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Escherichia coli is a Gram-negative ubiquitous bacteria occurring in a diversity of environments including water, soil, and the gastrointestinal tract of humans and warm-blooded animals, being classified into commensal and pathogenic strains. While empirical antibiotic therapy with fluoroquinolones, such a ciprofloxacin and norfloxacin, has been a common practice, resistance to broad-spectrum cephalosporins, mediated by extended-spectrum β-lactamases (ESBLs), has been alerted as a critical priority by the World Health Organization. Additionally, the convergence of virulence and resistance has been observed in some E. coli strains, which enable these bacteria to infect humans and animals, and can jeopardize their health. Mucoviscosity phenotype has been frequently described in highly-virulent Klebsiella pneumoniae strains, whereas this phenotypic behavior remains rarely reported in E. coli. Herein, we report microbiological, genomic, and anti-phagocytic activity of ciprofloxacin-induced mucoviscosity in a CTX-M-15 (ESBL)-positive E. coli. Noteworthy, genomic analysis revealed virulence genes responsible for the synthesis of the K23 capsule type, previously described in hypermucoviscous K. pneumoniae lineages, whereas phagocytosis assays confirmed the ability of K23 E. coli strain to evade the immune system under mucoviscosity induction by ciprofloxacin treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Changes in antibiotic resistance of bacteria in three different wastewater treatment plants (WTP) were investigated to determine their role they play in the dissemination of multidrug resistant bacteria (MDR). Water samples were collected from downstream of three (WTP) from where pollution parameters were detected and high-performance Liquid chromatography (HPLC) coupled with an ultraviolet (UV) detector was used to measure antibiotic residues. In addition, 88 bacilli Gram-negative (BGN) were collected; activated sludge, aerated lagoons and natural lagoons, and tested for resistance against 18 βeta-lactam antibiotics. We evaluated the production of Extended-spectrum β-lactamases (ESBLs) in isolates that were further confirmed by applying the automated VITEK-2 system. Among the 88 isolates, Klebsiella pneumoniae (60 %),Escherichia coli (23,33 %) and Serratia marcescens(32,14 %) were the most isolated species. The abundance of the CTX ESBL-producers strains was significantly higher in natural lagoons that may have a greater influence on the occurrence and prevalence of MDR, with the MAR index being the lowest for Serratia marcescens (0,27) and the highest for Citrobacter koseri (0,88), serving as a hotspot environment for the evolution of Antibiotic resistance. Controlling or avoiding this kind of treatment can reduce the chance of MDRs entrance to the environment., Competing Interests: Declaration of Competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background and Objectives: The bacterial adaptive immune system known as CRISPR-Cas (clustered regularly interspersed short palindromic repeats-CRISPR-associated protein) is engaged in defense against various mobile genetic elements (MGEs) such as plasmids and bacteriophages. The purpose of this study was to characterize the CRISPR-Cas systems in carbapenem-resistant Klebsiella pneumoniae isolates and assess any possible correlation between these systems with antibiotic susceptibility, biofilm formation, and bacterial virulence., Materials and Methods: A total of 156 CRKP isolates were collected from different specimens of the inpatients. Biofilm formation and antibiotic susceptibility testing were evaluated using standard methods. Furthermore, the CRISPR-Cas system subtype genes, 11 carbapenemase genes, and 17 virulence genes were identified using separate standard PCR reactions. The diversity of the isolates was determined by random amplified polymorphic DNA (RAPD)-PCR., Results: The development of biofilms and antibiotic susceptibility of several CRKP isolates were significantly correlated with the absence or presence of the CRISPR-Cas system. PCR analysis of carbapenemase genes revealed that the frequency of the bla NDM-1 gene was significantly higher in the isolates with the subtype I-E CRISPR-Cas system. Moreover, the isolates with the subtype I-E CRISPR-Cas system exhibited a propensity to possess more virulence genes such as allS, k2A, wcaG, aerobactin, rmpA, iroN, magA, rmpA2, kfu, iutA, iucB, ybtS, repA, and terW., Conclusion: CRISPR-Cas systems could affect the antibiotic susceptibility, capacity for biofilm formation, and virulence of Klebsiella pneumoniae. Our findings showed that the isolates containing the CRISPR-Cas system were moderate or strong biofilm producers and had a higher frequency of