-
The Journal of Antimicrobial... Aug 2023Infection with ESBL-producing Enterobacteriaceae infection is ubiquitous in some neonatal ICUs and increasing levels of antibiotic resistance are a cause for urgent...
BACKGROUND
Infection with ESBL-producing Enterobacteriaceae infection is ubiquitous in some neonatal ICUs and increasing levels of antibiotic resistance are a cause for urgent concern. Delineation of bacterial and viral sepsis can be challenging, often leading to patients receiving empirical antibiotics without or whilst waiting for a definitive causal diagnosis. Empirical therapy is often dependent on broad-spectrum 'Watch' antibiotics, contributing to further resistance.
METHODS
ESBL-producing Enterobacteriaceae clinical isolates found to have caused neonatal sepsis and meningitis underwent a detailed in vitro screening including susceptibility testing, chequerboard combination analysis and hollow-fibre infection model dynamic analyses using combinations of cefotaxime, ampicillin and gentamicin in combination with β-lactamase inhibitors.
RESULTS
Additivity or synergy was found for all antibiotic combinations against seven Escherichia coli and three Klebsiella pneumoniae clinical isolates. Cefotaxime or ampicillin plus sulbactam combined with gentamicin was able to consistently inhibit the growth of ESBL-producing isolates at typical neonatal doses, and the combination cleared the hollow-fibre infection model system of organisms resistant to each agent alone. The combination of cefotaxime/sulbactam and gentamicin was consistently bactericidal at clinically achievable concentrations (Cmax of 180, 60 and 20 mg/L for cefotaxime, sulbactam and gentamicin, respectively).
CONCLUSIONS
The addition of sulbactam to cefotaxime or ampicillin to the typical first-line empirical therapy could obviate the need for carbapenems and amikacin in settings with high ESBL-infection prevalence.
Topics: Infant, Newborn; Humans; Amikacin; Carbapenems; Sulbactam; Gentamicins; Neonatal Sepsis; Prevalence; Anti-Bacterial Agents; Cefotaxime; Ampicillin; Escherichia coli; beta-Lactamases; Microbial Sensitivity Tests
PubMed: 37283195
DOI: 10.1093/jac/dkad177 -
Diagnostic Microbiology and Infectious... Aug 2023Antibiotic resistance surveillance may be essential to identify patterns of antibiotic resistance and guide treatment choices. Therefore, this systematic review and... (Meta-Analysis)
Meta-Analysis Review
Antibiotic resistance surveillance may be essential to identify patterns of antibiotic resistance and guide treatment choices. Therefore, this systematic review and meta-analysis aimed to evaluate amikacin resistance and susceptibility in children with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE). From inception to September 5, 2022, relevant studies were searched via PubMed, Embase, Cochrane Library, and Web of Science databases. A network meta-analysis was conducted to explore the sequencing of resistance rates in amikacin and other antibiotics. Totally, 26 studies with 2582 clusters of bacterial isolates were included. The resistance rate of amikacin in children with ESBL-PE was 10.1%, higher than the resistance rate of tigecycline (0.0%), ertapenem (0.4%), meropenem (0.7%), and imipenem (3.0%). For the drug susceptibility rate in children with ESBL-PE, the susceptibility rate of amikacin (89.7%) was lower than tigecycline (99.6%), imipenem (96.8%), meropenem (97.3%), and ertapenem (95.6%). Amikacin showed a low drug resistance and a high drug resistance in children with ESBL-PE infection, making it a good option for the treatment of the infection caused by ESBL-PE.
Topics: Child; Humans; Amikacin; Ertapenem; Meropenem; Tigecycline; Escherichia coli; Klebsiella pneumoniae; Anti-Bacterial Agents; Imipenem; beta-Lactamases; Drug Resistance; Microbial Sensitivity Tests
PubMed: 37290259
DOI: 10.1016/j.diagmicrobio.2023.115956 -
The Journal of Infection Sep 2023Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the 2006 extensively drug-resistant tuberculosis definitions and old treatment regimens are being replaced, we aimed to estimate the proportion of extensively drug-resistant tuberculosis patients globally who achieved successful treatment outcomes.
