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International Journal of... Apr 2024Tuberculosis (TB), a global infectious threat, has seen a concerning rise in aminoglycoside-resistant Mycobacterium tuberculosis (M.tb) strains. The potential role of... (Comparative Study)
Comparative Study
Comparative Proteomic Analysis of Capsule Proteins in Aminoglycoside-Resistant and Sensitive Mycobacterium tuberculosis Clinical Isolates: Unraveling Potential Drug Targets.
BACKGROUND
Tuberculosis (TB), a global infectious threat, has seen a concerning rise in aminoglycoside-resistant Mycobacterium tuberculosis (M.tb) strains. The potential role of capsule proteins remains largely unexplored. This layer acts as the primary barrier for tubercle bacilli, attempting to infiltrate host cells and subsequent disease development.
METHODS
The study aims to bridge this gap by investigating the differentially expressed capsule proteins in aminoglycoside-resistant M.tb clinical isolates compared with drug-sensitive isolates employing two-dimensional gel electrophoresis, mass spectrometry, and bioinformatic approaches.
RESULTS
We identified eight proteins that exhibited significant upregulation in aminoglycoside-resistant isolates. Protein Rv3029c and Rv2110c were associated with intermediary metabolism and respiration; Rv2462c with cell wall and cell processes; Rv3804c with lipid metabolism; Rv2416c and Rv2623 with virulence and detoxification/adaptation; Rv0020c with regulatory functions; and Rv0639 with information pathways. Notably, the Group-based Prediction System for Prokaryotic Ubiquitin-like Protein (GPS-PUP) algorithm identified potential pupylation sites within all proteins except Rv3804c. Interactome analysis using the STRING 12.0 database revealed potential interactive partners for these proteins, suggesting their involvement in aminoglycoside resistance. Molecular docking studies revealed suitable binding between amikacin and kanamycin drugs with Rv2462c, Rv3804c, and Rv2623 proteins.
CONCLUSION
As a result, our findings illustrate the multifaceted nature of aminoglycoside resistance in M.tb and the importance of understanding how capsule proteins play a role in counteracting drug efficacy. Identifying the role of these proteins in drug resistance is crucial for developing more effective treatments and diagnostics for TB.
Topics: Mycobacterium tuberculosis; Humans; Proteomics; Bacterial Proteins; Aminoglycosides; Drug Resistance, Bacterial; Bacterial Capsules; Antitubercular Agents; Microbial Sensitivity Tests; Computational Biology; Electrophoresis, Gel, Two-Dimensional; Tuberculosis
PubMed: 38916392
DOI: 10.4103/ijmy.ijmy_47_24 -
Perioperative Medicine (London, England) Jun 2024Secondary peritonitis is the second leading cause of sepsis worldwide. Drug resistance to peritoneal cavity bacterial infection remains a public health threat,...
INTRODUCTION
Secondary peritonitis is the second leading cause of sepsis worldwide. Drug resistance to peritoneal cavity bacterial infection remains a public health threat, especially in resource-limited settings in Africa, including Uganda. This study aimed to determine the antibacterial susceptibility patterns and factors associated with secondary peritonitis among patients with acute abdomen who underwent surgery at a Regional Referral Hospital in Uganda.
METHODS
This was a cross-sectional study conducted at Hoima Regional Referral Hospital (HRRH) that enrolled 126 patients with acute abdomen. Clinical samples were aseptically collected at laparotomy from patients with secondary peritonitis for culture and sensitivity using standard Microbiological methods. Binary logistic regression was used to identify factors associated with secondary peritonitis among patients with acute abdomen.
RESULTS
The majority of the patients were males (61.9%) with a mean age of 37.9(SD ± 21.8). Secondary peritonitis was found in 57(45.2%) of the patients. Gram-negative bacteria were the most commonly isolated organisms with Escherichia coli (35.8%) and Klebsiella spp (17.0%) predominating. Imipenem 88.8%(8/9), Amikacin 88.8%(8/9), Ciprofloxacin 44.4%(4/9) and Gentamicin 44.4%(4/9) demonstrated sensitivity to the different isolated organisms at varying degrees. Being a male (AOR = 3.658; 95% CI = 1.570-8.519, p = 0.003) and presenting 3 days after onset of symptoms (AOR = 2.957; 95% CI = 1.232-7.099, p = 0.015) were independently associated with secondary peritonitis.
CONCLUSION
Imipenem, Amikacin, Ciprofloxacin, and Gentamicin should be considered for empirical therapy in cases of secondary peritonitis. Patients, more especially males with abdominal pain should be encouraged to present early to the hospital to minimize progression to secondary peritonitis.
