Enterobacter Cloacae Isolates Research Articles

Predictive Application Value of Metagenomic Next-Generation Sequencing in the Resistance of Carbapenem-Resistant Enterobacteriaceae.

Objective: Although metagenomic next-generation sequencing (mNGS) technology has achieved notable outcomes in pathogen detection, there remains a gap in the research regarding its application in predicting the antibiotic resistance of pathogenic bacteria. This study aims to analyze the clinical application value of mNGS in predicting the resistance of carbapenem-resistant Enterobacteriaceae (CRE), as well as the relevant influencing factors, thereby providing valuable insights for clinical antimicrobial therapy. Methods: Nonduplicate isolates of Enterobacterales bacteria collected from Liaocheng People's Hospital from April 2023 to June 2024 were selected, and CRE bacteria were screened. mNGS was used to detect resistance genes, and the results were compared with those of polymerase chain reaction (PCR) to evaluate the specificity and sensitivity of gene detection. Furthermore, the performance of mNGS in identifying pathogenic microorganisms and predicting antibiotic resistance was assessed by comparing the sequencing results with those of antimicrobial susceptibility testing (AST). Results: A total of 46 isolates were confirmed as CRE through traditional AST and were further identified using the Vitek MS and Vitek 2 systems. The results indicated 27 isolates of Klebsiella pneumoniae, 14 isolates of Escherichia coli, 2 isolates of Enterobacter hormaechei, 2 isolates of Enterobacter cloacae, and 1 isolate of Citrobacter freundii. These isolates were subjected to both mNGS and PCR for detection. The calculation of the area under the receiver operating characteristic (ROC) curve demonstrated the reliability of mNGS in detecting resistance genes. Conclusion: mNGS demonstrated high sensitivity in predicting the presence of carbapenemase resistance genes in CRE, showing potential in early indication of isolate resistance information, thereby facilitating timely guidance for clinical treatment strategies.

A comprehensive computer-based assessment of Deacetylnomilin as an inhibitor for antibiotic-resistant genes identified from the whole genome sequence of the multidrug-resistant Enterobacter cloacae isolate 1382.

The twenty-first century presents a serious threat to public health due to the growth in antibiotic resistance among opportunistic bacteria, particularly within the ESKAPE group, which includes Enterobacter species with high morbidity, mortality, virulence, and nosocomial dissemination rates. Enterobacter species, especially Enterobacter cloacae, bacteria have developed resistance to multiple antibiotics through mechanisms, such as continuous production of AmpC beta-lactamase. In this study, a comprehensive bioinformatics approach was employed to analyze the genome of Enterobacter cloacae, utilizing sequence data from GenBank (ID: OW968328.1).The AbritAMR and ResFinder tools were utilized to identify antibiotic-resistant genes, which included the presence of blaOXA-48, blaCMH, FosA, OqxA, and OqxB each conferring resistance to specific antibiotics such as β-lactams and fluoroquinolones. These proteins were analyzed using bioinformatics tools such as ProtParam, SOPMA, Robetta, I-TASSER, AlphaFold, and PROCHECK to investigate different structural models and their properties.The models from AlphaFold had the best quality in terms of structural accuracy, providing valuable insights into the 3D conformations of these resistant proteins. Based on the Molecular docking studies, these constructed targets were docked with 20 natural compounds known for their activity against Gram-negative bacteria. Among them, Deacetylnomilin showed the highest docking score and passed their ADMET properties. Molecular dynamic (MD) simulation was conducted for 100ns for Deacetylnomilin with different resistant proteins. Deacetylnomilin exhibited more favorable binding free energies compared to the reference compounds across all five proteins, indicating higher stability and affinity. These results suggest that Deacetylnomilin could be an effective inhibitor against the resistant proteins of Enterobacter cloacae, making it a promising candidate for further drug development.