METHODS
We conducted a systematic review of PubMed/MEDLINE, Scopus, Web of Science, and Embase from January 1, 2005, through April 3, 2023. Included studies reported WHO treatment outcomes, or adaptions hereof, for pre-extensively and/or extensively drug-resistant tuberculosis patients according to the 2006 WHO definition. Eligible studies included cohorts of at least 10 adults (aged>18 years) that were not pregnant. Using a random-effects model, we calculated pooled proportions of treatment outcomes and performed sensitivity and subgroup analyses. PROSPERO registration number: CRD42022340961.
RESULTS
Among 5056 studies reviewed, we identified 94 studies from 26 countries, involving 10,223 extensively drug-resistant tuberculosis patients. The pooled proportion of successful treatment outcomes was 44.2% (95%CI: 38.3-50.3). Sensitivity analyses consistently produced similar estimates. A slight improvement in treatment outcomes was observed after 2013. Furthermore, 25 studies reported outcomes for 3564 individuals with pre-extensively drug-resistant tuberculosis, of which 63.3% achieved successful treatment (95%CI: 43.1-72.5).
CONCLUSION
Globally, the success rate of extensively drug-resistant tuberculosis treatment is 44.2%, far below the WHO's target rate of 75%. These results may serve as a reference for future studies assessing extensively drug-resistant tuberculosis treatment outcomes under the 2021 definition treated with better treatment regimens available. Comprehensive surveillance data of extensively drug-resistant tuberculosis outcomes from the whole world are desirable to monitor treatment progress.
Topics: Humans; Adult; Pregnancy; Female; Extensively Drug-Resistant Tuberculosis; Tuberculosis, Pulmonary; Treatment Outcome; Tuberculosis, Multidrug-Resistant; Antitubercular Agents
PubMed: 37356629
DOI: 10.1016/j.jinf.2023.06.014 -
Clinical Microbiology and Infection :... Oct 2023Mycobacterium abscessus complex is responsible for 2.6-13.0% of all non-tuberculous mycobacterial pulmonary infections and these are notoriously difficult to treat due...
OBJECTIVES
Mycobacterium abscessus complex is responsible for 2.6-13.0% of all non-tuberculous mycobacterial pulmonary infections and these are notoriously difficult to treat due to the complex regimens required, drug resistance and adverse effects. Hence, bacteriophages have been considered in clinical practice as an additional treatment option. Here, we evaluated antibiotic and phage susceptibility profiles of M. abscessus clinical isolates. Whole-genome sequencing (WGS) revealed the phylogenetic relationships, dominant circulating clones (DCCs), the likelihood of patient-to-patient transmission and the presence of prophages.
METHODS
Antibiotic susceptibility testing was performed using CLSI breakpoints (n = 95), and plaque assays were used for phage susceptibility testing (subset of n = 88, 35 rough and 53 smooth morphology). WGS was completed using the Illumina platform and analysed using Snippy/snp-dists and Discovery and Extraction of Phages Tool (DEPhT).
RESULTS
Amikacin and Tigecycline were the most active drugs (with 2 strains resistant to amikacin, and one strain with Tigecycline MIC of 4 μg/mL). Most strains were resistant to all other drugs tested, with Linezolid and Imipenem showing the least resistance, at 38% (36/95) and 55% (52/95), respectively. Rough colony morphotype strains were more phage-susceptible than smooth strains (77%-27/35 versus 48%-25/53 in the plaque assays, but smooth strains are not killed efficiently by those phages in liquid infection assay). We have also identified 100 resident prophages, some of which were propagated lytically. DCC1 (20%-18/90) and DCC4 (22%-20/90) were observed to be the major clones and WGS identified 6 events of possible patient-to-patient transmission.
DISCUSSION
Many strains of M. abscessus complex are intrinsically resistant to available antibiotics and bacteriophages represent an alternative therapeutic option, but only for strains with rough morphology. Further studies are needed to elucidate the role of hospital-borne M. abscessus transmission.
Topics: Humans; Mycobacterium abscessus; Amikacin; Tigecycline; Bacteriophages; Phylogeny; Mycobacterium Infections, Nontuberculous; Anti-Bacterial Agents; Drug Resistance, Multiple; Delivery of Health Care; Microbial Sensitivity Tests
PubMed: 37364635
DOI: 10.1016/j.cmi.2023.06.026 -
Advanced Science (Weinheim,... Sep 2023The antibiotic resistances emerged in uropathogens lead to accumulative treatment failure and recurrent episodes of urinary tract infection (UTI), necessitating more...