virulence genes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The increasing challenge of carbapenem antibiotics resistance caused by Pseudomonas aeruginosa is one of the global healthcare problems. P. aeruginosa is a significant opportunistic infection. For epidemiological reasons, identifying resistance genes is essential, and it is also desirable to quickly identify the techniques for producing carbapenemase enzymes. So, the study aims to determine the prevalence of beta-lactamase encoding genes (blaIMP, blaVIM, bla GIM, and bla SPM) phenotypically and genotypically in P. aeruginosa isolates to address the epidemiological spread of these genes in Baghdad city. The study identified P. aeruginosa isolates from various clinical sources by chemical characterization and VITEK 2 system, the antibiogram test, phenotypic screening carbapenem resistance by Combined disk synergy test (CDST), and conventional PCR were used to detect presence of VIM, IMP, SPM, and GIM genes. Bacterial susceptibility testing revealed (40 %) of isolates were resistant to Imipenem and (85 %) of them positive to CDST. Genotypic screening on phenotypic Metallo-β-lactamase isolates showed that (100 %) isolates contained blaVIM genes, blaGIM genes (88 %), whereas (65 %) isolates carried blaSPM genes. In this investigation, there was no evidence of blaIMP among carbapenem-resistant isolates. The study appeared high prevalence of multi-drug resistance P. aeruginosa isolates that produce carbapenemase enzymes and having β-lactamase genes in local hospitalized patients compared to global ratio. Expanding the sample size and types of enzymes screening in MDR P. aeruginosa should be the main focus in the future research., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sawsan M. Kareem reports administrative support was provided by Mustansiriyah University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background & Aims: The alarming rise of antibiotic resistance presents a substantial and worrisome issue within the context of biliary obstruction, specifically in the treatment of cholangitis. This abovementioned scenario underscores the critical importance of addressing extended spectrum β-lactamase (ESBL) producers in the biliary system to adequately tackle cholangitis using third-generation cephalosporins. Hence, we aimed to determine the frequency of ESBL and carbapenemases among biliary Escherichia coli and Klebsiella pneumoniae isolated from patients with biliary obstruction., Methods: In this cross-sectional study, bile samples were collected via aspiration from patients diagnosed with biliary obstruction during the endoscopic retrograde cholangiopancreatography (ERCP) procedure. Subsequent culturing of these samples was performed, followed by phenotypic and molecular assessments for the detection of ESBL- and carbapenemase-producing strains of E. coli and K. pneumoniae., Results: Approximately 23.5 % of patients with biliary obstruction harbored biliary ESBL-producers, with the majority (70.2 %) being diagnosed with cholangitis. Moreover, 2.1 % of patients had biliary carbapenemase-producing K. pneumoniae strains. Molecular analysis confirmed the high prevalence of bla CTX-M and bla TEM in E. coli, and bla TEM and bla SHV in K. pneumoniae. Additionally, the presence of biliary K. pneumoniae harboring bla KPC , bla NDM , and bla IMP was observed., Conclusion: Our study reveals a noteworthy observation that over half of patients experiencing biliary obstruction harbor ESBL-producing bacteria in their biliary tract. Notably, we discovered a significant link between ESBL producers and the risk of cholangitis. These findings raise important concerns regarding the suitability of employing third-generation cephalosporins as initial treatment for cholangitis and other similar biliary infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aim: This study aimed to analyze the prevalence, phenotypes, and carriage of resistance genes of carbapenem-resistant Klebsiella michiganensis strains isolated in our hospital., Method: ology: Four K. michiganensis strains were collected from January 2015 to December 2023. Antimicrobial susceptibility was tested using 21 antibiotics with the BD Phoenix™ M50 System. Whole-genome sequencing of the four strains was performed on an Illumina NovaSeq 6000 platform. Species identification was performed using Kleborate software, sequence type (ST) was performed using MLST, and prediction of antibiotic resistance genes and virulence genes were performed using ABRicate. PlasmidFinder was used to search for plasmids. Whole genome data from 211 strains of carbapenem-resistant K. michiganensis were downloaded from the NCBI database; together with the strains in this study, these data were used to construct an phylogenetic