Emergence of Salmonella Infantis carrying the pESI-like plasmid from eggs in egg grading and packing plants in Korea.

The plasmid of emerging S. Infantis (pESI) or pESI-like plasmid in Salmonella enterica Infantis are consistently reported in poultry and humans worldwide. However, there has been limited research on these plasmids of S. Infantis isolated from eggs. Therefore, this study aimed to analyze the prevalence and characteristics of S. Infantis carrying the pESI-like plasmid from eggs in egg grading and packing plants. In this study, the pESI-like plasmid was only detected in 18 (78.3%) of 23 S. Infantis isolates, and it was absent in the other 9 Salmonella serovars. In particular, S. Infantis isolates carrying the pESI-like plasmid showed the significantly higher resistance to ß-lactams, phenicols, cephams, aminoglycosides, quinolones, sulfonamides, and tetracyclines than Salmonella isolates without the pESI-like plasmid (p < 0.05). Moreover, all S. Infantis isolates carrying the pESI-like plasmid were identified as extended-spectrum ß-lactamase (ESBL) producer, harboring the blaCTX-M-65 and blaTEM-1 genes, and carried non-ß-lactamase resistance genes (ant(3'')-Ia, aph(4)-Ia, aac(3)-IVa, aph(3')-Ic, sul1, tetA, dfrA14, and floR) against five antimicrobial classes. However, all isolates without the pESI-like plasmid only carried the blaTEM-1 gene among the ß-lactamase genes, and either had no non-ß-lactamase resistance genes or harbored non-ß-lactamase resistance genes against one or two antimicrobial classes. Furthermore, all S. Infantis isolates carrying the pESI-like plasmid carried class 1 and 2 integrons and the aadA1 gene cassette, but none of the other isolates without the pESI-like plasmid harbored integrons. In particular, D87Y substitution in the gyrA gene and IncP replicon type were observed in all the S. Infantis isolates carrying the pESI-like plasmid but not in the S. Infantis isolates without the pESI-like plasmid. The distribution of pulsotypes between pESI-positive and pESI-negative S. Infantis isolates was clearly distinguished, but all S. Infantis isolates were classified as sequence type 32, regardless of whether they carried the pESI-like plasmid. This study is the first to report the characteristics of S. Infantis carrying the pESI-like plasmid isolated from eggs and can provide valuable information for formulating strategies to control the spread of Salmonella in the egg industry worldwide.

Association Between Biofilm Formation and Extended-Spectrum Beta-Lactamase Production in Klebsiella pneumoniae Isolated from Fresh Fruits and Vegetables.

The presence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in fresh fruits and vegetables is a growing public health concern. The primary objective of this study was to investigate the relationship between biofilm formation and extended-spectrum ß-lactamase (ESBL) production in K. pneumoniae strains obtained from fresh fruits and vegetables. Out of 120 samples analysed, 94 samples (78%) were found to be positive for K. pneumoniae. Among the K. pneumoniae strains isolated, 74.5% were from vegetables, whereas the remaining (25.5%) were from fresh fruits. K. pneumoniae isolates were resistant to at least three different classes of antibiotics, with ceftazidime (90%) and cefotaxime (70%) showing the highest resistance rates. While the high occurrence of ESBL-producing and biofilm-forming K. pneumoniae strains were detected in vegetables (73.5% and 73.7%, respectively), considerable amounts of the same were also found in fresh fruits (26.5% and 26.3%, respectively). The results further showed a statistically significant (P < 0.001) association between biofilm formation and ESBL production in K. pneumoniae strains isolated from fresh fruits and vegetables. Furthermore, the majority (81%) of the ESBL-producing strains harbored the blaCTX-M gene, while a smaller proportion of strains carried the blaTEM gene (30%), blaSHV gene (11%) or blaOXA (8%). This study highlights the potential public health threat posed by K. pneumoniae in fresh fruits and vegetables and emphasizes the need for strict surveillance and control measures.

Global distribution and genetic characterization of blaOXA-positive plasmids in Escherichia coli.

