Epidemiology of extended-spectrum β-lactamase-producing Escherichia coli in Sweden 2007–2011

Extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae have been notifiable according to the Swedish Communicable Disease Act since 2007. A major increase in the number of cases has been observed, with 2099 cases in 2007 and 7225 cases in 2012. The majority of the isolates are Escherichia coli. Additionally, Swedish data on the prevalence of ESBL-producing invasive isolates of E. coli are available through EARS-Net, and through biannual point prevalence studies, where molecular characterization of isolates from the entire country is carried out. This paper describes major trends in the Swedish epidemiology of ESBL-producing E. coli in the period 2007–2012. Isolates from the point prevalence studies were subjected to antimicrobial susceptibility testing, ESBL genotyping, pulsed-field gel electrophoresis, multi-locus sequence typing and phylogenetic grouping with PCR. The distribution of sequence types, resistance genes and susceptibility levels were all stable over the three study periods. The dominating resistance gene conferring ESBL was bla_CTX-M-15, found in 54–58% of the isolates. ST131 represented 34–38% of the isolates. Other major sequence types were ST38, ST69, ST405, ST617 and ST648, each representing 2–6% of the isolates. Phylogenetic group B2 was the most common, and was observed in 41–47% of the isolates. However, among ST131 isolates the B2 phylogenetic group represented 90–98% of the isolates. The most important epidemiological difference seen over time was that the median age of infected women decreased from 62 to 52 years (p <0.0001) and infected men from 67 to 64 years. A potential explanation might be the shift towards a higher proportion of community-acquired infections in individuals lacking comorbidities.     

Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli from Rio de Janeiro,Brazil

Twenty-five extended-spectrum β-lactamase (ESBL)-producing Escherichia coli clinical isolates from Rio de Janeiro, Brazil were characterized by isoelectric focusing, PCR and sequencing of bla^ESBL genes, plasmid-mediated quinolone resistance determinants, phylogenetic groups, replicon typing, pulsed-field electrophoresis, and multilocus sequencing typing. Twenty-three (92%) ESBL-producing E. coli isolates were positive for bla^CTX-M genes, aac(6′)-Ib-cr, and qnrB. Genetic relatedness of ESBL producers clustered seven (28%) CTX-M-15-producing isolates as sequence type (ST)410, clonal complex (CC) 23, and two (8%) as clone O25-ST131. Our results illustrate the predominance of phylogroup A (52%), ST410 (CC 23) and CTX-M-15 among ESBL-producing E. coli isolates from hospitals in Rio de Janeiro.     

Extended-spectrum β-lactamase-producing Escherichia coli bacteremia: Comparison of pediatric and adult populations

Background/Purpose

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing worldwide. This study investigated the clinical features and bacteriology of pediatric patients with ESBL-producing E. coli bacteremia and compared their characteristics with those of adult patients.

Molecular and clinical characterization of plasmid-mediated AmpC β-lactamase-producing Escherichia coli bacteraemia: a comparison with extended-spectrum β-lactamase-producing and non-resistant E. coli bacteraemia

Plasmid-mediated AmpC β-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case–control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone.     

Prevalence and types of extended spectrum β-lactamases among urinary Escherichia coli isolates in Moroccan community

