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Antibiotics (Basel, Switzerland) Dec 2023The emergence of bacteria resistant to beta-lactam/beta-lactamase inhibitor combinations is insufficiently studied, wherein the role of the inoculum effect (IE) in...
Pharmacodynamics of Doripenem Alone and in Combination with Relebactam in an In Vitro Hollow-Fiber Dynamic Model: Emergence of Resistance of Carbapenemase-Producing and the Inoculum Effect.
The emergence of bacteria resistant to beta-lactam/beta-lactamase inhibitor combinations is insufficiently studied, wherein the role of the inoculum effect (IE) in decreased efficacy is unclear. To address these issues, 5-day treatments with doripenem and doripenem/relebactam combination at different ratios of the agents were simulated in a hollow-fiber dynamic model against carbapenemase-producing at standard and high inocula. Minimal inhibitory concentrations (MICs) of doripenem alone and in the presence of relebactam at two inocula were determined. Combination MICs were tested using traditional (fixed relebactam concentration) and pharmacokinetic-based approach (fixed doripenem-to-relebactam concentration ratio equal to the therapeutic 24-h area under the concentration-time curve (AUC) ratio). In all experiments, resistant subpopulations were noted, but combined simulations reduced their numbers. With doripenem, the IE was apparent for both isolates in combined treatments for one strain. The pharmacokinetic-based approach to combination MIC estimation compared to traditional showed stronger correlation between DOSE/MIC and emergence of resistance. These results support (1) the constraint of relebactam combined with doripenem against the emergence of resistance and IE; (2) the applicability of a pharmacokinetic-based approach to estimate carbapenem MICs in the presence of an inhibitor to predict the IE and to describe the patterns of resistance occurrence.
PubMed: 38136739
DOI: 10.3390/antibiotics12121705 -
Veterinary Medicine and Science Jul 2023Resistance to multiple drugs in Klebsiella pneumoniae (KPN) is an important issue in human and animal medicine. KPN phenotypic and genotypic aspects in poultry samples...
BACKGROUND
Resistance to multiple drugs in Klebsiella pneumoniae (KPN) is an important issue in human and animal medicine. KPN phenotypic and genotypic aspects in poultry samples have not been comprehensively explored in Bangladesh.
METHODS
This research focused on the prevalence of antibiotic resistance and the characterization of KPN in Bangladeshi poultry isolates using both phenotypic and genotypic approaches.
RESULTS
A total of 32 poultry samples were randomly obtained from a commercial poultry farm in Narsingdi, Bangladesh, and 43.90% (18/41) of the isolates were confirmed to be KPN, whereas all isolates were biofilm producers. The antibiotic sensitivity test revealed the most remarkable (100%) antibiotic resistance level against Ampicillin, Doxycycline and Tetracycline while remaining susceptible to Doripenem, Meropenem, Cefoxitin and Polymyxin B. Resistance to Nalidixic acid, Nitrofurantoin, Trimethoprim, Levofloxacin, Ciprofloxacin, Cefuroxime and Chloramphenicol ranges from 18% to 70%. Minimum inhibitory concentrations for carbapenem-resistant KPN ranged from 128 to 512 mg/mL for Meropenem, Imipenem, Gentamycin and Ciprofloxacin, respectively. [Correction added on 15 June 2023, after first online publication: 512 g/mL was corrected to 512 mg/mL in the preceding sentence]. Carbapenemase-producing KPN isolates harboured a single or multiple β-lactamase genes, bla , bla and bla as well as one ESBL gene (bla ) and plasmid-mediated quinolone resistance gene (qnrB). Furthermore, Cr and Co outperformed Cu and Zn in antibacterial effectiveness.
CONCLUSIONS
The results of this investigation showed that the high prevalence of multidrug-resistant pathogenic KPN in our chosen geographic location had displayed sensitivity to FOX/PB/Cr/Co, which might be regarded as an alternate treatment to reduce pressure of use on carbapenems.
