scholarly journals Activity of Meropenem-Vaborbactam against Carbapenem-Resistant Enterobacteriaceae in a Murine Model of Pyelonephritis

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
William J. Weiss ◽  
Mark E. Pulse ◽  
Phung Nguyen ◽  
Kelly Peterson ◽  
Jessica Silva ◽  
...  

ABSTRACT The recently approved combination of meropenem and vaborbactam (Vabomere) is highly active against Gram-negative pathogens, especially Klebsiella pneumoniae carbapenemase (KPC)-producing, carbapenem-resistant Enterobacteriaceae. We evaluated the efficacy of meropenem-vaborbactam against three clinically relevant isolates in a murine pyelonephritis model. The data indicate that the combination of meropenem and vaborbactam significantly increased bacterial killing compared to that with the untreated controls. These data suggest that this combination may have utility in the treatment of complicated urinary tract infections due to KPC-producing, carbapenem-resistant Enterobacteriaceae.

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Mojgan Sabet ◽  
Ziad Tarazi ◽  
Thomas Nolan ◽  
Jonathan Parkinson ◽  
Debora Rubio-Aparicio ◽  
...  

ABSTRACT Meropenem-vaborbactam (Vabomere) is highly active against Gram-negative pathogens, especially Klebsiella pneumoniae carbapenemase (KPC)-producing, carbapenem-resistant Enterobacteriaceae. The objective of these studies was to evaluate the efficacy of meropenem alone and in combination with vaborbactam in mouse thigh and lung infection models. Thighs or lungs of neutropenic mice were infected with KPC-producing carbapenem-resistant Enterobacteriaceae, with meropenem MICs ranging from ≤0.06 to 8 mg/liter in the presence of 8 mg/liter vaborbactam. Mice were treated with meropenem alone or meropenem in combination with vaborbactam every 2 h for 24 h to provide exposures comparable to 2-g doses of each component in humans. Meropenem administered in combination with vaborbactam produced bacterial killing in all strains tested, while treatment with meropenem alone either produced less than 0.5 log CFU/tissue of bacterial killing or none at all. In the thigh model, 11 strains were treated with the combination of meropenem plus vaborbactam (300 plus 50 mg/kg of body weight). This combination produced from 0.8 to 2.89 logs of bacterial killing compared to untreated controls at the start of treatment. In the lung infection model, two strains were treated with the same dosage regimen of meropenem and vaborbactam. The combination produced more than 1.83 logs of bacterial killing against both strains tested compared to untreated controls at the start of treatment. Overall, these data suggest that meropenem-vaborbactam may have utility in the treatment of infections due to KPC-producing carbapenem-resistant Enterobacteriaceae.


2014 ◽  
Vol 59 (1) ◽  
pp. 553-557 ◽  
Author(s):  
Kyle D. Brizendine ◽  
Sandra S. Richter ◽  
Eric D. Cober ◽  
David van Duin

