Extended-spectrum Β-lactamase Production Research Articles

Association between phenotypic characteristics of Escherichia coli and UTI recurrence in immunocompromised patients: A case-control study

Urinary tract infection (UTI) recurrence is important in immunocompromised patients. There is a trend to study genotypically and phenotypically the role of certain virulence factors of Escherichia coli in the diagnosis of recurrent UTI. The main objective of this study was to determine if there is an association between phenotypic characteristics of E coli and UTI recurrence in immunocompromised patients. A case-control study was performed on immunocompromised patients from Hospital Regional de Alta Especialidad del Bajío, Mexico. E coli strains isolated from these patients were identificated and antimicrobial susceptibility test were performed. Strains with filamented cell morphology, mucoid colonial phenotype, or biofilm production were considered cases. Strains without the characteristics were considered controls. UTI recurrence was identified based on clinical records. The odds ratio (OR) was calculated to quantify the magnitude of the association. An association between filamented cell morphology and UTI recurrence was found (OR=2.19 95% CI 1.06-4.51; P=.031). No association was found between mucoid colony morphology (P>.05) or biofilm production (P>.05) and UTI recurrence. An association between mucoid colony morphology and extended-spectrum β-lactamase production was found (OR=3.09 95% 1.59-5.99; P<.001). Filamented cell morphology and mucoid colonial phenotype may have a possible diagnostic value for the detection of UTI recurrence and antimicrobial resistance. Further diagnostic test studies are needed to fully assess their clinical utility.

Dynamics of Extended-spectrum Beta-lactamase–producing, Third-generation Cephalosporin-resistant and Tetracycline-resistant Escherichia coli in Feedlot Cattle With or Without Tylosin Administration

The impact of in-feed use of tylosin in feedlot cattle on Gram-negative foodborne bacteria is unknown. We evaluated the effect of continuous in-feed tylosin use on the concentration and prevalence of tetracycline-resistant (TETr)-, third-generation cephalosporin-resistant (3GCr)-, and extended-spectrum β-lactamase–producing (ESBLs) E. coli in feedlot cattle. A cohort of weaned calves (10 animals/group) were randomized to receive a feed ration with or without tylosin. Fecal samples, regularly collected over the entire feeding period, and pen surface and feed samples, collected at the end of the feeding period, were cultured on selective media. Enumeration and binary outcomes were analyzed by mixed effects linear regression or logistic regression, respectively, using treatment and days on feed as fixed factors, and animal ID as a random variable. Tylosin supplementation did not affect the fecal concentrations of TETrE. coli or fecal prevalence of 3GCrE. coli. However, cattle in the tylosin group were 1.5 times more likely (Odds ratio = 1.5: 95% confidence interval: 1.1–2.0) to harbor ESBLs E. coli than the control cattle. Regardless of tylosin treatment, fecal concentrations of TETrE. coli and the prevalence of 3GCr- and ESBLs-E. coli increased over time. Tylosin-supplemented feed did not affect the prevalence of TETrE. coli; 3GCr and ESBLs-E. coli were not detected from the feed samples. Most of the 3GCr- and ESBLs-E. coli isolates carried the blaCTX-M-15 gene, widely detected among ESBLs-E. coli human isolates. In summary, although in-feed tylosin use in feedlot cattle did not select for TETr- and 3GCr-E. coli, it increased the likelihood of detecting ESBL-producing E. coli. Furthermore, the study indicated that the feedlot production setting gradually increases the levels of E. coli resistant to the critically and/or important antibiotics for public health, indicating an increased risk of their dissemination beyond the feedlot environment.

Epidemiological analysis and antimicrobial susceptibility profile of Gram-negative bacilli that cause bacteremia in Japan

