Metallo Β-lactamase Research Articles

Molecular Investigation of Metallo B-Lactamase genes in Klebsiella Pneumoniae Bacteria from Clinical Isolates

Klebsiella pneumoniae is a significant nosocomial bacteria, that causes a large range of infections e.g. bacteremia, pneumonia, meningitis, and urinary tract infections. The current study intends to detect the existence of specific genes (blaNDM-1, blaNDM-2, blaVIM, blaIMP) associated with metallo-beta-lactamase (MBL) production in multidrug-resistant Klebsiella pneumoniae isolates attained from various clinical isolate. These genes are responsible for conferring resistance to a wide range of antibiotics, making an infection caused by such bacteria difficult to treat. Two hundred and seventy eight samples are collected from patients in Baquba Teaching Hospital during the period between December 2023 and May 2024. The samples included urine, sputums, burn, and wound swabs in addition to blood samples. The isolates are diagnosed microscopically and biochemically and the VITEK-2 compact system was used for diagnosis confirmation. It is found that 39.4%; n=69 is K. pneumoniae with 26%; n=18 of isolates are Multidrug resistant. Also, this study ascertains that multidrug-resistant (MDR) K.pneumoniae has the highest resistance against different types of antibiotics, including: AMP: 100%, AMC73: 36%, PIP: 81.16%, ATM: 72.46%, FEP: 71.01%, CAZ: 62.32%, CRO: 56.5%, IPM: 27.53%, MEM: 26.19%, AK: 47.82%, TOB: 43.47%, GM: 36.23%, LEV: 31.82%, OFX: 28.98%, CIP: 24.63% and SXT: 65.22%. Referring to phenotypic detection of MBL, 11 from 18 of MDR K. pneumoniae (61.11%) indicate a positive result. Also, during the molecular detection of Metallo B-lactamase genes, it was found that (81.81%; n=9) isolates were positive for blaNDM-1, blaNDM-2, and blaVIM gene, while no isolates showed positive results to blaIMP. Objective: Molecular detection of metallo-beta-lactamase genes in the bacteria Klebsiella pneumoniae.

Prevalence of some metallo β-lactamase enzymes genes in P. aeruginosa isolated from different clinical sample in Baghdad, Iraq

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.

Prevalence of Metallo β-Lactamase Genes Among MDR Pseudomonas <i>Aeruginosa</i> Isolated from Different Sources in Baghdad

Background: Pseudomonas aeruginosa is a gram-negative apportunistic pathogen that has ability to couse different type of infections and charecterised by their high resistance to commonly used antibiotics via different stratiges. Objective: The objective of this study is to detect the prevalence rate of MβL gene among MDR Pseudomonas aeruginosa. Methods: Forty clinical isolates of Pseudomonas aeruginosa were obtained from different hospitials in Baghdad/Iraq. Their identification was confirmed by using 16s rDNA as a housekeeping gene (reference gene). Specific primers were used to detect 3 types of Metallo β-lactamase (MβL) genes vim, spm1, and imp1 genes followed by sequencing the amplified fragment which was analyzed by Geneious software. Antibiotic sensitivity test for 15 antimicrobial agents was done using the Kirby-Bauer disc diffusion method. Results: The revealed resistance pattern was as following: 100% for the combination of Trimethoprim/Sulphamethoxazole and Nitrofurantoin, 95% for Tigecycline, 82.5% for Ciprofloxacin, 67.5% for Cefepime, 60% for Levofloxacin, 57.5% for Carbenicillin, 55% for Piperacillin, 50% for Amikacin, 47.5% for Tobramycin, 45% for both Imipenem and Ceftazidime, 27.5% for piperacillin/tazobactam, 22.5% for Aztreonam and 7.5% for Colistin. More than half (55%) of isolates were positive for MβL enzymes production during phenotypically assessed by combined disc test. The MIC of meropenem ranged from 16µg/ml to 32 µg/ml. The percentage of MβL genes among the total isolates during conventional PCR was as follows: 95% for vim, 25% of the isolates harbored both vim and imp1, while spm 1 are negative in all isolates. The result of the study explained that 10 isolates from the antibiotic susceptibility test were resistant to 10-14 antimicrobial agents that harbored both vim and imp1 genes. Conclusions: MβL gene could be used as a genetic marker to determine the degree of resistance in MDR P. aeruginosa which are more resistant than other isolates that have one gene of MβL responsible for break the β-lactam ring then inactivating the β-lactam antibiotic.