In recent years, the emergence of blaOXA-encoding Escherichia coli (E. coli) poses a significant threat to human health. Here, we systematically analyzed the global geographic distribution and genetic characteristics of 328 blaOXA-positive E. coli plasmids based on NCBI database. Twelve blaOXA variants have been discovered, with blaOXA-1 (57.93%) being the most common, followed by blaOXA-10 (11.28%) and blaOXA-48 (10.67%). Our results suggested that blaOXA-positive E. coli plasmids were widespread in 40 countries, mainly in China, the United States, and Spain. MLST analysis showed that ST2, ST43, and ST471 were the top three host STs for blaOXA-positive plasmids, deserving continuing attention in future surveillance program. Network analysis revealed a correlation between different blaOXA variants and specific antibiotic resistance genes, such as blaOXA-1 and aac (6')-Ib-cr (95.79%), blaOXA-181 and qnrS1 (87.88%). The frequent detection of aminoglycosides-, carbapenems- and even colistin-related resistance genes in blaOXA-positive plasmids highlights their multidrug-resistant potential. Additionally, blaOXA-positive plasmids were further divided into eight clades, clade I-VIII. Each clade displayed specificity in replicon types and conjugative transfer elements. Different blaOXA variants were associated with specific plasmid lineages, such as blaOXA-1 and IncFII plasmids in clade II, and blaOXA-48 and IncL plasmids in clade I. Overall, our findings provide a comprehensive insight into blaOXA-positive plasmids in E. coli, highlighting the role of plasmids in blaOXA dissemination in E. coli.

Whole-genome sequencing analysis of multidrug-resistant Serratia marcescens isolates in an intensive care unit in Brazil.

INTRODUCTION: Serratia marcescens is an opportunistic pathogen found ubiquitously in the environment and associated with a wide range of nosocomial infections. This multidrug-resistant bacterium has been a cause of concern for hospitals and healthcare facilities due to its ability to spread rapidly and cause outbreaks. Next generation sequencing genotyping of bacterial isolates has proven to be a valuable tool for tracking the spread and transmission of nosocomial infections. This has allowed for the identification of outbreaks and transmission chains, as well as determining whether cases are due to endogenous or exogenous sources. Evidence of nosocomial transmission has been gathered through genotyping methods. The aim of this study was to investigate the genetic diversity of carbapenemase-producing S. marcescens in an outbreak at a public hospital in Cuiaba, MT, Brazil. METHODOLOGY: Ten isolates of S. marcenses were sequenced and antibiotic resistance profiles analyzed over 12 days. RESULTS: The isolates were clonal and multidrug resistant. Gentamycin and tigecycline had sensitivity in 90% and 80% isolates, respectively. Genomic analysis identified several genes that encode ß-lactamases, aminoglycoside-modifying enzymes, efflux pumps, and other virulence factors. CONCLUSIONS: Systematic surveillance is crucial in monitoring the evolution of S. marcescens genotypes, as it can lead to early detection and prevention of outbreaks.

First Record of the Isolation of blaNDM-1-Producing Enterotoxigenic Enterobacter cloacae ssp. cloacae in Baghdad/Iraq.

BACKGROUND: Antibiotic resistance is a major problem threatening human beings. The genetic determinants that carry resistance genes can be transmitted in several ways in clinical and food environments. Hence, this research study aimed to investigate the presence of New Delhi metallo-beta-lactamase-1 (blaNDM-1) produced by enterotoxigenic Enterobacter cloacae in both clinical and food samples. METHODS AND RESULTS: Twenty-four isolates of Enterobacter spp. were isolated, seven isolates from food samples and 17 isolates from blood taken from neonates and children (1 day - 10 years old) resident in a children's hospital. Antibiotic susceptibility test to 14 antibiotics was performed for all isolates. Enterotoxigenicity of the clinical and foodborne isolates was detected phenotypically using Suckling mouse bioassay. Genomic deoxyribonucleic acid (DNA) was extracted from the isolated Enterobacter spp. that were detected resistant to imipenem. Polymerase chain reaction (PCR) was used to amplify blaNDM-1 gene followed by sequencing. The results of the bioassay revealed that 64.28% of E. cloacae ssp. cloacae isolates were enterotoxigenic. Two E. cloacae ssp. cloacae were imipenem resistant. CONCLUSIONS: This study showed that one isolate from a male child 1 < year was bla NDM-1 positive that was con-firmed by sequencing. This is the first report that revealed blaNDM-1 producing Enterobacter cloacae in Iraq.

Inappropriate use of antibiotic enhances antibiotic resistance dissemination in ESBL-EC: Role of ydcz in outer membrane vesicles biogenesis and protein transport.