We investigated the epidemiology and antimicrobial susceptibility profiles of seven major Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and Bacteroides spp.) that caused bacteremia in Japan. We collected clinical information and isolates from patients aged 20 years or older who developed bacteremia during a year at three Japanese university hospitals and performed microbiological examination. In total, 628 cases were included, half of which were caused by E. coli (315 isolates). P. aeruginosa (56 isolates) was isolated most frequently among non-fermenting bacteria and 33 Bacteroides spp. were isolated. Mortality rates were the highest for P. aeruginosa (7-day, 16.1%; 30-day, 26.8%). The 7- and 30-day mortality rates ranged 3.8–9.0% and 8.3–17.6%, respectively, for Enterobacterales, and they were 15.2% each for Bacteroides spp. Regarding antimicrobial resistance, Enterobacterales and Acinetobacter spp. showed susceptibility to carbapenems and amikacin (98.0–100.0%). The susceptibility rates to ceftolozane/tazobactam ranged 82.4–99.0% for Enterobacterales and 92.9% for P. aeruginosa. More than 30.0% of E. coli isolates were resistant to fluoroquinolone. Extended-spectrum β-lactamase (ESBL) producers were found in 21.0% of E. coli and approximately 80% of those were resistant to fluoroquinolones. The susceptibility of the 33 Bacteroides spp. to carbapenems, ampicillin/sulbactam, and piperacillin/tazobactam was 100.0%. Among the ESBL producers, blaCTX-M group 9 was the major subgroup in E. coli (77.3%), and blaCTX-M group 1 was detected in 18.2% of E. coli and 50.0% of Klebsiella spp. Continuous surveillance is needed to understand the epidemiology and consider appropriate therapeutic strategies.

Epidemiology and resistance profiles of Enterobacterales in a tertiary care hospital in Lebanon: a 4-year retrospective study.

Antimicrobial resistance (AMR) is a worldwide problem that threatens treatment effectiveness against the most serious bacterial infections. AMR in Enterobacterales is highly prevalent in Lebanon. However, recent reports regarding the distribution of Enterobacterales and related antimicrobial susceptibility are scarce. In this retrospective study at the Lebanese Hospital Geitaoui Medical Center in Lebanon, all data regarding culture specimens from urine, blood, sputum, deep tracheal aspirate, broncho-alveolar lavage, wounds, surgical sites, tissue, body fluids, and central venous catheter that were positive for at least one of the 4 bacterial isolates (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Proteus mirabilis) were collected. All susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines. A total of 4283 non-duplicate Enterobacterales were isolated during the study period (January 2017 to December 2020). Urine was the most common site of infection. E. coli was the most detected isolate as well as the leading pathogen in urine, wounds and surgical sites, and blood. Regarding antimicrobial susceptibility, the mean susceptibility to third generation cephalosporins was 55.53% and a mean extended-spectrum β-lactamases production of 31.2% was measured in E. coli. Mean carbapenem susceptibility was the lowest in K. pneumoniae and E. cloacae. The lowest mean susceptibility to fluoroquinolones was detected in E. coli isolates. This study identified the predominance of E. coli among Enterobacterales in Lebanese patients, with the urinary tract being the most common site of infection and underlined the high rates of AMR in Enterobacterales in Lebanon.

Distribution and Antibiotic Resistance Profile of Extended Spectrum Beta-Lactamase Producing Escherichia coli from Fish Farms within Abakaliki Metropolis

Background and Objectives: The emergence of antibiotic resistant determinant in fish farms and its spread is on the increase and has evolved into strains that are resistant to many classes of antibiotics. Thus, it is critical to identify the distribution and antibiotic resistance profile of Extended Spectrum Beta-lactamase (ESBL) producing Escherichia coli from fish farms within Abakaliki Metropolis.&#x0D; Methodology: Aseptically, fifty (50) milliliters of fishpond water was collected from twenty locations in fifteen (15) fish farms and were analyze using standard microbiological culture and identification of Escherichia coli. Detection of phenotypic extended spectrum β-lactamases production was performed using Double-Disk Synergy Test (DDST). Antibiotic susceptibility studies of extended spectrum β-lactamases producing Escherichia coli was determined using the Kirby–Bauer disk diffusion method and the results were construed using the Clinical Laboratory Standard Institute (CLSI) zone diameter breakpoints.&#x0D; Results: Extended spectrum beta-lactamase producing Escherichia coli distribution from fishpond water revealed overall occurrence rate of 34(11.3 %). The proportion of ESBL producing Escherichia coli was 5(25.0 %) from fish farm L followed by Farm A, Farm E, Farm G, which both accounted for 20.0 % respectively while the least occurrence of 1(5.0 %) was recorded against Farm I. ESBL-producing E. coli were resistant to cephalosporin particularly Ceftriaxone (88.2%), Ceftazidime (91.2 %), Cefotaxime (94.1) and Cefepime (85.3 %). This was followed by Amoxicillin-Clavulanate (91. 2 %), Azetronam (97.1 %). In all, Ciprofloxacin (82.4 %), Imipenem (97.1 %), and Meropenem (100 %) were the most effective antibiotic against ESBL-producing E. coli isolate.&#x0D; Conclusion: This study reveals the prevalence of the ESBL phenotype in fish farms. The increasing prevalence of resistance to routinely used antibiotics in medical and veterinary therapies among the study isolates from aquaculture products poses a significant challenge to the treatment of human and animal diseases. As a result, adequate antibiotic intervention is essential to ensure the continued efficacy of antibiotics for aquaculture and human health, as well as the industry's viability.