PubMed: 38915124
DOI: 10.1186/s13741-024-00425-4 -
BMC Infectious Diseases Jun 2024Acinetobacter baumannii is a health threat due to its antibiotic resistance. Herein, antibiotic susceptibility and its association with the Toxin-antitoxin (TA) system...
Evaluating the antibacterial effect of meropenem-loaded chitosan/sodium tripolyphosphate (TPP) nanoparticles on Acinetobacter baumannii isolated from hospitalized patients.
BACKGROUND
Acinetobacter baumannii is a health threat due to its antibiotic resistance. Herein, antibiotic susceptibility and its association with the Toxin-antitoxin (TA) system genes in A. baumannii clinical isolates from Iran were investigated. Next, we prepared meropenem-loaded chitosan nanoparticles (MP-CS) and investigated their antibacterial effects against meropenem-susceptible bacterial isolates.
METHODS
Out of 240 clinical specimens, 60 A. baumannii isolates were assessed. Antibiotic resistance of the isolates against conventional antibiotics was determined alongside investigating the presence of three TA system genes (mazEF, relBE, and higBA). Chitosan nanoparticles were characterized in terms of size, zeta potential, encapsulation efficiency, and meropenem release activity. Their antibacterial effects were assessed using the well diffusion method, minimum inhibitory concentration (MIC), and colony-forming unit (CFU) counting. Their cytotoxic effects and biocompatibility index were determined via the MTT, LDH, and ROS formation assays.
RESULTS
Ampicillin, ceftazidime, and colistin were the least effective, and amikacin and tobramycin were the most effective antibiotics. Out of the 60 isolates, 10 (16.7%), 5 (8.3%), and 45 (75%) were multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR), respectively. TA system genes had no significant effect on antibiotic resistance. MP-CS nanoparticles demonstrated an average size of 191.5 and zeta potential of 27.3 mV alongside a maximum encapsulation efficiency of 88.32% and release rate of 69.57%. MP-CS nanoparticles mediated similar antibacterial effects, as compared with free meropenem, against the A. baumannii isolates with significantly lower levels of meropenem. MP-CS nanoparticles remarkably prevented A549 and NCI-H292 cell infection by the A. baumannii isolates alongside demonstrating a favorable biocompatibility index.
CONCLUSION
Antibiotic-loaded nanoparticles should be further designed and investigated to increase their antibacterial effect against A. baumannii and assess their safety and applicability in vivo settings.
Topics: Acinetobacter baumannii; Meropenem; Chitosan; Anti-Bacterial Agents; Humans; Microbial Sensitivity Tests; Nanoparticles; Acinetobacter Infections; Iran; Polyphosphates
PubMed: 38914964
DOI: 10.1186/s12879-024-09522-7 -
PloS One 2024Current antimicrobial susceptibility testing (AST) requires 16-24 hours, delaying initiation of appropriate antibiotics. Hence, there is a need for rapid AST. This study...
Can flow cytometric measurements of reactive oxygen species levels determine minimal inhibitory concentrations and antibiotic susceptibility testing for Acinetobacter baumannii?
Current antimicrobial susceptibility testing (AST) requires 16-24 hours, delaying initiation of appropriate antibiotics. Hence, there is a need for rapid AST. This study aims to develop and evaluate the feasibility of a rapid flow cytometric AST assay to determine minimum inhibitory concentration (MIC) for carbapenem-resistant Acinetobacter baumannii (CRAB). Antibiotic exposure causes increased intracellular reactive oxygen species (ROS) in bacteria. We hypothesized that ROS can be used as a marker to determine MIC. We assessed three CRAB clinical isolates across fifteen antibiotics at various concentrations in a customized 96-well microtiter plate. The antibiotics assessed include amikacin, beta-lactams (ampicillin/sulbactam, aztreonam, cefepime, ceftolozane/tazobactam, doripenem, imipenem, meropenem, and piperacillin/tazobactam), levofloxacin, polymyxin B, rifampicin, trimethoprim/sulfamethoxazole, and tetracyclines (tigecycline and minocycline). These clinical CRAB isolates were assessed for ROS after antibiotic treatment. Increased ROS levels indicated by increased RedoxSensorTM Green (RSG) fluorescence intensity was assessed using flow cytometry (FCM). MIC was set as the lowest antibiotic concentration that gives a ≥1.5-fold increase in mode RSG fluorescence intensity (MICRSG). Accuracy of MICRSG was determined by comparing against microtiter broth dilution method performed under CLSI guidelines. ROS was deemed accurate in determining the MICs for β-lactams (83.3% accuracy) and trimethoprim/sulfamethoxazole (100% accuracy). In contrast, ROS is less accurate in determining MICs for levofloxacin (33.3% accuracy), rifampicin (0% accuracy), amikacin (33.3% accuracy), and tetracyclines (33.3% accuracy). Collectively, this study described an FCM-AST assay to determine antibiotic susceptibility of CRAB isolates within 5 hours, reducing turnaround time up to 19 hours.