Extended-spectrumß-lactam producing Escherichia coli (ESBL-EC) readily colonizes live poultry and serves as a major source of contamination in retail chicken meat, posing significant threats to public health. This study aims to investigate the impact of inappropriate antibiotic use on the dissemination and exacerbation of antibiotic resistance in ESBL-EC and explore the underlying molecular mechanisms. Through experimental analysis, we propose a hypothesis that inappropriate antibiotic use may exacerbate resistance by affecting vesicle formation and protein secretion. Experimental results demonstrate that under the influence of amoxicillin, the concentration of proteins secreted in outer membrane vehicles (OMVs) by ESBL-EC significantly increases, along with a significant upregulation in the expression of the CTX-M-55-type Extended-spectrum beta-lactamase (CTX-M-55). Proteomic analysis and differential gene knockout experiments identified the key protein YdcZ, associated with OMVs formation and protein transportation in ESBL-EC under amoxicillin treatment. Further investigations reveal direct interactions between YdcZ and other proteins (YdiH and BssR). Upon ydcz gene knockout, a significant decrease in protein concentration within OMVs is observed, accompanied by a noticeable reduction in protection against sensitive bacteria. These findings suggest a critical role of YdcZ in regulating the process of protein transportation to OMVs in ESBL-EC under the influence of amoxicillin. In summary, our research uncovers the significant role of inappropriate antibiotic use in promoting the secretion of OMVs by ESBL-EC, aiding the survival of antibiotic-sensitive bacteria in the vicinity of infection sites. These findings provide new insights into the mechanisms underlying antibiotic-induced bacterial resistance dissemination and offer novel avenues for exploring prevention and control strategies against bacterial resistance propagation.

Prevalence of ST1049-KL5 carbapenem-resistant Klebsiella pneumoniae with a blaKPC-2 and blaNDM-1 co-carrying hypertransmissible IncM1 plasmid.

Infection caused by KPC and NDM carbapenemases co-producing Klebsiella pneumoniae (KPC_NDM_CRKP) poses serious public health concerns. Here, we elucidate the prevalence of a hypertransmissible lncM1 plasmid, pKPC_NDM, co-carrying blaKPC-2 and blaNDM-1 genes in sequence type 1049 K_locus 5 (ST1049-KL5) KPC_NDM_CRKP isolates. Genetic and clonal relatedness analyses using pulsed-field gel electrophoresis, single nucleotide polymorphism analysis and core genome multilocus sequence typing suggested clonal dissemination of ST1049-KL5 KPC_NDM_CRKP strains in our hospital. Whole genome sequencing identified an identical 76,517 bp- blaKPC-2 and blaNDM-1 genes co-carrying IncM1 plasmid pKPC_NDM and a pLVPK-like hypervirulent plasmid in all ST1049-KL5 KPC_NDM_CRKP isolates. pKPC_NDM shared 100% identity with a previously sequenced plasmid CRKP35_unnamed4, demonstrating high transferability in conjugation assay, with conjugation frequencies reaching 10-4 and 10-5 in Escherichia coli and K. pneumoniae recipients, respectively. It also maintained favorable stability and flexible compatibility, with retention rates exceeding 80% after 10 days of continuous passage, and could be compatible with pre-existing blaKPC- or blaNDM-carrying plasmids in recipient strains. This study summarizes the characteristics of KPC_NDM_CRKP outbreaks and highlights the importance of ongoing surveillance and infection control strategies to address the challenges posed by ST1049 K. pneumoniae strains.

ß-lactamase expression induces collateral sensitivity in Escherichia coli.

Major antibiotic groups are losing effectiveness due to the uncontrollable spread of antimicrobial resistance (AMR) genes. Among these, ß-lactam resistance genes -encoding ß-lactamases- stand as the most common resistance mechanism in Enterobacterales due to their frequent association with mobile genetic elements. In this context, novel approaches that counter mobile AMR are urgently needed. Collateral sensitivity (CS) occurs when the acquisition of resistance to one antibiotic increases susceptibility to another antibiotic and can be exploited to eliminate AMR selectively. However, most CS networks described so far emerge as a consequence of chromosomal mutations and cannot be leveraged to tackle mobile AMR. Here, we dissect the CS response elicited by the acquisition of a prevalent antibiotic resistance plasmid to reveal that the expression of the ß-lactamase gene blaOXA-48 induces CS to colistin and azithromycin. We next show that other clinically relevant mobile ß-lactamases produce similar CS responses in multiple, phylogenetically unrelated E. coli strains. Finally, by combining experiments with surveillance data comprising thousands of antibiotic susceptibility tests, we show that ß-lactamase-induced CS is pervasive within Enterobacterales. These results highlight that the physiological side-effects of ß-lactamases can be leveraged therapeutically, paving the way for the rational design of specific therapies to block mobile AMR or at least counteract their effects.

