Characterization of extended-spectrum-beta-lactamase-producing Escherichia coli strains involved in maternal-fetal colonization: prevalence of E. coli ST131

Characterization of young infants with fecal carriage of multidrug-resistant Escherichia coli in Southern Taiwan

BACKGROUND

The accelerating prevalence of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistance (MDR) Escherichia coli(E. coli) become a public health challenge worldwide. This study aimed to discuss the prevalence of drug-resistant E. coli colonization and analyze its risk factors and clinical characteristics among young infants in Southern Taiwan.

METHODS

Stool samples were collected from young infants, aged less than three months, within three days of their hospitalization from September to December 2019 in a tertiary hospital. A questionnaire was designed for parents to complete. E. coli colonies were selected and analyzed for antimicrobial susceptibility. PCR-based multilocus sequence typing was to detect the presence of sequence type ST131 and blaCTX-M genes.

RESULTS

Among 100 enrolled infants, 36% had fecal carriage of E. coli isolates, of which twenty nine (80.5%) were MDR, thirteen (36.1%) were ESBL-producing isolates and five (13.8%) and ten (27.7%) were ST131 and strains carrying CTX-M-14 gene, respectively. Compared to non-ST131 and non-CTX-M-14 gene carrier, isolates of ST131 and CTX-M-14 gene carrier showed a significantly higher resistance rate to cefixime, ceftriaxone, and gentamycin, with p value all <0.05.

CONCLUSION

The prevalence of ESBL-producing and MDR E. coli fecal carriage were both high in young infants. The most common sequence type is ST131, of which all are strains carrying CTX-M-14. Further surveillance and investigation to control for the high prevalence of antimicrobial-resistant E. coli fecal carriage among infants in Taiwan are warranted.

Emergence of ST1193 Clone in Maternal and Neonatal ESBL-Producing E. coli Isolates

Objective

The emerging epidemic of extended-spectrum β-lactamase-producing E. coli (ESBL-EC) is a global public health crisis. ESBL-EC infections are increasing worldwide and contribute to morbidity and mortality among newborn infants. However, the antimicrobial resistance characteristics and clonal transmission of maternal and neonatal ESBL-EC isolates need to be further deciphered.

Materials and Methods

We performed phenotypic and genotypic characterization of 33 ESBL-EC isolates from pregnant women and newborn during 2019-2020.

Results

Minimum inhibitory concentrations of 17 antimicrobial agents showed that all isolates were multidrug-resistant (MDR) and had a resistance rate of 100% to ampicillin, and mild resistance to florfenicol, gentamicin, ceftazidime, and amoxicillin-clavulanate. Additionally, imipenem, meropenem, polymyxin, and tigecycline exhibited good activity against the tested ESBL-EC isolates with low MIC50 (0.06-1 μg/mL) and MIC90 (0.06-1 μg/mL). Whole genome sequencing indicated that ESBL-EC isolates contained diverse antimicrobial resistant genes (blaCTX-M, blaTEM, blaSHV, tetA, etc.) and toxin genes (ompA, csg, fimH, hybtA, etc.). blaCTX-M genes were the main ESBL genotype. ST1193 (18.2%) was the second most abundant ST among the ESBL-EC isolates (ST131 was the most common, with 30.3%), and this is the first report of its mother-to-infant colonization transmission in China.

Conclusion

These findings revealed the occurrence of high-risk ST1193 clone among ESBL-EC isolates from pregnant women and newborn colonization in China. Further national or regional multicenter studies are needed to assess the dissemination and evolution of ESBL-EC ST1193 clone as a nosocomial pathogen in China.

Interspecies Interactions within the Host: the Social Network of Group B Streptococcus

Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial infections. Additionally, the incidence of late-onset GBS neonatal disease remains unaffected and has sparked an emerging hypothesis that GBS-microbe interactions in developing neonatal gut microbiota may be directly involved in this disease process. This review summarizes our current understanding of GBS interactions with other resident microbes at the mucosal surface from multiple angles, including clinical association studies, agriculture and aquaculture observations, and experimental animal model systems. We also include a comprehensive review of in vitro findings of GBS interactions with other bacterial and fungal microbes, both commensal and pathogenic, along with newly established animal models of GBS vaginal colonization and in utero or neonatal infection. Finally, we provide a perspective on emerging areas of research and current strategies to design microbe-targeting prebiotic or probiotic therapeutic intervention strategies to prevent GBS disease in vulnerable populations.

Prevalence and molecular characterization of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from dogs suffering from diarrhea in and around Kolkata

BACKGROUND

Dogs are the favorite companion animals among humans. The close interaction between dogs and people increases the risk of antibiotic resistance spreading. Surveillance for antimicrobial resistance and the identification of ESBL-producing Escherichia coli as an indicator bacterium is an important tool for managing antimicrobial drug therapy.

AIMS

The present study targeted to identify and characterize ESBL-producing E. coli among dogs suffering from diarrhea in and around Kolkata.

METHODS

Isolation and identification of E. coli from dogs suffering from diarrhea (n=70) along with screening for the production of both ESBL and AmpC. The isolates were further characterized through antimicrobial resistance profiling, resistance genes (bla _CTX-M, bla _TEM, and bla _SHV) screening, and phylogenetic group study.

RESULTS

Among the 70 isolates, 21 (30%) were confirmed ESBL producers. An antibiogram typing of ESBL-producing E. coli revealed that the majority of them were resistant to norfloxacin (85.7%) followed by tetracycline (61.90%), doxycycline (57.14%), piperacillin/tazobactam (52.38%), cotrimoxazole (47.62%), gentamicin (42.62%), amikacin (23.81%), and chloramphenicol (19.05%). Major resistance genes included bla _CTX-M (100%), bla _TEM (28.57%), and bla _SHV (9.50%). The predominant phylogenetic groups were phylogroup A (76%) followed by phylogroup D (24%).

CONCLUSION

The current investigation reported a high prevalence of both ESBL and AmpC β-lactamase (AmpC) producing E. coli, co-resistance to a distinct group of antibiotics, and co-existence of different ESBL genes in dogs. Our findings highlight the importance of diagnostic antimicrobial susceptibility testing for proper antimicrobial therapy and to prevent antimicrobial resistance from spreading to humans from dogs in Kolkata and the surrounding area.