Topics: Acinetobacter baumannii; Flow Cytometry; Microbial Sensitivity Tests; Anti-Bacterial Agents; Reactive Oxygen Species; Humans; Carbapenems; Acinetobacter Infections
PubMed: 38913680
DOI: 10.1371/journal.pone.0305939 -
Clinical Microbiology and Infection :... Jun 2024Tuberculosis (TB) is the leading cause of mortality by an infectious disease world-wide. Despite national and international efforts, the world is not on track to end TB... (Review)
Review
BACKGROUND
Tuberculosis (TB) is the leading cause of mortality by an infectious disease world-wide. Despite national and international efforts, the world is not on track to end TB by 2030. Antibiotic treatment of TB is longer than for most infectious diseases and complicated by frequent adverse events. To counter emerging Mycobacterium tuberculosis drug resistance and provide effective, safe drug treatments of shorter duration, novel anti-TB medicines and treatment regimens are needed. Through a joint global effort, more candidate medicines are in the clinical phases of drug development than ever before.
OBJECTIVES
To review anti-TB medicines and treatment regimens under clinical evaluation for the future treatment of drug-susceptible and drug-resistant TB.
SOURCES
Pre-clinical and clinical studies on novel anti-TB drugs.
CONTENT
Description of novel protein synthesis inhibitors (oxazolidinones and oxaboroles), respiratory chain inhibitors (diarylquinolines and cytochrome bc1 complex inhibitor), cell wall inhibitors (DprE1 inhibitors, thioamides and carbapenems) and cholesterol metabolism inhibitor currently evaluated in clinical trials and novel clinical trial platforms for the evaluation of treatment regimens, rather than single entities.
IMPLICATIONS
A large number of potential anti-TB candidate medicines and innovations in clinical trial design for the evaluation of regimens, rather than single medicines, provide hope for improvements in the treatment of TB.
PubMed: 38909687
DOI: 10.1016/j.cmi.2024.06.016 -
Journal of Global Antimicrobial... Jun 2024Ceftolozane-tazobactam (C/T) is a combination of a cephalosporin and a β-lactamase inhibitor with activity against Gram-negative bacilli (GNB). The study aims were to...
In vitro activity of ceftolozane/tazobactam against Gram-negative bacilli isolated from pediatric patients: results from the Study for Monitoring Antimicrobial Resistance Trends (SMART) 2017-2021, China.
OBJECTIVES
Ceftolozane-tazobactam (C/T) is a combination of a cephalosporin and a β-lactamase inhibitor with activity against Gram-negative bacilli (GNB). The study aims were to evaluate the activity of C/T in vitro vs. comparators against clinical GNB isolated from Chinese pediatric patients.
METHODS
From 2017-2021, 660 GNB isolates were collected from 20 hospitals across China. The minimum inhibitory concentrations were tested using a Trek Diagnostic System (Thermo Fisher Scientific). Susceptibility was determined by CLSI broth microdilution and the results were interpreted according to CLSI M100 (2021) breakpoints.
RESULTS
GNB isolates were obtained from pediatric patients < 18 years old, mainly from the bloodstream (n=146), intraperitoneal cavity (n=138), lower respiratory (n=278) and urinary tract (n=96). Overall, C/T was active against 76.6% of 436 Enterobacterales, with a descending susceptibility rate of 100.0% to S. marcescens, 92.2% to E. coli, 83.3% to K. oxytoca, 66.7% to K. aerogenes, 66.7% to P. mirabilis, 58.6% to K. pneumoniae and 57.1% to E. cloacae. The susceptibility of P. aeruginosa to C/T was 89.4%, which was the highest among the β-lactams and was second only to amikacin (92.9%). Isolates of respiratory tract infection (RTI) derived P. aeruginosa were highly susceptible (93.8%) to C/T, while < 75% of isolates of RTI derived P. aeruginosa were susceptible to the other β-lactams tested, except for ceftazidime-avibactam (91.2%).
CONCLUSION
GNBs collected from pediatric patients in China showed a high susceptibility to C/T making this drug combination an effective choice for treating the pediatric population, especially those infected with P. aeruginosa.