This study was designed to characterize extended-spectrum-β-lactamases (ESBL) produced by Escherichia coli isolates causing community urinary tract infections over a 2-year period (2010 and 2011) in a Moroccan large geographical region. Molecular characterization was done by using PCR and sequencing of the β-lactamases genes and plasmid-mediated quinolone resistance determinants. Among 1174 isolates, 49 (4.1%) were ESBL producers. The bla_CTx-M-15 (n = 31) was the most frequent ESBL gene detected, followed by bla_CTx-M-1 (n = 5), bla_SHV-12 (n = 6), bla_PER-2 (n = 3), then bla_TEM-3, bla_TEM-20, bla_TEM-158, bla_SHV-27, bla_SHV-28, bla_SHV-36, bla_SHV-125, bla_CTx-M-14 and bla_CTx-M-27 with one isolate for each. The non-ESBL genes detected were bla_TEM-70 (n = 1), bla_TEM-176 (n = 1), bla_TEM-104 (n = 6), bla_TEM-1 (n = 15) and bla_OxA-1 (n = 12). Plasmid mediated AmpC β-lactamases genes; bla_ACT-5 (n = 1), bla_DHA-1(n = 2) and bla_CMY-2 (n = 4) were detected in seven isolates (14.2%). The bla_OxA-48 (n = 1) and bla_IMP-1 (n = 1) carbapenemases genes were detected among five carbapenem-resistant E. coli. Five isolates (10.2%) harboured qnr genes, qnrB1 (n = 3), qnrB2 (n = 1) and qnrS1 (n = 1) type were detected. Thirty isolates (61.2%) were positive for aac(6′)-Ib-cr gene. The class 1 integron was detected in twenty two (44.8%) isolates. Phylogenetic grouping revealed that 22 (44.8%) isolates belonged to group A, while 15 (30.6%), 11 (22.4%) and 1 (2%) belonged to B2, D and B1. Results of conjugation experiments indicated that bla_CTx-M-15, bla_TEM-1, bla_OxA-1, aac(6′)-Ib-cr and qnrB1 genes were co-transferred and that these genes were carried by a conjugative plasmid of high molecular weight. The results of this work reports the genetic diversity of ESBL genes, with the CTX-M-15 enzyme being the most common among ESBL-producing E. coli in Moroccan community.     

Impact of changes in CLSI and EUCAST breakpoints for susceptibility in bloodstream infections due to extended-spectrum β-lactamase-producing Escherichia coli

The impact of recent changes in and discrepancies between the breakpoints for cephalosporins and other antimicrobials, as determined by CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST), was analysed in patients with bloodstream infections caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli in Spain, was analysed. We studied a cohort of 191 episodes of bloodstream infection caused by ESBL-producing E. coli in 13 Spanish hospitals; the susceptibility of isolates to different antimicrobials was investigated by microdilution and interpreted according to recommendations established in 2009 and 2010 by CLSI, and in 2011 by EUCAST. Overall, 58.6% and 14.7% of isolates were susceptible to ceftazidime, and 35.1% and 14.7% to cefepime using the CLSI-2010 and EUCAST-2009/2011 recommendations, respectively (all isolates would have been considered resistant using the previous guidelines). Discrepancies between the CLSI-2010 and the EUCAST-2011 recommendations were statistically significant for other antimicrobials only in the case of amikacin (98.4% versus 75.9% of susceptible isolates; p <0.01). The results varied depending on the ESBL produced. No significant differences were found in the percentage of patients classified as receiving appropriate therapy, following the different recommendations. Four out of 11 patients treated with active cephalosporins according to CLSI-2010 guidelines died (all had severe sepsis or shock); these cases would have been considered resistant according to EUCAST-2011. In conclusion, by using current breakpoints, extended-spectrum cephalosporins would be regarded as active agents for treating a significant proportion of patients with bloodstream infections caused by ESBL-producing E. coli.     

Emergence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae during the years 2000 and 2004 in Helsinki,Finland

The molecular epidemiology of 33 Escherichia coli and 81 Klebsiella pneumoniae extended-spectrum β-lactamase-producing health-care-associated and community-acquired isolates collected in the Helsinki district during 2000–2004 was investigated. Clonality studies, antimicrobial susceptibility and genotyping of the isolates were performed. Newly emerging CTX-M-producing E. coli and bla_SHV-12-producing K. pneumoniae isolates were detected. Clonal clusters of both species persisted throughout the study period.     

Epidemiology and risk factors of community onset infections caused by extended-spectrum β-lactamase-producing Escherichia coli strains

Limited clinical information is available regarding community onset infections caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. A case-control study was performed to evaluate the epidemiology and risk factors of these types of infections. A case patient was defined as a person whose clinical sample yielded ESBL-producing E. coli. For each case patient, one control was randomly chosen from a group of outpatients from whom non-ESBL-producing E. coli had been isolated and for whom a clinical sample had been sent to the same laboratory for culturing during the following week. Of 108 cases of ESBL-producing E. coli, 56 (51.9%) were classified as health care associated (HCA). Univariate analysis showed male gender, HCA infection, severe underlying illness, and a prior receipt of antibiotics to be associated with ESBL-producing E. coli. In the multivariate analysis, HCA infection (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.67 to 6.06; P < 0.001) and previous use of antibiotics (OR, 4.88; 95% CI, 2.08 to 11.48; P < 0.001) were found to be significantly associated with the ESBL group. In a multivariate analysis that included each antibiotic, previous use of fluoroquinolone (OR, 7.32; 95% CI, 1.58 to 34.01; P = 0.011) was significantly associated with ESBL-producing E. coli. Of 101 isolates in which ESBLs and their molecular relationships were studied, all isolates produced ESBLs from the CTX-M family (CTX-M-14, 40 isolates; CTX-M-15, 39 isolates; and other members of the CTX-M family, 22 isolates). In conclusion, this study confirms that ESBL-producing E. coli strains are a notable cause of community onset infections in predisposed patients. HCA infection and previous use of fluoroquinolone were significant factors associated with ESBL-producing E. coli in community onset infections.     