Prevalence of the CRISPR-cas system and its association with antibiotic resistance in clinical Klebsiella pneumoniae isolates.

BACKGROUND AND OBJECTIVE(S): CRISPR-Cas is a prokaryotic adaptive immune system that protects bacteria and archaea against mobile genetic elements (MGEs) such as bacteriophages plasmids, and transposons. In this study, we aimed to assess the prevalence of the CRISPR-Cas systems and their association with antibiotic resistance in one of the most challenging bacterial pathogens, Klebsiella pneumoniae. MATERIALS AND METHODS: A total of 105 K. pneumoniae isolates were collected from various clinical infections. Extended-spectrum ß-lactamases (ESBLs) phenotypically were detected and the presence of ESBL, aminoglycoside-modifying enzymes (AME), and CRISPR-Cas system subtype genes were identified using PCR. Moreover, the diversity of the isolates was determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR. RESULTS: Phenotypically, 41.9% (44/105) of the isolates were found to be ESBL producers. A significant inverse correlation existed between the subtype I-E CRISPR-Cas system's presence and ESBL production in K. pneumoniae isolates. Additionally, the frequency of the ESBL genes blaCTX-M1 (3%), blaCTX-M9 (12.1%), blaSHV (51.5%), and blaTEM (33.3%), as well as some AME genes such as aac(3)-Iva (21.2%) and ant(2'')-Ia (3%) was significantly lower in the isolates with the subtype I-E CRISPR-Cas system in comparison to CRISPR-negative isolates. There was a significant inverse correlation between the presence of ESBL and some AME genes with subtype I-E CRISPR-Cas system. CONCLUSION: The presence of the subtype I-E CRISPR-Cas system was correlated with the antibiotic-resistant gene (ARGs). The isolates with subtype I-E CRISPR-Cas system had a lower frequency of ESBL genes and some AME genes than CRISPR-negative isolates.

Widespread prevalence of plasmid-mediated blaCTX-M type extended-spectrum beta-lactamase Escherichia coli in backyard broiler production systems in the United States.

Extended-spectrum beta-lactamase (ESBL) Escherichia coli (E. coli) is an emerging pathogen of high concern given its resistance to extended-spectrum cephalosporins. Broiler chicken, which is the number one consumed meat in the United States and worldwide, can be a reservoir of ESBL E. coli. Backyard poultry ownership is on the rise in the United States, yet there is little research investigating prevalence of ESBL E. coli in this setting. This study aims to identify the prevalence and antimicrobial resistance profiles (phenotypically and genotypically) of ESBL E. coli in some backyard and commercial broiler farms in the U.S. For this study ten backyard and ten commercial farms were visited at three time-points across flock production. Fecal (n = 10), litter/compost (n = 5), soil (n = 5), and swabs of feeders and waterers (n = 6) were collected at each visit and processed for E. coli. Assessment of ESBL phenotype was determined through using disk diffusion with 3rd generation cephalosporins, cefotaxime and ceftazidime, and that with clavulanic acid. Broth microdilution and whole genome sequencing were used to investigate both phenotypic and genotypic resistance profiles, respectively. ESBL E. coli was more prevalent in backyard farms with 12.95% of samples testing positive whereas 0.77% of commercial farm samples were positive. All isolates contained a blaCTX-M gene, the dominant variant being blaCTX-M-1, and its presence was entirely due to plasmids. Our study confirms concerns of growing resistance to fourth generation cephalosporin, cefepime, as roughly half (51.4%) of all isolates were found to be susceptible dose-dependent and few were resistant. Resistance to non-beta lactams, gentamicin and ciprofloxacin, was also detected in our samples. Our study identifies prevalence of blaCTX-M type ESBL E. coli in U.S. backyard broiler farms, emphasizing the need for interventions for food and production safety.

River waters in Greece: A reservoir for clinically relevant extended-spectrum-ß-lactamases-producing Escherichia coli.