Burden of Multidrug-Resistant Gram-Negative Bacterial Infections in a Tertiary Care Hospital

Multidrug-resistant (MDR) Gram-negative bacterial infections have emerged as a major public health concern. The aim of the present study was to detect the rate of infections due to MDR Gram-negative bacteria (GNB) in a tertiary care hospital, the rate of Carbapenemases and AmpC-β-lactamases production and the Antimicrobial susceptibility test pattern (AST) among MDR GNB. The rate of MDR GNB during the study period was 25.70%. Urine samples showed the highest contribution to the total MDR GNB. Among the total MDR GNB isolates, 166 were randomly selected and included in the present study. A higher rate of MDR GNB was reported among male patients (61.5%) compared to the females (38.5%) and most of them were from the patients aged between 61-70 years (30.7%). The most prevalent MDR GNB was Klebsiella pneumoniae 80 (48.12%), followed by Escherichia coli 43 (25.9%). AST of MDR GNB revealed their significant resistance to β-lactamases/β-lactamases inhibitors, cephalosporins, fluoroquinolones and carbapenem drugs (98%). Of 123 MDR Enterobacterales, 83% of them were found to be Metallo β-lactamase (MBLs) producers by mCIM and eCIM methods. Of 43 MDR non-fermenters, 29 (67.4%) of them were found to be carbapenemase producers by MHT. About 29.51% of MDR GNB isolates were found to be AmpC producers by AmpC disk test. A reliable and rapid phenotypic method to detect carbapenemases and AmpC β-lactamases among MDR GNB in a routine microbiology laboratory method is clinically important to guide antibiotic therapy and implementation of effective infection control practices.

Characterization and genetic analysis of extensively drug-resistant hospital acquired Pseudomonas aeruginosa isolates

BackgroundThe incidence of hospital-acquired infections in extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) has been increasing worldwide and is frequently associated with an increase in mortality and morbidity rates. The aim of this study was to characterize clinical XDR-PA isolates recovered during six months at three different hospitals in Egypt.ResultsSeventy hospital-acquired clinical isolates of P. aeruginosa were classified into multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR), according to their antimicrobial resistance profile. In addition, the possession of genes associated with mobile genetic elements and genes encoding antimicrobial resistance determinants among isolates were detected using polymerase chain reaction. As a result, a significant percentage of the isolates (75.7%) were XDR, while 18.5% were MDR, however only 5.7% of the isolates were non-MDR. The phenotypic detection of carbapenemases, extended-spectrum β-lactamases (ESBLs) and metallo β-lactamase (MBL) enzymes showed that 73.6% of XDR-PA isolates were carbapenemases producers, whereas 75.5% and 88.7% of XDR-PA isolates produced ESBLs and MBL respectively. In addition, PCR screening showed that oxa gene was the most frequently detected gene of carbapenemases (91.4%), while aac(6ʹ)-lb gene was mostly detected (84.3%) among the screened aminoglycosides-resistance genes. Furthermore, the molecular detection of the colistin resistance gene showed that 12.9% of isolates harbored mcr-1 gene. Concerning mobile genetic element markers (intI, traA, tnp513, and merA), intI was the highest detected gene as it was amplified in 67 isolates (95.7%). Finally, phylogenetic and molecular typing of the isolates via ERIC-PCR analysis revealed 10 different ERIC fingerprints.ConclusionThe present study revealed a high prevalence of XDR-PA in hospital settings which were resistant to a variety of antibiotics due to several mechanisms. In addition, 98% of the XDR-PA clinical isolates contained at least one gene associated with movable genetic elements, which could have aided the evolution of these XDR-PA strains. To reduce spread of drug resistance, judicious use of antimicrobial agents and strict infection control measures are therefore essential.

Detection of Metallo β-Lactamase in Acinetobacter Species Using Phenotypic Methods with their Antibiotic Resistance Profile in Tertiary Care Hospital