Prevalence of carriage of extended-spectrum β-lactamase-producing enterobacteria and associated factors in a French hospital

ObjectivesOur aim was to evaluate the prevalence and associated factors for carriage of extended-spectrum β-lactamase-producing enterobacteria (ESBL-PE) in a healthcare facility.MethodsIn 2016 a serial cross-sectional survey of ESBL-PE carriage in a French university hospital was conducted. All patients present on the day of the survey were screened for ESBL-PE carriage. Demographic characteristics and risk factors for ESBL-PE carriage were collected.ResultsIn all, 146/844 patients (17%) were digestive carriers of ESBL-PE; of these, 96 (66%) had not previously been identified. Among patients carrying ESBL-PE, Escherichia coli (62%) and CTX-M type (94%) predominated. Greater age, recent travel abroad, receipt of antibiotic, and prolonged hospitalization were associated with ESBL-PE carriage.ConclusionGiven the high prevalence of ESBL-PE and the high proportion of unknown carriers, our results strongly suggest reinforcing standard precautions rather than contact precautions for controlling the spread of ESBL-PE.     

High carriage rate of extended‐spectrum β‐lactamase Enterobacterales and diarrheagenic Escherichia coli in healthy donor screening for fecal microbiota transplantation

European Journal of Clinical Microbiology & Infectious Diseases - The safety of fecal microbiota transplantation (FMT) has been highlighted by extended-spectrum β-lactamase...     

Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals,and their putative impact on public health: a global perspective

The possible zoonotic spread of antimicrobial-resistant bacteria is controversial. This review discusses global molecular epidemiological data combining both analyses of the chromosomal background, using multilocus sequence typing (MLST), and analyses of plasmid (episomal) extended-spectrum β-lactamase (ESBL)/AmpC genes in Escherichia coli present in humans and animals. For consideration of major epidemiological differences, animals were separated into livestock and companion animals. MLST revealed the existence of ESBL-producing isolates thoughout the E. coli population, with no obvious association with any ancestral EcoR group. A similar distribution of major ESBL/AmpC types was apparent only in human isolates, regardless of their geographical origin from Europe, Asia, or the Americas, whereas in animals this varied extensively between animal groups and across different geographical areas. In contrast to the diversity of episomal ESBL/AmpC types, isolates from human and animals mainly shared identical sequence types (STs), suggesting transmission or parallel micro-evolution. In conclusion, the opinion that animal ESBL-producing E. coli is a major source of human infections is oversimplified, and neglects a highly complex scenario.     

Detection of β-lactamase and urovirulence genes in Escherichia coli serogroups isolated from urinary tract infection in cats

Sixty-five Escherichia coli isolates were recovered from cats with urinary tract infection and their serogroups were determined. The isolates were screened for the presence of β-lactamase (bla _TEM) and urovirulence (cnf1, cdtB, afaIB-C, papE-F, sfa/focD-E and iutA) genes. Serogroup determination of 65 uropathogenic E. coli isolates showed that 23 (35.38%) were O-typeable and belonged to 11 different O serogroups including: O1, O2, O4, O6, O8, O11, O25, O49, O75, O115 and O125. Fourteen (21.54%) isolates were positive for the bla _TEM gene. The bla _TEM-positive isolates were distributed in both typeable (five) and non-typeable (nine) serogroups. Eleven bla _TEM-positive isolates showed combination patterns of virulence genes, whereas the combination of cnf1-hlyA-papE-F-sfa/focDE was the most prevalent pattern. Polymerase chain reaction tests revealed that 38 isolates (58.46%) contained at least two urovirulence genes. Among the examined isolates, 56.92% had cnf1, 52.30% hlyA, 50.76% sfa/focD-E, 47.69% papE-F, 13.84% iutA and 6.15% afaIB-C. None of the isolates contained the cdtB gene. Eight different combinations of virulence genes were detected. The combination pattern of cnf1-hlyA-papE-F-sfa/focD-E was the most prevalent (30.77%), whereas the positive isolates fell into O2 (three), O6 (two), and O49 (one) serogroup and 14 isolates were O-non-typeable. In conclusion, feline E. coli isolates from urinary tract infections belonged to several serogroups and may possess β-lactamase and urovirulence coding genes.     

