In Silico Study of the Potential of Brazilein Sappan Wood as a Beta-Lactamase Inhibitor against Extended-Spectrum Beta-Lactamase-Encoding Genes.

Background: Infectious illnesses are a serious health concern in Indonesia. Widespread use of self-medication by the community increases the risk of developing multi-drug resistant (MDR) bacteria. This study assessed the potential of sappan wood as an inhibitor of extended-spectrum beta-lactamase (ESBL) encoded by blaSHV, blaTEM and blaCTX-M genes. Method: In silico testing was conducted to develop an effective and economical starting strategy. Thereby, this study significantly advances the development of novel treatments to combat antibiotic resistance. Using clavulanic acid as the benchmark medicine, the potency of the beta-lactamase inhibitor brazilein was predicted. Using the Molegro Virtual Docker computer tool, docking was performed to estimate the chemical and physical properties of the compounds, as well as the biological activity of brazilein toward the required receptor. The receptors used were SHV-1 beta-lactamase, PDB code: 2H0T; TEM-1 beta-lactamase, PDB code: 4OQG and CTX-M-14 beta-lactamase, PDB code: 6VHS. Data analysis was performed by comparing the binding energies of the docking results between the ligands and the target receptor. The more stable the bond that formed between the ligand and the target receptor, the lower the bond energy. Results: The in silico test results on the blaSHV gene were as follows: binding energy of ligand MA4_400[A] = -100.699, brazilein = -82.206, clavulanic acid = -79.3704; in the blaTEM gene: ligand bond energy 2UL_301[B] = -107.681, brazilein = -82.0296, clavulanic acid = -103.3; in the blaCTX-M gene: X57_301[A] ligand bond energy = -86.6197, and brazilein = -88.1586, clavulanic acid = -101.933. Conclusion: The findings of this study demonstrate the significant potential of brazilein sappan wood to block the beta-lactamase activity of blaCTX-M.

Cefazolin inoculum effect in methicillin-susceptible Staphylococcus aureus clinical isolates.

We investigated the prevalence and characteristics of Cefazolin inoculum effect (CInE) among clinical MSSA isolates in Japan. Although 35.5 % (39 isolates) were positive for the blaZ gene, none met the phenotypic criteria for CInE. Our findings suggested a very low prevalence of CInE among MSSA isolates in our clinical setting.

Phylogenetic group distribution and antibiotic resistance of Escherichia coli isolates in aquatic environments of a highly populated area.

Background: Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae including Escherichia coli (E. coli), are recognized as a global public health threat due to their multidrug-resistant (MDR) phenotypes and their rapid dissemination in aquatic environments. Nevertheless, studies investigating the prevalence and antimicrobial resistance (AMR) profile of ESBL-producing E. coli in Lebanese surface water are limited. Objective: This study aimed to assess the physicochemical properties and microbial contamination load and to determine the distribution of AMR patterns of ESBL-producing E. coli in surface water samples from different sites in the North Governorate of Lebanon. Methods: Water samples were collected from 25 major sites in North Lebanon. These samples were analyzed for the presence of total coliforms, E. coli, and fecal enterococci. Phenotypic and genetic characterizations were then performed for E. coli isolates to determine their resistance patterns and phylogenetic groups. Results: Fifty-six samples out of 100 samples were positive for ESBL-producing E. coli, mostly harboring blaCTX-M (40/56, 71%) including blaCTX-M-15 (33/40, 82%), blaTEM gene (36/56, 64%), blaSHV (20/56, 36%), and blaOXA (16/56, 29%) including blaOXA-48 gene (11/16, 69%). Most ESBL-producing E. coli isolates belonged to the extra-intestinal pathogenic phylogroup B2 (40/56, 71.4%) while 10/56 (17.9%) belonged to the commensal phylogroup A. Conclusion: Our results highlight the need to implement effective water monitoring strategies to control transmission of ESBL-producing E. coli in surface water and thus reduce the burden on human and animal health.

Clinical Outcomes in Patients Who Received a One-Time Aminoglycoside Dose for Extended-Spectrum Beta-Lactamase-Producing Enterobacterales or Pseudomonas aeruginosa Cystitis.