PubMed: 38908824
DOI: 10.1016/j.jgar.2024.05.017 -
Microbial Pathogenesis Jun 2024Severe infection caused by Carbapenem-resistant Enterobacteriaceae (CRE) is a challenge for clinical anti-infective therapy, and clinical intervention to improve control...
OBJECTIVES
Severe infection caused by Carbapenem-resistant Enterobacteriaceae (CRE) is a challenge for clinical anti-infective therapy, and clinical intervention to improve control of CRE is of great significance. The study aims to determine the molecular epidemiology and risk factors of CRE infections to provide evidence for effective control of nosocomial infection in patients with CRE.
METHODS
A total of 192 non-repetitive CRE strains were collected from January 2020 to December 2021 in Northwest China. To explore the risk factors of CRE infection by univariate and Logistic regression analysis, 1:1 case-control study was used to select Carbapenem sensitive Enterobacteriaceae (CSE) infection patients at the same period as the control group.
RESULTS
Among the 192 CRE strains, the most common isolates included Klebsiella pneumoniae (Kpn) and Enterobacter cloacae (Ecl). The CRE strain showed the lowest rate of resistance to amikacin at 58.3. 185 CRE strains carried carbapenemase resistance genes of concern in this study. KPC-2 (n=94) was the most common carbapenemase, followed by NDM-1 (n=69), NDM-5 (n=22) and IMP-4 (n=5). OXA-48 and VIM were not detected. And KPC-2 was the most common in all strains. Logistic regression analysis implicated days of invasive ventilator-assisted ventilation (OR=1.452; 95 % CI 1.250~1.686), antibiotic combination therapy (OR=2.149; 95 % CI 1.128~4.094), hypoalbuminemia (OR=6.137; 95 % CI 3.161~11.913), history of immunosuppressant use (OR=25.815; 95 % CI 6.821~97.706) and days of hospitalization (OR=1.020; 95 % CI 1.006~1.035) as independent risk factors associated with CRE infection. Age (OR=0.963; 95% CI 0.943~0.984) and history of hormone use (OR=0.119; 95 % CI 0.028~0.504) were protective factors for CRE infection (P < 0.05).
CONCLUSIONS
The resistance of commonly used antibiotics in clinical is severe, and CRE strains mainly carry KPC-2 and NDM-1. Multiple risk factors for CRE infection and their control can effectively prevent the spread of CRE.
PubMed: 38906492
DOI: 10.1016/j.micpath.2024.106728 -
The Journal of Infection Jun 2024The clinical relevance of Mycobacterium malmoense isolation from pulmonary specimens has been considered high compared with other non-tuberculous mycobacteria. In this... (Review)
Review
INTRODUCTION
The clinical relevance of Mycobacterium malmoense isolation from pulmonary specimens has been considered high compared with other non-tuberculous mycobacteria. In this study, we aimed to analyse all published clinical data of patients with M. malmoense isolation to investigate the clinical spectrum, relevance, and outcomes of infections with this uncommon mycobacterium.
METHODS
A systematic review of PubMed, Web of Science, Embase, and Scopus was performed to identify all clinical data about M. malmoense. Random effects meta-analyses of proportions were calculated for clinical relevance, treatment success, and mortality, as well as for other clinical characteristics. A logistic regression analysis, investigating predictors of mortality, as well as Kaplan-Meier survival analyses, were performed.
RESULTS
One hundred and eighty eight patients with individual data from 112 articles and 671 patients with pooled data from 12 articles were included in the meta-analyses. Of patients with individual data, pulmonary infection was the most common manifestation (n = 106/188, 56.4%). One third (n = 61/188, 32.4%) suffered from isolated extra-pulmonary and 21/188 (11.2%) from disseminated disease. In 288 patients with pooled data and pulmonary affection, clinical relevance was high with 68% (95% CI 44-85%) of patients fulfilling criteria for clinical disease. Macrolide and rifamycin-containing regimens were associated with improved survival (adjusted OR 0.12, 95% CI 0.03-0.42, p = 0.002, and 0.23, 95% CI 0.04-0.86, p = 0.03, for lethal events, respectively).
CONCLUSION
In this study, we provide a detailed clinical description of M. malmoense infections. The pathogen is of high clinical relevance for the individual patient with more than 2 out of 3 patients having relevant disease and >40% of manifestations being extra-pulmonary or disseminated. Macrolide and rifamycin-containing regimens are associated with improved survival.
PubMed: 38906266
DOI: 10.1016/j.jinf.2024.106203 -
Microbiology Spectrum Jun 2024The continuous advancement of molecular diagnostic techniques, particularly whole-genome sequencing (WGS), has greatly facilitated the early diagnosis of drug-resistant...