Background: Acinetobacter species are commonly found in nature, in water, and in soil, and also, and they have been isolated from humans and animals. In the hospital setting, Acinetobacter species has emerged as a major opportunistic pathogen, being able to colonize and develop infections in patients. In Acinetobacter species, β-lactamases and outer membrane alterations are likely to function together to impart resistance. Understanding the epidemiology, and resistance mechanism, and for infection management and preventing a potential global health crisis, techniques for identifying Carbapenem-Resistant-Acinetobacter species are essential. Aim: To detect Metallo β-Lactamase (MBL) in Acinetobacter species with their antimicrobial susceptibility pattern. Material and Methods: 100 Acinetobacter species isolates from various clinical samples such as blood, cerebrospinal fluid, sputum, bronchoalveolar lavage, pus, urine, wound swab, and body fluids were included in the study. Phenotypic tests such as, Disc Potentiation test & Modified Hodge test were used to detect the presence of Metallo β-lactamase in imipenem & meropenem-resistant isolates. Results: The highest prevalence of Acinetobacter was found in blood (37%), followed by sputum (31%) and others [pus, urine, ascitic fluid, cerebrospinal fluid (CSF), bronchoalveolar Lavage (BAL), and pleural fluid]. A maximum number of Acinetobacter were isolated from MICU followed by medicine and surgery. The Modified Hodge test yielded the largest percentage of MBL-positive Acinetobacter isolates (67.26%) when compared to the Disc Potentiation test method (50.45%). Conclusion: Early detection of Metallo β-lactamase production is essential for planning appropriate treatment according to the resistance mechanisms of the multi-drug resistant strains, as well as for efficient infection control procedures to prevent the spread of infection.

Phenotypic identification of different β-Lactamases in intrinsic and acquired colistin resistant uropathogenic gram negative bacteria.

Identification of MBL, AmpC and ESBLs in colistin intrinsic and acquired resistant uropathogenic gram negative bacteria. Urine samples were collected from Hayatabad Medical Complex, Peshawar during 17 January to 30 June 2019. Collected urine samples were aseptically transported microbiology lab of Health Research Institution (HRI), National Institute of Health (NIH), Khyber Medical College, Peshawar and streaked on different media. Positive growth was identified by API-10s. Antibiotic sensitivity profile was done by Modified Kirby Bauer disc diffusion method. Detection of metallo βlactamases (MBL) production by Imipenem EDTA synergy test, Double Disc Synergy Test (DDST) for detection of ESBLs and D-test for the detection of inducible AmpC beta lactamases test was used. Colistin resistance was identified via broth micro dilution according to CLSI manual. Colistin resistant bacteria was divided in two categories; acquired and intrinsic resistant bacteria according to CLSI manual. Out of 2000 urine samples, 281(14%) gram-negative bacteria were isolated. Among positive samples, acquired colistin resistant bacteria were 241 and intrinsic resistant bacteria were 40 isolates. MBL was produce by twenty one (11.7%) E.coli and seventeen (40.5%) Pseudomonas aeruginosa. E. coli, Pseudomonas aeruginosa, Klebsiella Pneumoniae, Serratia Oderifora and Proteus Marblis were ESBLs producing bacteria. AmpC production was prevalent in fourteen (7.8%) E. coli and twelve (28.6%) Pseudomonas aeruginosa. Fifty-five samples showed resistance to colistin out of 241 samples. In colistin resistant bacteria, two E.coli were MBL, ESBLs, while one E.coli was ESBLs, AmpC co-producing bacteria. The most prevalent extended drug resistant bacteria were Pseudomonas aeruginosa (28.6%) and Escherichia coli (6.1%), While 155(86.6%) Escherichia coli, 25 (59.5%) Pseudomonas aeruginosa and 22 (95.7%) Serratia Oderifora was multi drug resistant bacteria. Current study concluded that ESBL, MBL AmpC enzymes and their co-expression was observed with colistin resistance in E.coli and Pseudomonas aeruginosa.

Carbapenemase genes in clinical and environmental isolates of Acinetobacter spp. from Quito, Ecuador.

Carbapenem-resistant Acinetobacter spp. is associated with nosocomial infections in intensive care unit patients, resulting in high mortality. Although Acinetobacter spp. represent a serious public health problem worldwide, there are a few studies related to the presence of carbapenemases in health care facilities and other environmental settings in Ecuador. The main aim of this study was to characterize the carbapenem-resistant Acinetobacter spp. isolates obtained from four hospitals (52) and from five rivers (27) close to Quito. We used the disc diffusion and EDTA sinergy tests to determine the antimicrobial susceptibility and the production of metallo β-lactamases, respectively. We carried out a multiplex PCR of gyrB gene and the sequencing of partial rpoB gene to bacterial species identification. We performed molecular screening of nine carbapenem-resistant genes (blaSPM, blaSIM, blaGIM, blaGES, blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143) by multiplex PCR, followed by identification using sequencing of blaOXA genes. Our findings showed that carbapenem-resistant A. baumannii were the main species found in health care facilities and rivers. Most of the clinical isolates came from respiratory tract samples and harbored blaOXA-23, blaOXA-366, blaOXA-72, blaOXA-65, blaOXA-70, and blaOXA-143-like genes. The river isolates harbored only the blaOXA-51 and probably blaOXA-259 genes. We concluded that the most predominant type of carbapenem genes among isolates were both blaOXA-23 and blaOXA-65 among A. baumannii clinical isolates.