The Infectious Diseases Society of America (IDSA) recommends a single dose of an aminoglycoside for uncomplicated cystitis caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E) and difficult-to-treat Pseudomonas aeruginosa. However, there is very little recent clinical evidence to support this recommendation. The objective of this study was to evaluate the safety and efficacy of a single-dose aminoglycoside for cystitis caused by ESBL-E or Pseudomonas aeruginosa. This was a multicenter, retrospective, cohort study. Patients who received ≥3 days of standard of care were compared to patients who received a one-time dose of an aminoglycoside with or without a short course of effective therapy before. The primary outcome was the rate of relapse defined as requiring escalation of antibiotics or starting new antibiotic therapy within 14 days after the completion of antibiotics. A total of 66 patients were included in this study, with 33 patients in each arm. There were more males and complicated cystitis patients in the standard-of-care group. There was no difference found in the rate of relapse. The length of stay was significantly shorter in the aminoglycoside group (4.5 ± 4.4 days vs. 14.1 ± 10.1 days, p < 0.0001). A one-time dose of an aminoglycoside did not increase the risk of relapse and was associated with a shorter length of stay when used to treat cystitis caused by ESBL-E or Pseudomonas aeruginosa.

Central role of the ramAR locus in the multidrug resistance in ESBL-Enterobacterales.

The aim of this study was to evaluate the proportion of resistance to a temocillin, tigecycline, ciprofloxacin, and chloramphenicol phenotype called t2c2 that resulted from mutations within the ramAR locus among extended-spectrum ß-lactamases-Enterobacterales (ESBL-E) isolated in three intensive care units for 3 years in a French university hospital. Two parallel approaches were performed on all 443 ESBL-E included: (i) the minimal inhibitory concentrations of temocillin, tigecycline, ciprofloxacin, and chloramphenicol were determined and (ii) the genomes obtained from the Illumina sequencing platform were analyzed to determine multilocus sequence types, resistomes, and diversity of several tetR-associated genes including ramAR operon. Among the 443 ESBL-E strains included, isolates of Escherichia coli (n = 194), Klebsiella pneumoniae (n = 122), and Enterobacter cloacae complex (Ecc) (n = 127) were found. Thirty-one ESBL-E strains (7%), 16 K. pneumoniae (13.1%), and 15 Ecc (11.8%) presented the t2c2 phenotype in addition to their ESBL profile, whereas no E. coli presented these resistances. The t2c2 phenotype was invariably reversible by the addition of Phe-Arg-ß-naphthylamide, indicating a role of resistance-nodulation-division pumps in these observations. Mutations associated with the t2c2 phenotype were restricted to RamR, the ramAR intergenic region (IR), and AcrR. Mutations in RamR consisted of C- or N-terminal deletions and amino acid substitutions inside its DNA-binding domain or within key sites of protein-substrate interactions. The ramAR IR showed nucleotide substitutions involved in the RamR DNA-binding domain. This diversity of sequences suggested that RamR and the ramAR IR represent major genetic events for bacterial antimicrobial resistance.IMPORTANCEMorbimortality caused by infectious diseases is very high among patients hospitalized in intensive care units (ICUs). A part of these outcomes can be explained by antibiotic resistance, which delays the appropriate therapy. The transferable antibiotic resistance gene is a well-known mechanism to explain the high rate of multidrug resistance (MDR) bacteria in ICUs. This study describes the prevalence of chromosomal mutations, which led to additional antibiotic resistance among MDR bacteria. More than 12% of Klebsiella pneumoniae and Enterobacter cloacae complex strains presented mutations within the ramAR locus associated with a dysregulation of an efflux pump called AcrAB-TolC and a porin: OmpF. These dysregulations led to an increase in antibiotic output notably tigecycline, ciprofloxacin, and chloramphenicol associated with a decrease of input for beta-lactam, especially temocillin. Mutations within transcriptional regulators such as ramAR locus played a major role in antibiotic resistance dissemination and need to be further explored.

Susceptibility evaluation of novel beta-lactam/beta-lactamase inhibitor combinations against carbapenem-resistant Klebsiella pneumoniae from bloodstream infections in hospitalized patients in Brazil.