In the current study, the genotypic characteristics such as antimicrobial resistance and virulence genes, and plasmid replicons and phenotypic characteristics such as biofilm formation and antimicrobial resistance of 87 extended-spectrum beta-lactamase (ESBL)-producing E. coli (ESBL-Ec) isolated from 7 water bodies in northern Greece were investigated. Our data show a high prevalence (60.0 %) of ESBL-Ec in surface waters that exhibit high genetic diversity, suggesting multiple sources of their transmission into the aquatic environment. When evaluating the antimicrobial resistance of isolates, wide variation in their resistance profiles has been detected, with all isolates being multi-drug resistant (MDR). Regarding biofilm formation capacity and phylogenetic groups, the majority (54.0 %, 47/87) of ESBL-Ec were classified as no biofilm producers mainly assigned to phylogroup A (35.6 %; 31/87), followed by B2 (26.5 %; 23/87). PCR screening showed that a high proportion of the isolates tested positive for the blaCTX-M-1 group genes (69 %, 60/87), followed by blaTEM (55.2 %, 48/87), blaOXA (25.3 %, 22/87) and blaCTX-M-9 (17.2 %, 15/87). A subset of 28 ESBL-Ec strains was further investigated by applying whole genome sequencing (WGS), and among them, certain clinically significant sequence types were identified, such as ST131 and ST10. The corresponding in silico analysis predicted all these isolates as human pathogens, while a significant proportion of WGS-ESBL-Ec were assigned to extraintestinal pathogenic E. coli (ExPEC; 32.1 %), and urinary pathogenic E. coli (UPEC; 28.6 %) pathotypes. Comparative phylogenetic analysis, showed that the genomes of the ST131-O25:H4-H30 isolates are genetically linked to the human clinical strains. Here, we report for the first time the detection of a plasmid-mediated mobile colistin resistance gene in ESBL-Ec in Greece isolated from an environmental source. Overall, this study underlines the role of surface waters as a reservoir for antibiotic resistance genes and for presumptive pathogenic ESBL-Ec.

Unveiling the ecological landscape of bacterial ß-lactam resistance in Delhi-national capital region, India: An emerging health concern.

Inappropriate antibiotic use not only amplifies the threat of antimicrobial resistance (AMR), moreover exacerbates the spread of resistant bacterial strains and genes in the environment, underscoring the critical need for effective research and interventions. Our aim is to assess the prevalence and resistance characteristics of ß-lactam resistant bacteria (BLRB) and ß-lactamase resistant bacterial genes (BLRBGs) under various environmental conditions within Delhi NCR, India. Using a culture-dependent method, we isolated 130 BLRB from 75 different environmental samples, including lakes, ponds, the Yamuna River, agricultural soil, aquatic weeds, drains, dumping yards, STPs, and gaushalas. Tests for antibiotic susceptibility were conducted in addition to phenotypic and genotypic identification of BLs and integron genes. The water and sediment samples recorded an average bacterial abundance of 3.6 × 106 CFU/mL and an average ampicillin-resistant bacterial count of 2.2 × 106 CFU/mL, which can be considered a potent reservoir of BLRB and BLRBGs. The majority of the BLRB discovered are opportunistic pathogens from the Bacillus, Aeromonas, Pseudomonas, Enterobacter, Escherichia, and Klebsiella genera, with Multiple Antibiotic Resistance (MAR) index ≥0.2 against a wide variety of ß-lactams and ß-lactamase (BLs) inhibitor combinations. The antibiotic resistance pattern was similar in the case of bacteria isolated from STPs. Meanwhile, bacteria isolated from other sources were diverse in their antibiotic resistance profile. Interestingly, we discovered that 10 isolates of various origins produce both Extended Spectrum BLs and Metallo BLs, as well as found harboring blaTEM, blaCTX, blaOXA, blaSHV, int-1, and int-3 genes. Enterobacter cloacae (S50/A), a common nosocomial pathogen isolated from Yamuna River sediment samples at Nizamuddin point, possesses three BLRBGs (blaTEM, blaCTX, and blaOXA) and a MAR index of 1.0, which is a major cause for concern. Therefore, identifying the source, origin and dissemination of BLRB and BLRGs in the environment is of the utmost importance for designing effective mitigation approaches to reduce a load of antimicrobial resistance factors in the environmental settings.