ABSTRACTCarbapenem-resistantKlebsiella pneumoniae(CRKP) is an emerging pathogen with a devastating impact on organ transplant recipients (OTRs). Data describing urinary tract infections (UTIs) due to CRKP, compared to extended-spectrum β-lactamase (ESBL)-producing and susceptibleK. pneumoniae, are lacking. We conducted a retrospective cohort study comparing OTRs with a first episode of UTI due to CRKP, ESBL-producingK. pneumoniae, or susceptibleK. pneumoniae. We identified 108 individuals; 22 (20%) had UTIs due to CRKP, 22 (20%) due to ESBL-producingK. pneumoniae, and 64 (60%) due to susceptibleK. pneumoniae. Compared to susceptibleK. pneumoniae(27%), patients with UTIs due to CRKP or ESBL-producingK. pneumoniaewere more likely to have a ≥24-hour stay in the intensive care unit (ICU) before or after development of the UTI (64% and 77%, respectively;P< 0.001). Among 105/108 hospitalized patients (97%), the median lengths of stay prior to UTI with CRKP or ESBL-producingK. pneumoniae(7 and 8 days, respectively) were significantly longer than that for susceptibleK. pneumoniae(1 day;P< 0.001). Clinical failure was observed for 8 patients (36%) with CRKP, 4 (18%) with ESBL-producingK. pneumoniae, and 9 (14%) with susceptibleK. pneumoniae(P= 0.073). Microbiological failure was seen for 10 patients (45%) with CRKP, compared with 2 (9%) with ESBL-producingK. pneumoniaeand 2 (3%) with susceptibleK. pneumoniae(P< 0.001). In multivariable logistic regression analyses, CRKP was associated with greater odds of microbiological failure (versus ESBL-producingK. pneumoniae: odds ratio [OR], 9.36, 95% confidence interval [CI], 1.94 to 72.1; versus susceptibleK. pneumoniae: OR, 31.4, 95% CI, 5.91 to 264). In conclusion, CRKP is associated with ICU admission, long length of stay, and microbiological failure among OTRs with UTIs. Greater numbers are needed to determine risk factors for infection and differences in meaningful endpoints associated with carbapenem resistance.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S524-S524
Author(s):  
Helio S Sader ◽  
Robert K Flamm ◽  
Mariana Castanheira ◽  
Rodrigo E Mendes

Abstract Background Complicated urinary tract infections (cUTIs) represent a major cause of healthcare-associated infection and a major source of gram-negative (GN) bacteremia. We evaluated the antimicrobial activities of recently approved β-lactamase inhibitor combinations and comparators against GN bacteria isolated from patients with cUTIs in the US hospitals in 2018. Methods Unique patient isolates were consecutively collected from patients with cUTIs in 65 hospitals in 2018, and the GN organisms (n = 4,371) were susceptibility (S) tested by reference broth microdilution methods. Enterobacterales (ENT) with elevated cephalosporin MICs were screened for β-lactamase-encoding genes by whole-genome sequencing. Results The most common GN organisms were E. coli (44.5%), K. pneumoniae (19.6%), P. mirabilis (6.7%), and P. aeruginosa (PSA; 5.3%). The most active agents against ENT were ceftazidime–avibactam (CAZ-AVI; 99.9%S), amikacin (AMK; 99.7%S), and meropenem (MEM; 99.4%S; table). Extended-spectrum β-lactamase (ESBL) genes were identified in 315 ENT (7.6%; excluding carbapenemase co-producers), including CTX-M-15 (63% of ESBL producers), other CTX-M types (25%), OXA-1/OXA-30 (39%), and SHV type (30%); approximately 50% of ESBL producers had ≥2 ESBL genes, mainly a CTX-M-type and an OXA-type (37% of isolates). The most active agents against ESBL producers were CAZ-AVI (100.0%S), AMK (99.7%S), and MEM (99.4%S); whereas ceftolozane–tazobactam (C-T) and piperacillin–tazobactam (PIP-TAZ) were active against 90.6% and 84.8% of ESBL producers, respectively. Only CAZ-AVI (87.0%S), colistin (COL; 87.0%S), and tigecycline (95.7%S) exhibited good activity against carbapenem-resistant ENT (CRE). Only 3 ENT isolates (0.07%) were CAZ-AVI resistant and all had a metallo-β-lactamase gene (2 VIM-1 and 1 NDM-1). CAZ-AVI (97.0%S) and C-T (99.1%S) were the most active β-lactams tested against PSA; other compounds with > 90%S for PSA were COL (99.6%), AMK (97.8%), tobramycin (93.5%), and CAZ (90.4%). Conclusion CAZ-AVI was highly active against a large collection of contemporary GN bacteria isolated from patients with cUTIs in US hospitals and provided greater coverage than the agents currently available in the US to treat cUTIs. Disclosures All authors: No reported disclosures.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Nayara Helisandra Fedrigo ◽  
Josmar Mazucheli ◽  
James Albiero ◽  
Danielle Rosani Shinohara ◽  
Fernanda Gomes Lodi ◽  
...  