Whole-genome sequencing-based phylogeny, antibiotic resistance, and invasive phenotype of Escherichia coli strains colonizing the cervix of women in preterm labor

Background

Escherichia coli is a major neonatal pathogen and the leading cause of early-onset sepsis in preterm newborns. Maternal E. coli strains are transmitted to the newborn causing invasive neonatal disease. However, there is a lack of data regarding the phenotypic and genotypic characterization of E. coli strains colonizing pregnant women during labor.

Methods

This prospective study performed at the University of Oklahoma Medical Center (OUHSC) from March 2014 to December 2015, aimed to investigate the colonization rate, and the phylogeny, antibiotic resistance traits, and invasive properties of E. coli strains colonizing the cervix of fifty pregnant women diagnosed with preterm labor (PTL). Molecular analyses including bacterial whole-genome sequencing (WGS), were performed to examine phylogenetic relationships among the colonizing strains and compare them with WGS data of representative invasive neonatal E. coli isolates. Phenotypic and genotypic antibiotic resistance traits were investigated. The bacteria’s ability to invade epithelial cells in vitro was determined.

Results

We recruited fifty women in PTL. Cervical samples yielded E. coli in 12 % (n=6). The mean gestational age was 32.5 (SD±3.19) weeks. None delivered an infant with E. coli disease. Phenotypic and genotypic antibiotic resistance testing did not overall demonstrate extensive drug resistance traits among the cervical E. coli isolates, however, one isolate was multi-drug resistant. The isolates belonged to five different phylogroups, and WGS analyses assigned each to individual multi-locus sequence types. Single nucleotide polymorphism-based comparisons of cervical E. coli strains with six representative neonatal E. coli bacteremia isolates demonstrated that only half of the cervical E. coli isolates were phylogenetically related to these neonatal invasive strains. Moreover, WGS comparisons showed that each cervical E. coli isolate had distinct genomic regions that were not shared with neonatal E. coli isolates. Cervical and neonatal E. coli isolates that were most closely related at the phylogenetic level had similar invasion capacity into intestinal epithelial cells. In contrast, phylogenetically dissimilar cervical E. coli strains were the least invasive among all isolates.

Conclusions

This pilot study showed that a minority of women in PTL were colonized in the cervix with E. coli, and colonizing strains were not phylogenetically uniformly representative of E. coli strains that commonly cause invasive disease in newborns. Larger studies are needed to determine the molecular characteristics of E. coli strains colonizing pregnant women associated with an increased risk of neonatal septicemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02389-7.

Intense intestinal carriage and subsequent acquisition of multidrug-resistant enterobacteria in neonatal intensive care unit in Morocco

This study was conducted in order to know the colonization rate of MDR enterobacteria in neonates during their hospitalization in neonatal intensive care unit (NICU). Furthermore, we investigated risk factors for potential colonization and molecular epidemiology of isolated resistant bacteria. This prospective study was carried out in the neonatology and intensive care unit department of the University Hospital of Fez (Morocco) from February 2013 to July 2015. All consecutive admitted newborns were screened for intestinal and nasal carriage of MDR enterobacteria at admission of the babies and during the hospitalization. During the study period, a total of 641 Enterobacteriaceae were isolated and Klebsiella pneumoniae was the predominated bacteria. Bacterial identification and antibiograms were performed according to the international standards. On admission, 455 newborns were screened. A median age of these newborns was 1 day with an extended 147 days and their average weight was 2612 ± 1023 grams. 22.4% of neonates were found colonized by an ESBL producing Enterobacteriaceae (ESBL-E), 8.7% by a carbapenemases producing Enterobacteriaceae (CPE). During hospitalization, 207 of newborns were included in the acquisition study. 59.4% of newborns acquired an ESBL-E during their stay, 12.5% has acquired CPE. The blaCTXM-15 gene was the most frequently detected (81.2%) among ESBL-E. While, all CPE has expressed the blaOXA-48 gene exclusively. Two risk factors have been significantly associated with MDR enterobacteria colonization at admission which are newborns admission from maternity of the university hospital (95% CI, 1.859-5.129, P = 0.000) and neurological distress (95% CI, 1.038 to 4.694, P = 0.040). During hospitalization, the none risk factor was significantly associated with the carriage of MDR-E. The high rate of colonization, the MDR enterobacteria and the resistance genes found represent good indicator of cross-transmission in the NICU. An active strategy to control the spread of MDR enterobacteria should be applied.

Maternal Vaginal Colonization and Extended-Spectrum Beta-Lactamase-Producing Bacteria in Vietnamese Pregnant Women

Extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) resistance to commonly prescribed drugs is increasing in Vietnam. During pregnancy, ESBL-E may predispose women to reproductive tract infections and increases the risk for neonatal morbidity. Vaginal colonization and infections by Escherichia coli and Klebsiella pneumoniae are seldom studied in Vietnam. In this study, we investigated ESBL-producing Enterobacterales in the birth canal of pregnant women. Between 2016 and 2020, vaginal swabs were collected from 3104 pregnant women (mean gestational age of 31 weeks) and inoculated onto MacConkey agar plates. Colonies were subjected to direct identification and antimicrobial susceptibility testing using the VITEK^®-2 automated compact system and disk diffusion. ESBL production was determined phenotypically. E. coli, Klebsiella species were identified in 30% (918/3104) of the vaginal swabs, with E. coli being the most common (73%; 667/918). ESBL-production was detected in 47% (432/918) of Enterobacterales, with frequent multidrug-resistant phenotype. The overall prevalence of carbapenem resistance was low (8%). Over 20% of Klebsiella spp. were carbapenem-resistant. Pregnant women had a high prevalence of colonization and may transmit ESBL-E to neonates at birth, an important risk factor to be considered. The high rate of ESBL-producers and carbapenem resistance in Enterobacterales in Vietnam emphasizes the need for consequent surveillance and access to molecular typing.

