ESBL-producing Enterobacteriaceae Strains Research Articles

Prevalence of Esbl-Producing Enterobacteriaceae Strains Isolated to the University Hospital Center of N’djamena and their Sensitivity to Antibiotics

Prevalence of Esbl-Producing Enterobacteriaceae Strains Isolated to the University Hospital Center of N’djamena and their Sensitivity to Antibiotics

Investigation of major carbapenemase genes in ESBL-producing Escherichia coli and Klebsiella pneumoniae strains isolated from raw milk in Black Sea region of Turkey

The prevalence of blaKPC, blaNDM, blaOXA-48, blaIMP and blaVIM genes and phenotypic carbapenemase production was investigated in ESBL-producing Enterobacteriaceae strains isolated from 150 raw cow milk samples collected from the Black Sea region of Turkey. A total of 47 phenotypic ESBL producers, 41 Escherichia coli and six Klebsiella pneumoniae, were investigated in terms of carbapenemase activity. The presence of carbapenemase genes was investigated using five single PCR assays. Seven of the 47 isolates were found resistant to imipenem and/or meropenem. PCR assays revealed that 33 of the 47 isolates were found to harbour at least one of the analysed carbapenemase genes. For blaKPC, blaOXA-48, blaIMP and blaVIM genes, BLAST search indicated 97.9%, 97.2%, 97.1% and 97% nucleotide identity to corresponding sequences, respectively. Carbapenemase-producing E. coli and K. pneumoniae were found higher in milk compared with studies conducted worldwide and carbapenemase production was associated with blaOXA-48 and blaKPC.

Isolation Frequency of Uropathogenic Strains and Search for ESBL Producing Enterobacteriaceae Isolated from Patients with UTI in Bechar (Algeria)

Background: The emergence of multidrug-resistant uropathogenic strains, mainly the global spread of extended-spectrum beta-lactamase (ESBL) genes accompanied both by the uncontrolled use of antibacterial agents and a considerable decrease in their activities, makes the monitoring of the resistance pattern one of the necessary means that could help the medical practitioners to choose the best treatment. For this purpose and during four months from March 1 to June 30 (2019), an experimental study has been carried out on urine specimens of 123 inpatients (IP) and outpatients (OP) at infectious disease service Boudjemaa TOURABI Public Hospital of Bechar (Algeria), aiming the detection of ESBL-producing Enterobacteriaceae uropathogenic strains. Methods: Firstly, the antibiotic susceptibility testing has been carried out by using the disk diffusion method to determine not only the multidrug resistance patterns, but also the multiple antibiotic resistance MAR indexes of uropathogenic strains that were isolated from clinical IP and OP samples. Secondly, the ESBL detection was done using the following methods: synergy tests based on the synergy between a third-generation cephalosporin and clavulanate, double-disc synergy test (DDST) and phenotypic tests on a cloxacillin-containing agar. Results: As a result, 56 patients had a urinary tract infection (UTI) in overall 123 patients; thus, a frequency of 45,52%. Through a UTI’s frequency of 64,7%, the female gender was the most affected. All age groups were affected by UTI, with a mean age of 38,47±19,97 years old. Knowing that UTIs’ patients aging from 16 to 49 years old were the most affected compared to other ages’ groups, with a frequency of 66,6 and 50% for female and male gender, respectively. The microbial strains represented by the bacteria group were predominant, i.e. (98,22%) followed by yeasts (1,78%), where Gramnegative bacilli showed (96,36%) of the uropathogenic agents, so (3,64%) were Gram-positive bacteria. The antibiotic resistance profile of isolated Enterobacteriaceae showed very high resistance rates for the species of Escherichia coli, Klebsiella spp, and Proteus spp to aminopenicillins, cephalosporins, and less against carbapenems and other drug groups. E. coli had presented the highest multidrug resistance followed by Klebsiella spp with a MAR index ranged from 0,53 to 0,82. Within this range, a total of 28 isolate (25 E. coli, 2 Klebsiella spp, and 1 Proteus mirabilis) had shown resistance against 9 to 14 out of the 17 tested antibiotics. The rate of ESBL-producing Enterobacteriaceae strains was 23,07 and 55,26% for inpatients and outpatients, respectively, where E. coli was the most important ESBL producers out of all isolated strains. Conclusion: An alarming ESBLs rate for outpatients is usually higher among inpatients with UTI, who receive several classes of antibiotics. Such conditions should be considered as a major public health concern, and measures must be taken to establish the sources and drivers of this issue. Thus, the findings of this research push the health sector stakeholders as well as the scientific communities to act on reducing the transmission of the multidrug-resistant strains that threaten several classes of life-saving antibiotics.