Whole genome-based characterization of extended-spectrum β-lactamase-producing Enterobacter cloacae from orthopedic patients and environment of a tertiary referral hospital in Tanzania

ObjectivesWe investigated the genomic epidemiology of extended-spectrum β-lactamase-producing Enterobacter cloacae (ESBL-Ec) isolates from patients and hospital environment to better understand their distribution to help devising effective strategies for infection prevention and control. MethodsWe screened ESBL-Ec at Bugando Medical Center (BMC) in Mwanza, Tanzania. Rectal swabs from orthopedic patients on admission and swabs from the neighboring inanimate environment were collected. Following microbial culture, DNA was extracted from pure ESBL-Ec, and whole-genome sequencing was done. Sequence typing (ST), plasmid replicons, drug resistance, and virulence genes were deciphered using the Rapid Microbial Analysis Pipeline (rMAP). ResultsWe obtained 209 ESBL isolates, of which 15 (7.2%) were ESBL-Ec [8 (53.30%) from patients and 7 (46.7%) from the environment]. Seven isolates were novel and eight were diverse each with a unique ST. All isolates harbored two to five β-lactamase genes, with the predominance of blaCTX-M-15(15/15), blaOXA-1(14/15), blaTEM(14/15) and blaACT(12/15). The most common non β-lactam drug resistance genes were aac(3)-IIa (14/15), aac(6’)-Ib-cr (14/15), fosA (14/15), and qnrB1 (12/15), aph(3’’)-Ib (10/15) and aph(6)-Id (10/15). Eleven different types of plasmid replicons were identified in 14/15 of the isolates, harboring one to five plasmids, with the most common plasmids being IncFII (11/15) and IncFIB (10/15). All isolates harbored the outer membrane protein (ompA), and curli protein (csg) was in 14/15 isolates. ConclusionAdmitted orthopedic patients and the hospital environment act as a reservoir of ESBL-Ec with diverse STs and endowed with drug resistance and arsenals of virulence genes, calling for their routine screening on admission for mitigation of potential subsequent infections.

Chemical characterization and antibacterial activity of lipopolysaccharide extracted from the local isolate of Enterobacter cloacae

Chemical characterization and antibacterial activity of lipopolysaccharide extracted from the local isolate of Enterobacter cloacae

In Vitro Synergistic Activity of Ceftazidime-Avibactam and Aztreonam against New Delhi Metallo-β-Lactamase-Producing Clinical Enterobacterales Isolates

Background: Carbapenemase-producing-Enterobacterales (CPE) infections are on the rise and associated with increased morbidity and mortality, due to a limited number of therapeutic options. The goal of this study was to assess the synergistic activity of ceftazidime-avibactam (CZA) and aztreonam (ATM) combination against phenotypically and genetically characterized blaMBL-producing Enterobacterales.Methods: In this study, forty (n=40) non-repeat, CPE clinical isolates, including: n=35 Klebsiella pneumoniae, n=2 each of Escherichia coli and Klebsiella oxytoca, and n=1 Enterobacter cloacae isolates were identified and susceptibilities were assessed using the Vitek-II compact (bioMérieux, Inc., France) and Microscan Walkaway (Beckman Coulter) systems. Genotypic analysis of clinically relevant carbapenemases was performed by using Xpert-Carba-R assay on GeneXpert (Cepheid, USA). The minimum inhibitory concentrations (MICs) and synergy testing of CZA and ATM, were tested by the Etest fixed ratio method (bioMérieux, Inc., France). The fractional inhibitory concentration index (FICI) was calculated for each antibiotic.Results: Our results showed that 97.5% of blaMBL-producing Enterobacterales isolates were susceptible to an in-vitro CZA + ATM combination regimen. The fractional inhibitory concentration index (FICI) ranged from 0.001 to 1.001. Among the tested CPE isolates, Synergy was observed in 36/40 (90%), an additive effect was observed in 5% (n=2)’ while two (5%) isolates showed indifference. There was no antagonism observed in our study.Conclusion: Our study exhibited a potent activity of CZA and ATM combination synergy against clinical CPE metallo- β-lactamase producers. More extensive studies involving a variety of Gram-negative pathogens with different resistance mechanisms are required to determine the efficacy of this combination regimen.Keywords: Synergy; Aztreonam; Ceftazidime-Avibactam; Carbapenem-Resistant Enterobacterales; Etest

ENTEROBACTER CLOACAE LIPOPOLYSACCHARIDE EXPORT SYSTEM PROTEIN (LPTC) GENE EXPRESSION VARIATION VIA EXPOSE TO BIOSYNTHESIZED ZINC OXIDE NANOPARTICLES