Microbiological quality assessment of fresh produce: Potential health risk to children and urgent need for improved food safety in school feeding schemes.

About 388 million school-going children worldwide benefit from school feeding schemes, which make use of fresh produce to prepare meals. Fresh produce including leafy greens and other vegetables were served at 37% and 31% of school feeding programs, respectively, in Africa. This study aimed at assessing the microbiological quality of fresh produce grown onsite or supplied to South African schools that are part of the national school feeding programs that benefit over 9 million school-going children. Coliforms, Escherichia coli, Enterobacteriaceae, and Staphylococcus aureus were enumerated from fresh produce (n = 321) samples. The occurrence of E. coli, Listeria monocytogenes, Salmonella spp., and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae was determined. Presumptive pathogens were tested for antimicrobial resistance. E. coli was further tested for diarrheagenic virulence genes. Enterobacteriaceae on 62.5% of fresh produce samples (200/321) exceeded previous microbiological guidelines for ready-to-eat food, while 86% (276/321 samples) and 31.6% (101/321 samples) exceeded coliform and E. coli criteria, respectively. A total of 76 Enterobacteriaceae were isolated from fresh produce including E. coli (n = 43), Enterobacter spp. (n = 15), and Klebsiella spp. (n = 18). Extended-spectrum β-lactamase production was confirmed in 11 E. coli, 13 Enterobacter spp., and 17 Klebsiella spp. isolates. No diarrheagenic virulence genes were detected in E. coli isolates. However, multidrug resistance (MDR) was found in 60.5% (26/43) of the E. coli isolates, while all (100%; n = 41) of the confirmed ESBL and AmpC Enterobacteriaceae showed MDR. Our study indicates the reality of the potential health risk that contaminated fresh produce may pose to school-going children, especially with the growing food safety challenges and antimicrobial resistance crisis globally. This also shows that improved food safety approaches to prevent foodborne illness and the spread of foodborne pathogens through the food served by school feeding schemes are necessary.

The emergence of Klebsiella pneumoniae sequence type 395 non-susceptible to carbapenems and colistin from Turkey

PurposeOXA-48 producing Klebsiella pneumoniae is an emerging threat and outbreaks due to specific sequence types have been commonly reported. Here, we report an outbreak due to multidrug-resistant ST395 K. pneumoniae ST395. To the best of our knowledge, this is the first outbreak of K. pneumoniae ST395 harbouring blaOXA-48 genes in our country. MethodsThe strains were characterized by antimicrobial susceptibility, extended-spectrum β-lactamase (ESBL) and carbapenemase production, plasmid-mediated colistin, high-level aminoglycoside, and quinolone resistance. Also multidrug efflux pumps and porin coding genes were investigated. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), wzi typing and plasmid analysis were used for the epidemiological relationships. ResultsAll strains were positive for blaOXA-48 with at least one of the β-lactamase genes (blaCTX-M, blaTEM, blaSHV) and harboured IncL plasmids. 16 of 20 (80%) isolates carried qnrA. All isolates were positive for aac(6’)-1b, acrAB-tolC, ompK35, and ompK36 genes but none of them harboured 16s rRNA methyltransferase, mcr-1-5, qepA, oqxAB, and mdtK genes. All strains had the same PFGE pattern, that is, wzi type K2 and found to be ST395 with MLST. ConclusionThe association of ST395 with OXA-48-producers could be an emerging threat for Turkey and continuous monitoring is crucial to prevent the spread of these powerful strains.

Characterization of avian pathogenic Escherichia coli isolates based on biofilm formation, ESBL production, virulence-associated genes, and phylogenetic groups.