Fosfomycin in the treatment of extended spectrum beta-lactamase-producing Enterobacteriaceae- related urinary tract infections.

We aimed to demonstrate if fosfomycin tromethamine (FT) treatment could be the treatment of choice in ESBL-producing Enterobacteriaceae strains as an alternative to carbapenem particularly in patients who we would like to treat on an outpatient basis. We retrospectively analyzed the medical records of all patients who admitted to infectious disease outpatient clinic with complaints of dysuria and frequency and received FT for lower UTI between May 2016 and May 2017. A total of 48 patients, 19 females (39.6%) and 29 males (60.4%), with a mean age of 62.5 (ranging from 27 to 85) years were included the study. 26 (76.4%) of patients with a history of urinary operation or intervention had also a history of antibiotic use within the past 3 months. The isolated pathogens included Escherichia Coli (n = 32), Klebsiella spp. (n = 12), Enterobacter spp. (n = 4). The overall microbiological response after treatment was 70.8% (34/48) and the clinical response was 75% (36/48). Clinical and microbiological response rates of patients with and without urinary operation/intervention, diabetes mellitus, history of antibiotic use and malignancy were found similar (p > 0.05). However, patients with a urinary stone disease history had significantly higher response rates than those without a urinary stone disease history (P = 0.042). Oral fosfomycin tromethamine might be the treatment of choice in ESBL-producing enterobactericea related UTIs especially caused by Escherichia Coli.

ESBL colonization and acquisition in a hospital population: The molecular epidemiology and transmission of resistance genes.

A prospective cohort study (German Clinical Trial Registry, No. 00005273) was performed to determine pre-admission colonization rates, hospital acquisition risk factors, subsequent infection rates and colonization persistence including the respective molecular epidemiology and transmission rates of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (EPE). A total of 342 EPEs were isolated from rectal swabs of 1,334 patients on admission, at discharge and 6 months after hospitalization. Inclusion criteria were patients’ age > 18 years, expected length of stays > 48 hours, external referral. The EPEs were characterized by routine microbiological methods, a DNA microarray and ERIC-PCR. EPE colonization was found in 12.7 % of admitted patients, with the highest rate (23.8 %) in patients from nursing homes. During hospitalization, 8.1 % of the patients were de novo EPE colonized, and invasive procedures, antibiotic and antacid therapies were independent risk factors. Only 1/169 patients colonized on admission developed a hospital-acquired EPE infection. Escherichia coli was the predominant EPE (88.9 %), and 92.1% of the ESBL phenotypes could be related to CTX-M variants with CTX-M-1/15 group being most frequent (88.9%). A corresponding β-lactamase could not be identified in five isolates. Hospital-acquired EPE infections in patients colonized before or during hospitalization were rare. The diversity of the EPE strains was much higher than that of the underlying plasmids. In seven patients, transmission of the respective plasmid across different species could be observed indicating that the current strain-based surveillance approaches may underestimate the risk of inter-species transmission of resistance genes.