tree using genome single nucleotide polymorphisms (SNP)., Results: Antimicrobial susceptibility showed that K. michiganensis was highly resistant to β-lactams. For the three carbapenems, strain WF0046 was only resistant to ertapenem, while WF0047, WF0052, and WF0053 were resistant to all three carbapenems tested. The four strains of K. michiganensis only showed complete sensitivity to polymyxin E and tigecycline. The four K. michiganensis strains were found to have 43 resistance genes, and all carried carbapenem resistance genes; WF0046 carried the carbapenem resistance gene bla IMP-4 , while the other three strains carried bla NDM-1 . Among the other resistance genes, β-lactam resistance genes were predicted most (11 types), followed by eight types of aminoglycoside resistance genes. Of the strains characterized in this study, WF0046 belonged to ST158, WF0047 belonged to ST40, WF0052 belonged to ST533, and WF0053 belonged to ST13. These four strains, along with 211 carbapenem-resistant K. michiganensis strains downloaded from NCBI, were divided into five clades; WF0052 belonged to clade A, WF0046 belonged to clade C, and WF0047 and WF0053 both belonged to clade D. The four strains had relatively distant genetic relationships; WF0046, WF0047, and WF0053 were closely related to strains of human origin from other regions of China, while WF0052 was genetically close with a strain of K. michiganensis isolated in the United States., Conclusion: The strains of K. michiganensis from our hospital were resistant to multiple antibiotics, and all strains carried carbapenem resistance genes along with multiple other antibiotic resistance genes. The phylogenetic results showed that these four strains had distant genetic relationships and different ST types, indicating that they came from different sources and the possibility of polyclonal transmission., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The intensification of livestock farming has led to the widespread use of massive amounts of antibiotics worldwide. Poultry production, including white meat, eggs and the use of their manure as fertiliser, has been identified as one of the most crucial reservoirs for the emergence and spread of resistant bacteria, including E. coli in poultry as an important opportunistic pathogen representing the greatest biological hazard to human and wildlife health. Thus, this study aimed to analyse E. coli in the faecal carriage of healthy poultry flocks and to investigate the phenotypic and genotypic characteristics of antimicrobial resistance, including integrons genes and phylogenetic groups. A total of 431 cloacal swabs from apparently healthy poultry from four regions in Eastern Algeria from December 2021 to October 2022. 360 E. coli were isolated; from broilers (n = 151), broiler breeders (n = 91), laying hens (n = 72), and breeding hens (n = 46). Among this, 281 isolates exhibited multidrug resistance (MDR) phenotype, 17 of the 360 E. coli isolates exhibited ESBL, and one isolate exhibited both ESBL/pAmpC. A representative collection of 183 among 281 MDR E. coli was selected for further analysis by PCR to detect genes encoding resistance to different antibiotics, and sequencing was performed on all positive PCR products of bla CTX-M and bla CMY-2 genes. Phylogenetic groups were determined in 80 E. coli isolates (20 from each of the four kinds of poultry). The bla CTX-M gene was found in 16 (94.11 %) ESBL-producing E. coli isolates within 11 strains co-expressing the bla SHV gene and 8 strains co-expressing the bla TEM gene. Sequence analysis showed frequent diversity in CTX-M-group-1, with bla CTX-M-15 being the most predominant (n = 11), followed by bla CTX-M-1 (n = 5). The bla CMY-2 gene was detected only in one ESBL/pAmpC isolate. Among the 183 tested isolates, various antimicrobial resistance genes were found (number of strains) bla TEM (n = 121), bla SHV (n = 12), tetA (n = 100), tetB (n = 29), sul1(n = 67), sul2 (n = 32), qnrS (n = 45), qnrB (n = 10), qnrA (n = 1), catA1(n = 13), aac-(6')-Ib (n = 3). Furthermore, class 1 and class 2 integrons were found in 113 and 2 E. coli, respectively. The isolates were classified into multiple phylogroups, including A (35 %), B1 (27.5 %), B2 and D each (18.75 %). The detection of integrons and different classes of resistance genes in the faecal carriage of healthy poultry production indicates that commensal E. coli could potentially act as a reservoir for antimicrobial resistance, posing a significant One Health challenge encompassing the interconnected domains of human, animal health and the environment. Here, we present the first investigation to describe the diversity of bla CTX-M producing E. coli isolates with widespread detection of CTX-M-15 and CTX-M-1 in healthy breeders (Broiler