Mortality factors and antibiotic options in carbapenem-resistant Enterobacterales bloodstream infections: Insights from a high-prevalence setting with co-occurring NDM-1 and OXA-48.

Bloodstream infections (BSI) caused by carbapenem-resistant Enterobacterales (CRE) are associated with a high mortality rate. This study aimed to investigate factors associated with 14-day mortality and identify a potential treatment option. A retrospective cohort study was conducted on patients with CRE-BSI in Thailand from 2015 to 2020. The multivariate Cox proportional-hazards model was employed to identify factors influencing 14-day mortality. Out of 134 diagnosed cases of CRE-BSI, the all-cause 14-day mortality rate was 35.1%. The most prevalent organism isolated was Klebsiella pneumoniae (85.8%), followed by Escherichia coli (11.9%). Among the 60 isolates tested for carbapenemase genes, the majority exhibited co-occurring blaNDM-1 and blaOXA-48 (51.7%), followed by blaOXA-48 (31.7%) and blaNDM-1 (15.0%). In the multivariate analysis, neutropenia (adjusted hazard ratio [aHR] 2.55; 95% confidence interval [95%CI] 1.28-5.06; p = 0.008), sepsis/septic shock (aHR 3.02; 95%CI 1.33-6.86; p = 0.008), and previous metronidazole exposures (aHR 3.58; 95%CI 1.89-6.71; p < 0.001) were identified as independent factors for 14-day mortality. The fosfomycin-based regimen was found to be protective (aHR 0.37; 95%CI 0.15-0.92; p = 0.032). In patients with CRE-BSI, particularly in regions with a high occurrence of co-occurring blaNDM-1 and blaOXA-48, neutropenia, sepsis/septic shock, and previous metronidazole exposures emerged as independent risk factors for mortality. Moreover, the fosfomycin-based regimen showed an improvement in the survival rate.

The detection of KPC-2, NDM-1, and VIM-2 carbapenemases in international clones isolated from fresh vegetables highlights an emerging food safety issue.

Resistance to carbapenems emerged in clinical settings and has rapidly spread to other sectors, such as food and the environment, representing a One Health problem. In this regard, vegetables contaminated by critical priority pathogens have raised global concerns. Here, we have performed a whole-genome sequence-based analysis of extensively drug-resistant Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa strains isolated from cabbage, spinach, and lettuce, respectively. Genomic analysis revealed the emergence of international and high-risk clones belonging to ST340, ST155, and ST233, harboring a broad resistome to clinically important antimicrobials. In this context, K. pneumoniae, E. coli, and P. aeruginosa strains carried blaKPC-2, blaNDM-1, and blaVIM-2, respectively. The blaKPC-2 gene with a non-Tn4401 element (NTEKPC-Ic) was located on an IncX3-IncU plasmid, while the blaVIM-2 gene was associated with a Tn402-like class 1 integron, In559, on the chromosome. Curiously, the blaNDM-1 gene coexisted with the blaPER-2 gene on an IncC plasmid and the regions harboring both genes contained sequences of Tn3-like element ISKox2-like family transposase. Comparative genomic analysis showed interspecies and clonal transmission of carbapenemase-encoding genes at the human-animal-environmental interface. These findings raise a food safety alert about hospital-associated carbapenemase producers, supporting that fresh vegetables can act as a vehicle for the spread of high-risk clones.

Detection of carbapenemase producing Acinetobacter baumannii ST19 from Georgia and Ukraine carrying bla OXA-23, bla OXA-72, and/or bla NDM-5, December 2019 to June 2023.

In 2003-2023, amid 5,436 Acinetobacter baumannii isolates collected globally through the Multidrug-Resistant Organism Repository and Surveillance Network, 97 were ST19PAS, 34 of which carbapenem-resistant. Strains (n = 32) sampled after 2019 harboured either bla OXA-23, bla OXA-72, and/or bla NDM-5. Phylogenetic analysis of the 97 isolates and 11 publicly available ST19 genomes revealed three sub-lineages of carbapenemase-producing isolates from mainly Ukraine and Georgia, including an epidemic clone carrying all three carbapenemase genes. Infection control and global surveillance of carbapenem-resistant A. baumannii remain important.

Dissemination of clinical Escherichia coli strains harboring mcr-1, blaNDM-7 and siderophore-producing plasmids in a Chinese hospital.