Characterisation of the Resistance Patterns to Non Beta-Lactam Antimicrobials in Esbl-Producing Enterobacteriaceae Isolated from Dogs and Their Owners

Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBL) enzymes are resistant to beta-lactam agents and are also commonly multidrug resistant being associated with the resistance to other classes of antibiotics.The aim of our study was to characterise resistance patterns in non-beta-lactam antibiotics of ESBL-producing Enterobacteriaceae strains isolated from faecal matter of pets and owners.The study was carried out on 63 samples of faecal matter (42 from pets and 21 from owners). The ESBL screening was carried out using the Brilliance ESBL Oxoid chromogenic medium. The isolated strains that generated characteristic presumptive ESBL-producing colonies were cultivated on 5% sheep blood medium for the extraction of bacterial DNA using the boiled preps technique. The confirmation of E. coli species was performed molecularly based on the detection of blauidA and blauspA genes. Other Enterobacteriaceae species were identified based on the minimum biochemical characteristics using the MIU and TSI medium. The phenotypical confirmation of presumptive ESBL-producing strains was carried out using the Double Disc Synergy Test (DDST) using a combination of 3rd generation cephalosporins and beta-lactamase inhibitor agents. The determination of the resistance degree in other classes of antibiotics was carried out through the Kirby-Bauer diffusimetric method, and the results were interpreted according to the CLSI standard.Following the species investigation of isolates, 60/63 (95.28%) belonged to the E. coli species and 3/63 (4.72%) to the K. pneumoniae species. Animal isolates were resistant to sulphonamides (54.76% resistance to SXT), fluoroquinolones (45.23% resistance to ENR) and tetracyclines (54.75% resistance to TE). In addition to strains of animal origin for isolates of human origin, an increased resistance has been noticed to phenicols and aminoglycosides.This study has identified a high prevalence of ESBL-producing Enterobacteriaceae strains and associated with multidrug resistance for pets and their owners.

English

Increasing bacterial resistance to antimicrobial agents has become an issue of concern. A major problem of the treatment of infections caused by Enterobacteriaceae using antibiotics is the emergence of Extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae. This study aims to determine the prevalence of ESBL-producing Enterobacteriaceae strains in Ouagadougou, Burkina Faso, and describe their resistance profile to other antibiotics commonly used in the infections treatment. 486 clinical strains of Enterobacteriaceae were obtained from patients attending three health centers in Ouagadougou (Burkina Faso) from November 2014 to October 2015. Biochemical identification was performed and antibiotics susceptibility test was performed using the disk diffusion method. Data was analyzed with the Excel and ANOVA one-way software GraphPad Prism version 5.01 software. Results revealed occurrence of Escherichia coli (60.9%, 194) predominated followed by Klebsiella spp. (22.4%, 109). Antibiotics susceptibility test revealed that 86.8% strains were resistant to amoxicillin, 81.3% to trimethoprim-sulfamethoxazole, 61.9% to ceftriaxone, 58.6% to cefotaxime and 58.4% to cefepime. It was observed that 99.8% were susceptible to imipenem while 16.6% were resistant to fosfomycin and 12.3% to amikacin. However, 38.5% (187/486) of the strains were ESBL-producing, 67.9% (127/187) of which came from Yalgado Ouedraogo University Hospital Center, 23.5% (44/187) from Charles De Gaulle Paediatric University Hospital Center and 8.6% (16/187) from Saint Camille Hospital. This study thus showed a high prevalence of Extended-Spectrum Β-Lactamases producing Enterobacteriaceae strains in Ouagadougou (38.5%). It underlined the need for routine detection and systematic reporting of ESBL strains in different health facilities in Burkina Faso, so that measures could be taken to prevent their spread and treatment failures. Key words: Enterobacteriaceae, Extended-Spectrum Beta-lactamases (ESBL), Burkina Faso.

Genetic background of novel sequence types of CTX-M-8- and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae from public wastewater treatment plants in São Paulo, Brazil.