The continuous advancement of molecular diagnostic techniques, particularly whole-genome sequencing (WGS), has greatly facilitated the early diagnosis of drug-resistant tuberculosis patients. Nonetheless, the interpretation of results from various types of mutations in drug-resistant-associated genes has become the primary challenge in the field of molecular drug-resistance diagnostics. In this study, our primary objective is to evaluate the diagnosis accuracy of the World Health Organization (WHO) catalog of mutations and five WGS analysis tools (PhyResSE, Mykrobe, TB Profiler, Gen-TB, and SAM-TB) in drug resistance to 10 anti- (MTB) drugs. We utilized the data of WGS collected between 2014 and 2017 in Zhejiang Province, consisting of 110 MTB isolates as detailed in our previous study. Based on phenotypic drug susceptibility testing (DST) results using the proportion method on Löwenstein-Jensen medium with antibiotics, we evaluated the predictive accuracy of genotypic DST obtained by these tools. The results revealed that the WHO catalog of mutations and five WGS analysis tools exhibit robust predictive capabilities concerning resistance to isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, and capreomycin. Notably, Mykrobe, SAM-TB, and TB Profiler demonstrate the most accurate predictions for resistance to pyrazinamide, prothionamide, and para-aminosalicylic acid, respectively. These findings are poised to significantly guide and influence future clinical treatment strategies and resistance monitoring protocols.IMPORTANCEWhole-genome sequencing (WGS) has the potential for the early diagnosis of drug-resistant tuberculosis. However, the interpretation of mutations of drug-resistant-associated genes represents a significant challenge as the amount and complexity of WGS data. We evaluated the accuracy of the World Health Organization catalog of mutations and five WGS analysis tools in predicting drug resistance to first-line and second-line anti-TB drugs. Our results offer clinicians guidance on selecting appropriate WGS analysis tools for predicting resistance to specific anti-TB drugs.
PubMed: 38904370
DOI: 10.1128/spectrum.03341-23 -
Frontiers in Cellular and Infection... 2024Ceftazidime/avibactam (CZA) is indicated against multidrug-resistant , particularly those that are carbapenem resistant. CZA resistance in producing PER, a class A...
INTRODUCTION
Ceftazidime/avibactam (CZA) is indicated against multidrug-resistant , particularly those that are carbapenem resistant. CZA resistance in producing PER, a class A extended-spectrum β-lactamase, has been well documented . However, data regarding clinical isolates are scarce. Our aim was to analyze the contribution of PER to CZA resistance in non-carbapenemase-producing clinical isolates that were ceftazidime and/or carbapenem non-susceptible.
METHODS
Antimicrobial susceptibility was determined through agar dilution and broth microdilution, while gene was screened through PCR. All PER-positive isolates and five PER-negative isolates were analyzed through Whole Genome Sequencing. The mutational resistome associated to CZA resistance was determined through sequence analysis of genes coding for PBPs 1b, 3 and 4, MexAB-OprM regulators MexZ, MexR, NalC and NalD, AmpC regulators AmpD and AmpR, and OprD porin. Loss of gene was induced in a PER-positive isolate by successive passages at 43°C without antibiotics.
RESULTS
Twenty-six of 287 isolates studied (9.1%) were CZA-resistant. Thirteen of 26 CZA-resistant isolates (50%) carried . One isolate carried but was CZA-susceptible. PER-producing isolates had significantly higher MICs for CZA, amikacin, gentamicin, ceftazidime, meropenem and ciprofloxacin than non-PER-producing isolates. All PER-producing isolates were ST309 and their gene was associated to ISCR1, an insertion sequence known to mobilize adjacent DNA. PER-negative isolates were classified as ST41, ST235 (two isolates), ST395 and ST253. PER-negative isolates carried genes for narrow-spectrum β-lactamases and the mutational resistome showed that all isolates had one major alteration in at least one of the genes analyzed. Loss of gene restored susceptibility to CZA, ceftolozane/tazobactam and other β-lactamsin the evolved isolate.
DISCUSSION
PER-3-producing ST309 is a successful multidrug-resistant clone with gene implicated in resistance to CZA and other β-lactams.
Topics: Ceftazidime; Pseudomonas aeruginosa; Azabicyclo Compounds; Microbial Sensitivity Tests; Humans; Drug Combinations; beta-Lactamases; Anti-Bacterial Agents; Pseudomonas Infections; Bacterial Proteins; Drug Resistance, Multiple, Bacterial; Chile; Whole Genome Sequencing; Mutation
PubMed: 38903939
DOI: 10.3389/fcimb.2024.1410834