Topics: Humans; Animals; Klebsiella pneumoniae; Meropenem; Bangladesh; Poultry; Anti-Bacterial Agents; beta-Lactamases; Ciprofloxacin; Metals, Heavy
PubMed: 37252894
DOI: 10.1002/vms3.1168 -
Research Square Sep 2023During head and neck cancer treatment, off-target ionizing radiation damage to the salivary glands commonly causes a permanent loss of secretory function. Due to the...
During head and neck cancer treatment, off-target ionizing radiation damage to the salivary glands commonly causes a permanent loss of secretory function. Due to the resulting decrease in saliva production, patients have trouble eating, speaking and are predisposed to oral infections and tooth decay. While the radioprotective antioxidant drug Amifostine is FDA approved to prevent radiation-induced hyposalivation, it has intolerable side effects that limit its use, motivating the discovery of alternative therapeutics. To address this issue, we previously developed a salivary gland mimetic (SGm) tissue chip platform. Here, we leverage this SGm tissue chip for high-content drug discovery. First, we developed in-chip assays to quantify glutathione and cellular senescence (β-galactosidase), which are biomarkers of radiation damage, and we validated radioprotection using WR-1065, the active form of Amifostine. Other reported radioprotective drugs including Edaravone, Tempol, N-acetylcysteine (NAC), Rapamycin, Ex-Rad, and Palifermin were also tested to validate the ability of the assays to detect cell damage and radioprotection. All of the drugs except NAC and Ex-Rad exhibited robust radioprotection. Next, a Selleck Chemicals library of 438 FDA-approved drugs was screened for radioprotection. We discovered 25 hits, with most of the drugs identified exhibiting mechanisms of action other than antioxidant activity. Hits were down-selected using EC50 values and pharmacokinetic and pharmacodynamic data from the PubChem database. This led us to test Phenylbutazone (anti-inflammatory), Enoxacin (antibiotic), and Doripenem (antibiotic) for in vivo radioprotection in mice using retroductal injections. Results confirm that Phenylbutazone and Enoxacin exhibited radioprotection equivalent to Amifostine. This body of work demonstrates the development and validation of assays using a SGm tissue chip platform for high-content drug screening and the successful in vitro discovery and in vivo validation of novel radioprotective drugs with non-antioxidant primary indications pointing to possible, yet unknown novel mechanisms of radioprotection.
PubMed: 37790388
DOI: 10.21203/rs.3.rs-3246405/v1 -
Veterinary World Nov 2023Antibiotic resistance is a major global health threat. The increasing prevalence of drug-resistant bacteria poses a serious challenge to the effective treatment of...
BACKGROUND AND AIM
Antibiotic resistance is a major global health threat. The increasing prevalence of drug-resistant bacteria poses a serious challenge to the effective treatment of infections in both humans and animals. Water is a major source of human and animal exposure to bacteria, and the presence of drug-resistant bacteria in water could present a severe threat to public health and animal production. This study investigated the presence of drug-resistant bacteria in Lam Pao Dam (LPD) water in Kalasin, Thailand.
MATERIALS AND METHODS
Ampicillin-resistant strains were obtained from LPD water and identified using 16s rDNA sequencing. Antibiotic resistance genes were detected by polymerase chain reaction using specific primers. The presence of antibiotic-resistant bacteria was evaluated using 16s amplicon analysis. The minimum inhibitory concentration (MIC) of strains against antibiotics was determined.
RESULTS
A total of 12 , 4 , and 4 isolates were resistant to ampicillin. Almost all strains harbored and genes, and two strains also harbored the gene. All four strains harbored the gene. The most abundant species in the LPD sample was , followed by and . The MICs of 10 strains against five antibiotics revealed that all strains were resistant to ampicillin but susceptible to meropenem, doripenem, ertapenem, and imipenem.
CONCLUSION
These findings suggest a high prevalence of drug-resistant bacteria in LPD water. This is a cause for concern, as it could spread antibiotic-resistant infections in the community.
PubMed: 38152267
DOI: 10.14202/vetworld.2023.2321-2328 -
BioRxiv : the Preprint Server For... Jul 2023During head and neck cancer treatment, off-target ionizing radiation damage to the salivary glands commonly causes a permanent loss of secretory function. Due to the...