The release of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae to the environment is a public health issue worldwide. The aim of this study was to investigate the genetic background of genes encoding ESBLs in wastewater treatment plants (WWTPs) in São Paulo, southeastern Brazil. In 2009, during a local surveillance study, seven ESBL-producing Enterobacteriaceae strains were recovered from five WWTPs and screened for ESBL genes and mobile genetic elements. Multilocus sequence typing (MLST) was carried out, and wild plasmids were transformed into electrocompetent Escherichia coli. S1-PFGE technique was used to verify the presence of high molecular weight plasmids in wild-type strains and in bla ESBL-containing E. coli transformants. Strains harbored bla CTX-M-8, bla CTX-M-15, and/or bla SHV-28. Sequencing results showed that bla CTX-M-8 and bla CTX-M-15 genes were associated with IS26. MLST revealed new sequence types for E. coli (ST4401, ST4402, ST4403, and ST4445) and Klebsiella pneumoniae (ST1574), except for one K. pneumoniae from ST307 and Enterobacter cloacae from ST131. PCR and S1-PFGE results showed CTX-M-producing E. coli transformants carried heavy plasmids sizing 48.5-209 kb, which belonged to IncI1, IncF, and IncM1 incompatibility groups. This is the first report of CTX-M-8 and SHV-28 enzymes in environmental samples, and the present results demonstrate the plasmid-mediated spread of CTX-M-encoding genes through five WWTPs in São Paulo, Brazil, suggesting WWTPs are hotspots for the transfer of ESBL genes and confirming the urgent need to improve the management of sewage in order to minimize the dissemination of resistance genes to the environment.

Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Hospital Food: A Risk Assessment

Determine the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) contamination of food and colonization of food handlers in a hospital kitchen and compare retrieved ESBL-PE strains with patient isolates. Cross-sectional study. A 2,200-bed tertiary care university hospital in Switzerland. Food handlers. Raw and prepared food samples were obtained from the hospital kitchen, with a comparator group from local supermarkets. Fecal samples collected from food handlers and selectively pre-enriched homogenized food samples were inoculated onto selective chromogenic media. Phenotypic confirmation of ESBL production was performed using the double disk method. Representative ESBL-PE were characterized using polymerase chain reaction (PCR) and sequencing for blaCTX-M, blaSHV, and blaTEM genes, and Escherichia coli strains were typed using phylotyping, repetitive element palindromic PCR, and multilocus sequence typing. Meat samples were screened for antibiotic residues using liquid chromatography time-of-flight mass spectrometry. Sixty (92%) of the raw chicken samples were ESBL-PE positive, including 30 (86%) of the hospital samples and all supermarket samples. No egg, beef, rabbit, or cooked chicken samples were ESBL-PE positive. No antibiotic residues were detected. Six (6.5%) of 93 food handlers were ESBL-PE carriers. ESBL-PE strains from chicken meat more commonly possessed blaCTX-M-1 and blaCTX-M-2, whereas blaCTX-M-14 and blaCTX-M-15 were predominant among strains of human origin. There was partial overlap in the sequence type of E. coli strains of chicken and human origin. No E. coli ST131 strains or blaCTX-M-15 genes were isolated from meat. Although there is significant ESBL-PE contamination of delivered chicken meat, current preventive strategies minimize risks to food handlers, hospital staff, and patients.

High prevalence of ESBL-producing Enterobacteriaceae carriage in Dutch community patients with gastrointestinal complaints

The aim of this study was to determine the rate of carriage of ESBL-producing Enterobacteriaceae (ESBL-E) in the community in the Netherlands and to gain understanding of the epidemiology of these resistant strains. Faecal samples from 720 consecutive patients presenting to their general practitioner, obtained in May 2010, and between December 2010 and January 2011, were analysed for presence of ESBL-E. Species identification and antibiotic susceptibility testing were performed according to the Dutch national guidelines. PCR, sequencing and microarray were used to characterize the genes encoding for ESBL. Strain typing was performed with amplified fragment length polymorphism (AFLP) and multilocus sequence typing (MLST). Seventy-three of 720 (10.1%) samples yielded ESBL-producing organisms, predominantly E. coli. No carbapenemases were detected. The most frequent ESBL was CTX-M-15 (34/73, 47%). Co-resistance to gentamicin, ciprofloxacin and cotrimoxazole was found in (9/73) 12% of the ESBL-E strains. AFLP did not show any clusters, and MLST revealed that CTX-M-15-producing E. coli belonged to various clonal complexes. Clonal complex ST10 was predominant. This study showed a high prevalence of ESBL-producing Enterobacteriaceae in Dutch primary care patients with presumed gastrointestinal discomfort. Hence, also in the Netherlands, a country with a low rate of consumption of antibiotics in humans, resistance due to the expansion of CTX-M ESBLs, in particular CTX-M-15, is emerging. The majority of ESBL-producing strains do not appear to be related to the international clonal complex ST131.