The antibiotic resistances emerged in uropathogens lead to accumulative treatment failure and recurrent episodes of urinary tract infection (UTI), necessitating more innovative therapeutics to curb UTI before systematic infection. In the current study, the combination of amikacin and nitrofurantoin is found to synergistically eradicate Gram-negative uropathogens in vitro and in vivo. The mechanistic analysis demonstrates that the amikacin, as an aminoglycoside, induced bacterial envelope stress by introducing mistranslated proteins, thereby constitutively activating the cpxA/R two-component system (Cpx signaling). The activation of Cpx signaling stimulates the expression of bacterial major nitroreductases (nfsA/nfsB) through soxS/marA regulons. As a result, the CpxA/R-dependent nitroreductases overexpression generates considerable quantity of lethal reactive intermediates via nitroreduction and promotes the prodrug activation of nitrofurantoin. As such, these actions together disrupt the bacterial cellular redox balance with excessively-produced reactive oxygen species (ROS) as "Domino effect", accelerating the clearance of uropathogens. Although aminoglycosides are used as proof-of-principle to elucidate the mechanism, the synergy between nitrofurantoin is generally applicable to other Cpx stimuli. To summarize, this study highlights the potential of aminoglycoside-nitrofurantoin combination to replenish the arsenal against recurrent Gram-negative uropathogens and shed light on the Cpx signaling-controlled nitroreductase as a potential target to manipulate the antibiotic susceptibility.
Topics: Humans; Nitrofurantoin; Reactive Oxygen Species; Amikacin; Escherichia coli; Anti-Bacterial Agents; Urinary Tract Infections; Aminoglycosides; Nitroreductases; Protein Kinases; Escherichia coli Proteins
PubMed: 37407509
DOI: 10.1002/advs.202300938 -
Frontiers in Microbiology 2024Non-Tuberculous mycobacteria (NTM) are opportunistic environmental bacteria. Globally, NTM incidence is increasing and modeling suggests that, without new interventions,... (Review)
Review
Non-Tuberculous mycobacteria (NTM) are opportunistic environmental bacteria. Globally, NTM incidence is increasing and modeling suggests that, without new interventions, numbers will continue to rise. Effective treatments for NTM infections remain suboptimal. Standard therapy for complex, the most commonly isolated NTM, requires a 3-drug regime taken for approximately 18 months, with rates of culture conversion reported between 45 and 70%, and high rates of relapse or reinfection at up to 60%. New therapeutic options for NTM treatment are urgently required. A survey of ongoing clinical trials for new NTM therapy listed on ClinicalTrials.Gov using the terms '', '', '', 'Non tuberculous Mycobacteria' and 'Nontuberculous Mycobacteria' and a selection criterion of interventional studies using antibiotics demonstrates that most trials involve dose and combination therapy of the guideline based therapy or including one or more of; Amikacin, Clofazimine, Azithromycin and the anti-TB drugs Bedaquiline and Linezolid. The propensity of NTMs to form biofilms, their unique cell wall and expression of both acquired and intrinsic resistance, are all hampering the development of new anti-NTM therapy. Increased investment in developing targeted treatments, specifically for NTM infections is urgently required.
PubMed: 38887711
DOI: 10.3389/fmicb.2024.1394220 -
The Journal of Antimicrobial... Jul 2023To assess the global and regional distribution of ESBLs in Enterobacterales and carbapenemases in Enterobacterales and Pseudomonas aeruginosa.
OBJECTIVES
To assess the global and regional distribution of ESBLs in Enterobacterales and carbapenemases in Enterobacterales and Pseudomonas aeruginosa.
METHODS
Antimicrobial susceptibility of isolates collected from ATLAS (2017-2019) was determined per CLSI guidelines. Enterobacterales exhibiting meropenem MICs ≥2 mg/L and/or ceftazidime/avibactam and/or aztreonam/avibactam MICs ≥16 mg/L, Escherichia coli and Klebsiella pneumoniae with aztreonam and/or ceftazidime MICs ≥2 mg/L, and P. aeruginosa with meropenem MICs ≥4 mg/L were screened for β-lactamases by PCR and sequencing.