Escherichia coli is a part of both animal and human commensal microbiota. Avian pathogenic E. coli (APEC) is responsible for colibacillosis in poultry, an economically important disease. However, the close similarities among APEC isolates make it difficult to differentiate between pathogenic and commensal bacteria. The aim of this study was to determine phenotypic and molecular characteristics of APEC isolates and to compare them with their in vivo pathogenicity indices. A total of 198 APEC isolates were evaluated for their biofilm-producing ability and extended-spectrum β-lactamase (ESBL) production phenotypes. In addition, 36 virulence-associated genes were detected, and the isolates were classified into seven phylogenetic groups using polymerase chain reaction. The sources of the isolates were not associated with biofilms, ESBL, genes, or phylogroups. Biofilm and ESBL production were not associated with pathogenicity. Group B2 had the highest pathogenicity index. Groups B2 and E were positively associated with high-pathogenicity isolates and negatively associated with low-pathogenicity isolates. In contrast, groups A and C were positively associated with apathogenic isolates, and group B1 was positively associated with low-pathogenicity isolates. Some virulence-associated genes showed positive or negative associations with specific phylogenetic groups. None of the individual techniques produced results that correlated with the in vivo pathogenicity index. However, the combination of two techniques, namely, detection of virulence-associated genes and the phylogenetic groups, could help the classification of the isolates as pathogenic or commensal.

P11 Evaluation of in vitro activity of double β-lactam ‘therapy’ in Escherichia coli: what is the association between ‘synergy’ and in vitro susceptibility?

Abstract Background Emerging antimicrobial resistance is a leading cause of patient morbidity/mortality worldwide. A potential strategy in the treatment of resistant infections is the use of combination antibiotics, with the hope of achieving greater in vitro activity, including synergy. It is currently assumed that combinations generating the greatest synergistic effect in vitro will be associated with the greatest improvement in in vitro susceptibility (as defined by EUCAST—see Methods). The aim of this study was to determine if this was indeed the case. Methods We systematically determined the relationship between double β-lactam therapy against 7 Escherichia coli strains of variable resistance in vitro (4 clinical/3 purchased). This included fully susceptible and low-level resistance isolates (N = 4), extended-spectrum β-lactamase producers (ESBLs) (N = 2) and carbapenemase producers (CPEs) (N = 1). For each of 10 β-lactam antibiotics, the MIC was determined individually, and subsequently in combination, using the MTS™ ‘cross’ synergy method (Liofilchem, 2012). The fractional inhibitory concentration (FIC) was calculated by dividing the MIC of each drug in combination by the MIC of each drug alone and adding the results. See Figure 1. Results were analysed according to EUCAST clinical breakpoints to determine if synergistic combinations correlated with a potentially improved in vitro susceptibility phenotype. A susceptibility phenotype improvement was defined: R/R or R/I or I/I monotherapy, improving to R/S, I/S or S/S combination therapy (where S = susceptible, I = intermediate and R = resistant). Results Overall, 86/630 (13.7%) combinations showed synergy; 408/630 (64.7%) = additive; 136/630 (21.6%) = indifferent. No antagonism was identified. Synergy was most detected in ESBL producers (32% of combinations; Figure 2) and less frequently in CPEs (2% combinations) and fully susceptible isolates (4% combinations). 31/630 (5%) combinations showed improvement in EUCAST susceptibility between mono/combination therapy (according to our definitions). Of these 31 combinations, 8 (26%) were synergistic, 15 (48%) additive and 8 (26%) indifferent (by FIC index). Of 599/630 combinations that showed no improvement in susceptibility, 78 (13%) = synergistic, 393 (65.6%) = additive and 128 (21.4%) = indifferent. It is however important to note that in 284/630 (45%), initial monotherapy susceptibility was S/S (i.e. further improvement not possible). Synergy was more common in combinations that improved EUCAST susceptibility versus those that did not; χ2, P = 0.04). Ceftazidime/avibactam + amoxicillin was the combination most commonly associated with synergy (12/86 synergistic combinations). Conclusions In the β-lactam combinations tested, synergy or additive effects were common (78.4%), similar to our previous work with Fosfomycin/β-Lactam combinations (89%), but higher than fosfomycin/non-β-lactam combinations (28%). Synergy was most detected in ESBL producers with most synergistic combinations containing one/two β-lactamase inhibitors. Overall, however, this rarely leads to an improvement in in vitro susceptibility by EUCAST criteria and is highly bug–drug–drug combination dependent. Further work using alternative validating methodology and in more isolates is required.