Novel beta-lactams/beta-lactamase inhibitors (BIBLI) combinations are commercially available and they have been used for treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Continuous surveillance of susceptibility profile and resistance mechanisms identification are necessary to monitor the evolution of resistance as these agents are used. The purpose of this study was to evaluate susceptibility rates to ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam in CRKP isolates from patients with bloodstream infection screened for a randomized clinical trial in Brazil. Minimum inhibitory concentration (MIC) was determined by gradient diffusion strip method for meropenem, ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam. Carbapenemase genes were detected by multiplex qPCR. KPC-producing isolates showing resistance to any BLBLI and NDM-producing isolates showing susceptibility to any BLBLI were further submitted to whole genome sequencing. From a total of 69 CRKP isolates, 39 were positive for blaKPC, 19 for blaNDM and 11 for blaKPC and blaNDM. KPC-producing isolates demonstrated susceptibility rates above 94% for all BLBLI. Two isolates with resistance to meropenem/vaborbactam showed a Gly and Asp duplication at OmpK36 protein and truncated ompK35 genes. All NDM-producing isolates, including KPC and NDM coproducers, demonstrated susceptibility rates for ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam of 0%, 9.1 to 21.1% and 9.1 to 26.3%, respectively. Five NDM-producing isolates that presented susceptibility to BLBLI also demonstrated alterations in porins. This study demonstrated that, although high susceptibility rates to the BLBLI were found, KPC-2 isolates can also demonstrate resistance due to porin mutations. Additionally, NDM-1 isolates can demonstrate susceptibility in vitro to the BLBLI.

PBP-3 Directed Therapy in VIM-producing Pseudomonas aeruginosa Creates Bacterial Transformers, Persisters in Disguise.

OBJECTIVES: The proliferation of metallo-beta-lactamase-producing Pseudomonas aeruginosa represents a significant public health threat. P. aeruginosa can undergo significant phenotypic changes that can drastically impair antibiotic efficacy. This study's objectives were (1) to quantify the time-course of killing of VIM-2-producing P. aeruginosa in response to aztreonam-based therapies (including avibactam for coverage of AmpC), and (2) to document the capacity of P. aeruginosa to undergo morphological transformations that facilitate persistence. METHODS: A well-characterized, clinical VIM-2-producing P. aeruginosa was studied in the Hollow Fiber Infection Model (HFIM) over 9 days (7 days of active antibiotic therapy, 2 days treatment withdrawal) at a 107.5 CFU/mL starting inoculum. HFIM treatment arms included: growth control, aztreonam, ceftazidime/avibactam, aztreonam/|ceftazidime/|avibactam, polymyxin B, and aztreonam/|ceftazidime/|avibactam/|polymyxin B. In addition, real-time imaging studies were conducted under static conditions to determine the time-course of the reversion of persister cells. RESULTS: A pronounced discrepancy was observed between OD620 and bacterial counts obtained from plating methods (hereafter referred to as 'OD-count discrepancy'). For aztreonam monotherapy, observed counts were 0 CFU/mL by 120 h. Despite this, there was a significant OD-count discrepancy as compared to the pre-treatment 0h. Between therapy withdrawal at 168h and 216h, all arms with suppressed counts had re-grown to the system carrying capacity. Real-time imaging of the P. aeruginosa filaments after drug removal showed rapid reversion from a long, filamentous phenotype to many individual rods within 2 h. CONCLUSION: Managing MBL-producing P. aeruginosa will require a multi-faceted approach, focused on maximizing killing and minimizing proliferation of resistant and persistent subpopulations, which will involve eliminating drug-induced phenotypic transformers.

Favourable effect of clavulanic acid on the minimum inhibitory concentrations of cefixime and ceftibuten in ESBL-producing Escherichia coli and Klebsiella pneumoniae.