Rectovaginal Colonization With Pathogenic Escherichia coli During Pregnancy And Neonatal Outcomes

Purpose

The role of pathogenic Escherichia coli colonization in asymptomatic pregnant women is not well understood. The purpose of this work was to determine the prevalence, antimicrobial susceptibility, and neonatal outcomes of pathogenic E. coli colonization in pregnant women.

Patients and methods

A total of 137 women from southern Taiwan with singleton pregnancies were enrolled between March 2016 and June 2017. The women were prospectively screened for E. coli colonization in the rectovaginal region during prenatal examination. The exclusion criteria are twin pregnancy of the mother and major anomaly of the neonate. All E. coli isolates were identified as either pathogenic or commensal strains, and their susceptibility to various antimicrobials was investigated. Clinical data of the infants were retrieved from their medical records.

Results

Results showed that 35.8% of asymptomatic pregnant women had pathogenic E. coli colonization in the rectovaginal region. Neonates born to such mothers showed significant morbidities, including hospitalization (OR= 3.74, 95% CI= 1.18~11.87), hyperbilirubinemia (OR= 2.81, 95% CI= 1.24~6.38), and gastrointestinal symptoms (OR= 5.53, 95% CI= 1.39~21.94). Maternal colonization with pathogenic E. coli at rectoanal site was a risk factor for neonatal hyperbilirubinemia after Benjamini–Hochberg (BH) adjustment (52% vs 24%, adjusted P= 0.048).

Conclusion

The prevalence of pathogenic E. coli colonization in Taiwanese asymptomatic pregnant women was high, and the neonates born to colonized mothers exhibited potential neonatal morbidities. Larger studies are necessary to confirm these findings.

The Arginine Deiminase Operon Is Responsible for a Fitness Trade-Off in Extended-Spectrum-β-Lactamase-Producing Strains of Escherichia coli

We previously identified an operon involved in an arginine deiminase (ADI) pathway (arc operon) on a CTX-M-producing plasmid from an O102-ST405 strain of Escherichia coli As the ADI pathway was shown to be involved in the virulence of various Gram-positive bacteria, we tested whether the ADI pathway could be involved in the epidemiological success of extended-spectrum-β-lactamase (ESBL)-producing E. coli strains. We studied two collections of human E. coli isolated in France (n = 493) and England (n = 1,509) and show that the prevalence of the arc operon (i) is higher in ESBL-producing strains (12.1%) than in nonproducers (2.5%), (ii) is higher in CTX-M-producing strains (16%) than in other ESBL producers (3.5%), and (iii) increased over time in ESBL-producing strains from 0% before 2000 to 43.3% in 2011 to 2012. The arc operon, found in strains from various phylogenetic backgrounds, is carried by IncF plasmids (85%) or chromosomes (15%) in regions framed by numerous insertion sequences, indicating multiple arrivals. Competition experiments showed that the arc operon enhances fitness of the strain in vitro in lysogeny broth with arginine. In vivo competition experiments showed that the arc operon is advantageous for the strain in a mouse model of urinary tract infection (UTI), whereas it is a burden in a mouse model of intestinal colonization. In summary, we have identified a trait linked to CTX-M-producing strains that is responsible for a trade-off between two main E. coli lifestyles, UTI and gut commensalism. This trait alone cannot explain the wide spread of ESBLs in E. coli but merits epidemiological surveillance.

Colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae in pregnant/post-partum women: Systematic review and meta-analysis

OBJECTIVES

Maternal colonisation with extended-spectrum β-lactamase (ESBL)-producing micro-organisms can lead to transmission of such pathogens to neonates, resulting in considerable morbidity. The aim of this study was to determine the global prevalence of maternal colonisation with ESBL-producing Enterobacteriaceae (ESBL-E).

METHODS

A systematic review of PubMed, Embase, Scopus, Web of Science and ProQuest databases as well as the grey literature was performed. Studies reporting the prevalence of ESBL-E colonisation during pregnancy or postpartum period were included. Prevalence data were grouped by geographic region. The pooled prevalence and 95% confidence interval (CI) was estimated by meta-analysis using a random-effects model.

RESULTS

Nineteen studies with reports from 16 countries (seven studies from Africa, one study from South America, two studies from Asia and nine studies from Europe) reporting data for 7352 pregnant/postpartum women were included. The pooled prevalence of ESBL-E colonisation was 8% (95% CI 5-10%). Prevalence estimates were 15% (95% CI 5-24%) in Africa, 6% (95% CI 4-10%) in South America, 5% (95% CI 4-6%) in Asia and 4% (95% CI 2-5%) in Europe. The pooled prevalence was higher in studies with low risk of bias (10%; 95% CI 7-13%) compared with those with high risk of bias (3%; 95% CI 2-3%).

CONCLUSION

There was heterogeneity regarding ESBL-E colonisation rates in different continents. The pooled prevalence rate was higher in Africa compared with other areas. Given that the highest rate was observed in Africa, implementing screening efforts for ESBL-E colonisation during pregnancy may be justified.

Detection of Carbapenemase-Producing Enterobacteriaceae in Positive Blood Culture Using an Immunochromatographic RESIST-4 O.K.N.V. Assay

We evaluated the performance of the RESIST-4 O.K.N.V. assay (Coris) with 98 isolates to detect OXA-48-like and KPC-, NDM-, and VIM-type carbapenemases directly on positive human blood cultures. OXA-48-like and KPC-type isolates were correctly detected, but the detection of NDM- and VIM-type carbapenemases was weak and variable. We show that repeating the test on a 4-h subculture improves the detection of NDM- and VIM-type carbapenemases to 100%.

[Antibiotic prophylaxis in preterm premature rupture of membranes: CNGOF preterm premature rupture of membranes guidelines]

OBJECTIVE

To analyse benefits and risks of antibiotic prophylaxis in the management of preterm premature rupture of membranes.

METHODS

PubMed and Cochrane Central databases search.