During head and neck cancer treatment, off-target ionizing radiation damage to the salivary glands commonly causes a permanent loss of secretory function. Due to the resulting decrease in saliva production, patients have trouble eating, speaking and are predisposed to oral infections and tooth decay. While the radioprotective antioxidant drug Amifostine is approved to prevent radiation-induced hyposalivation, it has intolerable side effects that limit its use, motivating the discovery of alternative therapeutics. To address this issue, we previously developed a salivary gland mimetic (SGm) tissue chip platform. Here, we leverage this SGm tissue chip for high-content drug discovery. First, we developed in-chip assays to quantify glutathione and cellular senescence (β-galactosidase), which are biomarkers of radiation damage, and we validated radioprotection using WR-1065, the active form of Amifostine. Following validation, we tested other reported radioprotective drugs, including, Edaravone, Tempol, N-acetylcysteine (NAC), Rapamycin, Ex-Rad, and Palifermin, confirming that all drugs but NAC and Ex-Rad exhibited robust radioprotection. Next, a Selleck Chemicals library of 438 FDA-approved drugs was screened for radioprotection. We discovered 25 hits, with most of the drugs identified with mechanisms of action other than antioxidant activity. Hits were down-selected using EC values and pharmacokinetics and pharmacodynamics data from the PubChem database leading to testing of Phenylbutazone (anti-inflammatory), Enoxacin (antibiotic), and Doripenem (antibiotic) for radioprotection in mice using retroductal injections. Results confirm that Phenylbutazone and Enoxacin exhibited equivalent radioprotection to Amifostine. This body of work demonstrates the development and validation of assays using a SGm tissue chip platform for high-content drug screening and the successful discovery and validation of novel radioprotective drugs with nonantioxidant primary indications pointing to possible, yet unknown novel mechanisms of radioprotection.
PubMed: 37503292
DOI: 10.1101/2023.07.12.548707 -
Microorganisms Aug 2023The emergence of carbapenem-resistant Enterobacterales (CRE) has been recognized as a significant concern globally. Ceftazidime/avibactam (CZA) is a novel...
The emergence of carbapenem-resistant Enterobacterales (CRE) has been recognized as a significant concern globally. Ceftazidime/avibactam (CZA) is a novel β-lactam/β-lactamase inhibitor that has demonstrated activity against isolates producing class A, C, and D β-lactamases. Here-in, we evaluated the in vitro activity of CZA and comparator antimicrobial agents against 858 CRE isolates, arising from the Southeast Asian region, collected from a large tertiary hospital in Singapore. These CRE isolates mainly comprised (50.5%), (29.4%), and complex (17.1%). Susceptibility rates to levofloxacin, imipenem, meropenem, doripenem, aztreonam, piperacillin/tazobactam, cefepime, tigecycline, and polymyxin B were low. CZA was the most active β-lactam agent against 68.9% of the studied isolates, while amikacin was the most active agent among all comparator antibiotics (80% susceptibility). More than half of the studied isolates (51.4%) identified were carbapenemase (KPC)-2 producers, 25.9% were New Delhi metallo-β-lactamase (NDM) producers, and Oxacillinase (OXA)-48-like producers made up 10.7%. CZA was the most active β-lactam agent against KPC-2, OXA-48-like, and Imipenemase (IMI) producers (99.3% susceptible; MIC: ≤1/2 mg/L). CZA had excellent activity against the non-carbapenemase-producing CRE (91.4% susceptible; MIC: ≤1/8 mg/L). Expectedly, CZA had no activity against the metallo-β-lactamases (MBL)-producing CRE (NDM- and Imipenemase MBL (IMP) producers; 27.2% isolates), and the carbapenemase co-producing CRE (NDM + KPC, NDM + OXA-48-like, NDM + IMP; 3.0% isolates). CZA is a promising addition to our limited armamentarium against CRE infections, given the reasonably high susceptibility rates against these CRE isolates. Careful stewardship and rational dosing regimens are required to preserve CZA's utility against CRE infections.
PubMed: 37764002
DOI: 10.3390/microorganisms11092158 -
Journal of Infection and Public Health Oct 2023Enterobacterales carrying bla represent an emerging challenge in treating infectious diseases. In this study, we aimed to investigate the characteristics of...