OBJECTIVES: The use of cephalosporins combined with clavulanate for the treatment of ESBL-harbouring Enterobacteriaceae has been scarcely described. We aimed to describe the effect of different concentrations of clavulanate in the MIC of cefixime and ceftibuten of ESBL-producing Escherichia coli and Klebsiella pneumoniae. METHODS: ESBL-producing E. coli and K. pneumoniae isolates were studied. Fixed concentrations of cefixime and ceftibuten (ranges of 32-0.25 and 64-0.5 ng/ml, respectively) were used. Combinations of cefixime/clavulanate and ceftibuten/clavulanate in different ratios (1:0, 1:1, 2:1, 4:1, 8:1, 16:1, 32:1) were tested. MIC were determined by broth microdilution. RESULTS: A total of 6 ESBL-producing E. coli, 6 ESBL-producing K. pneumoniae and 2 control E. coli were tested. When different quantities of clavulanate were added to cefixime and ceftibuten, greater than two-fold decreases in the MIC were observed. When testing the 1:1 cefixime/clavulanate ratio, 10/12 isolates were susceptible. When the ratios 2:1, 4:1, 8:1, and 16:1 were tested, susceptibility was noted for 9/12, 8/12, 4/12, and 5/12 isolates, respectively. Only 2/12 K. pneumoniae isolates were susceptible when the ratio 32:1 was tested. When testing ceftibuten/clavulanate, all isolates remained susceptible across all experiments. CONCLUSIONS: Clavulanic acid has a favourable effect in reducing the MIC of cefixime and ceftibuten in isolates of ESBL-producing E. coli and K. pneumoniae. Combining clavulanate with ceftibuten or cefixime could be a useful treatment strategy.

Risk factors and clinical impact of multidrug resistance in healthcare-associated bacteremic urinary tract infections: a post-hoc analysis of a multicenter prospective cohort in Spain.

INTRODUCTION: The global burden associated with antimicrobial resistance is of increasing concern. The aim of this study was to evaluate risk factors associated with multidrug-resistant (MDR) infection and its clinical impact in a cohort of patients with healthcare-associated (HCA) bacteremic urinary tract infections (BUTI). METHODS: This is a post-hoc analysis a prospective multicenter study of patients with HCA-BUTI (ITUBRAS-2). The primary outcome was MDR profile. Secondary outcomes were clinical response (at 48-72h and at hospital discharge) and length of hospital stay from onset of BUTI. Logistic regression was used to evaluate variables associated with MDR profile and clinical response. Length of hospital stay was evaluated using multivariate median regression. RESULTS: 443 episodes were included, of which 271 (61.17%) were classified as expressing an MDR profile. In univariate analysis, MDR profile was associated with E. coli episodes (OR 3.13, 95% CI 2.11-4.69, p<0.001) and the extensively drug-resistant (XDR) pattern with P. aeruginosa etiology (OR 7.84, 95% CI 2.37-25.95; p=0.001). MDR was independently associated with prior use of fluoroquinolones (aOR 2.43; 95% CI 1.25-4.69), cephalosporins (aOR 2.14; 95% CI 1.35-3.41) and imipenem or meropenem (aOR 2.08; 95% CI 1.03-4.20) but not with prior ertapenem. In terms of outcomes, MDR profile was not associated with lower frequency of clinical cure, but with longer hospital stay. CONCLUSIONS: MDR profile was independently associated with prior use of fluoroquinolones, cephalosporins, imipenem and meropenem, but not with prior ertapenem. MDR-BUTI episodes were not associated with worse clinical cure, although was independently associated with longer duration of hospital stay.

Genome Sequences of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Recovered from Mid-Stream Urine Samples in Accra, Ghana.

Escherichia coli, a member of the commensal intestinal microbiota, is a significant aetiology of urinary tract infections (UTIs) and has a propensity for acquiring multidrug resistance characteristics, such as extended-spectrum beta-lactamases (ESBLs). Despite the increase in the incidence of ESBL-producing E. coli infections in sub-Saharan Africa, routine ESBL detection in Ghana is often absent, and molecular data on ESBL genotypes is scarce. Eleven ESBL-producing E. coli recovered from mid-stream urine samples were subjected to antimicrobial susceptibility testing and whole-genome sequence analyses. All isolates exhibited multidrug resistance, demonstrating phenotypic resistance to third-generation cephalosporins, such as cefotaxime, ceftazidime, and cefpodoxime. Three isolates demonstrated resistance to norfloxacin (a fluoroquinolone), and one isolate demonstrated intermediate resistance to ertapenem (a carbapenem). Analysis of the draft genomes identified multiple antimicrobial resistance genes including ESBL genotypes blaTEM-1B/TEM-190 (6/11 and 1/11, respectively), blaCTX-M-15/CTX-M-3 (7/11 and 1/11) and blaOXA-1/OXA-181 (3/11 and 1/11). The strains belong to 10 different serotypes and 10 different multilocus sequence types. This study provides information on phenotypic resistance in 11 ESBL E. coli from Ghana and AMR genotypes within their genomes.