English

The rising rate of antimicrobial drug resistance in Enterobacteriaceae reduces the number of reliably effective drugs that can be used to treat infections. Gram negative bacteria producing β-lactamases that are resistant to many other antibiotics and very few antimi- crobial agents remain effective as treatment option. Since the initial description of Extended Spectrum β-lactamases (ESBLs) production by Klebseilla pneumonia & Escherichia coli in the 1980s, strains of Enterobacteriaceae resistant to third-generation cephalosporins are increasingly being recognized globally. ESBL-producing Enterobacteriaceae strains have been frequently implicated in outbreaks in all intensive care units especially pediatric Intensive Care Unit (PICUs) and Neonatal Intensive Care Unit (NICU). Therefore, there have been many recent calls to intensify current infection control efforts aimed at reducing the emergence and dissemination of infections caused by antibiotic-resistant bacteria. The widespread use of Cefriaxone and/or cefotaximine has been proposed as a reason for the emergence of CTX-M enzymes. The increased frequency of isolation & reporting of CTX-M ESBLs is alarming and is likely to represent only the tip of iceberg for the underdeveloped continents where molecular technology for the analysis of ESBL enzymes is scares. To further delineate the mode of successful dissemination of ESBLs CTX-M-15 and to gain insights into the mechanism underlying this phenomenon we de- signed this study to assesses clonality & diversity of Enterobacteriaceae strains isolated from PICUs and NICUs of our hospital. Total of 100 blood samples were received from PICU and NICU during the study period of two months. 10 ESBLs were isolated from total 55 Gram negative bacteria, of that five were possessing CTX-M-15 by PCR methods.

Clinical profiles of patients colonized or infected with extended-spectrum beta-lactamase producing Enterobacteriaceae isolates: a 20 month retrospective study at a Belgian University Hospital

BackgroundDescription of the clinical pictures of patients colonized or infected by ESBL-producing Enterobacteriaceae isolates and admitted to hospital are rather scarce in Europe. However, a better delineation of the clinical patterns associated with the carriage of ESBL-producing isolates may allow healthcare providers to identify more rapidly at risk patients. This matter is of particular concern because of the growing proportion of ESBL-producing Enterobacteriaceae species isolates worldwide.MethodsWe undertook a descriptive analysis of 114 consecutive patients in whom ESBL-producing Enterobacteriaceae isolates were collected from clinical specimens over a 20-month period. Clinical data were obtained through retrospective analysis of medical record charts. Microbiological cultures were carried out by standard laboratory methods.ResultsThe proportion of ESBL-producing Enterobacteriaceae strains after exclusion of duplicate isolates was 4.5% and the incidence rate was 4.3 cases/1000 patients admitted. Healthcare-associated acquisition was important (n = 104) while community-acquisition was less frequently found (n = 10). Among the former group, two-thirds of the patients were aged over 65 years and 24% of these were living in nursing homes. Sixty-eight (65%) of the patients with healthcare-associated ESBL, were considered clinically infected. In this group, the number and severity of co-morbidities was high, particularly including diabetes mellitus and chronic renal insufficiency. Other known risk factors for ESBL colonization or infection such as prior antibiotic exposure, urinary catheter or previous hospitalisation were also often found. The four main diagnostic categories were: urinary tract infections, lower respiratory tract infections, septicaemia and intra-abdominal infections. For hospitalized patients, the median hospital length of stay was 23 days and the average mortality rate during hospitalization was 13% (Confidence Interval 95%: 7-19). Escherichia coli, by far, accounted as the most common ESBL-producing Enterobacteriaceae species (77/114; [68%]) while CTX-M-1 group was by far the most prevalent ESBL enzyme (n = 56).ConclusionIn this retrospective study, the clinical profiles of patients carrying healthcare-associated ESBL-producing Enterobacteriacae is characterized by a high prevalence rate of several major co-morbidities and potential known risk factors. Both, the length of hospital stay and overall hospital mortality rates were particularly high. A prospective case-control matched study should be designed and performed in order to control for possible inclusion bias.