BACKGROUND
Enterobacterales carrying bla represent an emerging challenge in treating infectious diseases. In this study, we aimed to investigate the characteristics of bla-producing Enterobacterales from three hospitals in southern Taiwan.
METHODS
Enterobacterales strains that were nonsusceptible to more than one carbapenem (ertapenem, meropenem, imipenem, or doripenem) were collected from hospitalized patients. Molecular typing for New Delhi metallo-β-lactamase (NDM) and antibiotic susceptibility tests were performed, followed by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and plasmid analysis by PCR-based replicon typing.
RESULTS
A total of 1311 carbapenem-nonsusceptible Enterobacterales were isolated from 2017 to 2021. bla-encoding genes were detected in 108 isolates, with 53 (49.1%) harboring bla and 55 (50.9%) harboring bla. The rate of bla detection among isolates decreased to 2% in 2021. However, the rate of E. coli harboring bla increased from 1% to 12% of total isolates during the study period. Of 47 NDM-5-positive E. coli isolates, 44 (93.6%) were ST8346 with high genetic relatedness. E. coli ST8346 isolates showed high-level resistance to both carbapenems and aminoglycosides. Most (38 out of 47, 80.9%) bla-harboring E. coli isolates co-harbored bla. We analyzed the regions harboring bla in E. coli ST8346 via PCR amplification. bla and bla were located on two separate plasmids, IncF and IncX3, respectively.
CONCLUSION
The dissemination of E. coli ST8346 caused an increase in bla and bla co-harboring Enterobacterales in southern Taiwan, which show high-level resistance to both carbapenems and aminoglycosides. We identified a distinct IncF plasmid encoding bla that has the potential for rapid spread and needs further surveillance.
Topics: Humans; Escherichia coli; Multilocus Sequence Typing; Taiwan; Anti-Bacterial Agents; Carbapenems; Aminoglycosides
PubMed: 37633229
DOI: 10.1016/j.jiph.2023.08.007 -
Microbiology Spectrum Sep 2023Two novel variants of carbapenemase (KPC) associated with resistance to ceftazidime-avibactam (CZA) and designated as KPC-113 and KPC-114 by NCBI were identified in...
Two novel variants of carbapenemase (KPC) associated with resistance to ceftazidime-avibactam (CZA) and designated as KPC-113 and KPC-114 by NCBI were identified in 2020, in clinical isolates of in Brazil. While of ST16 harbored the variant on an IncFII-IncFIB plasmid, of ST11 carried the variant on an IncN plasmid. Both isolates displayed resistance to broad-spectrum cephalosporins, β-lactam inhibitors, and ertapenem and doripenem, whereas producing KPC-114 showed susceptibility to imipenem and meropenem. Whole-genome sequencing and analysis revealed that KPC-113 presented a Gly insertion between Ambler positions 264 and 265 (R264_A265insG), whereas KPC-114 displayed two amino acid insertions (Ser-Ser) between Ambler positions 181 and 182 (S181_P182insSS) in KPC-2, responsible for CZA resistance profiles. Our results confirm the emergence of novel KPC variants associated with resistance to CZA in international clones of circulating in South America. IMPORTANCE KPC-2 carbapenemases are endemic in Latin America. In this regard, in 2018, ceftazidime-avibactam (CZA) was authorized for clinical use in Brazil due to its significant activity against KPC-2 producers. In recent years, reports of resistance to CZA have increased in this country, limiting its clinical application. In this study, we report the emergence of two novel KPC-2 variants, named KPC-113 and KPC-114, associated with CZA resistance in strains belonging to high-risk clones ST11 and ST16. Our finding suggests that novel mutations in KPC-2 are increasing in South America, which is a critical issue deserving active surveillance.
PubMed: 37671877
DOI: 10.1128/spectrum.00374-23 -
Infectious Diseases & Clinical... Sep 2023This study aimed to determine the effect of prophylactic use of carbapenems for acute pancreatitis on clinical outcomes. (Review)
Review
OBJECTIVE
This study aimed to determine the effect of prophylactic use of carbapenems for acute pancreatitis on clinical outcomes.