Efficacy of carbapenems and alternative antimicrobials for treating complicated urinary tract infections caused by third-generation cephalosporin-resistant gram-negative bacteria: A systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Specific data concerning the efficacy of alternative antibiotics for carbapenems against complicated urinary tract infections (cUTIs) attributed to antimicrobial-resistant (AMR) uropathogens are lacking. OBJECTIVES: This study aimed to assess the efficacy of carbapenems and non-carbapenem antibiotics in the clinical outcomes of cUTIs caused by AMR uropathogens. METHODS: In this systematic review and meta-analysis, databases, including MEDLINE/PubMed, the Cochrane Library, Embase and ClinicalTrials.gov, were searched. The study eligibility criteria were research articles conducted as randomised controlled trials that evaluated the composite outcomes of cUTIs. Participants were adult patients with cUTIs caused by gram-negative uropathogens resistant to third-generation cephalosporins. The intervention involved a non-carbapenem class of antimicrobial agents with in vitro activities against gram-negative uropathogens resistant to third-generation cephalosporins. Two independent researchers assessed the risk-of-bias using the second version of the Cochrane risk-of-bias tool for randomised trials. The treatment effects on each outcome were estimated as a risk ratio (RR) with a 95 % confidence interval (CI) using the random-effects model. Heterogeneity was assessed using the Cochrane Q-test and I2 statistics. RESULTS: Through database searches, 955 articles were retrieved. After screening the titles and abstracts, 52 articles were screened in full text. Finally, 12 studies met the inclusion criteria. No significant differences in efficacy were observed between alternative antibiotics and carbapenems (composite outcome, RR, 0.96; 95 % CI, 0.63-1.49; I2 = 21 %; low certainty of evidence). CONCLUSIONS: Alternative antibiotics had clinical efficacy similar to that of carbapenems for treating patients with cUTI caused by gram-negative uropathogens resistant to third-generation cephalosporins.

Controlling the hospital aquatic reservoir of multidrug-resistant organisms: a cross-sectional study followed by a nested randomized trial of sink decontamination.

OBJECTIVES: The hospital water environment is an important reservoir of multidrug-resistant organisms (MDROs) and presents a risk for patient safety. We assessed the effectiveness of thermal and chemical interventions on sinks contaminated with MDRO in the hospital setting. METHODS: We conducted a cross-sectional assessment of MDRO contamination of sinks and toilets in 26 clinical wards of a tertiary care hospital. MDRO-contaminated sink traps were then replaced and randomized (1:1:1) to receive chemical (sodium hypochlorite), thermal disinfection (steam), or no intervention. Interventions were repeated weekly for 4 weeks. Sinks were resampled 7 days after the last intervention. The primary outcome was the proportion of decontaminated sinks. MDROs of interest were extended spectrum beta-lactamase (ESBL) producing and carbapenemase-producing Enterobacterales, and non-fermentative Gram-negative bacilli. RESULTS: In the cross-sectional assessment, at least one MDRO was identified in 258 (36%) of the 748 samples and in 91 (47%) of the 192 water sources. In total, 57 (42%) of the 137 sinks and 34 (62%) of the 55 toilets were contaminated with 137 different MDROs. The most common MDRO were ESBL Enterobacterales (69%, 95/137), followed by Verona Integron-Borne Metallo-ß-Lactamase (VIM) carbapenemase producing Pseudomonas aeruginosa (9%, 12/137) and Citrobacter spp. (6%, 5/137). In the nested randomized trial, five of the 16 sinks (31%) in the chemical disinfection group were decontaminated, compared with 8 of 18 (44%) in the control group (OR 0.58; 95% CI, 0.14-2.32) and 9 of 17 (53%) in the thermal disinfection group (OR 1.40; 95% CI, 0.37-5.32). DISCUSSION: Our study failed to demonstrate an added benefit of repeated chemical or thermal disinfection, beyond changing sink traps, in the MDRO decontamination of sinks. Routine chlorine-based disinfection of sinks may need to be reconsidered.