Molecular study of blaVIM and blaIMP genes in Acinetobacter baumannii strains isolated from burn patients in Duhok City, Iraq.

Acinetobacter baumannii (A. baumannii) is an opportunistic pathogenic bacterium mainly associated with hospital acquired infections and in immunocompromised individuals who stay in hospitals for a long time. In recent years, it has become increasingly resistant to many different types of antibiotics. The production of the metallo-beta-lactamase (MBL) enzyme is one of the primary causes of this resistance. This study aimed to detect the presence of MBL genes that belong to the verona integrin metallo-β-lactamase (bla-VIM) and imipenemase (bla-IMP) groups in the isolates of Acinetobacter baumannii from burn patients. One hundred and seventeen (117) isolates of A. baumannii were obtained from patient specimens using traditional methods followed by using the VITEK 2 (BioMérieux, Les Pennes-Mirabeau, France) identification system. Metallo β-lactamases were detected in the imipenem-resistant strains by using imipenem disks on Muller-Hinton agar. The polymerase chain reaction (PCR) technique was utilized to examine 117 isolates for the detection of MBLs encoding genes such as bla-VIM, and bla-IMP. Imipenem resistance was detected in 78.6% of the patients. The PCR assays of the isolates identified bla-VIM-1, bla-VIM-2, bla-IMP-1 and bla-IMP-2 genes at the rates of 17%, 40.1%, 29.9% and 4.2%, respectively. The findings suggest that the majority of A. baumannii isolates harbour one or more of the detected genes, signifying that the production of MBLs plays a pivotal role in resistance mechanisms.

Rhodanine derived enethiols react to give 1,3-dithiolanes and mixed disulfides.

Rhodanines have been characterised as 'difficult to progress' compounds for medicinal use, though one rhodanine is used for diabetes mellitus treatment and others are in clinical development. Rhodanines can undergo hydrolysis to enethiols which are inhibitors of metallo-enzymes, such as metallo β-lactamases. We report that in DMSO, rhodanine derived enethiols undergo dimerisations to give 1,3-dithiolanes and mixed disulfides. The results highlight the potential of rhodanines and enethiols to give multiple products. They suggest that where possible DMSO should be avoided as a storage solvent for rhodanines/enethiols and highlight the need for further research on biologically relevant enethiols/mixed disulfides.

Prevalence of extended-spectrum and metallo β-lactamase production in Pseudomonas aeruginosa isolate

Due to intrinsically developed resistance in Pseudomonas aeruginosa, with extended-spectrum β-lactamase (ESBL) and metallo β-lactamase (MBL)-producing genes, such P. aeruginosa isolates have become a major threat to public health. Therefore, in this study, the synthesis of MBL and the prevalence of ESBL were observed phenotypically in P. aeruginosa using the DDST test. Seventy-six out of 120 strains of P. aeruginosa were obtained from animal milk and human sputum, blood, respiratory tract, and abscess. A total of 76 isolates (51.31%) synthesized ESBLs, 48.6% produced MBL, and 68.6% produced AmpC. The genotypic prevalence of MBL and ESBL for bla TEM-1 and bla IMP-1 was 20.12 and 17.8%, respectively. The results demonstrated a considerable prevalence of MBL and ESBL among P. aeruginosa isolates, with different enzyme variants detected in each sample. The data was significant for the P values less than 0.05.

2782. In vitro activity of ceftazidime-avibactam against Gram-negative strains in patients with bacteremia and skin and soft-tissue infections in Colombia 2019-2021