RESULTS

Streptoccoccus agalactiae (group B streptococcus) and Escherichia coli are the two main bacteria identified in early neonatal sepsis (EL3). Antibiotic prophylaxis at admission is associated with significant prolongation of pregnancy (EL2), reduction in neonatal morbidity (EL1) without impact on neonatal mortality (EL2). Co-amoxiclav could be associated with an increased risk for neonatal necrotising enterocolitis (EL2). Antibiotic prophylaxis at admission in women with preterm premature rupture of the membranes is recommended (Grade A). Monotherapy with amoxicillin, third generation cephalosporin and erythromycin can be used as well as combination of erythromycin and amoxicillin (Professional consensus) for 7 days (GradeC). Shorter treatment is possible when initial vaginal culture is negative (Professional consensus). Co-amxiclav, aminoglycosides, glycopeptides, first and second generation cephalosporin, clindamycin and metronidazole are not recommended (Professional consensus).

CONCLUSIONS

Antibiotic prophylaxis against Streptoccoccus agalactiae (group B streptococcus) and E. coli is recommended in women with preterm premature of the membranes (Grade A). Monotherapy with amoxicillin, third generation cephalosporin or erythromycin, as well as combination of erythromycin and amoxicillin are recommended (Professional consensus).

Vagino-rectal colonization and maternal-neonatal transmission of Enterobacteriaceae producing extended-spectrum β-lactamases or carbapenemases: a cross-sectional study

This study sought to determine the prevalence and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in 815 mothers and 800 newborns using a cross-sectional design; 59 women and 13 neonates were colonized by ESBL-E (prevalence (95% confidence interval): 6.7% (5.2-8.7) and 1.6 (0.7-2.5), respectively). No CPE were found. The most frequent ESBL-E were CTX-M-14 and SHV-12. Vertical transmission occurred in 14% of colonized mothers. The risk factors for colonization were, in mothers: complications in previous pregnancies, more than one urinary tract infection, non-Caucasian ethnicity, and frequently having the main meal outside home; in newborns: colonized mother and vaginal delivery.

Extended-spectrum β-lactamase-encoding genes are spreading on a wide range of Escherichia coli plasmids existing prior to the use of third-generation cephalosporins

To understand the evolutionary dynamics of extended-spectrum β-lactamase (ESBL)-encoding genes in Escherichia coli, we undertook a comparative genomic analysis of 116 whole plasmid sequences of human or animal origin isolated over a period spanning before and after the use of third-generation cephalosporins (3GCs) using a gene-sharing network approach. The plasmids included 82 conjugative, 22 mobilizable and 9 non-transferable plasmids and 3 P-like bacteriophages. ESBL-encoding genes were found on 64 conjugative, 6 mobilizable, 2 non-transferable plasmids and 2 P1-like bacteriophages, indicating that these last three types of mobile elements also play a role, albeit modest, in the diffusion of the ESBLs. The network analysis showed that the plasmids clustered according to their genome backbone type, but not by origin or period of isolation or by antibiotic-resistance type, including type of ESBL-encoding gene. There was no association between the type of plasmid and the phylogenetic history of the parental strains. Finer scale analysis of the more abundant clusters IncF and IncI1 showed that ESBL-encoding plasmids and plasmids isolated before the use of 3GCs had the same diversity and phylogenetic history, and that acquisition of ESBL-encoding genes had occurred during multiple independent events. Moreover, the blaCTX-M-15 gene, unlike other CTX-M genes, was inserted at a hot spot in a blaTEM-1-Tn2 transposon. These findings showed that ESBL-encoding genes have arrived on wide range of pre-existing plasmids and that the successful spread of blaCTX-M-15 seems to be favoured by the presence of well-adapted IncF plasmids that carry a Tn2-blaTEM-1 transposon.

Molecular characterization of extended spectrum β -lactamases enterobacteriaceae causing lower urinary tract infection among pediatric population

Background

The β-lactam antibiotics have traditionally been the main treatment of Enterobacteriaceae infections, nonetheless, the emergence of species producing β- Lactamases has rendered this class of antibiotics largely ineffective. There are no published data on etiology of urinary tract infections (UTI) and antimicrobial resistance profile of uropathogens among children in Qatar. The aim of this study is to determine the phenotypic and genotypic profiles of antimicrobial resistant Enterobacteriaceae among children with UTI in Qatar.

Methods

Bacteria were isolated from 727 urine positive cultures, collected from children with UTI between February and June 2017 at the Pediatric Emergency Center, Doha, Qatar. Isolated bacteria were tested for antibiotic susceptibility against sixteen clinically relevant antibiotics using phoenix and Double Disc Synergy Test (DDST) for confirmation of extended-spectrum beta-lactamase (ESBL) production. Existence of genes encoding ESBL production were identified using polymerase chain reaction (PCR). Statistical analysis was done using non-parametric Kappa statistics, Pearson chi-square test and Jacquard's coefficient.

Results

201 (31.7%) of samples were confirmed as Extended Spectrum β -Lactamases (ESBL) Producing Enterobacteriaceae. The most dominant pathogen was E. coli 166 (83%) followed by K. pneumoniae 22 (11%). Resistance was mostly encoded by ^bla CTX-M (59%) genes, primarily ^bla CTX-MG1 (89.2%) followed by ^bla CTX-MG9 (7.7%). 37% of isolated bacteria were harboring multiple ^bla genes (2 genes or more). E. coli isolates were categorized into 11 clusters, while K. pneoumoniae were grouped into five clonal clusters according to the presence and absence of seven genes namely ^bla TEM, ^bla SHV, ^bla CTX-MG1, ^bla CTX-MG2, ^bla CTX-MG8 ^bla CTX-MG9,^bla CTX-MG25.

Conclusions

Our data indicates an escalated problem of ESBL in pediatrics with UTI, which mandates implementation of regulatory programs to reduce the spread of ESBL producing Enterobacteriaceae in the community. The use of cephalosporins, aminoglycosides (gentamicin) and trimethoprim/sulfamethoxazole is compromised in Qatar among pediatric population with UTI, leaving carbapenems and amikacin as the therapeutic option for severe infections caused by ESBL producers.

Rectal carriage of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae among hospitalised neonates in a neonatal intensive care unit in Fez, Morocco

OBJECTIVES

The aim of this study was to investigate the faecal carriage and molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBLE) isolated from rectal samples of neonates hospitalised in a neonatal intensive care unit (NICU) of a university hospital in Fez, Morocco.