Binding selectivity analysis of new delhi metallo-beta-lactamase-1 inhibitors using molecular dynamics simulations: Exploring possibilities for decoding antimicrobial drug resistance.

BACKGROUND: New Delhi metallo-beta-lactamase-1 (NDM1) confers resistance to several bacterial species against a broad range of beta-lactam antibiotics and turning them into superbugs that pose a significant threat to healthcare systems worldwide. As such, it is a potentially relevant biological target for counteracting bacterial infections. Given the lack of effective treatment options against NDM1 producing bacteria, finding a reliable inhibitor for the NDM1 enzyme is crucial. METHODS: Using molecular dynamics simulations, the binding selectivities and affinities of three ligands, viz. PNK, 3S0, and N1G were investigated against NDM1. RESULTS: The results indicate that N1G binds with more affinity to NDM1 than PNK and 3S0. The binding energy decomposition analysis revealed that residues I35, W93, H189, K211, and N220 showed significant binding energies with PNK, 3S0, and N1G, and hence are crucially involved in the binding of the ligands to NDM1. Molecular dynamics trajectory analysis further elicited that the ligands influence dynamic flexibility of NDM1 morphology, which contributes to the partial selectivities of PNK, 3S0, and N1G. CONCLUSIONS: This in silico study offers a vital information for developing potential NDM1 inhibitors with high selectivity. Nevertheless, in vitro and in vivo experimental validation is mandated to extend the possible applications of these ligands as NDM1 inhibitors that succor in combating antimicrobial resistance.

Structural insight into the subclass B1 metallo-ß-lactamase AFM-1.

The emergence of drug-resistant bacteria, facilitated by metallo-beta-lactamases (MBLs), presents a significant obstacle to the effective use of antibiotics in the management of clinical drug-resistant bacterial infections. AFM-1 is a MBL derived from Alcaligenes faecalis and shares 86% homology with the NDM-1 family. Both AFM-1 and NDM-1 demonstrate the ability to hydrolyze ampicillin and other ß-lactam antibiotics, however, their substrate affinities vary, and the specific reason for this variation remains unknown. We present the high-resolution structure of AFM-1. The active center of AFM-1 binds two zinc ions, and the conformation of the key amino acid residues in the active center is in accordance with that of NDM-1. However, the substrate-binding pocket of AFM-1 is considerably smaller than that of NDM-1. Additionally, the mutation of amino acid residues in the Loop3 region, as compared to NDM-1, results in the formation of a dense hydrophobic patch comprised of hydrophobic amino acid residues in this area, which facilitates substrate binding. Our findings lay the foundation for understanding the molecular mechanism of AFM-1 with a high affinity for substrates and provide a novel theoretical foundation for addressing the issue of drug resistance caused by B1 MBLs.

Multidrug-resistant phenotypes of genetically diverse Escherichia coli isolates from healthy domestic cats.

Β-lactamases-producing Escherichia coli are a widely distributed source of antimicrobial resistance (AMR), for animals and humans. Little is known about the sensitivity profile and genetic characteristics of E. coli strains isolated from domestic cats. We report a cross-sectional study that evaluated E. coli strains isolated from domestic cats in Panama. For this study the following antibiotics were analyzed: ampicillin, amoxicillin-clavulanate cefepime, cefotaxime, cefoxitin, ceftazidime, aztreonam, imipenem, gentamicin, kanamycin, streptomycin, tetracycline, ciprofloxacin, nalidixic acid, trimethoprim-sulfamethoxazole, and chloramphenicol. The data obtained were classified as resistant, intermediate, or sensitive. MDR strains were established when the strain presented resistance to at least one antibiotic from three or more antimicrobial classes. Forty-eight E. coli isolates were obtained, of which 80% presented resistance to at least one of the antibiotics analyzed, while only 20% were sensitive to all (p = 0.0001). The most common resistance was to gentamicin (58%). Twenty-nine percent were identified as multidrug-resistant isolates and 4% with extended spectrum beta-lactamase phenotype. The genes blaTEM (39%), blaMOX(16%), blaACC (16%) and blaEBC (8%) were detected. Plasmid-mediated resistance qnrB (25%) and qnrA (13%) are reported. The most frequent sequence types (STs) being ST399 and we reported 5 new STs. Our results suggest that in intestinal strains of E. coli isolated from domestic cats there is a high frequency of AMR.