Abstract Background In vitro activity of Ceftazidime-avibactam (CAZ-AVI) in patients with bacteremia and skin and soft tissue infections (SSTIs) is unknown. The study aimed to analyze the in vitro antimicrobial activity of CAZ-AVI and other antimicrobials against Gram-negative bacilli collected in hospitals in Colombia in patients with bacteremia and SSTIs. Methods Enterobacterales and P. aeruginosa from patients with bacteremia and SSTIs were analyzed. Strains were collected from four ATLAS-reporting hospitals in Colombia between 2019 and 2021. Results Enterobacterales: A total of 600 Enterobacterales were collected. The most susceptible antimicrobials to Enterobacterales were CAZ-AVI (96.5%), tigecycline (95%), and amikacin (92.17%). The incidence of carbapenem-resistant Enterobacterales (CRE) was 13.5% (n= 81), and the antimicrobials with the best activity were tigecycline (93.83%), CAZ-AVI (74.07%), and amikacin (50.62%) (Figure 1). Tigecycline, CAZ-AVI, and amikacin were the antimicrobials with the best in vitro activity against MDR Enterobacterales, extended-spectrum β-lactamase-producing (ESBL) Enterobacterales, and KPC-producing Enterobacterales (Figure 2). K. pneumoniae (n= 198), E. coli (n= 167), Enterobacter cloacae (n= 46), and Serratia marcescens (n= 41) were the strains most frequently isolated (Table 1). Tigecycline and CAZ-AVI had excellent in vitro activity against all four species, as well as for those ESBL-producers, MDR, and carbapenem-resistant (CR). P. aerugniosa: A total of 259 P. aeruginosa were analyzed. CAZ-AVI was the antimicrobial with the best in vitro activity against P. aeruginosa with a susceptibility of 83.4%, as well as against CR (S= 44%), MDR (S= 50.58%), and DTR Pseudomonas (S= 33.33%). Figure 1 Antimicrobial activity among isolates of Enterobacterales and Carbapenem-resistant Enterobacterales (CRE) collected in Colombia between 2019 - 2021 S: susceptible; NS: Not susceptible; Pip/taz: Piperacillin-tazobactam; CZA: Ceftazidime-Avibactam; S: susceptible; NS: Not susceptible; CRE: Carbapenem-resistant Enterobacterales Figura 2 Not susceptibility among isolates of Extended-spectrum β-lactamase Enterobacterales, Multidrug-resistant Enterobacterales, Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacterales, and metallo β-lactamase producing enterobacterales in Colombia A. Not susceptibility among isolates of Extended-spectrum β-lactamase enterobacterales (green color) and Multidrug-resistant Enterobacterales (orange color) B. Not susceptibility among Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacterales (green color) and metallo β-lactamase producing enterobacterales (orange color) Pip/taz: Piperacillin-tazobactam; CZA: Ceftazidime-Avibactam; MDR: Multidrug-resistant Conclusion Tigecycline and CAZ-AVI were the two antimicrobials with excellent in vitro activity against clinical specimens from patients with bacteremia and SSTIs caused by CRE, MDR Enterobacterales, and ESBL- and KPC-producing Enterobacterales. Against MDR, CR, and DTR P. aeruginosa, CAZ-AVI and amikacin were the antimicrobials with the best in vitro activity (Figure 3). Disclosures Elkin Lemos-Luengas, MD MSc PhD, Pfizer Colombia: Honoraria Sixta Romelia Rentería-Valoyes, Md, Pfizer: Senior Associate Medicines Business /Medical Scientific Liaison MD for Pfizer Colombia Diana Marcela Almario Muñoz, MD, MSc, Pfizer Colombia: Medical Scientific Liaison Carlos David Gamboa Orozco, Md, Pfizer: Medical Scientific Liaison for Pfizer Colombia Juan Camilo Olivella Gómez, n/a, Pfizer Colombia: Medical Student Jorge Ramos-Castaneda, PhD, Pfizer: Advisor/Consultant

Carbapenemase producing Enterobacterales clinical isolates from a tertiary care hospital in Egypt

BackgroundCarbapenem resistant Enterobacterales (CRE) is on the rise globally, triggering a significant health threat and a substantial concern for infection control management. We aimed to detect and characterize carbapenemases producing Enterobacterales (CPE) clinical isolates over a period of nearly one-year duration in Theodor Bilharz Research Institute, a tertiary care hospital in Egypt through molecular and phenotypic methods using carbapenemase detection combination inhibitor disk set (Enterobacterales) MASTDISCS ID (MDI) (MAST, UK), with the addition of temocillin disk.ResultsCRE represented 6.5% of Enterobacterales. Healthcare-associated infections were frequently high representing 87% of the CRE isolated from hospitalized patients. Most of the CRE isolates were Klebsiella pneumonia (68%) followed by Escherichia coli (22%), Enterobacter cloacae (4%), Serratia marcescens (4%) and Citrobacter freundii (2%). Phenotypic detection revealed metallo-β lactamases in 84% of isolates, followed by oxacillinase-48 {(OXA-48) 6%} and Klebsiella pneumoniae carbapenemase in 2% of the isolates. The most prevalent gene detected by conventional PCR was blaNDM (84%) followed by blaOXA-48 (6%) and blaKPC (2%). Excellent agreement was found between PCR and MDI for detection of carbapenemase production.ConclusionsNDM carbapenemase is prevalent in our hospital. Carbapenemase detection combination inhibitor disk set (Enterobacterales) MASTDISCS ID is a useful tool for rapid and precise confirmation of the detection of CPE.