Synthetic nanoparticles (NPs) have become more widely used in the disinfection and health sectors owing to their ability to effectively penetrate biological systems. Recent research has demonstrated the ability of microbial proteins and enzymes to function as reducing agents throughout the NP-production process, providing a different option to chemical and physical techniques. This method not only saves money and is effective, but also has the least possible environmental impact. This work used Lactobacillus spp., as the reducing and capping agent to create zinc oxide nanoparticles, (ZnO NPs). Numerous analytical techniques were employed to examine the generated ZnO NPs; these techniques include ultraviolet–visible spectroscopy (UV–vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). As an opportunistic pathogenic bacterium, Enterobacter cloaca possesses several virulence characteristics that enable it to infiltrate target tissues. However, bacteria can become resistant to antibiotics, which in turn makes treating bacterial infections becomes more difficult. With the development of science at the biotechnology level, using zinc oxide ZnO NPs on isolates of Enterobacter cloacae, we conducted research in the promising field of nanotechnology. The impact of three different concentrations of ZnO NPs on the gene expression of Enterobacter cloaca lipopolysaccharide transport (Lpt) proteins in isolates obtained from some patients suffering of various infections was investigated. Bacteria with the highest multidrug resistance were selected for further analysis. Expression of LptC gene was reduced significantly at concentration of 125 mg/mL (P < 0.01) for all the isolate that treated with ZnO NPs.

Quantitative Analysis of Swertiamarin Content from Fagraea fragrans Leaf Extract using HPLC Technique and its Correlation to Antibacterial Activity

The rise in drug resistance poses escalating challenges for antibacterial medications, leading to an urgent demand for the exploration and innovation of new antibacterial drugs. Fagraea fragrans Roxb., belonging to the Gentianaceae family, is one of the common herbal medicines which can be found abundantly in Southeast Asia. The secoiridoid glucoside swertiamarin, one of the major compounds in F. fragrans leaf, exhibits antimicrobial effects. To guarantee the medicinal effectiveness of F. fragrans leaves, it is essential to identify a standardized analytical method for quantifying the active compound. In this study, the optimized HPLC method following ICH guideline was validated for the quantitative analysis of swertiamarin content in F. fragrans leaf in terms of linearity (y = 5733.5x - 369.1; R2 = 0.9999), accuracy (93.57-96.39% recovery), precision (0.91% RSD for repeatability precision; 1.19% RSD for intermediate precision), limit of detection (0.73 µg/mL), limit of quantitation (2.23 µg/mL), specificity (peak purity index = 0.999995) and robustness (% RSD <1).The maximum wavelength of swertiamarin was found to be at 238 nm. The amount of swertiamarin content in F. fragrans leaf extract conducted from the validated HPLC method was found to be 0.0259 ± 0.0005 g/100 g crude drug. The leaf extract exhibited antimicrobial activity against clinical isolates of Enterobacter cloacae, Klebsiella pneumonia, and Escherichia coli at 0.125 mg/mL, and Pseudomonas aeruginosa at 0.5, showing minimum inhibitory concentration (MIC) values. Whereas swertiamarin exhibited even lower MIC values. The developed HPLC analysis effectively determines swertiamarin content as a chemical marker to ensure the antimicrobial potential of F. fragrans leaves.

Scolopax rusticola Carrying Enterobacterales Harboring Antibiotic Resistance Genes.

The Eurasian woodcock (Scolopax rusticola) belongs to those bird species that make systematic migratory flights in spring and autumn in search of favorable breeding and wintering areas. These specimens arrive in the Mediterranean Area from northeastern European countries during the autumn season. The purpose of this study was to assess whether woodcocks can carry antibiotic resistance genes (ARGs) along their migratory routes. Although the role of migratory birds in the spread of some zoonotic diseases (of viral and bacterial etiology) has been elucidated, the role of these animals in the spread of antibiotic resistance has not yet been clarified. In this study, we analyzed the presence of beta-lactam antibiotic resistance genes. The study was conducted on 69 strains from 60 cloacal swabs belonging to an equal number of animals shot during the 2022-2023 hunting season in Sicily, Italy. An antibiogram was performed on all strains using the microdilution method (MIC) and beta-lactam resistance genes were investigated. The strains tested showed no phenotypic resistance to any of the 13 antibiotics tested; however, four isolates of Enterobacter cloacae and three of Klebsiella oxytoca were found to carry the blaIMP-70, blaVIM-35, blaNDM-5 and blaOXA-1 genes. Our results confirm the importance of monitoring antimicrobial resistance among migratory animals capable of long-distance bacteria spread.