METHODS

From February-July 2013, all neonates hospitalised in the NICU were screened for ESBLE carriage at discharge. ESBLs were identified by double-disk synergy test, PCR and DNA sequencing analysis. ESBLE were analysed by pulsed-field gel electrophoresis (PFGE), and conjugation was performed by the broth mating method.

RESULTS

In this study, 169 Enterobacteriaceae were collected from 164 neonates. The prevalence of faecal carriage of ESBLE was 58.0% (98/169), predominantly Klebsiella pneumoniae (65/98; 66.3%). A high rate of multiresistance in ESBLE was noted. bla_CTX-M-1 group (78.5%) was the most frequent ESBL gene detected, and all isolates harboured the CTX-M-15 variant. The prevalence of carbapenemase-producing Enterobacteriaceae was 1.8%, and bla_OXA-48 was the only gene found in these isolates. Sequencing revealed subgroups corresponding to bla_{(CTX-M-15,TEM-1,TEM-104,SHV-1,SHV-44,SHV-49andSHV-133)} genes. Conjugation experiments showed the transferability of bla_CTX-M-15 and bla_TEM, but not bla_SHV. These genes were carried by a high-molecular-weight conjugative plasmid (ca. 125kb). PFGE profiles demonstrated high clonal dissemination of ESBL-positive strains in the NICU.

CONCLUSIONS

These results demonstrate the existence of high clonal transmission of ESBLE in a Moroccan NICU. This finding provides useful information to implement a screening policy for resistant Enterobacteriaceae among neonates hospitalised in this ward.

Guiding Empiric Treatment for Serious Bacterial Infections via Point of Care [Formula: see text]-Lactamase Characterization

Fever is one of the most common symptoms of illness in infants and represents a clinical challenge due to the potential for serious bacterial infection. As delayed treatment for these infections has been correlated with increased morbidity and mortality, broad-spectrum [Formula: see text]-lactam antibiotics are often prescribed while waiting for microbiological lab results (1-3 days). However, the spread of antibiotic resistance via the [Formula: see text]-lactamase enzyme, which can destroy [Formula: see text]-lactam antibiotics, has confounded this paradigm; empiric antibiotic regimens are increasingly unable to cover all potential bacterial pathogens, leaving some infants effectively untreated until the pathogen is characterized. This can lead to lifelong sequela or death. Here, we introduce a fluorescent, microfluidic assay that can characterize [Formula: see text]-lactamase derived antibiotic susceptibility in 20 min with a sensitivity suitable for direct human specimens. The protocol is extensible, and the antibiotic spectrum investigated can be feasibly adapted for the pathogens of regional relevance. This new assay fills an important need by providing the clinician with hitherto unavailable point of care information for treatment guidance in an inexpensive and simple diagnostic format.

Epidemic potential of Escherichia coli ST131 and Klebsiella pneumoniae ST258: a systematic review and meta-analysis

OBJECTIVES

Observational studies have suggested that Escherichia coli sequence type (ST) 131 and Klebsiella pneumoniae ST258 have hyperendemic properties. This would be obvious from continuously high incidence and/or prevalence of carriage or infection with these bacteria in specific patient populations. Hyperendemicity could result from increased transmissibility, longer duration of infectiousness, and/or higher pathogenic potential as compared with other lineages of the same species. The aim of our research is to quantitatively estimate these critical parameters for E. coli ST131 and K. pneumoniae ST258, in order to investigate whether E. coli ST131 and K. pneumoniae ST258 are truly hyperendemic clones.

PRIMARY OUTCOME MEASURES

A systematic literature search was performed to assess the evidence of transmissibility, duration of infectiousness, and pathogenicity for E. coli ST131 and K. pneumoniae ST258. Meta-regression was performed to quantify these characteristics.

RESULTS

The systematic literature search yielded 639 articles, of which 19 data sources provided information on transmissibility (E. coli ST131 n=9; K. pneumoniae ST258 n=10)), 2 on duration of infectiousness (E. coli ST131 n=2), and 324 on pathogenicity (E. coli ST131 n=285; K. pneumoniae ST258 n=39). Available data on duration of carriage and on transmissibility were insufficient for quantitative assessment. In multivariable meta-regression E. coli isolates causing infection were associated with ST131, compared to isolates only causing colonisation, suggesting that E. coli ST131 can be considered more pathogenic than non-ST131 isolates. Date of isolation, location and resistance mechanism also influenced the prevalence of ST131. E. coli ST131 was 3.2 (95% CI 2.0 to 5.0) times more pathogenic than non-ST131. For K. pneumoniae ST258 there were not enough data for meta-regression assessing the influence of colonisation versus infection on ST258 prevalence.

CONCLUSIONS

With the currently available data, it cannot be confirmed nor rejected, that E. coli ST131 or K. pneumoniae ST258 are hyperendemic clones.

Outbreak of multidrug-resistant Escherichia coli sequence type 131 in a neonatal intensive care unit: efficient active surveillance prevented fatal outcome

BACKGROUND

Outbreaks of infections with multidrug-resistant bacteria in neonatal intensive care units (NICUs) pose a major threat, especially to extremely preterm infants. This study describes a 35-day outbreak of multidrug-resistant Escherichia coli (E. coli) in a tertiary-level NICU in Germany.

AIM

To underline the importance of surveillance policies in the particularly vulnerable cohort of preterm infants and to describe the efficacy of outbreak control strategies.

METHODS

Data were collected retrospectively from medical reports. Infants and environment were tested for E. coli.

FINDINGS

The outbreak affected a total of 13 infants between 25(+1) and 35(+0) weeks of gestation with seven infants showing signs of infection. The outbreak strain was identified as E. coli sequence type 131. Environmental screening provided no evidence for an environmental source. Through colonization surveillance and immediate and adequate treatment of potentially infected preterm infants, no fatalities occurred. Outbreak control was achieved by strict contact precautions, enhanced screening and temporary relocation of the NICU. Relocation and reconstruction improved the NICU's structural layout, focusing on isolation capacities. Follow-up indicated carriage for several months in some infants.