and breeding hens) in Eastern Algeria., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The present study aimed to determine the presence of Klebsiella pneumoniae and Escherichia coli with extended-spectrum β-lactamase (ESBL)s property from treated wastewater effluents. Treated effluent samples were collected from two major water treatment plants which located at Avaniyapuram and Sakkimangalam, Madurai, Tamil Nadu, India. Among the 51 isolates, 56.86 % represented E. coli (18 from Avaniyapuram and 11 from Sakkimangalam) and 43.14 % were K. pneumoniae (7 from Avaniyapuram and 15 from Sakkimangalam). Based on the ESBL propensity, E. coli was overrepresented in the present study. All the isolates turned positive for ESBL, while 5.88 % of K. pneumoniae and 7.84 % of E. coli were positive for carbapenemases. Further, K. pneumoniae isolates from both sites showed 100 % resistance to beta-lactams, with resistance to other antibiotics such as tetracycline and meropenem. E. coli isolates were 100 % resistant to ceftazidime and cefuroxime, and 88.9 % were resistant to amoxicillin/clavulanate and ceftriaxone. The MAR indices observed in the present study for E. coli and K. pneumoniae were above the threshold value of 0.2 suggested a high risk of environmental contamination. These findings highlighted the need for routine surveillance at appropriate intervals for the presence of ESBL producing pathogens and other MDR pathogens in the environment to provide proper clinical management, develop various counter measures and policies to address and halt the spread of such potential threats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aim -To isolate bacteriophages targeting extended-spectrum beta-lactamase-producing K. pneumoniae and evaluate their effectiveness across diverse models, incorporating innovative alternatives in animal testing., Methods and Results: vB_kpnS-Kpn15 was isolated from sewage sample from Thane district. It produced a clear plaques on K. pneumoniae ATCC 700603. It has a flexible, non-contractile long tail and an icosahedral head and the Siphoviridae family of viruses in the order Caudovirales matched all of its structural criteria. Sequencing of vB_kpnS-Kpn15 revealed a 48,404 bp genome. The vB_KpnS-Kpn15 genome was found to contain 50 hypothetical proteins, of which 16 were found to possess different functions. The vB_KpnS-Kpn15 was also found to possess enzymes for its DNA synthesis. It was found to be lytic for the planktonic cells of K. pneumoniae and bactericidal for up to 48 h and potentially affected established K. pneumoniae biofilms. It demonstrated a broad host range and caused lytic zones on about 46 % of K. pneumoniae multi-drug resistant strains. In an in vitro wound and burn infection model, phage vB_kpnS-Kpn15 in combination with other phages resulted in successful cell proliferation and wound healing. Based on vB_kpnS-Kpn15's lytic properties, it can be incorporated in a bacteriophage cocktail to combat ESBL strains., Conclusions: The phages isolated during this research are better candidates for phage therapy, and therefore provide new and exciting options for the successful control of antibiotic-resistant bacterial infections in the future. The utilization of animal alternative models in this study elucidates cellular proliferation and migration, underscoring its significance in screening novel drugs with potential applications in the treatment of wound and burn infections., Significance and Impact of the Research: The findings of this research have implications for the creation of innovative, promising strategies to treat ESBL K. pneumoniae infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Staphylococcus aureus is a bacterial pathogen that causes bloodstream infections, pneumonia, and skin abscesses and is the primary pathogen responsible for medical devices associated with biofilm infections, accounting for approximately 70 % of cases. Therefore, the World Health Organization (WHO) has designated this microorganism as a top priority due to its role in causing over 20,000 bacteremia-related deaths in the US each year. The issue of pathogen resistance to antibiotics, mainly by a biofilm, further complicates these infections since biofilms render the bacterial colony impervious to antibiotics. However, many natural and synthetic substances also induce bacterial biofilm formation. Therefore, we investigated whether the most common active pharmaceutical ingredients (APIs) could induce biofilm formation in two clinical isolates of extended-spectrum beta-lactamase Staphylococcus aureus, one of them also methicillin-resistant (A2M) and two medical devices. We detected biofilm inducers, inhibitors, and destabilizers. Microbial strain, medical devices, API structure, and concentration