Detection of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella pneumoniae

Background: Detecting plasmid-mediated AmpC (pAmpC) β-lactamase-producing organism is important for optimal infection control and providing accurate and effective treatment option for physicians. Objectives: The aim of this study was to investigate the prevalence of pAmpC β-lactamase and compare the results of boronic acid (BA) disk test with other phenotypic tests detecting AmpC positive isolates. Materials and Methods: A total of 273 clinical isolates of Klebsiella pneumoniae (n: 82) and Escherichia coli (n: 191) were analysed. The presence of pAmpC β-lactamase was determined by BA disk test, cefoxitin (FOX) screening test, modified three dimensional test (M3DT), and multiplex polymerase chain reaction (PCR). Pulsed-field gel electrophoresis was performed to evaluate the genetic similarities between isolates. To detect extended spectrum β-lactamases (ESBL) in the presence of AmpC β-lactamase, ESBL confirmation test was carried out with and without BA solution. Results: Of the 273 strains tested, 127 strains were found FOX resistant, 114 were positive by M3DT, 108 were positive in BA disk test, and the multiplex PCR detected 24 pAmpC β-lactamase-positive isolate. The prevalence of AmpC-producing strains was 10.9% in E. coli and 3.6% in K. pneumoniae in the tested population by PCR. CIT and MOX group genes were predominant type in these strains. Conclusion: These results emphasize that clinical laboratories should consider testing the presence of pAmpC enzymes particularly in FOX-resistant isolates, and BA disk test will improve detection of this emerging resistance phenotype.     

Cluster of Escherichia coli Isolates Producing a Plasmid-Mediated OXA-48 β-Lactamase in a Spanish Hospital in 2012

Three unrelated sequence type 131 (ST131), ST58, and ST83 Escherichia coli isolates with low-level resistance to imipenem and resistance to ertapenem were recovered in a Spanish hospital from July to October 2012. They were positive for bla_OXA-48 carried by an IncL/M conjugative plasmid, which may have been acquired from Klebsiella pneumoniae.     

Potentialization of β-lactams with colistin: in case of extended spectrum β-lactamase producing Escherichia coli strains isolated from children with urinary infections

Five strains producing extended-spectrum β-lactamases (ESBL) bacteria, identified as Escherichia coli, were isolated from children with urinary infections hospitalized at Roubaix hospital in the north of France. The DNA genotypes of these non-nosocomial isolates were determined by Random Amplified Polymorphic DNA (RAPD) method. Further, their DNA plasmids content revealed the presence of two distinct plasmids for S1, S2, S3 and one plasmid for S4 and S5. The antibacterial susceptibility of these ESBL bacteria was tested mainly against antibiotics of β-lactams family. The ESBL producing bacteria were resistant to ticarcillin and cefotaxime but the combination of these antibiotics with colistin has dropped the MIC of ticarcillin below its breakpoint (isolates S2, S3 and S4), and has almost reached the breakpoint for cefotaxime (isolate S2). Thus, kill curves analyses carried out with only isolates S1 and S2, strengthened the bactericidal activity of the combinations of colistin-ticarcillin and colistin-cefotaxime against ESBL E. coli. Indeed, reduction of 3 log₁₀ colony count were observed after 24 h of incubation.     