CONCLUSION

Routine surveillance allowed early detection of the outbreak. The identification of carriers of the outbreak strain was successfully used to direct antibiotic treatment in case of infection. Enhanced hygienic measures and ward relocation were instrumental in controlling the outbreak.

ESBL-producing Enterobacteriaceae in 24 neonatal units and associated networks in the south of England: no clustering of ESBL-producing Escherichia coli in units or networks

OBJECTIVES

The objectives of this study were to characterize ESBL-producing Enterobacteriaceae present in 24 neonatal units (NNUs) in eight networks participating in a multicentre probiotic study and to test the hypothesis that specific strains would cluster within individual units and networks.

METHODS

We performed analysis of stool samples for the presence of ESBL-producing Enterobacteriaceae at 2 weeks post-natal age and 36 weeks post-menstrual age. ESBL-producing Enterobacteriaceae were characterized and typed using molecular methods.

RESULTS

ESBL-producing Enterobacteriaceae (n = 71) were isolated from 67/1229 (5.5%) infants from whom we received a sample at either sampling time or both sampling times, and from infants in 18 (75%) of the 24 recruiting NNUs. Thirty-three Escherichia coli, 23 Klebsiella spp. and 6 Enterobacter spp. strains were characterized. ESBL-producing E. coli were all distinguishable within individual NNUs by antibiotic resistance genotype, serogroup (O25b), phenotype, phylotype or ST. Ten of the 33 were ST131 and 9 of the 10 ST131 isolates were ciprofloxacin resistant. Seven of the 10 ST131 isolates carried genes encoding CTX-M group 1 enzymes. ST131 isolates were isolated from centres within five of the eight NNU networks. There were clusters of indistinguishable ESBL-producing Klebsiella and Enterobacter isolates associated with specific NNUs.

CONCLUSIONS

Strains of E. coli ST131 were distributed across neonatal networks in the south of England. There was no evidence of clustering of clonally related ESBL-producing E. coli strains, by contrast with Klebsiella spp. and Enterobacter spp., which did cluster within units. The possibility that ESBL-producing E. coli strains are spread by vertical transmission requires further investigation.

Extended-spectrum β-lactamase-producing Enterobacteriaceae among pregnant women in Norway: prevalence and maternal-neonatal transmission

OBJECTIVE

To study (i) the prevalence and risk factors for carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in pregnant women, (ii) the maternal-neonatal transmission rate of ESBL-E at birth and (iii) the prevalence of ESBL-E in expressed breast milk of colonized mothers.

STUDY DESIGN

In this cross-sectional, population-based study with case follow-up on maternal-neonatal transmission of ESBL-E, women were screened for rectal ESBL-E colonization at 36 weeks of pregnancy and delivery. Possible risk factors for colonization were studied by logistic regression. Infants of ESBL-E-positive mothers were screened for ESBL-E during their first weeks of life. ESBL-encoding genes were detected by PCR and clonal relatedness was investigated by pulsed-field gel electrophoreses.

RESULTS

In total, 26 out of 901 (2.9%) women were colonized by ESBL-producing Escherichia coli at 36 weeks of pregnancy. One of the women carried an additional ESBL Klebsiella pneumoniae strain. Adjusted for traveling, African or Asian nationality was a risk factor for colonization; OR=5.62 (2.21, 14.27) (LR-p=0.003). Fourteen women remained ESBL-E carriers at delivery. ESBL-E strains indistinguishable from the strains isolated from their respective mothers were detected in 5 (35.7%) infants during their first days of life (median day 3; range=2 to 8). A total of 146 expressed milk samples were cultured from 25 out of 26 colonized mothers, all were ESBL-E negative.

CONCLUSIONS

The prevalence of ESBL-E carriage among pregnant women was low in our region, but the high maternal-neonatal transmission rate suggests that colonized mothers represent a substantial risk for infant colonization.

[Management of urinary tract infections in children. Recommendations of the Pediatric Infectious Diseases Group of the French Pediatrics Society and the French-Language Infectious Diseases Society]

Urine dipsticks have to be used more frequently for the screening of urinary tract infections (UTI) in febrile infants and children (grade A). Confirmation of the UTI by urine culture should prefer other methods of sampling than the urine bag: sampling jet, urethral catheterization, or pubic puncture (grade A). The percentage of Escherichia coli producing extended-spectrum beta-lactamases (ESBL) in children accounts for less than 10 % in France and does not justify revising the 2007 recommendations (grade B). An increase in the use of carbapenems in first-line treatment is a major environmental hazard and exposes the patient to the risk of untreatable infections. For febrile UTI, the expert group recommended: (1) recover the results of susceptibility testing as soon as possible to quickly adapt treatment for possible resistant strains; (2) favor initial treatment with aminoglycosides (particularly amikacin) which remain active in the majority of ESBL strains for patients seen in the pediatric emergency department and/or hospital; (3) ceftriaxone (IV or IM) remains an appropriate treatment for patients seen in the emergency department or outpatient clinic because the percentage of ESBL-producing enterobacteria strains remains low; (4) use oral cefixime (grade B) in nonsevere cases and low-risk patients defined as age>3 months, general condition preserved, disease duration of fever<4 days, no associated comorbidity, and no history of urinary tract infection, uropathy, or prior antibiotic therapy in the last 3 months; (5) oral relay for parenteral treatment is guided by in vitro susceptibility testing, in an attempt to reduce the use of oral cephalosporins to limit the selection of resistant bacterial strains. The total duration of treatment recommended is usually 10 days. Except for special circumstances, there is no need to prescribe retrograde cystography or antibiotic prophylaxis after a first febrile urinary tract infection. For cystitis, the panel recommends systematic urinalysis and initial prescription before the results of the urine culture of one of the three following oral antibiotics: amoxicillin-clavulanate, cotrimoxazole, cefixime. The total duration of antibiotic treatment is 5days to tailor treatment based on clinical progression and antibiotic susceptibility.

Escherichia coli ST131, an intriguing clonal group

In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131.

