selected pathogens in community and university hospitals. DESIGN Observational, retrospective, multicenter laboratory surveillance study. METHODS Data on bloodstream infections from 2008 through 2014 were obtained from the Swiss infection surveillance system, which is part of the Swiss Centre for Antibiotic Resistance (ANRESIS). We compared pathogen prevalences across 26 acute care hospitals. A subanalysis for community-acquired and hospital-acquired bloodstream infections in community and university hospitals was performed. RESULTS A total of 42,802 bloodstream infection episodes were analyzed. The most common etiologies were Escherichia coli (28.3%), Staphylococcus aureus (12.4%), and polymicrobial bloodstream infections (11.4%). The proportion of E. coli increased from 27.5% in 2008 to 29.6% in 2014 (P = .04). E. coli and S. aureus were more commonly reported in community than university hospitals (34.3% vs 22.7%, P<.001 and 13.9% vs 11.1%, P<.001, respectively). Fifty percent of episodes were community-acquired, with E. coli again being more common in community hospitals (41.0% vs 32.4%, P<.001). The proportion of E. coli in community-acquired bloodstream infections increased in community hospitals only. Community-acquired polymicrobial infections (9.9% vs 5.6%, P<.001) and community-acquired coagulase-negative staphylococci (6.7% vs 3.4%, P<0.001) were more prevalent in university hospitals. CONCLUSIONS The role of E. coli as predominant pathogen in bloodstream infections has become more pronounced. There are distinct patterns in community and university hospitals, potentially influencing empirical antibiotic treatment. Infect Control Hosp Epidemiol 2016;37:1060-1067.

Similarly Lethal Strains of Extraintestinal Pathogenic Escherichia coli Trigger Markedly Diverse Host Responses in a Zebrafish Model of Sepsis

In individuals with sepsis, the infecting microbes are commonly viewed as generic inducers of inflammation while the host background is considered the primary variable affecting disease progression and outcome. To study the effects of bacterial strain differences on the maladaptive immune responses that are induced during sepsis, we employed a novel zebrafish embryo infection model using extraintestinal pathogenic Escherichia coli (ExPEC) isolates. These genetically diverse pathogens are a leading cause of sepsis and are becoming increasingly dangerous because of the rise of multidrug-resistant strains. Zebrafish infected with ExPEC isolates exhibit many of the pathophysiological features seen in septic human patients, including dysregulated inflammatory responses (cytokine storms), tachycardia, endothelial leakage, and progressive edema. However, only a limited subset of ExPEC isolates can trigger a sepsis-like state and death of the host when introduced into the bloodstream. Mirroring the situation in human patients, antibiotic therapy reduced ExPEC titers and improved host survival rates but was only effective within limited time frames that varied, depending on the infecting pathogen. Intriguingly, we find that phylogenetically distant but similarly lethal ExPEC isolates can stimulate markedly different host transcriptional responses, including disparate levels of inflammatory mediators. These differences correlate with the amounts of bacterial flagellin expression during infection, as well as differential activation of Toll-like receptor 5 by discrete flagellar serotypes. Altogether, this work establishes zebrafish as a relevant model of key aspects of human sepsis and highlights the ability of genetically distinct ExPEC isolates to induce divergent host responses independently of baseline host attributes. IMPORTANCE Sepsis is a life-threatening systemic inflammatory condition that is initiated by the presence of microorganisms in the bloodstream. In the United States, sepsis due to ExPEC and other pathogens kills well over a quarter of a million people each year and is associated with tremendous health care costs. A high degree of heterogeneity in the signs and symptomology of sepsis makes this disease notoriously difficult to effectively diagnose and manage. Here, using a zebrafish model of sepsis, we find that similarly lethal but genetically distinct ExPEC isolates can elicit notably disparate host responses. These variances are in part due to differences in the levels and types of flagellin that are expressed by the infecting ExPEC strains. A better understanding of the variable impact that bacterial factors like flagellin have on host responses during sepsis could lead to improved diagnostic and therapeutic approaches to these often deadly infections. Podcast: A podcast concerning this article is available.

Dissemination of Extended-Spectrum β-Lactamase- and AmpC β-Lactamase-Producing Escherichia coli within the Food Distribution System of Ho Chi Minh City, Vietnam

To investigate the dissemination of ESBL/pAmpC-producing E. coli within the food distribution system of Ho Chi Minh City (HCMC), Vietnam, the prevalence of ESBL/pAmpC-producing E. coli strains in chicken meat, pork, beef, and fish/shrimp samples obtained from slaughterhouses, a wholesale market, and supermarkets was examined. Among the total of 330 collected food samples, ESBL/pAmpC-producing E. coli was detected in 150 samples (45.5%). The highest prevalence of these isolates was in chicken meat (76/82, 92.7%), followed by pork (32/92, 34.8%), beef (18/74, 34.3%), and fish/shrimp (24/82, 29.3%). A total of 342 strains of ESBL/pAmpC-producing E. coli were isolated from 150 positive food samples. The most prevalent genes responsible for ESBL or pAmpC activity belonged to the CTX-M-9 (110/342, 31.2%), CTX-M-1 (102/342, 29.8%), and CIT (118/342, 34.5%) groups. To our knowledge, this is the first report of the high occurrence of pAmpC (37.1%) in animal-based food in Vietnam. Among the 342 total ESBL/pAmpC-producing E. coli isolates, 276 (80.7%) were resistant to at least 6 antibiotic agents. Notably, high percentages of resistance to ciprofloxacin and fosfomycin were found in isolates from chicken (80.5% and 50.8%, resp.). These findings demonstrate that animal-based food products in HCMC represent a major reservoir of ESBL/pAmpC-producing E. coli.