BACKGROUND: Carbapenem-resistant E. coli (CREco) pose a significant public health threat due to their multidrug resistance. Colistin is often a last-resort treatment against CREco; however, the emergence of colistin resistance gene mcr-1 complicates treatment options. METHODS: Two E. coli strains (ECO20 and ECO21), recovered from hospitalized patients in distinct wards, exhibited resistance to carbapenems and colistin. Whole-genome sequencing and phenotypic characterization were employed to study resistance patterns, plasmid profiles, transferability of resistance and virulence genes, and siderophore production capabilities. Comparative genome analysis was used to investigate the genetic environment of mcr-1, blaNDM-7, and virulence clusters. RESULTS: Both E. coli strains exhibited thr presence of both mcr-1 and blaNDM-7 genes, showing high resistance to multiple antibiotics. Genomic analysis revealed the clonal transmission of these strains, possessing identical plasmid profiles (pMCR, pNDM, and pVir) associated with colistin resistance, carbapenem resistance, and virulence factors. Conjugation experiments confirmed the transferability of these plasmids, indicating their potential to disseminate resistance and virulence traits to other strains. Comparative genomic analyses unveiled the distribution of mcr-1 (IncX4-type) and blaNDM (IncX3-type) plasmids across diverse bacterial species, emphasizing their adaptability and threat. The novelty of pVir indicates its potential role in driving the evolution of highly adaptable and pathogenic strains. CONCLUSIONS: Our findings underscore the co-occurrence of mcr-1, blaNDM-7, and siderophore-producing plasmids in E. coli, which poses a significant concern for global health. This research is crucial to unravel the complex mechanisms governing plasmid transfer and recombination and to devise robust strategies to control their spread in healthcare settings.

Genetic characteristics of chromosomally integrated carbapenemase gene (blaNDM-1) in isolates of Proteus mirabilis.

OBJECTIVE: This study aims to conduct an in-depth genomic analysis of a carbapenem-resistant Proteus mirabilis strain to uncover the distribution and mechanisms of its resistance genes. METHODS: The research primarily utilized whole-genome sequencing to analyze the genome of the Proteus mirabilis strain. Additionally, antibiotic susceptibility tests were conducted to evaluate the strain's sensitivity to various antibiotics, and related case information was collected to analyze the clinical distribution characteristics of the resistant strain. RESULTS: Study on bacterial strain WF3430 from a tetanus and pneumonia patient reveals resistance to multiple antibiotics due to extensive use. Whole-genome sequencing exposes a 4,045,480 bp chromosome carrying 29 antibiotic resistance genes. Two multidrug-resistant (MDR) gene regions, resembling Tn6577 and Tn6589, were identified (MDR Region 1: 64.83 Kb, MDR Region 2: 85.64 Kbp). These regions, consist of integrative and conjugative elements (ICE) structures, highlight the intricate multidrug resistance in clinical settings. CONCLUSION: This study found that a CR-PMI strain exhibits a unique mechanism for acquiring antimicrobial resistance genes, such as blaNDM-1, located on the chromosome instead of plasmids. According to the results, there is increasing complexity in the mechanisms of horizontal transmission of resistance, necessitating a comprehensive understanding and implementation of targeted control measures in both hospital and community settings.

International and regional spread of carbapenem-resistant Klebsiella pneumoniae in Europe.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) are of particular concern due to the spread of antibiotic resistance genes associated with mobile genetic elements. In this study, we collected 687 carbapenem-resistant strains recovered among clinical samples from 41 hospitals in nine Southern European countries (2016-2018). We identified 11 major clonal lineages, with most isolates belonging to the high-risk clones ST258/512, ST101, ST11, and ST307. blaKPC-like was the most prevalent carbapenemase-encoding gene (46%), with blaOXA-48 present in 39% of isolates. Through the combination and comparison of this EURECA collection with the previous EuSCAPE collection (2013-2014), we investigated the spread of high-risk clones circulating in Europe exhibiting regional differences. We particularly found blaKPC-like ST258/512 in Greece, Italy, and Spain, blaOXA-48 ST101 in Serbia and Romania, blaNDM ST11 in Greece, and blaOXA-48-like ST14 in Türkiye. Genomic surveillance across Europe thus provides crucial insights for local risk mapping and informs necessary adaptions for implementation of control strategies.

Virulent-MDR-ESBL E. coli and Klebsiella pneumoniae report from North Sinai calves diarrhea and in vitro antimicrobial by Moringa oleifera.