influenced the modulatory effects of biofilm. In all devices tested, including microplates, FR18 duodenal probe, and respiratory probe, the clinic isolate methicillin-resistant S. aureus A2M exhibited lower susceptibility to biofilm formation than S. aureus A1. The anti-inflammatory acetaminophen, the hypocholesterolemic lovastatin, and the diuretic hydrochlorothiazide all induced biofilm. However, verapamil, an antihypertensive, and cetirizine, an antihistamine, inhibited biofilm on S. aureus A2M, while propranolol, another antihypertensive, inhibited biofilm on S. aureus A1. Additionally, diclofenac, an analgesic, and cetirizine destabilized the biofilm, resulting in more free bacteria and possibly making them more susceptible to external agents such as antibiotics. Nonetheless, further epidemiologic analyses and in vivo assays are needed to confirm these findings and to establish a correlation between drug use, the onset of bacterial infections in patients, and the use of medical devices. This work provides information about the probable clinical implications of drugs in patients using medical devices or undergoing surgical procedures. Inhibitory APIs could also be used as drug repurposing or templates to design new, more potent biofilm inhibitors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Antibiotic resistance is increasing among Gram-negative bacteria, prompting the development of new antibiotics as well as alternative treatment approaches. Klebsiella pneumoniae Carbapenemases (KPC) has become a major concern in the treatment of infections, since KPC-producing bacteria are resistant to a number of β -lactam and non β-lactam antibiotics in addition to hydrolyzing carbapenemases. The aim of this study is to examine the synergistic effect of human Glucose-dependent Insulinotropic Polypeptide (GIP) on KPC producer. The K. pneumoniae isolates were identified by using biochemical tests and PCR genotyping. The disc diffusion method was used to assess the antimicrobial susceptibility of each isolate, and the modified Hodge test (MHT) was used to find carbapenemases. Agar well diffusion and minimum inhibitory concentration (MIC) assays were used to validate the synergistic effect of GIP against Klebsiella species. MIC values of chosen antimicrobial compounds demonstrated a considerable synergism impact when combined with human GIP, particularly against KPC strains. The antibacterial activity of the antimicrobial compounds was boosted by 4-16 times due to human GIP, reducing the MIC values. The fractional inhibitory concentration (FIC) ranged from 0.032 to 0.25 for examined antibiotics. Thus, GIP can be considered an antibacterial adjuvant with the potential to supplement the current antibiotic spectrum., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The bacterium Escherichia coli is one of the main causes of urinary tract infections. The formation of bacterial biofilms, especially associated with the use of urinary catheters, contributes to the establishment of recurrent infections and the development of resistance to treatment. Strains of E. coli that produce extended-spectrum beta-lactamases (ESBL) have a greater ability to form biofilms. In addition, there is a lack of drugs available in the market with antibiofilm activity. Promethazine (PMZ) is an antihistamine known to have antimicrobial activity against different pathogens, including in the form of biofilms, but there are still few studies of its activity against ESBL E. coli biofilms. The aim of this study was to evaluate the antimicrobial activity of PMZ against ESBL E. coli biofilms, as well as to assess the application of this drug as a biofilm prevention agent in urinary catheters. To this end, the minimum inhibitory concentration and minimum bactericidal concentration of PMZ in ESBL E. coli strains were determined using the broth microdilution assay and tolerance level measurement. The activity of PMZ against the cell viability of the in vitro biofilm formation of ESBL E. coli was analyzed by the MTT colorimetric assay and its ability to prevent biofilm formation when impregnated in a urinary catheter was investigated by counting colony-forming units (CFU) and confirmed by scanning electron microscopy (SEM). PMZ showed bactericidal activity and significantly reduced (p < 0.05) the viability of the biofilm being formed by ESBL E. coli at concentrations of 256 and 512 μg/ml, as well as preventing the formation of biofilm on urinary catheters at concentrations starting at 512 μg/ml by reducing the number of CFUs, as also observed by SEM. Thus, PMZ is a promising candidate to prevent the formation of ESBL E. coli biofilms on abiotic surfaces., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for β-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of