Mode of delivery and other risk factors for Escherichia coli infections in very low birth weight infants

Background

Infections in newborns remain one of the most significant problems in modern medicine. Escherichia coli is an important cause of neonatal bloodstream and respiratory tract infections and is associated with high mortality. The aim of our study was to investigate the epidemiology of E. coli infection in Polish neonatal intensive care units (NICUs) and resistance to antibiotics, with particular reference to the safety of very low birth weight infants.

Methods

Continuous prospective infection surveillance was conducted in 2009–2012 in five NICUs, including 1,768 newborns whose birth weight was <1.5 kg. Escherichia coli isolates from different diagnostic specimens including blood, tracheal/bronchial secretions and others were collected. All isolates were tested using disk diffusion antimicrobial susceptibility methods. Pulsed-field gel electrophoresis was used to determine the possible horizontal transfer of E. coli among patients.

Results

The incidence of E. coli infections was 5.4% and 2.0/1,000 patient-days. The occurrence of E. coli infections depended significantly on the NICU and varied between 3.9% and 17.9%. Multivariate analysis that took into account the combined effect of demographic data (gender, gestational age and birth weight) and place of birth showed that only the place of hospitalisation had a significant effect on the E. coli infection risk. The highest levels of resistance among all E. coli isolates were observed against ampicillin (88.8%) and amoxicillin/clavulanic acid (62.2%). Among E. coli isolates, 17.7% were classified as multidrug resistant. Escherichia coli isolates showed different pulsotypes and dominant epidemic clones were not detected.

Conclusions

Our data indicate that antibiotic prophylaxis in the presence of symptoms such as chorioamnionitis and premature rupture of membranes did not help reduce the risk of E. coli infection. Multivariate analysis demonstrated only one significant risk factor for E. coli infection among infants with a birth weight <1.5 kg, that is, the impact of the NICU, it means that both neonatal care and care during pregnancy and labour were found to be significant.

Extended-spectrum beta-lactamase-producing Escherichia coli infections in children: are community-acquired strains different from nosocomial strains?

Infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are an important cause of morbidity and mortality, especially in children. We compared 58 epidemiologically unrelated ESBL-producing E. coli strains that caused infections. They were isolated between 2008 and 2012 in two Parisian pediatric hospitals and grouped according to their origin into either community-acquired (CA) (n=37) or nosocomially acquired (NA) (n=21) strains. Molecular characteristics of the ESBLs, phylogenetic traits of the strains including their belonging to clone O25b-ST131, prevalence of associated virulence genes, growth capacities in different media, metabolic phenotype and biofilm formation abilities were studied. ESBL type, associated resistance and distribution of phylogenetic groups were similar in the CA and NA groups. More than 60% of the B2 phylogroup strains in both groups belonged to the ST131 clone. Interestingly, CA strains possessed more genes encoding virulence factors and the distribution of these genes differed significantly between the two groups: fyuA, hlyC, papC and papGII were more frequent in the CA group, whereas iroN was more frequent in the NA group. CA strains also showed enhanced growth capacities in Luria Bertani rich medium. They tended to produce more biofilm but the difference was not significant. This study confirms the wide spread of clone ST131 among infected children, regardless of whether their infections were community- or nosocomially acquired. It highlights genotypic and phenotypic differences according to the origin of the strains that could indicate adaptability of these multi-resistant bacteria to specific environmental and host factors.

A new clone sweeps clean: the enigmatic emergence of Escherichia coli sequence type 131

Escherichia coli sequence type 131 (ST131) is an extensively antimicrobial-resistant E. coli clonal group that has spread explosively throughout the world. Recent molecular epidemiologic and whole-genome phylogenetic studies have elucidated the fine clonal structure of ST131, which comprises multiple ST131 subclones with distinctive resistance profiles, including the (nested) H30, H30-R, and H30-Rx subclones. The most prevalent ST131 subclone, H30, arose from a single common fluoroquinolone (FQ)-susceptible ancestor containing allele 30 of fimH (type 1 fimbrial adhesin gene). An early H30 subclone member acquired FQ resistance and launched the rapid expansion of the resulting FQ-resistant subclone, H30-R. Subsequently, a member of H30-R acquired the CTX-M-15 extended-spectrum beta-lactamase and launched the rapid expansion of the CTX-M-15-containing subclone within H30-R, H30-Rx. Clonal expansion clearly is now the dominant mechanism for the rising prevalence of both FQ resistance and CTX-M-15 production in ST131 and in E. coli generally. Reasons for the successful dissemination and expansion of the key ST131 subclones remain undefined but may include increased transmissibility, greater ability to colonize and/or persist in the intestine or urinary tract, enhanced virulence, and more-extensive antimicrobial resistance compared to other E. coli. Here we discuss the epidemiology and molecular phylogeny of ST131 and its key subclones, possible mechanisms for their ecological success, implications of their widespread dissemination, and future research needs.

Evaluation of existence and transmission of extended spectrum beta lactamase producing bacteria from post-delivery women to neonates at Bugando Medical Center, Mwanza-Tanzania

BACKGROUND

Extended spectrum beta-lactamase producing bacteria (ESBL) are common causes of neonatal sepsis worldwide. Neonatal sepsis due to ESBL is associated with increased morbidity and mortality at Bugando Medical Centre (BMC). Due to limited information on the sources of these ESBL strains at BMC, this study was conducted to evaluate the existence, magnitude and transmission of ESBL from post-delivery women to neonates at BMC, Mwanza-Tanzania.

RESULTS

A cross-sectional study was conducted at obstetrics and neonatal wards from May to July 2013, involving post-delivery women and their neonates. Rectal swabs were collected and processed to identify the ESBL strains and their antimicrobial susceptibility patterns. Patients' data were obtained using a standardized data collection tool. We enrolled 113 women and 126 neonates with mean age of 26.5 ± 5.5 years and median gestation age [IQR] of 39 [35-40] weeks respectively. The prevalence of ESBL carriage among women and neonates were 15% (17/113) and 25.4% (32/126) respectively. The acquisition of ESBL isolates among neonates on day 1, day 3 and day 7 were 60.0% (21/35), 25.7% (9/35) and 14.3% (5/35) respectively. There was no phenotypic similarity between ESBL strains from women and their respective neonates, suggesting other sources of transmission. Neonates given antibiotics were more likely to carry ESBL than those not given [100% (32/32) versus 86% (81/94), p = 0.018].