Prevalence and antimicrobial susceptibility patterns of extended spectrum β-lactamase producers and non-producers Pseudomonas aeruginosa in Peshawar

Prevalence and antimicrobial susceptibility patterns of extended spectrum β-lactamase producers and non-producers Pseudomonas aeruginosa in Peshawar

Extended-Spectrum B-Lactamase (ESBL)-Producing Escherichia coli Isolated from Children under 5 years with and without Diarrhoea in Two Hospitals in Dschang, Cameroon

Introduction: Extended-Spectrum β-Lactamase (ESBL) mediating resistance in Enterobacterales is a global public health issue, especially in Low-and Middle-Income Countries (LMICs) such as Cameroon. ESBL-producing Enterobacterales reduce therapeutic options and lead to the use of last resort drugs such as carbapenems even in vulnerable populations like children under five years. This study aims at determining the phenotypic and genotypic characteristics of ESBL-producing Escherichia coli (ESBL-Ec) isolated from children under five years with and without diarrhoea in two health care facilities in Dschang. Materials and Methods: A cross-sectional study was conducted from 3 February to 19 May 2022 in two hospitals in the city of Dschang, Cameroon. Stool collected were cultured on Eosine Methylen Blue (EMB) medium. Enterosystem 18R kit was used for bacterial identification. Evaluation of the resistance patterns and detection of ESBL production were performed with, the Kirby Bauer disk diffusion method and CHROMagar® ESBL medium, respectively. The genomic DNA of ESBL-Ec was extracted using the boiling method and subjected to conventional and multiplex PCRs for detection of blaSHV, blaCTX-M and blaTEM genes. Data were entered into ExcelTM 2016. Epi info and R software were used for statistical analyses with a p-value &lt;0.05 considered statistically significant. Results: Out of the 125 children enrolled, 67.2% (84/125) were colonized by E. coli. Among these, 57.14% (48/84) were colonized by ESBL-Ec. The prevalence of ESBL-Ec per hospitals, was higher in H1 than that of H2 although without statistical significance (60.42% vs 39.58%, p=0.24). ESBL-Ec isolates showed high levels of resistance to amoxicillin-clavulanic acid (96.22%), cefotaxime (75.47%), ceftriaxone (73.58%), ofloxacin (67.92%), levofloxacin (56.6%) and ciprofloxacin (54.71%). The majority of ESBL-Ec isolates (52.83%; 28/53) were co-producers of blaCTX-M and blaTEM. Conclusion: Infection prevention and control measures coupled with antimicrobial stewardship strategies need to be strengthened to reduce emergence and dissemination of ESBL-Ec among this vulnerable population.

Utility of the MBT STAR-Cepha kit in detecting extended-spectrum β-lactamase producers in clinical urine samples and positive blood cultures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Urinary tract infection (UTI) and bloodstream infection (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing bacteria are important healthcare problems. Appropriate infection management requires the direct detection of organisms in clinical specimens. We assessed the capability of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based MBT STAR-Cepha kit to detect ESBL producers in clinical urine and blood samples. Over a 1-year period, 90 urine samples and 55 positive monomicrobial (Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, or Proteus mirabilis) blood cultures were collected from patients with UTI or BSI at Hamamatsu University Hospital. β-lactamase activity in these samples was directly detected using the MBT STAR-Cepha kit, and the results were compared with those of antimicrobial susceptibility testing and polymerase chain reaction detection assay for the isolates. In receiver operating characteristic curve analysis, the kit assay showed low accuracy in detecting ESBL producers in urine samples (area under the curve [AUC], 0.69). Meanwhile, the AUC for detecting all ESBL-producing bacteria in positive blood cultures was 0.81. The kit assay detected cefotaxime (CTX) resistance (mainly in CTX-M-type ESBL producers) with high accuracy in positive blood cultures; however, it did not accurately detect ESBL producers in urine samples and CTX-susceptible isolates with other ESBL-associated genes (e.g., TEM and SHV types) in positive blood cultures. MBT STAR-Cepha testing can accurately discriminate CTX-resistant ESBL producers in BSI cases and thus can contribute to effective infection management. The results suggest that different sample types, antibiotic resistance profiles, and resistance genes can affect the kit performance.

Correlation Between Antimicrobial Resistance And Virulence Genes In Klebsiella Pneumoniae Isolates From Egypt.