The first report of the mobile colistin resistance gene, mcr-10.1, in Kenya and a novel mutation in the phoQ gene (S244T) in a colistin-resistant Enterobacter cloacae clinical isolate.

This study describes the identification of the mcr-10.1 gene in a clinical isolate of an ST1 Enterobacter cloacae isolate cultured in 2015 in Kenya. The isolate was multidrug resistant, phenotypically non-susceptible to various antibiotics, including colistin. Whole genome sequence analyses indicated carriage of chromosomally encoded antimicrobial resistance genes and the colistin-resistant gene mcr-10.1 located on a 72-kb plasmid designated pECC011b with an IncFIA(HI1) replicon directly adjacent to tyrosine recombinase gene, xerC, and downstream of an ISKPn26 insertion sequence. Studies have shown that expression of mcr-10.1 may not be sufficient to confer colistin resistance, but a novel non-synonymous mutation (S244T) was identified in the phoQ gene known to influence colistin resistance within lipid modification pathways, which could have complemented the mcr-10.1 resistance mechanism. In silico analysis of the mutant phoQ protein shows the location of the mutation to be at the Histidine kinases, Adenyl cyclases, Methyl-accepting proteins and Phosphatases (HAMP) region, which plays a crucial role in the protein's activity. This study and our previous report of mcr-8 in Klebsiella pneumoniae indicate the presence of mobile mcr genes in the Enterobacterales order of bacteria in Kenya. The study points to the importance of regulation of colistin in the animal industry and enhancing surveillance in both human and animal health to curb the spread of mcr genes and accurately assess the risks posed by these mobile genetic elements in both sectors.IMPORTANCEThis paper reports the detection of new colistin resistance mechanisms in Kenya in a clinical isolate of Enterobacter cloacae in a patient with a healthcare-associated infection. The plasmid-mediated resistance gene, mcr-10.1, and a novel amino acid mutation S244T in the phoQ gene, located in a region of the protein involved in membrane cationic stability contributing to colistin resistance, were detected. Colistin is a critical last-line drug for multidrug-resistant (MDR) gram-negative human infections and is used for treatment and growth promotion in the animal industry. The emergence of the resistance mechanisms points to the potential overuse of colistin in the animal sector in Kenya, which enhances resistance, threatens the utility of colistin, and limits treatment options for MDR infections. This study highlights the need to enhance surveillance of colistin resistance across sectors and strengthen One Health policies that ensure antimicrobial stewardship and implementation of strategies to mitigate the spread of antibiotic resistance.

Screening of Tetracycline’s Resistance Genes among Enterobacter cloacae and Citrobacter spp. isolates

There has been a growing prevalence of tetracycline-resistant bacteria across many species and genera. As a consequence, the efficacy of tetracycline treatment has diminished with time. So this work aimed to study of tetracycline-resistant genes among Enterobacter cloacae and Citrobacter spp. Out of a total of 364 clinical specimens, 135 (37.08%) exhibited bacterial growth. Out of the total, 22 (6.04%) were classified as gram-positive bacteria, 102 (28.02%) as gram-negative bacteria, and 11 (3.02%) as mixed growth (including both gram-negative and gram-positive bacteria). The Vitek-2 system findings indicated that the proportion of Enterobacter cloacae was 25 (6.86%), whereas Citrobacter spp. accounted for just 2 (0.54%) cases. The Enterobacter cloacae and Citrobacter isolates exhibited significant levels of resistance to several antibiotics, as shown by their drug susceptibility results. The PCR findings indicated that the tetrA gene was present in 8 out of 25 isolates (32%) of E. cloacae, and in 1 out of 2 isolates (50%) of Citrobacter spp. The tetrB gene was found in 92% of E. cloacae isolates (23 out of 25) and in 100% of Citrobacter spp. isolates (2 out of 2). In this study, the tetraC gene was identified in 6 out of 25 (24%) E. cloacae isolates and in 1 out of 2 (50%) Citrobacter spp. isolates. The TetraD and TetraE genes were not identified in the current study. The amino acid sequence analysis of the tetA and tetB genes revealed a similarity rate of 83% and 95% respectively.