RESULTS
Globally, ESBL-positive E. coli (23.7%, 4750/20047) and K. pneumoniae (35.1%, 6055/17229) carried predominantly the CTX-M-15 variant (E. coli: 53.9%; K. pneumoniae: 80.0%) with highest incidence in Africa/Middle East (AfME). Among carbapenem-resistant (CR) E. coli (1.1%, 217/20047) and Enterobacter cloacae (3.8%, 259/6866), NDMs were predominant (E. coli in AfME: 62.5%; E. cloacae in Asia Pacific: 59.7%). CR K. pneumoniae (13.3%, 2299/17 229) and P. aeruginosa (20.3%, 4187/20 643) carried predominantly KPC (30.9%) and VIM (14.7%), respectively, with highest frequency in Latin America. Among ESBL-positive Enterobacterales, susceptibility to ceftazidime/avibactam (>90.0%) and amikacin (>85.0%) was higher than to piperacillin/tazobactam (>45.0%) and ciprofloxacin (>7.4%). In CR Enterobacterales, susceptibility to amikacin (>54.0%) and ceftazidime/avibactam (>31.0%) was higher than to ciprofloxacin (>2.7%) and piperacillin/tazobactam (>0.5%). CR P. aeruginosa similarly demonstrated higher susceptibility to amikacin (63.4%) and ceftazidime/avibactam (61.9%) than to ciprofloxacin (26.2%) and piperacillin/tazobactam (25.3%).
CONCLUSIONS
Varied distribution of resistance genotypes across regions among ESBL-positive Enterobacterales and CR Enterobacterales and P. aeruginosa provide crucial insights on major resistance mechanisms and trends observed in recent years. Continued surveillance is warranted for monitoring global dissemination and resistance.
Topics: Ceftazidime; Pseudomonas aeruginosa; Anti-Bacterial Agents; Amikacin; Aztreonam; Meropenem; Escherichia coli; Incidence; Azabicyclo Compounds; beta-Lactamases; Piperacillin, Tazobactam Drug Combination; Klebsiella pneumoniae; Drug Combinations; Ciprofloxacin; Microbial Sensitivity Tests
PubMed: 37161662
DOI: 10.1093/jac/dkad127 -
Heliyon Dec 2023Canine Pyometra, also known as cystic endometrial hyperplasia complex, is a common reproductive issue in bitches. This study aimed to identify associated risk factors,...
Canine Pyometra, also known as cystic endometrial hyperplasia complex, is a common reproductive issue in bitches. This study aimed to identify associated risk factors, hematological variation, bacteria involved, and the most potent anti-bacterial against bacterial isolates of canine pyometra. Forty-five bitches of different habitats, breeds, and ages infected with pyometra were included in the study. The samples were cultured to isolate bacteria associated with the pyometra and antibiotic sensitivity was done for each bacterial isolates to get antibiogram. The study findings showed that potential risk factors such as age group, medroxyprogesterone acetate administration, and changes in the white blood cells parameters were significantly associated (P < 0.05) with the type of pyometra. Closed cervix pyometra in dogs showed significantly higher prevalence of clinical signs including depression, vomiting, abdominal enlargement, and fever compared to the open cervix pyometra. Low levels of red blood cells, pack cell volume, and hemoglobin indicated that the pyometra-infected dogs were more likely to have normocytic, normochromic, and non-regenerative anemia. Pyometra was attributed to an increase in AST (Aspertate aminotransferase), ALT (Alanine transaminase), ALP (Alkaline phosphatase), BUN (Blood Urea Nitrogen), and Creatinine while a decrease in serum albumin. Of the all bacterial isolates, (35.55%) was the most common pathogen isolated from canine pyometra, followed by spp. (26.66%). and spp. were susceptible to Imipenem, Amikacin, and Gentamicin while highly resistant to Ampicillin and Erythromycin. Imipenem, Amikacin, and Gentamicin were the most sensitive antibiotics, while Ampicillin and Erythromycin were the most resistant antibiotics for the bacterial strain isolated from canine pyometra. Multidrug resistant was observed in 26 of the isolated bacteria, indicating acquired resistance due to improper and uncontrolled use. Hence early diagnosis and close monitoring of antimicrobial susceptibility before therapeutic intervention is indispensable in preventing the global threat of antimicrobial resistance.