To genotypically assess the relationship between certain resistance and virulence determinants. The cross-sectional study was conducted at Kafrelsheikh University, Egypt, from March 2019 to May 2021, and comprised pathologicalsamples, like blood,sputum, urine, vaginalswabs and wound swabs, that had been taken from patients who had never received treatment. The sample were collected from Kafrelsheikh and Mansoura University hospitals, and Klebsiella pneumoniae isolates were obtained. Resistance and virulence determinants were tested phenotypically. Uniplex polymerase chain reaction was used to evaluate the presence of several resistance accompanied genes and virulence genes in the isolates. Disc diffusion method was used to assess the isolates' susceptibility in accordance with the Clinical and Laboratory Standards Institute criteria for identifying diverse resistance patterns. There were 23 isolatesfrom 16 patients. Of the tested isolates, 22(95.65%)showed drug resistance; 19(82.6%) had multidrug resistance, and 3(13.04%) had extensive drug resistance. There was no case of pan drug resistance. CTX-M-15, NDM, CTX-M-1, VIM-1 and qnr B genes were detected in 14(60.86%), 13(56.5%), 6(26.08%), 6(26.08%) and 6(26.08%) isolates, respectively. Moreover, 6(26.08%) isolates exhibited extended-spectrum β-lactamase producers, and 12(52.17%) ofsuch isolates contained both CTX-M-1 and CTX-M-15 genes, 6 and 33.3% contained CTX-M-1, CTX M-15 and fox genes. Type 3 fimbriae adhesin mrkD and mucoviscosity regulatory gene uge were found in the tested isolates. However, gene of iron uptake system kfu wasfound in 8(34.78%) isolates, and increased serum survival protein is and mucoviscosity accompanied gene magA were detected in 3(13.04%) isolates. A direct correlation was found among 5 from 8 Klebsiella pneumoniae virulence genes and antimicrobial resistance genes. There was a direct correlation between the existence of virulence factors and resistance to antimicrobials.

Diversity of genetic platforms harboring the blaPER-2 gene in Enterobacterales and insights into the role of ISPa12 in its mobilization and dissemination

The production of PER-like extended-spectrum β-lactamases has recently been associated with reduced susceptibility to the last resort drugs aztreonam/avibactam and cefiderocol. PER-2 has been mainly confined to Argentina and neighboring countries. Until now, only three plasmids harboring blaPER-2 genes have been characterized but very little is known about the involvement of different plasmid groups in its dissemination. The diversity of genetic platforms associated with blaPER-2 genes from a collection of PER-producing Enterobacterales was analysed by describing the close environment and the plasmid backbones. Full sequences of 11 plasmids were obtained by short read (Illumina) and long read (Oxford Nanopore or PacBio) sequencing technologies. De novo assemblies, annotation and sequence analysis were performed by Unicycler, Prokka and BLAST. Plasmid analysis revealed that the blaPER-2 gene is encoded on plasmids of different incompatibility groups (A, C, FIB, HI1B, N2), indicating that this gene may have been disseminated through a variety of plasmids. Comparison with the few publicly available nucleotide sequences describing the blaPER-2 genetic environment, including those from the environmental species Pararheinheimera spp. (considered as the progenitor of blaPER genes), indicates a role of ISPa12 in blaPER-2 gene mobilization from the chromosome of Pararheinheimera spp. Also, the blaPER-2 gene was carried by a novel ISPa12-composite transposon, Tn7390. In addition, its association with ISKox2-like elements in the close genetic environment in all plasmids analysed suggests a role of these insertion sequence elements in further dissemination of blaPER-2 genes.

MALDI-TOF MS Approaches for the Identification of the Susceptibility of Extended-Spectrum β-Lactamases in Escherichia coli.

The increase in multidrug-resistant microorganisms that produce extended-spectrum β-lactamases (ESBLs) and carbapenemases is a serious problem worldwide. Recently, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used for the rapid detection of antibiotic-resistant bacteria. The objective of this study was to establish a method to detect ESBL-producing Escherichia coli by monitoring the hydrolyzation of cefotaxime (CTX) using MALDI-TOF MS. According to the ratio of the peak intensity of CTX and hydrolyzed-CTX-related compounds, the ESBL-producing strains could be clearly distinguished after 15 min of incubation. Moreover, the minimum inhibitory concentration (MIC) values for E. coli were 8 μg/mL and lower than 4 μg/mL, which could be distinguished after 30 min and 60 min of incubation, respectively. The enzymatic activity was determined using the difference in the signal intensity of the hydrolyzed CTX at 370 Da for the ESBL-producing strains incubated with or without clavulanate. The ESBL-producing strains with low enzymatic activity or blaCTX-M genes could be detected by monitoring the hydrolyzed CTX. These results show that this method can rapidly detect high-sensitivity ESBL-producing E. coli.