The health of calves has a significant impact on the production of cows and livestock. Some desert plants have pharmacological importance, as they can be used to reduce antibiotic resistance. Our hypothesis is designed to detect Virulent- Multidrug-Resistant and Extended- spectrum Beta- lactamase Enterobacteriaceae (Virulent-MDR-ESBL Enterobacteriaceae and to determine whether Moringa oleifera has antibacterial activity against the detected isolates. A total of 39 Enterobacteriaceae isolates from 28 diarrheic samples were collected from calves aged between 20 days and 20 months from 3 different flocks in North Sinai, Sahl-Eltina region, Egypt. E.coli 46% (18/39), O157 13% (5/39), Klebsiella pneumoniae 41% (16/39). MDR members accounted for 87%, while ESBL isolates accounted for 43%. The antibacterial activity is represented by microdilution. Minimum inhibition concentration (MIC) for the methanol extract of Moringa oleifera ranged from 2.5,5,10, and 25mg/ ml among E.coli isolates, and O157 was susceptible to (2.5mg/ ml), Klebsiella pneumoniae isolates were susceptible to (5-50mg/ ml). Analysis of the methanol extract revealed that ferulic acid was the dominant phenolic compound with a concentration of 29,832 parts per million (ppm). In silico docking study expected the active site of ferulic acid to act on the tyrosine bacterial enzyme through Pi-alkyl, Pi-anion, Carbon hydrogen bonds, and extra ionic attractive interactions with copper ions which can stabilize ferulic acid inside the targeted pocket Diverse virulent gene profiles were observed in E. coli. The Shiga toxin-producing Escherichia coli (STEC) was reported in 83% of the isolated E. coli, while the DNA gyrase (gyrA) was harbored in 100% of Klebsiella pneumoniae isolates. Various profiles of antibiotic resistance genes for both E. coli and Klebsiella pneumoniae isolates were distinguished. blaTEM genes were detected in 99% of E. coli and 100% of Klebsiella pneumoniae. Sequence analysis for E. coli strain DRC-North Sinai-Eg was placed in accession numbers (OP955786) for the Shiga toxin 2 gene (Stx2A), (OP997748) and (OP997749) for the Adhesion to host cell gene (Eae). For the hemolysine gene (hylA), the accession number was (OP946183). Klebsiella pneumoniae strain DRC-North Sinai-Eg was placed in (OP946180) for (gyrA). This study has proven the broad range of Moringa oliefera's antibacterial effects in vitro against the virulent-MDR- ESBL E. coli and Klebsiella pneumoniae isolated from North Sinai calves diarrhea. These are congruent with the disability effect on bacterial tyrosinase enzyme through docking study therefore, we recommend the usage of this desert plant as a prospective feed additive, we endorse this as an antibacterial new insight natural source and for the medication of considered pathogens with zoonotic impacts.

Novel quinoxaline compound against extended-spectrum beta-lactamases producing bacteria.

OBJECTIVE: Extended-spectrum beta-lactamases (ESBLs) targeting beta-lactam antibiotics pose a major healthcare challenge. Carbapenems are known to be less impacted. However, the emergence of carbapenem-resistant strains can add further complexity to this existing challenge. With slow drug discovery and rapid resistance, repurposing existing drugs is crucial. This research study aims to provide insight into the antimicrobial effectiveness of 3-hydrazinoquinoxaline-2-thiol against diverse clinical ESBL-producing isolates. MATERIALS AND METHODS: The broth microdilution assay was conducted on a total of sixty-nine clinical ESBL-producing isolates to assess the minimum inhibitory concentrations (MICs) of 3-hydrazinoquinoxaline-2-thiol. The assay was conducted in triplicate, and the average MIC values were calculated. RESULTS: The most repeatedly observed MIC was 64 µg/ml (37.7%), followed by 256 µg/ml (23.2%) and 128 µg/ml (17.4%). Other MICs: 32 µg/ml (11.6%), 16 µg/ml (7.2%), 4-8 µg/ml (1.4%). CONCLUSIONS: This study demonstrated an effect of 3-hydrazinoquinoxaline-2-thiol on various ESBL-producing strains in vitro, indicating its promising therapeutic potential. To comprehensively understand the drug, rigorous testing, including pharmacokinetics, resistance assays, safety assessments, and exploration of potential synergies with other antibiotics against ESBL-producing organisms, is crucial.