EVALUATION OF QUORUM SENSING SIGNALS OF STRONG BIOFILM PRODUCING BACTERIA VIA LC-MSMS, HPLC AND BIOSENSORS

This study aimed to show presence of Quorum Sensing (QS) signals of Gram-negative and Gram-positive biofilm producing bacteria isolated from real dairy process lines. Defining the profile and chemical composition of QS-signals is an important factor in control of microbial resistance and biofilm production. We especially focused on unusual behaviour of Gram-positive and Gram-negative isolates. Long-chain acyl-homoserine lactones (AHLs) signals (C14-HSL, C16-HSL and C18-HSL) and DFD (4,5-dihidroksi-2,3-pentanedione)-AI-2 signals of the isolates were studied by High-performance liquid chromatography (HPLC) and Liquid Chromatography with tandem mass spectrometry (LC-MSMS) methods. All Gram-positive isolates were defined as AHL-producers. All Gram-negative isolates, formerly defined as non-AHL producers by both biosensors and HPLC methods, were identified as AHL-producers. DFD signal was only detected from Gram-negative Klebsiella pneumonia, Enterobacter cloacae and Klebsiella oxytoca isolates. The results demonstrated that the QS-system is a complex system and biosensor microorganism may not be the best method for QS-signal identification. The results also provided new insights in defining the profile and chemical composition of QS-signals importance for interrupting the chemical communication completely to reduce biofilm formation and prevent resistance gain of microorganisms.

Isolation and Diagnosis of Bacteria in Bacteremia Patients and Study Their Resistance to Antibiotics in Kirkuk Hospitals

313 blood samples were collected from bacteremia patients, including 146 samples (30 from patients and 116 from outpatients) from Azadi teaching hospital, 36 samples from the dialysis unit at Kirkuk General Hospital, 126 samples (42 from inpatients and 84 from outpatients) from the Children's Hospital, and 5 samples from the Women's and Obstetrics Hospital in Kirkuk province, for the period from January 24, 2022, to September 10, 2022. The study, including the isolation and diagnosis of bacteria and the study of their resistance to antibiotics, The results show that 32 (17.87%) positive growth cultures were obtained from febrile patients, 3 (8.33%) from dialysis patients in the dialysis unit, and 15 (65.21%) from burn and wound patients. Fifty bacterial isolates were obtained, all of which were gram-positive. Staphylococcus was the highest with 28 isolates, including [(11) S.homoinis, (4) S.epidermidis epidermidis, (2) isolates each of S.haemolyticus and S. Wagner, and (9) Staphylococcus spp.], while Enterococcus faecalis was one isolate. The gram-negative bacteria were [(11) Pseudomonas aeruginosa, (5) Escherichia coli, (2) isolates of Enterobacter cloacae, and followed by one isolate of Raoultella terrigena, Acinetobacter spp., and Klebsiella spp.). Staphylococcus spp. resistance to 20 antibiotics was studied, and the species S.homoinis showed 100% resistance to (Oxacillin, Benzylpenicillin, and Amoxicillin). Whereas S.epidermidis epidermidis was 100% antibiotic-resistant (Oxacillin, Benzylpenicillin, and Amoxicillin). S. hemolyticus was resistant to (erythromycin, benzylbeniclin, amosiclin, amikachin, gentamicin, torramichin, and tetracycline) by 100%. S. warneri was resistant to (oxacillin, benzylpenicillin, amoxicillin, and dusidic Acid) at a rate of one hundred percent.