Antimicrobial Susceptibility of Community-acquired Urine Bacterial Isolates in French Amazonia.

Bacterial resistance in community-acquired urinary tract infections (UTIs) is increasing worldwide. Our study aimed to assess the microbiological epidemiology and antimicrobial susceptibility patterns of community-acquired urine bacterial isolates in French Amazonia. Our study is retrospective. It was conducted from January 2015 to December 2019 in the microbiology laboratory of the Cayenne General Hospital (French Guiana). It includes all positive urine samples from adult (> 18 years) outpatients (N = 2,533). Isolated microorganisms were Gram-negative rods in 83.9%, mainly Enterobacterales (98.4%). The main isolated bacteria were Escherichia coli (58.7%) and Klebsiella pneumoniae (13.3%). Among the isolated E. coli, 37.2% were susceptible to amoxicillin, 77.9% to amoxicillin/clavulanic acid, 94.9% to cefotaxime, 78.9% to ofloxacin, and 98.9% to nitrofurantoin. In 106 cases (5.1%), isolated Enterobacterales were extended-spectrum β-lactamase producers (5% of E. coli and 8.9% of K. pneumoniae). Overall, high levels of cross- and co-resistance were registered. The main isolated Gram-positive bacteria was Staphylococcus saprophyticus (28.9%). It was resistant to oxacillin in 52.5% of cases and susceptible to nitrofurantoin in 99.1% of cases. Patients with S. saprophyticus were young women in almost all cases. In conclusion, the most isolated microorganisms from outpatient urinalyses were E. coli and K. pneumoniae. They showed a high resistance rate to amoxicillin, but they were susceptible to the most remaining antibiotics. S. saprophyticus was isolated mainly in young women and was resistant to oxacillin in half of the cases. Interestingly, nitrofurantoin was active against most isolated organisms and can be considered as empirical treatment in uncomplicated UTIs.

Antimicrobial resistance, Extended-Spectrum β-Lactamase production and virulence genes in Salmonella enterica and Escherichia coli isolates from estuarine environment.

The impact of antimicrobial resistance (AMR) on global public health has been widely documented. AMR in the environment poses a serious threat to both human and animal health but is frequently overlooked. This study aimed to characterize the association between phenotype and genotype of AMR, virulence genes and Extended-Spectrum β-Lactamase (ESBL) production from estuarine environment. The Salmonella (n = 126) and E. coli (n = 409) were isolated from oysters and estuarine water in Thailand. The isolates of Salmonella (96.9%) and E. coli (91.4%) showed resistance to at least one antimicrobial agent. Multidrug resistance (MDR) was 40.1% of Salmonella and 23.0% of E. coli. Resistance to sulfamethoxazole was most common in Salmonella (95.2%) and E. coli (77.8%). The common resistance genes found in Salmonella were sul3 (14.3%), followed by blaTEM (11.9%), and cmlA (11.9%), while most E. coli were blaTEM (31.5%) and tetA (25.4%). The ESBL production was detected in Salmonella (1.6%, n = 2) of which one isolate was positive to blaTEM-1. Eight E. coli isolates (2.0%) were ESBL producers, of which three isolates carried blaCTX-M-55 and one isolate was blaTEM-1. Predominant virulence genes identified in Salmonella were invA (77.0%), stn (77.0%), and fimA (69.0%), while those in E. coli isolates were stx1 (17.8%), lt (11.7%), and stx2 (1.2%). Logistic regression models showed the statistical association between resistance phenotype, virulence genes and ESBL production (p < 0.05). The findings highlighted that estuarine environment were potential hotspots of resistance. One Health should be implemented to prevent AMR bacteria spreading.