MATERIALS AND METHODS
It was conducted according to the preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by using the keywords "Pancrea AND carbapenem OR imipenem OR ertapenem OR meropenem OR doripenem." Primer outcomes were mortality, surgical intervention, and pancreatic and non-pancreatic infection. Subgroup analyses were also performed to reduce the risk of bias.
RESULTS
Ten studies with 4038 patients were included in the meta-analyses. While eight of ten were randomized controlled trials, two were observational studies. The prophylactic use of carbapenems had no statistically significant effect on mortality (OR=0.82, 95% CI=0.65-1.04, I²=0%) and surgical intervention. (OR=0.81, 95% CI=0.57-1.17, I²=0%). However, the real impact of prophylaxis on reducing the incidence of mortality and surgical intervention was uncertain due to the insufficient sample size. The prophylactic use of carbapenems was significantly associated with a lower risk of peripancreatic (OR=0.37, 95% CI=0.25-0.55, I²=61%) and non-pancreatic infection risk (OR=0.60, 95% CI=0.46-0.78, I²=65%). The definitions of infection in the articles were not clear, and the diagnostic approach to infection was based on subjective criteria. In addition, there was inadequate collateral damage and safety assessments. In high-quality studies with a low risk of bias, prophylactic carbapenems had no effect on peripancreatic infection (RR=1.54, 95% CI=0.65-3.47, I²=0%) and non-pancreatic infection (RR=0.72, 95% CI=0.48-1.07, I²=0%).
CONCLUSION
Although there is a reduction in the infection risk, routine carbapenem use in acute pancreatitis cases should not be recommended based on current evidence. Cooperation with Infectious Disease specialists and developing diagnostic algorithms are required instead of routine prophylaxis to prevent infection, especially non-pancreatic infection.
PubMed: 38633556
DOI: 10.36519/idcm.2023.239 -
Annals of Clinical Microbiology and... Mar 2024Infections caused by Stenotrophomonas maltophilia are clinically important due to its intrinsic resistance to a broad range of antibiotics. Therefore, selecting the most... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Infections caused by Stenotrophomonas maltophilia are clinically important due to its intrinsic resistance to a broad range of antibiotics. Therefore, selecting the most appropriate antibiotic to treat S. maltophilia infection is a major challenge.
AIM
The current meta-analysis aimed to investigate the global prevalence of antibiotic resistance among S. maltophilia isolates to the develop more effective therapeutic strategies.
METHOD
A systematic literature search was performed using the appropriate search syntax after searching Pubmed, Embase, Web of Science and Scopus databases (May 2023). Statistical analysis was performed using Pooled and the random effects model in R and the metafor package. A total of 11,438 articles were retrieved. After a thorough evaluation, 289 studies were finally eligible for inclusion in this systematic review and meta-analysis.
RESULT
Present analysis indicated that the highest incidences of resistance were associated with doripenem (97%), cefoxitin (96%), imipenem and cefuroxime (95%), ampicillin (94%), ceftriaxone (92%), aztreonam (91%) and meropenem (90%) which resistance to Carbapenems is intrinsic. The lowest resistance rates were documented for minocycline (3%), cefiderocol (4%). The global resistance rate to TMP-SMX remained constant in two periods before and after 2010 (14.4% vs. 14.6%). A significant increase in resistance to tigecycline and ceftolozane/tazobactam was observed before and after 2010.
CONCLUSIONS
Minocycline and cefiderocol can be considered the preferred treatment options due to low resistance rates, although regional differences in resistance rates to other antibiotics should be considered. The low global prevalence of resistance to TMP-SMX as a first-line treatment for S. maltophilia suggests that it remains an effective treatment option.
Topics: Humans; Trimethoprim, Sulfamethoxazole Drug Combination; Minocycline; Stenotrophomonas maltophilia; Microbial Sensitivity Tests; Anti-Bacterial Agents; Cefiderocol; Drug Resistance, Microbial; Gram-Negative Bacterial Infections
PubMed: 38504262
DOI: 10.1186/s12941-024-00685-4