Mechanisms of ceftazidime/avibactam resistance in drug-naïve bacteraemic Enterobacterales strains without metallo-beta-lactamase production: Associated with ceftazidime impedance

In order to investigate ceftazidime/avibactam (CZA) resistance characteristics and mechanisms of bacteraemic Enterobacterales strains that had not been treated previously with CZA, 9708 strains were collected from 43 hospitals in 18 provinces across China from January 2019 to June 2020. The minimum inhibitory concentration (MIC) values of CZA in 165 (1.70%) strains were ≥8/4 mg/L. Ten (6.06%) CZA-resistant strains without metallo-β-lactamase production were obtained from the individuals without prior exposure to CZA, including six Escherichia coli isolates, three Klebsiella pneumoniae isolates and one Enterobacter cloacae isolate. Whole-genome sequencing revealed that ECB88611, ECB142593 and ECB144539 had encoded disrupted OmpF loss of function. OmpF of ECB126041 had a 2_9 MKRNILAV deletion; OmpK35 of three K. pneumoniae isolates harboured amino acid fragment deletions from positions 1 to 38; and ELB117287 had encoded disrupted OmpF. The G132D amino acid substitution of OmpC of ECB88611, ECB142593 and ECB144539, and the 134_135GD insertion of OmpK36 of three K. pneumoniae isolates were predicted to alter ceftazidime permeability. 333_334 YRIK or YRIN insertions occurred in PBP3 of six E. coli isolates. The relative expression of blaKPC-2 in KPB125108 was 4.527 ± 0.2166 times higher than the control strain, and the relative expression of acrF in six E. coli isolates was 2-3 times higher than the control strain. The addition of phenylalanine-arginine-β-naphthylamine at 100 mg/L decreased the MIC values of CZA against nine strains significantly. In conclusion, the antimicrobial resistance mechanisms in 10 isolates included increased expression of blaKPC-2, non-functional OMPs, upregulation of efflux pump activity, and variants of PBP3. Most of these mechanisms affected the antimicrobial activity of CZA by impeding ceftazidime.

Characterization of functional amyloid curli in biofilm formation of an environmental isolate Enterobacter cloacae SBP-8.

The biofilm formation by bacteria is a complex process that is strongly mediated by various genetic and environmental factors. Biofilms contribute to disease infestation, especially in chronic infections. It is, therefore important to understand the factors affecting biofilm formation. This study reports the role of a functional amyloid curli in biofilm formation at various abiotic surfaces, including medical devices, by an environmental isolate of Enterobacter cloacae (SBP-8) which has been known for its pathogenic potential. A knockout mutant of csgA, the gene encoding the major structural unit of curli, was created to study the effect of curli on biofilm formation by E. cloacae SBP-8. Our findings confirm the production of curli at 25°C and 37°C in the wild-type strain. We further investigated the role of curli in the attachment of E. cloacae SBP-8 to glass, enteral feeding tube, and foley latex catheter. Contrary to the previous studies reporting the curli production below 30°C in the majority of biofilm-forming bacterial species, we observed its production in E. cloacae SBP-8 at 37°C. The formation of more intense biofilm in wild-type strain on various surfaces compared to curli-deficient strain (ΔcsgA) at both 25°C and 37°C suggested a prominent role of curli in biofilm formation. Further, electron and confocal microscopy studies demonstrated the formation of diffused monolayers of microbial cells on the abiotic surfaces by ΔcsgA strain as compared to the thick biofilm by respective wild-type strain, indicating the involvement of curli in biofilm formation by E. cloacae SBP-8. Overall, our findings provide insight into biofilm formation mediated by curli in E. cloacae SBP-8. Further, we show that it can be expressed at a physiological temperature on all surfaces, thereby indicating the potential role of curli in pathogenesis.

Characterization of cephalosporin and fluoroquinolone resistant Enterobacterales from Irish farm waste by whole genome sequencing.