β-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC β-lactamase and extended-spectrum β-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Pseudomonas aeruginosa is a significant pathogen responsible for severe multisite infections with high morbidity and mortality rates. This study analyzed carbapenem-resistant Pseudomonas aeruginosa (CRPA) at a tertiary hospital in Shandong, China, using whole-genome sequencing (WGS). The objective was to explore the mechanisms and molecular characteristics of carbapenem resistance. A retrospective analysis of 91 isolates from January 2022 to March 2023 was performed, which included strain identification and antimicrobial susceptibility testing. WGS was utilized to determine the genome sequences of these CRPA strains, and the species were precisely identified using average nucleotide identification (ANI), with further analysis on multilocus sequence typing and strain relatedness. Some strains were found to carry the ampD and oprD genes, while only a few harbored carbapenemase genes or related genes. Notably, all strains possessed the mexA, mexE, and mexX genes. The major lineage identified was ST244, followed by ST235. The study revealed a diverse array of carbapenem resistance mechanisms among hospital isolates, differing from previous studies in mainland China. It highlighted that carbapenem resistance is not due to a single mechanism but rather a combination of enzyme-mediated resistance, AmpC overexpression, OprD dysfunction, and efflux pump overexpression. This research provides valuable insights into the evolutionary mechanisms and molecular features of CRPA resistance in this region, aiding in the national prevention and control of CRPA, and offering references for targeting and developing new drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Commercial broiler farms face challenges of extended spectrum beta-lactamase (ESBL)-producing Escherichia coli transmitted from both vertical and horizontal routes. Understanding the dynamics of ESBL-E. coli transmission in compromised biosecurity settings of small-scale rural poultry farms is essential. This study aimed to elucidate the probable transmission pathways of ESBL-E. coli in such settings, employing phylogenetic analysis and molecular docking simulations to explore the catalytic properties of β-lactamase variants. Sampling was conducted on a small-scale poultry farm in West Bengal, India, collecting 120 samples at three intervals during the broiler production cycle. E. coli isolates underwent resistance testing against eight antimicrobials, with confirmation of ESBL production. Genotypic analysis of ESBL genes and sequencing were performed, alongside molecular docking analyses and phylogenetic comparisons with publicly available sequences. Among 173 E. coli isolates, varying resistance profiles were observed, with complete resistance to cefixime and high resistance to amoxicillin and tetracycline. The incidence of ESBL-E. coli fluctuated over the production cycle, with dynamic changes in the prevalence of bla CTX-M -type and bla SHV -type genes. Phylogenetic analysis indicated partial clonal relationships with human clinical strains and poultry strains from the Indian subcontinent. Molecular docking confirmed the catalytic efficiencies of these ESBL variants. The study highlights probable vertical transmission of ESBL-E. coli and emphasizes drinking water as a potential source of horizontal transmission in small-scale poultry farms. Strict biosecurity measures could prevent the spread of antimicrobial-resistant bacteria in birds and their products in a small scale poultry farm., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: The emergence of carbapenem-resistant Pseudomonas putida (CRPP) has raised public awareness. This study investigated two strains from the Pseudomonas putida group that were resistant to carbapenem, tigecycline, and aztreonam-avibactam (ATM-AVI), with a focus on their microbial and genomic characteristics., Methods: We assessed the antibiotic resistance profile using broth dilution, disk diffusion, and E-test methods. Efflux pump phenotype testing and real-time quantitative PCR were employed to evaluate efflux pump activity in tigecycline resistance, while polymerase chain reaction was utilized to detect common carbapenem genes. Additionally, whole-genome sequencing was performed to analyze genomic characteristics. The transferability of bla IMP-1 and bla AFM-4 was assessed through a conjugation experiment. Furthermore, growth kinetics and biofilm formation were examined using growth curves and crystal violet staining., Results: Both strains demonstrated resistance to carbapenem, tigecycline, and ATM-AVI. Notably, NMP can restore sensitivity to tigecycline. Subsequent analysis