PubMed: 38076069
DOI: 10.1016/j.heliyon.2023.e22368 -
Neurology India 2023Mycobacterium abscessus complex (MabC) has emerged as an important cause of human infections, including meningitis. In the absence of correct microbiological... (Review)
Review
BACKGROUND
Mycobacterium abscessus complex (MabC) has emerged as an important cause of human infections, including meningitis. In the absence of correct microbiological identification, cases of MabC meningitis are treated with conventional anti-tubercular therapy, thereby worsening the outcome.
OBJECTIVE
The current study was conducted to determine the clinical features, antimicrobial susceptibility, and outcome of patients with MabC meningitis.
MATERIAL AND METHODS
Cerebrospinal fluid specimens processed between 2011 and 2021 were subjected to smear, culture, MALDI TOF identification, hsp65 gene sequencing, and susceptibility testing using Sensititre™ RAPMYCOI plates along with a literature review.
RESULTS
12 cases of MabC meningitis were identified between 2011 and 2021, 11 of which were M. abscessus subspecies abscessus on hsp65 gene sequencing. A pioneer case of meningitis with M. abscessus subspecies bolletii was also identified. The common predispositions were TB elsewhere, HIV positivity, and head injury. Two patients had dual infections, both MabC and TB. Ten patients succumbed to infection with a mean survival of 11 months. All isolates were susceptible to amikacin and tigecycline and subspecies bolletii had a higher minimum inhibitory concentration (MIC) than subspecies abscessus. A combined analysis with the available literature, reporting 19 more cases, revealed that the overall mortality of MabC meningitis was 61.3% (19/31) and that of shunt-associated/neurosurgical intervention-related MabC meningitis was 66.7% (12/20). To date, out of 20 MabC meningitis isolates in which subspecies identification was carried, 13 were M. abscessus, six were M. massiliense, and one was M. bolletii.
CONCLUSION
MabC is an important differential diagnosis of chronic meningitis. Prompt identification and speciation are imperative for targeted therapy, thus improving the overall patient outcome.
Topics: Humans; Mycobacterium abscessus; Tigecycline; Tuberculosis; Meningitis; Anti-Bacterial Agents
PubMed: 37929432
DOI: 10.4103/0028-3886.388095 -
JAC-antimicrobial Resistance Oct 2023Omadacycline is an aminomethylcycline antibiotic in the tetracycline class that was approved by the US FDA in 2018 for the treatment of community-acquired bacterial...
BACKGROUND
Omadacycline is an aminomethylcycline antibiotic in the tetracycline class that was approved by the US FDA in 2018 for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections. It is available in both IV and oral formulations. Omadacycline has broad-spectrum activity and clinical efficacy against infections caused by Gram-positive and Gram-negative pathogens. Omadacycline is being evaluated in a 3 month placebo-controlled Phase 2 clinical trial of oral omadacycline versus placebo in adults with non-tuberculous mycobacteria (NTM) pulmonary disease caused by (NCT04922554).
OBJECTIVES
To determine if omadacycline has intracellular antimicrobial activity against NTM, bacteria that can cause chronic lung disease, in an model of intracellular infection.
METHODS
Two strains of were used to infect THP-1 macrophages. Intracellular was then challenged with omadacycline and control antibiotics at multiples of the MIC over time to evaluate intracellular killing.
RESULTS
At 16 × the MIC at 72 h, omadacycline treatment of intracellular NTM yielded a log reduction in cfu of 1.1 (91.74% reduction in cfu) and 1.6 (97.65% reduction in cfu) consistent with killing observed with tigecycline, whereas amikacin and clarithromycin at 16 × the MIC did not show any reduction in cfu against the intracellular .
CONCLUSIONS
Omadacycline displayed intracellular activity against within macrophages. The activity was similar to that of tigecycline; as expected, intracellular killing was not observed with clarithromycin and amikacin.
PubMed: 37720564
DOI: 10.1093/jacamr/dlad104