The Enterobacterales are a group of Gram-negative bacteria frequently exhibiting extended antimicrobial resistance (AMR) and involved in the transmission of resistance genes to other bacterial species present in the same environment. Due to their impact on human health and the paucity of new antibiotics, the World Health Organization (WHO) categorized carbapenem resistant and ESBL-producing as critical. Enterobacterales are ubiquitous and the role of the environment in the transmission of AMR organisms or antimicrobial resistance genes (ARGs) must be examined in tackling AMR in both humans and animals under the one health approach. Animal manure is recognized as an important source of AMR bacteria entering the environment, in which resistant genes can accumulate. To gain a better understanding of the dissemination of third generation cephalosporin and fluoroquinolone resistance genes between isolates in the environment, we applied whole genome sequencing (WGS) to Enterobacterales (79 E. coli, 1 Enterobacter cloacae, 1 Klebsiella pneumoniae, and 1 Citrobacter gillenii) isolated from farm effluents in Ireland before (n = 72) and after (n = 10) treatment by integrated constructed wetlands (ICWs). DNA was extracted using the MagNA Pure 96 system (Roche Diagnostics, Rotkreuz, Switzerland) followed by WGS on a MiSeq platform (Illumina, Eindhoven, Netherlands) using v3 chemistry as 300-cycle paired-end runs. AMR genes and point mutations were identified and compared to the phenotypic results for better understanding of the mechanisms of resistance and resistance transmission. A wide variety of cephalosporin and fluoroquinolone resistance genes (mobile genetic elements (MGEs) and chromosomal mutations) were identified among isolates that mostly explained the phenotypic AMR patterns. A total of 31 plasmid replicon types were identified among the 82 isolates, with a subset of them (n = 24), identified in E. coli isolates. Five plasmid replicons were confined to the Enterobacter cloacae isolate and two were confined to the Klebsiella pneumoniae isolate. Virulence genes associated with functions including stress, survival, regulation, iron uptake secretion systems, invasion, adherence and toxin production were identified. Our study showed that antimicrobial resistant organisms (AROs) can persist even following wastewater treatment and could transmit AMR of clinical relevance to the environment and ultimately pose a risk to human or animal health.

In vitro efficacy of cephamycins against multiple extended-spectrum β-lactamase-producing Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter cloacae isolates from dogs and cats.

The susceptibility of 218 extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolates from companion animals to three cephamycins (cefmetazole, flomoxef, and latamoxef) was investigated. Phenotypic testing found 8 of 120 Klebsiella pneumoniae (KP) and 15 of 69 Enterobacter cloacae (EC) isolates were ESBL and AmpC β-lactamase (ABL) co-producers. Isolates of KP, Proteus mirabilis, and EC that only produced ESBL exhibited susceptibility rates to cefmetazole (95.5%, 82.7%, and 9.3%), flomoxef (99.1%, 96.6%, and 74.0%), and latamoxef (99.1%, 100%, and 100%), respectively. Notably, isolates of KP and EC co-producing ESBL and ABL had significantly lower susceptibility rates to the studied drugs when compared with only ESBL producers. This implies that the in vitro activity of cephamycins against ESBL-producing bacteria can differ depending on ABL production and bacterial species.

Variation in antibiotic resistance patterns for children and adults treated at 166 non-affiliated US facilities using EHR data.

Antibiotic resistance (AR) is a global public health threat. Surveillance of baseline AR and trends and emerging resistance among priority bacterial isolates with respect to the age of the patients and the type of healthcare setting are required due to differences in antimicrobial need and use in these populations. We performed a retrospective study using deidentified electronic health record (EHR) data in the Cerner Health Facts™ data warehouse. Antibiotic susceptibility data were extracted for all bacterial isolates of interest at 166 non-affiliated healthcare facilities reporting microbiology susceptibility results of the FDA recommended antibiotics between the years 2012 to 2017. We assessed and visualized the slope coefficient from linear regression to compare changes in resistance over time for the four patient care groups. The trends in resistance rates to clinically relevant antibiotics were influenced by age and care setting. For example, ertapenem-resistant Enterobacter cloacae isolates from children overall increased significantly compared with adults (0.7% to 9.8%, 2.1% to 2.8%, P = 0.00013) and isolates from children in paediatric facilities increased significantly compared with facilities treating adults and children (0.1% to 27.1%, 0.9% to 3.8%, P = 0.0002). Large-scale analysis of EHR data from 166 facilities shows that AR patterns for some bug-drug combinations vary by care setting and patient age. We describe novel data visualizations to interpret large-scale EHR data on the prevalence and trends of AR that should influence antimicrobial prescribing and antimicrobial stewardship programme interventions.