Carriage of multidrug-resistant carbapenemase-producing gram-negative bacteria in patients admitted to NHS Greater Glasgow and Clyde hospitals: Implications for treatment.

Infections caused by gram-negative carbapenemase-producing organisms (CPO) have become a global phenomenon. Screening of patients for CPO that was carried out at 48-h intervals enables early detection of carriers for infection control purposes and planning therapy. We investigated the bacterial flora detected on screening, the enzymes that conferred resistance and the proportion of patients who developed bacteraemia with CPO and their therapy. In all, 27 patients had a positive screen for CPO. A small but significant (7.5%) proportion of patients were not detected on initial screening. Escherichia coli and Klebsiella were predominant. New-Delhi metallo β-lactamase and oxacillin carbapenemases were the main enzymatic mechanisms of resistance. Four (14.8%) patients developed bacteraemia with CPO (30- and 90-day survival 100% and 75%, respectively). A single negative screen does not rule out colonisation. A significant proportion of patients colonised with CPO develop bacteraemia. Vigilance is needed to prevent the nosocomial spread of CPO.

Prediction of Phytochemicals for Their Potential to Inhibit New Delhi Metallo β-Lactamase (NDM-1).

The effectiveness of all antibiotics in the β-lactam group to cure bacterial infections has been impaired by the introduction of the New Delhi Metallo-β-lactamase (NDM-1) enzyme. Attempts have been made to discover a potent chemical as an inhibitor to this enzyme in order to restore the efficacy of antibiotics. However, it has been a challenging task to develop broad-spectrum inhibitors of metallo-β-lactamases. Lack of sequence homology across metallo-β-lactamases (MBLs), the rapidly evolving active site of the enzyme, and structural similarities between human enzymes and metallo-β-lactamases, are the primary causes for the difficulty in the development of these inhibitors. Therefore, it is imperative to concentrate on the discovery of an effective NDM-1 inhibitor. This study used various in silico approaches, including molecular docking and molecular dynamics simulations, to investigate the potential of phytochemicals to inhibit the NDM-1 enzyme. For this purpose, a library of about 59,000 phytochemicals was created from the literature and other databases, including FoodB, IMPPAT, and Phenol-Explorer. A physiochemical and pharmacokinetics analysis was performed to determine possible toxicity and mutagenicity of the ligands. Following the virtual screening, phytochemicals were assessed for their binding with NDM-1using docking scores, RMSD values, and other critical parameters. The docking score was determined by selecting the best conformation of the protein-ligand complex. Three phytochemicals, i.e., butein (polyphenol), monodemethylcurcumin (polyphenol), and rosmarinic acid (polyphenol) were identified as result of pharmacokinetics and molecular docking studies. Furthermore, molecular dynamics simulations were performed to determine structural stabilities of the protein-ligand complexes. Monodemethylcurcumin, butein, and rosmarinic acid were identified as potential inhibitors of NDM-1 based on their low RMSD, RMSF, hydrogen bond count, average Coulomb-Schrödinger interaction energy, and Lennard-Jones-Schrödinger interaction energy. The present investigation suggested that these phytochemicals might be promising candidates for future NDM-1 medication development to respond to antibiotic resistance.

Phenotypic and genotypic detection of antibiotic resistance among Pseudomonas aeruginosa isolates from orthopedic wounds from Chukwuemeka Odumegwu Ojukwu University Teaching Hospital (Coouth), Awka Anambra Nigeria