revealed that they co-produced bla IMP-1 , bla AFM-4 , tmexCD-toprJ, and bla OXA-1041 , belonging to a novel sequence type ST268. Although they were closely related on the phylogenetic tree, they exhibited different levels of virulence. Genetic environment analysis indicated variations compared to prior studies, particularly regarding the bla IMP-1 and bla AFM-4 genes, which showed limited horizontal transferability. Moreover, it was observed that temperature exerted a specific influence on their biological factors., Conclusion: We initially identified two P. putida ST268 strains co-producing bla IMP-1 , bla AFM-4 , bla OXA-1041 , and tmexCD-toprJ. The resistance to tigecycline and ATM-AVI can be attributed to the presence of multiple drug resistance determinants. These findings underscore the significance of P. putida as a reservoir for novel antibiotic resistance genes. Therefore, it is imperative to develop alternative antibiotic therapies and establish effective monitoring of bacterial resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The accelerative outgrowth of extended spectrum β-lactamases (ESBLs) producing Escherichia coli (E. coli) and Proteus mirabilis (P. mirabilis) was mainly due to incessant relentless influence of antibiotics thereby increasing incidence and death rate which was obvious from the survey of ESBLs producing bacteria related health problem. In the present paper, we synthesized and characterized zinc oxide nanoparticles (ZnO NPs) employing using Camellia japonica leaf extract, bactericidal action of these NPs against extended spectrum β lactamases (ESBLs) positive E. coli and P. mirabilis clinical strains owing the minimal inhibitory concentration (MIC) percentage 83, 81% at 100 μg/mL concentration and minimum bactericidal concentration (MBC) final inhibiting concentration at 150 μg/mL. Moreover, confocal laser scanning microscopy (CLSM) and scanning electron microscope (SEM) results evident for loss of viability, cell shrinkage, disarrangement of cell membrane, and cell wall lysis activity of ZnO NPs against ESBLs positive E. coli BDUMS3 (KY617770) and P. mirabilis BDUMS1 (KY617768) strains. From the results, it was observed that the biologically synthesized ZnO NPs has stronger antibacterial effect against ESBLs producing bacterial strains. Nevertheless, current date there is no reports of antibacterial activity of metal oxide (ZnO) NPs against ESBL producing gram negative bacteria. Consequently, this finding is the first report in this respect and it shows band gap energy and ROS accumulation to damage the cell wall and inhibit the growth of ESBL producing gram negative strains., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Extended spectrum β-lactamases (ESBLs) are a group of enzymes that can hydrolyze a variety of β-lactams including fourth generation cephalosporins and compromise the efficacy of all β-lactams, except cephamycins and carbapenems. In the worldwide, the ESBL group of enzymes are found widely and causes a severe infection on human health which leads to various diseases. This review primarily focusses on analyzing the prevalence and drug resistance patterns in the African continent. From the earlier reported data shown only the minimal amount of surveillance information's has been summarized with respect to antimicrobial resistance on ESBLs producing Enterobacteriaceae both in hospital and community settings. To bring the present scenario in limelight, the present study explores the prevalence of ESBL-producing Enterobacteriaceae in various countries in Africa and specifically, to identify most common ESBL genes in hospital and community. The observation was initiated with the exhaustive literature search using PubMed and other databases to broaden the study from the earlier investigations in the African countries concerned about the prevalence rate of ESBL producing Enterobacteriaceae. Further, this study was extended to review various hypothesis of the hydrolytic mechanism, which was detailed by several authors performed earlier through computational approaches. Interestingly, the ESBLs class A and D were found to be common classes in Africa, with the gene CTX-M-15 being most prevalent. Notably, the present review highlights the prevalence on individual countries in Africa and it is extremely significant to prevent the dissemination of ESBL-producing Enterobacteriaceaea. Hence, this review on surveillance will be the benchmark to enhance the research on antimicrobial resistance patterns for all classes and genes. Furthermore, explored in-sights in this paper will be helpful for the further investigations to develop quicker, cost effective, and reliable diagnostic strategies and new effective therapies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)