Populations of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae are different in human-polluted environment and food items: a multicentre European study

ObjectivesTo assess the extent to which food items are a source of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli (ESBL-Ec) and ESBL-producing Klebsiella pneumoniae (ESBL-Kp) for humans in five European cities.MethodsWe sampled 122 human polluted (hp)-environments (sewers and polluted rivers, as a proxy of human contamination) and 714 food items in Besançon (France), Geneva (Switzerland), Sevilla (Spain), Tübingen (Germany) and Utrecht (The Netherlands). A total of 254 ESBL-Ec and 39 ESBL-Kp isolates were cultured. All genomes were fully sequenced to compare their sequence types (ST) and core genomes, along with the distribution of bla_ESBL genes and their genetic supports (i.e. chromosome or plasmid).ResultsSequence data revealed that ESBL-Ec and ESBL-Kp isolates from hp-environments were genetically different from those contaminating food items. ESBL-Ec ST131 was widespread in the hp-environment (21.5% of the isolates) but absent from the food items tested. ESBL-Ec ST10 was in similar proportions in hp-environments and food items (15 and 10 isolates, respectively) but mostly carried reservoir-specific bla_ESBL. bla_CTX-M-1 and bla_SHV-12 predominated in food-related E. coli isolates (32% and 34% of the isolates, respectively), whereas bla_CTX-M-15 and bla_CTX-M-27 predominated in isolates from hp-environments (52% and 15% of the isolates, respectively).ConclusionsWe found a very limited connection between ESBL-Ec and ESBL-Kp populations retrieved in food items and from hp-environments and bla_ESBL. This suggests that human-to-human contamination, rather than the food chain, is possibly the most frequent route of ESBL-Ec and ESBL-Kp transmission in high-income countries.     

Shift of CTX-M genotypes has determined the increased prevalence of extended-spectrum β-lactamase-producing Escherichia coli in south-western Sweden

The prevalence of Escherichia coli producing extended-spectrum β-lactamases (ESBLs) markedly increased during 2004–2008 in south-western Sweden, with a greater increase in urinary isolates in hospitals (0.2–2.5%) than in the community (0.2–1.6%). ESBLs of genotype CTX-M predominated, with a significant (p <0.02) shift from the CTX-M-9 to CTX-M-1 phylogroup occurring among urinary ESBL-producing E. coli isolated early (n = 41) as compared with late (n = 221) in the study period. The increase in ESBL-producing E. coli was polyclonal, and only partly attributable to an increase (0–24%) in the number of O25b-ST131 isolates carrying CTX-M-15. The increase was prominent in men and in elderly patients, and warrants continued surveillance.     

CTX-M-14 type β-Lactamase producing Escherichia coli isolated from hospitalized patients in Tunisia

Escherichia coli (E.coli) with a CTX-M resistance phenotype was selected from hospitalized patients in a university Hospital of Tunisia between January 2010 and June 2010. PCR analysis and sequencing demonstrated that it harboured CTX-M-14 β-lactamase. Characterization of the regions surrounding the bla(CTX-M-14) showed the ISEcp1 elements located in the upstream region of the bla gene. PFGE and multilocus sequence typing revealed two different types which corresponds to sequence types ST38 complex and ST131. These results reinforce the potential for spreading of this gene among E. coli clinical strains in the coming years in Tunisia.     

Extended-spectrum β-lactamase-producing Escherichia coli isolated from poultry: a review of current problems,illustrated with some laboratory findings

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been documented in humans as well as in food-producing birds, including chickens, and for unknown reasons the prevalence has increased significantly during the last decade. With E. coli as a major opportunistic pathogen in chickens and with a potential for zoonotic transfer to human beings, ESBL-producing E. coli represents a major risk both to poultry production and to human health. This review presents some of the current problems with ESBL-producing E. coli in relation to poultry production, with a focus on chickens. To illustrate issues in relation to screening and typing, two case studies are included where one collection of ESBL-producing E. coli isolates was obtained from asymptomatic carrier chickens while the other was obtained from lesions in chickens. Pulsed-field gel electrophoresis and multi-locus sequence typing revealed a highly heterogeneous population of ESBL-producing E. coli. All isolates harboured between one and three large plasmids (>100 kb). Among isolates associated with asymptomatic chickens, the ESBL types SHV and TEM dominated, while CTX-M-1 dominated in disease-associated isolates. The isolates from diseased birds were occasionally of sequence types often associated with human infections, such as ST131. With improved tools to trace and screen for ESBL-producing E. coli at farm level, strategies can be selected that aim to reduce or eliminate the presence of ESBL-producing E. coli in poultry and poultry products meant for human consumption.