Appearance of aac(6′)-Ib-cr gene among extended-spectrum β-lactamase-producing Enterobacteriaceae in a French hospital

The aac(6')-Ib gene encodes many variants of an aminoglycoside-acetyltransferase enzyme that is responsible for amikacin resistance. Recently, a new variant aac(6')-Ib-cr capable of modifying aminoglycosides and fluoroquinolones has been described. The aim of our study was to observe the appearance and the location of the aac(6')-Ib gene in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae strains. Sixty-six and nine non-clonal ESBL-producing Enterobacteriaceae strains were isolated, respectively, for one 3-year period from 1999 to 2001 and one 2-month period in 2005 in a French Hospital (Paris, France). Among these isolates, 35 of them carried the aac(6')-Ib gene. Fourteen out of the aac(6')-Ib genes of the period 1 and two of the period 2 were genes cassette located within class 1 integrons, whereas 16 and 3, respectively, were outside integrons. One of these encoded an aminoglycoside-acetyltransferase enzyme leading to an acetyltransferase that confers resistance to all aminoglycosides. The new -cr variant of aac(6')-Ib was detected in three Escherichia coli isolates in 2005 always associated with CTX-M-15 enzyme. The aac(6')-Ib-cr gene, responsible for antibiotic resistance to two very different drugs, is emerging in ESBL-producing Enterobacteriaceae strains isolated in France especially in strains carrying the bla(CTx-M-15) gene.

Performance of chromID ESBL, a chromogenic medium for detection of Enterobacteriaceae producing extended-spectrum β-lactamases

The chromogenic agar medium chromID ESBL (bioMérieux) was compared with BLSE agar medium (AES) for selective isolation and presumptive identification of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae from clinical samples. A total of 765 samples (468 rectal swabs, 255 urine samples and 42 pulmonary aspirations) obtained from 547 patients was processed. All bacterial strains isolated on either medium were further characterized using biochemical tests, and ESBL producers were confirmed by synergy testing. Genetic characterization of ESBL genes was determined by PCR. A total of 33 ESBL-producing Enterobacteriaceae strains [Escherichia coli (n=16), Klebsiella pneumoniae (n=8), Enterobacter spp. (n=3), Citrobacter spp. (n=5) and Proteus mirabilis (n=1)] was recovered. The sensitivity after 24 h incubation was 88 % for chromID ESBL and 85 % for BLSE agar. At 48 h, the sensitivity of chromID ESBL increased to 94 % and was higher than that obtained with BLSE agar. The positive predictive value at 24 h for chromID ESBL was 38.7 % [95 % confidence interval (95 % CI) 28.3 -50.2 %)], which was significantly higher than that for BLSE agar [15.4 %, 95 % CI 10.1 -21.5 %]. On both media, false-positive results were mostly due to Pseudomonas aeruginosa and to Enterobacteriaceae overproducing chromosomal cephalosporinase (Enterobacter spp.) or a chromosomal penicillinase (Klebsiella oxytoca). This study showed that chromID ESBL, a ready-to-use chromogenic selective medium, is sensitive and specific for rapid, presumptive identification of ESBL-producing Enterobacteriaceae. Its chromogenic properties and its selectivity are particularly useful in specimens containing resident associated flora.