Pseudomonas aeruginosa is well known orthopedic wounds-associated bacterial pathogen, responsible for prolonged wound treatment, due to its resistance, mediated by different types of extended-spectrum beta-lactamases (ESBL). The present study was undertaken to find the prevalence of extended-spectrum β lactamase (ESBL), Metallo-β lactamase (MBL), and AmpC β lactamase in P. aeruginosa isolated from orthopedic wound samples. Wound swabs were processed and P. aeruginosa was identified by standard protocols. The Kirby-Bauer disc diffusion method was used in ascertaining the antibiotic sensitivity of the isolates. Special screening and confirmatory tests were performed for the phenotypic and genotypic detection of resistance. The resistance rate to gentamicin, ofloxacin, ciprofloxacin and ceftazidime were 2.6%, 2.6%, 2.6, and 5.1% respectively. P. aeruginosa expressed very high resistance to amoxicillin (97.4%), nitrofurantoin (100%), and two of the 3rd generation cephalosporins: cefuroxime (100%), and cefixime (100%). The aminoglycoside and the quinolones were the most effective drugs against the P. aeruginosa isolates with susceptibilities of 97.4% and 94.9% respectively. Out of the 38 isolates of P. aeruginosa, 11 (28.9%) and 14 (36.8%) were ESBL and MBL positive, respectively. The blaTEM genes were the only prevalent genes detected in all 38 (100%) isolates and mediated the phenotypic and genotypic resistance observed. MBL production was observed in 14 (36.8%) while AmpC and co-expression of genes were not observed. The blaTEM genotypic resistance was observed to be common among the isolates. This calls for great concern and continuous monitoring of antimicrobial resistance with the implementation of stringent mediation practices toward infection prevention and control.

Whole genome-based genetic insights of blaNDM producing clinical E. coli isolates in hospital settings of Pakistan.

Carbapenem resistance among Enterobacterales has become a global health concern. Clinical Escherichia coli isolates producing the metallo β-lactamase NDM have been isolated from two hospitals in Faisalabad, Pakistan. These E. coli strains were characterized by MALDI-TOF, PCR, antimicrobial susceptibility testing, XbaI and S1 nuclease pulsed-field gel electrophoresis (PFGE), conjugation assay, DNA hybridization, whole genome sequencing, bioinformatic analysis, and Galleria mellonella experiments. Thirty-four blaNDM producing E. coli strains were identified among 52 nonduplicate carbapenem-resistant strains. More than 90% of the isolates were found to be multidrug resistant by antimicrobial susceptibility testing. S1 PFGE confirmed the presence of blaNDM gene on plasmids ranging from 40 kbps to 250 kbps, and conjugation assays demonstrated transfer frequencies of blaNDM harboring plasmids ranging from 1.59 × 10-1 to 6.46 × 10-8 per donor. Whole genome sequencing analysis revealed blaNDM-5 as the prominent NDM subtype with the highest prevalence of blaOXA-1, blaCTX-M-15, aadA2, aac(6')-Ib-cr, and tet(A) associated resistant determinants. E. coli sequence types: ST405, ST361, and ST167 were prominent, and plasmid Inc types: FII, FIA, FIB, FIC, X3, R, and Y, were observed among all isolates. The genetic environment of blaNDM region on IncF plasmids included partial ISAba125, the bleomycin ble gene, and a class I integron. The virulence genes terC, traT, gad, fyuA, irp2, capU, and sitA were frequently observed, and G. mellonella experiments showed that virulence correlated with the number of virulence determinants. A strong infection control management in the hospital is necessary to check the emergence of carbapenem resistance in Gram-negative bacteria.IMPORTANCEWe describe a detailed analysis of highly resistant clinical E. coli isolates from two tertiary care centers in Pakistan including carbapenem resistance as well as common co-resistance mechanisms. South Asia has a huge problem with highly resistant E. coli. However, we find that though these isolates are very difficult to treat they are of low virulence. Thus the Western world has an increasing problem with virulent E. coli that are mostly of low antibiotic resistance, whereas, South Asia has an increasing problem with highly resistant E. coli that are of low virulence potential. These observations allow us to start to devise methodologies to limit both virulence and resistance and combat problems in developing nations as well as the Western world.

DETECTION OF BIOFILM PRODUCTION AMONG MBLS-PRODUCING PSEUDOMONAS AERUGINOSA CARRYING ALGD, PELF, PSLD GENES ISOLATED FROM BURN CENTER IN AL-NAJAF GOVERNORATE, IRAQ