Phenotypic characterization and antibiotic suceptibility patterns of extended spectrum beta-lactamase producing enterobacteriaceae

The rise of Enterobacteriaceae strains that produce an extended spectrum b-lactamase (ESBL) has become a global concern for epidemiological surveillance and the prevention of nosocomial acquired infections in the modern era. The choice of appropriate antibiotics to be employed in the treatment of infections brought on by ESBL-producing bacteria relies greatly on the detection and identification of these ESBLs in the laboratory. Limitations in ESBL detection have aided in the unbridled emergence of bacterial resistance and constitute a major health concern. Isolation and identification of ESBL among Enterobacteriaceae by phenotypic methodswith their Antibiogram.Phenotypic techniques were used to identify ESBL-producing Enterobacteriaceae (ESBLs-E) isolates from diverse clinical samples. Kirby Baur disc diffusion technique was performed to determine antimicrobial's susceptibility.Among 212 Enterobacteriaceae isolates 124(58.3%) were positive for ESBL production. E.coli(74.5%) &amp; K.pneumoniae (52.2%) two main isolates that produce ESBLs. Maximum ESBL producing Enterobacteriaceae isolates were obtained from blood samples 82% (41/50) followed by urine 59 % (62/105). Meropenem (96.7%), Amikacin (82.1%), and Cefoxitin were most susceptible antibiotics for ESBL-producing isolates while high resistance was observed in ceftazidime (62%), followed by Ciprofloxacin (60%). The majority of ESBLs-E was mostly found in urine and blood samples.It was observed that E.coli produced the most ESBLs. There was a high prevalence of ESBLs-E in tertiary care hospital of central India. Therefore, strong infection control strategies must be implemented in hospital settings

Serogroup and Pathogenicity Island Marker Distributions Among Uropathogenic Escherichia coli Isolates in Rasht, Iran

Background: Urinary tract infections (UTIs) are among the most prevalent infections in hospitals and communities worldwide. Objectives: Due to the medical importance of UTIs caused by uropathogenic Escherichia coli (UPEC), this study aimed to investigate pathogenicity island (PAI) markers, O-antigen serogroups, and resistance to antibiotic agents associated with UPEC isolates obtained from hospitalized patients in Rasht city hospitals. Methods: A total of 110 urine samples were taken from patients with UTI referred to selected hospitals in Rasht, Iran. The double-disk synergy test (DDST) was used to detect the isolate’s ability to produce extended-spectrum β-lactamase (ESBL). Using particular primers, eight PAIs were detected (ie, PAI I536, PAI II536, PAI III536, PAI IV536, PAI ICFT073, PAI IICFT073, PAI IJ96, and PAI IIJ96). Results: According to the antibiotic susceptibility pattern, a high level of antibiotic resistance was observed against nalidixic acid (81.8%) and co-trimoxazole (78.2%), while the most effective agent was amikacin (85.5%). Double-disk synergy test revealed that the incidence of ESBL-positive strains was 62.7% (69/110). Of the 110 UPEC isolates, 106 (96.4%) carried at least one of the investigated PAI markers. Uropathogenic E. coli isolates with PAI IV536 (81.8%) had the highest prevalence, and PAI J196 (6.4%) had the lowest PAI marker. The most predominant serogroup O was O25 (36.4%), followed by O16 (17.3%), while the O4 and O7 serogroups (0.9%) were the lowest serogroups among UPEC isolates. Conclusions: The characterization of our strain revealed the co-occurrence of PAI and serogroups, confirming the importance of antibiotic resistance among the distinct serogroups and PAI markers. Our results have potential application for epidemiological studies and designing UTI treatment strategies against UTIs caused by UPEC.

The evolution and international spread of extensively drug resistant Shigella sonnei

Shigella sonnei causes shigellosis, a severe gastrointestinal illness that is sexually transmissible among men who have sex with men (MSM). Multidrug resistance in S. sonnei is common including against World Health Organisation recommended treatment options, azithromycin, and ciprofloxacin. Recently, an MSM-associated outbreak of extended-spectrum β-lactamase producing, extensively drug resistant S. sonnei was reported in the United Kingdom. Here, we aimed to identify the genetic basis, evolutionary history, and international dissemination of the outbreak strain. Our genomic epidemiological analyses of 3,304 isolates from the United Kingdom, Australia, Belgium, France, and the United States of America revealed an internationally connected outbreak with a most recent common ancestor in 2018 carrying a low-fitness cost resistance plasmid, previously observed in travel associated sublineages of S. flexneri. Our results highlight the persistent threat of horizontally transmitted antimicrobial resistance and the value of continuing to work towards early and open international sharing of genomic surveillance data.