Risk Factors and Outcomes of Patients Colonized with KPC and NDM Carbapenemase-Producing Enterobacterales.

Carbapenemase-producing enterobacterales (CPE) poses an increasing threat in hospitals worldwide. Recently, the prevalence of different carbapenemases conferring carbapenem resistance in enterobacterales changed in our country, including an increase in New Delhi Metallo-beta-lactamase (NDM)-CPE. We conducted a comparative historical study of adult patients colonized with Klebsiella pneumoniae carbapenemase (KPC)-CPE (July 2016 to June 2018, a historical cohort) vs. NDM-CPE (July 2016 to January 2023). We identified patients retrospectively through the microbiology laboratory and reviewed their files, extracting demographics, underlying diseases, Charlson Comorbidity Index (CCI) scores, treatments, and outcomes. This study included 228 consecutive patients from whom a CPE rectal swab screening was obtained: 136 NDM-CPE positive and 92 KPC-CPE positive. NDM-CPE-colonized patients had a shorter hospitalization length and a significantly lower 30-day post-discharge mortality rate (p = 0.002) than KPC-CPE-colonized patients. Based on multivariate regression, independent risk factors predicting CPE-NDM colonization included admission from home and CCI < 4 (p < 0.001, p = 0.037, respectively). The increase in NDM-CPE prevalence necessitates a modified CPE screening strategy upon hospital admission tailored to the changing local CPE epidemiology. In our region, the screening of younger patients residing at home with fewer comorbidities should be considered, regardless of a prior community healthcare contact or hospital admission.

ESBL-Producing Enterobacterales at the Human-Domestic Animal-Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil.

The use, misuse, and overuse of antimicrobials is one of the main public health threats of the 21st century. We investigated the risk factor of the presence of extended-spectrum, cephalosporin-resistant Enterobacterales in feces of non-domestic and domestic birds and other domestic animals in Piauí State, northeast Brazil. We collected a total of 387 cloacal and rectal swab samples of free-living birds, domestic birds, and domestic mammals in five municipalities: Amarante, Água Branca, Lagoa Alegre, Parnaíba, and Teresina. A total of 59/387 (15.2%) of these samples harbored extended spectrum beta-lactamase (ESBL)-producing Enterobacterales. Using the MALDI-TOF technique, we identified fifty-seven samples as Escherichia coli and two samples as Klebsiella pneumoniae. Teresina and Parnaíba had the highest prevalence of animals with resistant bacteria (32.1% and 27.1%, respectively) and highest exposure risk factor (OR of 16.06 and 8.58, respectively, and p < 0.001 for all). Multidrug-resistant, ESBL-producing Enterobacterales were observed in 72.8% of the samples (43/59). For the free-living birds, the positive samples belonged to a great kiskadee (Pitangus sulphuratus) and a semipalmated sandpiper (Calidris pusilla) in migratory and resident species, respectively. For domestic animals, the swine samples showed the highest prevalence of antimicrobial resistance. The lack of access to veterinary care and information regarding antimicrobial therapy, along with the easy access to antimicrobials without medical prescription, favors the inadequate use of antimicrobials in Piauí.

Potential involvement of beta-lactamase homologous proteins in resistance to beta-lactam antibiotics in gram-negative bacteria of the ESKAPEE group.