THE PREVALENCE OF BLANDM, BLAVIM GENES AMONG ENTEROBACTER CLOACAE BACTERIA

This study was aimed to detect the prevalence of blaVIM and blaNDM genes among Enterobacter cloacae isolates that were isolated from Iraqi patients. About 50 bacterial isolates were collected from different hospitals in Baghdad city and all these isolates were diagnosed using biochemical tests and CHROMagar culture media and conformed using the Vitek II system. The antibiotic susceptibility for E.cloacae isolates was determined using the disk diffusion (Kirby Bauer) method and the results showed that these bacteria were showed resistance to Cefepime and Meropenem antibiotics in percentage (50%), (40%) respectively. In addition it is resistant to Amikacin, ampicillin/sulbactam, Piperacillin, and aztreonam was (20%), (50%), (40%), and (55%) respectively. Also it has been noted that all isolates showed resistance to Cefixime in percentage (100%). EDTA combined disc test was used to detect the ability of E. cloacae isolates to produce carbapenemase and the results were showed that only 8 isolates were gave positive results , While the prevalence of blaVIM and blaNDM was determined using the conventional Polymerase chain reaction technique. And the result showed that only four isolates harbored blaNDM while blaVIM was present in 3 isolates

Efficacy of diversely isolated lytic phages against multi-drug resistant Enterobacter cloacae isolates in Kenya.

BackgroundEnterobacter cloacae causes nosocomial infections in 15% of patients in low- and middle-income countries with emergence of carbapenem resistance. The utilisation of bacteriophages for therapeutic purposes is crucial for eradicating these resistant bacterial strains.ObjectiveThis study evaluated the efficacy of lytic phages on bacterial isolates of E. cloacae and determined their stability in various physicochemical conditions.MethodsTwenty-nine lytic phages were isolated from the waste water of six informal settlements in Nairobi County, Kenya, from July 2019 to December 2020 and cross-reacted with 30 anonymised clinical isolates of E. cloacae. Six phages were then selected for physicochemical property studies. Phages were described as potent upon lysing any bacterial strain in the panel.ResultsSelected phages were stable at 4 °C – 50 °C with a 5.1% decrease in titre in four of six phages and a 1.8% increase in titre in two of six phages at 50 °C. The phages were efficient following two weeks incubation at 4 °C with optimal activity at human body temperature (37 °C) and an optimal pH of 7.5. Phages were active at 0.002 M and 0.015 M concentrations of Ca2+ ions. The efficiency of all phages decreased with increased exposure to ultraviolet light. All phages (n = 29) showed cross-reactivity against anonymised clinical isolates of E. cloacae strains (n = 30). The most potent phage lysed 67.0% of bacterial strains; the least potent phage lysed 27.0%.ConclusionThis study reveals the existence of therapeutic phages in Kenya that are potent enough for treatment of multi-drug resistant E. cloacae.

Insights Into the Dynamics and Composition of Biofilm Formed by Environmental Isolate of Enterobacter cloacae.

Bacterial biofilms are clinically admissible and illustrate an influential role in infections, particularly those related to the implant of medical devices. The characterization of biofilms is important to understand the etiology of the diseases. Enterobacter cloacae are known for causing infections by forming biofilms on various abiotic surfaces, such as medical devices. However, a detailed characterization in terms of morphology and the molecular composition of the formed biofilms by this bacterium is sparse. The present study provides insights into the biofilm formation of E. cloacae SBP-8, an environmental isolate, on various surfaces. We performed assays to understand the biofilm-forming capability of the SBP-8 strain and characterized the adhering potential of the bacteria on the surface of different medical devices (foley latex catheter, enteral feeding tube, and glass) at different temperatures. We found that medical devices exhibited strong colonization by E. cloacae SBP-8. Using field emission-scanning electron microscopy (FE-SEM) studies, we characterized the biofilms as a function of time. It indicated stronger biofilm formation in terms of cellular density and EPS production on the surfaces. Further, we characterized the biofilm employing surface-enhanced Raman spectroscopy (SERS) and identified the vast heterogenic nature of the biofilm-forming molecules. Interestingly, we also found that this heterogeneity varies from the initial stages of biofilm formation until the maturation and dispersion. Our studies provide insights into biofilm composition over a period of time, which might aid in understanding the biofilm dispersion phases, to enhance the presently available treatment strategies.