Background: Pseudomonas aeruginosa is a worldwide cause of chronic and acute infections of burn wounds. Aim of study: Detection of algD, pelF, and pslD genes encoding biofilm formation among isolates of Pseudomonas aeruginosa that producing metallo β-lactamases. Materials and Methods: 93 isolates of Pseudomonas aeruginosa were isolated from 362 inpatients with infected burn wounds at the burn center in Al-Najaf Governorate, Iraq, from September 2022 to February 2023. Results: Pseudomonas aeruginosa isolates were identified microscopically, phenotypically, culturally, and biochemically then by using the double-disc synergy method to test their capacity to produce metallo β-lactamases. Out of the 25 MBLs-producers, 22 (88%) were biofilm-producing isolates when tested by tissue culture plate method, 4 (16%), 10 (40%), and 8 (32%) were, respectively, weak, medium, and strongly biofilm producers. 25 metallo β-lactamases-producers under study, which had previously been evaluated using biofilm phenotypic method, were subjected to the investigation of biofilm encoding genes by using polymerase chain reaction technique. This molecular technique detected 21 (84%) isolates carried single and multiple biofilm encoding genes, 10(40%) isolates had algD gene, 6 (24%) isolates harbored algD and pslD genes and 5(20%) isolates carried algD, pelF and pslD genes. The single pslD and pelF genes were not detected among test isolates. Conclusions: There was a high prevalence of biofilmproducers among metallo β-lactamases-producing P. aeruginosa isolates. In addition, a clear positive correlation was observed between the multiple genes encoding biofilm and the degree of biofilm production among metallo β-lactamases-producers and close association between metallo β-lactamases and biofilms production, which explains the prevalence of carbapenems resistance and biofilm-production in this study because biofilm provides the appropriate environment for antibiotic resistance in general and carbapenems in particular

Prevalence, molecular characterization of integrons and its associated gene cassettes in Klebsiella pneumoniae and K. oxytoca recovered from diverse environmental matrices

The high prevalence of infections arising from Klebsiella species is related to their ability to acquire and disseminate exogenous genes associated with mobile genetic elements such as integrons. We assessed the prevalence, diversity, and associated gene cassettes (GCs) of integrons in Klebsiella species. The isolates recovered from wastewater and hospital effluents, rivers, and animal droppings were identified using the conventional Polymerase Chain Reaction (PCR) with primers targeting the gryA, pehX, and 16S–23S genes. The antimicrobial resistance profile and the Extended-Spectrum and Metallo β-lactamases production were carried out using standard microbiological techniques. PCR, DNA sequencing analyses, and Restriction Fragment Length Polymorphism were used to characterize the integrons and their associated GCs. Furthermore, the genotypic relationships between the different isolated K. pneumoniae were determined using Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR. About 98% (51/52) of the confirmed isolates harboured an integrase gene, with 80% intI1, while the remaining 20% concurrently harboured intI1 and intI2, with no intI3 observed. About 78% (40/51) of the bacterial strains were positive for a promoter, the P2R2, investigated, while 80% (41/51) harboured at least one of the qacEΔ1 and sul1. Three different GCs arrangements identified were aac(6′)-Ib, aadA1-dfrA1, and dfrA1-sat2. At a similarity index of 60%, the ERIC-PCR fingerprints generated were categorized into nine clusters. Our study is the first to reveal the features of integrons in Klebsiella spp. recovered from environmental sources in the Eastern Cape Province, South Africa. We conclude that the organisms' sources are repositories of integrons harbouring various gene cassettes, which can be readily mobilized to other microorganisms in similar or varied niches.

Synthesis, characterization, and biological evaluation of Ni, Co, and Cu Metal Complexes with Heterocyclic Compounds

Two new clinically active Schiff bases and their transition metal complexes were synthesized and studied by different spectroscopic and physicochemical methods like NMR, IR, UV-Visible, ESR, TGA, XRD, mass, elemental analysis, molar conductivity and magnetic character. Synthesized complexes and Schiff bases were assessed for invitro antituberculosis activity for Mycobacterium tuberculosis (ATCC–27294) and for antimicrobial activity against drug resistant ESBL (Extended Spectrum β-lactamase) and MBL (Metallo β-lactamase) producing microbial strains. The biological activity of Schiff base was found to improve in presence of transition metal ions. Among the studied metal complexes, copper complexes displayed superior biological activity against all of the microbial strains. Binary complexes of Cu(II), Ni(II), and Co (II) ions have been synthesized by reacting metal salts with a Schiff base, 2-((E)-(5-methylisoxazol-3-ylimino)methyl)-4-methoxyphenol (MIIMMP) in an alcoholic medium. All the metal complexes and schiff base have been characterized by using elemental analysis, IR, UV-VIS, 1H-NMR, 13C-NMR, Mass, ESR spectral data, magnetic moments, TG, and DTA studies. Based on the analytical, spectral data and molecular modeling studies, Ni (II) and Co (II) metal complexes have octahedral geometry, whereas Cu(II) complex has tetragonal geometry. The antimicrobial and cytotoxic activities of the Schiff base and its metal complexes were studied on bacteria, fungi, and human cervical carcinoma cells (HeLa).