BACKGROUND: Enzymatic degradation mediated by beta-lactamases constitutes one of the primary mechanisms of resistance to beta-lactam antibiotics in gram-negative bacteria. This enzyme family comprises four molecular classes, categorized into serine beta-lactamases (Classes A, C, and D) and zinc-dependent metallo-beta-lactamases (Class B). Gram-negative bacteria producing beta-lactamase are of significant concern, particularly due to their prevalence in nosocomial infections. A comprehensive understanding of the evolution and dissemination of this enzyme family is essential for effective control of these pathogens. In this study, we conducted the prospecting, phylogenetic analysis, and in silico analysis of beta-lactamases and homologous proteins identified in 1827 bacterial genomes with phenotypic data on beta-lactam resistance. These genomes were distributed among Klebsiella pneumoniae (45%), Acinetobacter baumannii (31%), Pseudomonas aeruginosa (14%), Escherichia coli (6%), and Enterobacter spp. (4%). Using an HMM profile and searching for conserved domains, we mined 2514, 8733, 5424, and 2957 proteins for molecular classes A, B, C, and D, respectively. This set of proteins encompasses canonical subfamilies of beta-lactamases as well as hypothetical proteins and other functional groups. Canonical beta-lactamases were found to be phylogenetically distant from hypothetical proteins, which, in turn, are closer to other representatives of the penicillin-binding-protein (PBP-like) and metallo-beta-lactamase (MBL) families. The catalytic amino acid residues characteristic of beta-lactamases were identified from the sequence alignment and revealed that motifs are less conserved in homologous groups than in beta-lactamases. After comparing the frequency of protein groups in genomes of resistant strains with those of sensitive ones applying Fisher's exact test and relative risk, it was observed that some groups of homologous proteins to classes B and C are more common in the genomes of resistant strains, particularly to carbapenems. We identified the beta-lactamase-like domain widely distributed in gram-negative species of the ESKAPEE group, which highlights its importance in the context of beta-lactam resistance. Some hypothetical homologous proteins have been shown to potentially possess promiscuous activity against beta-lactam antibiotics, however, they do not appear to expressly determine the resistance phenotype. The selective pressure due to the widespread use of antibiotics may favor the optimization of these functions for specialized resistance enzymes.

Urinary tract infections in older adults: associated factors for extended-spectrum beta-lactamase production.

Objective: Urinary tract infections (UTIs) due to extended-spectrum beta-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae are among the leading causes of morbidity and mortality in older adults. Identifying associated factors for ESBL production may contribute to more appropriate empirical treatment. Materials and methods: This was a prospective observational study. Hospitalized patients of age > 65 with community-onset or hospital-acquired upper UTI due to E. coli or Klebsiella pneumoniae were included. A multivariate analysis was performed. Results: A total of 97 patients were included. ESBL prevalence among UTIs with E. coli or Klebsiella pneumoniae was 69.1% (n = 67). CRP values at the time of UTI diagnosis were found to be significantly higher in the ESBL-producing group (p = 0.004). The multivariate analysis revealed that male gender (OR: 2.72, CI: 1.02-7.25), prior recurrent UTI (OR: 3.14, CI: 1.21-8.14), and the development of secondary bacteremia (OR: 4.95, CI: 1.03-23.89) were major associated factors for UTI in older adults due to ESBL-producing E. coli and Klebsiella pneumoniae. Conclusion: Severe UTI in older men with a history of recurrent UTI may be a warning to the clinician for ESBL production in the setting of high ESBL prevalence. Carbapenems may be prioritized in the empirical treatment of patients with known risk factors for ESBL.

Clinical scoring model for predicting cefotaxime-resistance in Klebsiella pneumoniae bacteremia: development and validation based on portal of entry.

We developed a prediction model for cefotaxime resistance in patients with K. pneumoniae bacteremia. Adult patients with K. pneumoniae bacteremia were grouped into derivation (from March 2018 to December 2019) and validation (from January 2020 to August 2020) cohorts. The prediction scoring system was based on factors associated with cefotaxime resistance identified by the logistic regression model. A total of 358 patients were enrolled (256 for derivation, 102 for validation). In the multivariable analysis, age ≥65 years, hospital-acquired infection, prior antimicrobial use, and an updated Charlson comorbidity index ≥3 points were associated with cefotaxime resistance in the derivation cohort. When each variable was counted as 1 point, the values of the area under the curve were 0.761 in the derivation and 0.781 in the validation cohorts. The best cutoff value using the Youden index was ≥2 with 73.6% sensitivity and 67.5% specificity. Our simple scoring system favorably predicted cefotaxime resistance.