ABSTRACT Fosfomycin is widely used for the treatment of uncomplicated urinary tract infection (UTI), and it has recently been recommended that fosfomycin be used to treat infections caused by multidrug-resistant (MDR) Gram-negative bacilli. Whether urine acidification can improve bacterial susceptibility to fosfomycin oral dosing regimens has not been analyzed. The MIC of fosfomycin for 245 Gram-negative bacterial isolates, consisting of 158 Escherichia coli isolates and 87 Klebsiella isolates which were collected from patients with urinary tract infections, were determined at pH 6.0 and 7.0 using the agar dilution method. Monte Carlo simulation of the urinary fosfomycin area under the concentration-time curve (AUC) after a single oral dose of 3,000 mg fosfomycin and the MIC distribution were used to determine the probability of target attainment (PTA). Fosfomycin was effective against E. coli (MIC90 ≤ 16 μg/ml) but not against Klebsiella spp. (MIC90 > 512 μg/ml). Acidification of the environment increased the susceptibility of 71% of the bacterial isolates and resulted in a statistically significant decrease in bacterial survival. The use of a regimen consisting of a single oral dose of fosfomycin against an E. coli isolate with an MIC of ≤64 mg/liter was able to achieve a PTA of ≥90% for a target pharmacodynamic index (AUC/MIC) of 23 in urine; PTA was not achieved when the MIC was higher than 64 mg/liter. The cumulative fractions of the bacterial responses (CFR) were 99% and 55% against E. coli and Klebsiella spp., respectively, based on simulated drug exposure in urine with an acidic pH of 6.0. A decrease of the pH from 7.0 to 6.0 improved the PTA and CFR of the target pharmacodynamic index in both E. coli and Klebsiella isolates.


2019 ◽  
Vol 8 (41) ◽  
Author(s):  
James Nguyen ◽  
Laith Harb ◽  
Russell Moreland ◽  
Mei Liu ◽  
Jason J. Gill ◽  
...  

Proteus mirabilis is a Gram-negative enteric bacterium associated with complicated human urinary tract infections. Here, we present the complete genome annotation for P. mirabilis siphophage Saba. With a 60,056-bp genome and 75 predicted genes, Saba is most similar at the nucleotide and protein levels to phage Chi and Chi-like viruses.


2013 ◽  
Vol 81 (8) ◽  
pp. 3009-3017 ◽  
Author(s):  
Caitlin N. Murphy ◽  
Martin S. Mortensen ◽  
Karen A. Krogfelt ◽  
Steven Clegg

ABSTRACTCatheter-associated urinary tract infections are biofilm-mediated infections that cause a significant economic and health burden in nosocomial environments. Using a newly developed murine model of this type of infection, we investigated the role of fimbriae in implant-associated urinary tract infections by the Gram-negative bacteriumKlebsiella pneumoniae, which is a proficient biofilm former and a commonly isolated nosocomial pathogen. Studies have shown that type 1 and type 3 fimbriae are involved in attachment and biofilm formationin vitro, and these fimbrial types are suspected to be important virulence factors during infection. To test this hypothesis, the virulence of fimbrial mutants was assessed in independent challenges in which mouse bladders were inoculated with the wild type or a fimbrial mutant and in coinfection studies in which the wild type and fimbrial mutants were inoculated together to assess the results of a direct competition in the urinary tract. Using these experiments, we were able to show that both fimbrial types serve to enhance colonization and persistence. Additionally, a double mutant had an additive colonization defect under some conditions, indicating that both fimbrial types have unique roles in the attachment and persistence in the bladder and on the implant itself. All of these mutants were outcompeted by the wild type in coinfection experiments. Using these methods, we are able to show that type 1 and type 3 fimbriae are important colonization factors in the murine urinary tract when an implanted silicone tube is present.


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