CONCLUSION

The carriage rate of ESBL strains among post-delivery women and neonates at BMC is high. Our findings suggest that neonates acquire these strains from sources other than post-delivery women and more than half acquire them on the first day of life. More studies are recommended to further explore the sources of ESBL strains among neonates.

The mother as most important risk factor for colonization of very low birth weight (VLBW) infants with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E)

OBJECTIVES

This study aimed to determine the prevalence of and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and methicillin-resistant Staphylococcus aureus (MRSA) in very low birth weight (VLBW; <1500 g) infants and their mothers.

METHODS

This investigation was conducted in the perinatal centre at the Charité Berlin between May 2012 and June 2013. VLBW infants and their mothers were screened for colonization with ESBL-E and MRSA. Demographic and clinical data were obtained from the German nationwide surveillance system for nosocomial infections in VLBW infants (NEO-KISS) and used to perform univariate and multivariate analyses.

RESULTS

Of 209 VLBW infants, 12 (5.7%) were colonized with ESBL-E. Eighteen of 209 (8.6%) ESBL-E-tested neonates were related to an ESBL-E-positive mother. Univariate analysis, strain typing and multivariate analysis (OR 7.4, 95% CI 2.1-26.7, P = 0.002) identified an ESBL-E-positive mother and maternal-neonatal transmission as a main source of colonization. The prevalence of MRSA was 2.3% (5 of 221) among VLBW infants. One of the 221 (0.5%) MRSA-tested neonates was related to an MRSA-positive mother. No risk factors for transmission of MRSA could be detected in this study.

CONCLUSIONS

Our study demonstrated that maternal-neonatal transmission of ESBL-E from mother to child is an important risk factor for colonization of VLBW infants. As a consequence, routine ESBL-E screening of neonates and mothers should be considered as a means of reducing neonatal morbidity and mortality.

Perinatal vertical transmission of antibiotic-resistant bacteria: a systematic review and proposed research strategy

BACKGROUND

Antibiotic-resistant bacteria contribute to both early- and late-onset sepsis and outbreaks in neonatal intensive care units (NICUs). The extent to which vertical transmission of these resistant bacteria contributes to colonisation or infection of vulnerable infants in NICUs is unclear. Risk factors for vertical transmission of antibiotic-resistant bacteria are not well described.

OBJECTIVES

To identify studies describing vertical transmission of antibiotic-resistant bacteria, risk factors for transmission and the impact of colonisation on neonatal outcomes.

SEARCH STRATEGY

EMBASE, CINAHL, Cochrane, PubMed, and MEDLINE databases were searched using selected terminology. Titles and abstracts were screened by two reviewers. Selected papers were reviewed in full by two individuals to ascertain whether they fulfilled the inclusion criteria.

SELECTION CRITERIA

Any original article investigating perinatal vertical transmission of antibiotic-resistant bacteria between a mother and neonate was included.

DATA COLLECTION AND ANALYSIS

Data were extracted on study design, organism, antibiotic resistance, and means of ascertaining vertical transmission.

MAIN RESULTS

Five papers out of 4839 titles fulfilled the inclusion criteria. Four studies were predominantly observational and one was a case report. Each demonstrated perinatal transmission. No study reported risk factors for the transmission of resistant bacteria or the impact of colonisation on neonatal outcomes.

AUTHOR'S CONCLUSIONS

There is an absence of research into the perinatal transmission of resistant organisms despite the potential implications of such a situation. We outline objectives that need to be addressed in future research and describe a study design to ascertain the prevalence and risk factors for vertical transmission.

Spread of CTX-M-15 extended-spectrum β-lactamase-producing Escherichia coli isolates through household contact and plasmid transfer

We document the household spread of extended-spectrum β-lactamase-producing Escherichia coli. One isolate belonged to sequence type 1193 and caused urinary tract infection in a 4-month-old female, and the other isolate belonged to sequence type 131 and colonized three family members, including the index patient. These isolates carried similar Inc-I1-Iγ plasmids, harboring blaCTX-M-15.

Prevalence of day-care centre children (France) with faecal CTX-M-producing Escherichia coli comprising O25b:H4 and O16:H5 ST131 strains

OBJECTIVES

Determining the prevalence of children in day-care centres (DCCs) carrying faecal extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and molecularly characterizing those belonging to the Escherichia coli species.

METHODS

Stools were collected from children's diapers (January-April 2012) in randomly chosen DCCs and plated onto ChromID ESBL. Colonies growing on this medium were identified by the Vitek 2 system and tested for antibiotic susceptibility and for ESBL production by the double-disc synergy test. ESBL genotypes were determined as well as phylogenetic groups, ERIC-2 (enterobacterial repetitive intergenic consensus) PCR profiles and sequence types (STs) for the E. coli isolates. Serotypes, virotypes, fimH alleles, ESBL-carrying plasmids and PFGE patterns were determined for the ST131 E. coli isolates.

RESULTS

Among 419 children from 25 participating DCCs, 1 was colonized by CTX-M-15-producing Klebsiella pneumoniae and 27 (6.4%) by E. coli, which all produced CTX-M enzymes [CTX-M-15 (37%), CTX-M-1 (26%), CTX-M-14 (22%), CTX-M-27 (11%) and CTX-M-22 (4%)]. The 27 E. coli isolates, 55.5% belonging to group B2, displayed 20 ERIC-2 PCR profiles and 16 STs. The ST131 E. coli isolates were dominant (44%), displayed serotypes O25b:H4 and O16:H5, fimH alleles 30 and 41 and virotypes A and C. According to the PFGE patterns, one strain of E. coli ST131 producing a CTX-M-15 enzyme carried by an IncF F2:A1:B- plasmid had spread within one DCC.

CONCLUSIONS

This study shows a notable prevalence (6.4%) of DCC children with faecal CTX-M-producing E. coli isolates comprising a high proportion of E. coli ST131 isolates, suggesting that these children might be a reservoir of this clone.