In vitro activity of manogepix and comparators against infrequently encountered yeast and mold isolates from the SENTRY Surveillance Program (2017-2022)

Manogepix is a potent new antifungal agent targeting the fungal Gwt1 enzyme. Manogepix has previously demonstrated potent in vitro activity against clinical isolates of both Candida (except Candida krusei) and Aspergillus species. This study determined the in vitro activity of manogepix and comparators against a large collection of infrequently encountered yeast and molds. Manogepix demonstrated potent in vitro activity against infrequently encountered yeasts exhibiting elevated MIC values to other drug classes, including Candida spp. (MIC50/90, 0.008/0.12 mg/L), Saprochaete clavata (Magnusiomyces clavatus) (MIC50/90, 0.03/0.06 mg/L), Magnusiomyces capitatus (MICrange, 0.016-0.06 mg/L), Rhodotorula minuta (MIC, 0.016 mg/L), and Rhodotorula mucilaginosa (MIC50/90, 0.03/0.12 mg/L). Similarly, manogepix was active against infrequently encountered mold isolates and strains exhibiting elevated MIC/MEC values to echinocandins, azoles, and amphotericin B, including Coprinopsis cinerea (MEC, 0.004 mg/L), Fusarium spp. (MEC50/90, 0.016/0.06 mg/L), Fusarium (Gibberella) fujikuroi species complex (MEC50/90, 0.016/0.03 mg/L), Lomentospora prolificans (MEC50/90, 0.03/0.06 mg/L), Microascus cirrosus (MEC, 0.008 mg/L), Paecilomyces spp. (MEC50/90, ≤0.008/0.016 mg/L), Pleurostomophora richardsiae (MEC, 0.06 mg/L), Sarocladium kiliense (MEC range, 0.016-0.12 mg/L), and Scedosporium spp. (MEC50/90, 0.03/0.06 mg/L). Manogepix demonstrated potent activity against a majority of the infrequently encountered yeast and mold isolates tested including strains with elevated MIC/MEC values to other drug classes. Additional clinical development of manogepix (fosmanogepix) in difficult-to-treat, resistant fungal infections is warranted.

1363. Sulopenem Activity Against Enterobacteriaceae Isolates From Patients With Urinary Tract Infection or Intra-Abdominal Infection

Background

Sulopenem is a thiopenem antibacterial with oral and parenteral formulations being developed for the treatment of urinary tract infection (UTI) or complicated intra-abdominal infection (cIAI). The activity of sulopenem aligns with the most urgent drug-resistant antimicrobial threats defined by the Centers for Disease Control (CDC), including ESBL-producing strains of Escherichia coli and Klebsiella species. We evaluated the in vitro antibacterial activity of sulopenem against clinical Enterobacteriaceae isolates from patients in North America with UTI or cIAI collected during 2016–2017.

Methods

Sulopenem and other antimicrobial agents were tested for in vitro activity against 1,008 recent (2016–2017) consecutive Enterobacteriaceae isolates collected through the SENTRY Antimicrobial Surveillance Program from patients in North America with UTI (906 isolates) or cIAI (102 isolates). Reference broth microdilution susceptibility testing was conducted using frozen-form panels produced by JMI Laboratories according to CLSI (M07, 2018) guidelines using cation-adjusted Mueller–Hinton broth. Quality control (QC) and interpretation of results were performed in accordance with CLSI M100 (2018) guidelines.

Results

Table 1. Activity of sulopenem and comparator antimicrobial agents against 1,008 Enterobacteriaceae North American isolates

The sulopenem MIC_50/90 values for Enterobacteriaceae were 0.03/0.25 µg/mL. For Escherichia coli, Klebsiella species and Proteus mirabilis, the MIC_50/90 results were 0.03/0.03 µg/mL, 0.03/0.06 µg/mL, and 0.12/0.25 µg/mL, respectively.

Conclusion

Sulopenem demonstrated potent in vitro activity against organisms commonly implicated in UTI and cIAI. These data support the further clinical development of sulopenem for Gram-negative infections.

Disclosures

S. Puttagunta, Iterum Therapeutics: Employee and Shareholder, Salary. S. Aronin, Iterum Therapeutics: Employee and Shareholder, Salary. M. Huband, JMI Labs: Research Contractor, Grant recipient. R. K. Flamm, Allergan: Research Contractor, Research support. M. Dunne, Iterum Therapeutics: Employee and Shareholder, Salary.

WCK 5222 (Cefepime-Zidebactam) Antimicrobial Activity against Clinical Isolates of Gram-Negative Bacteria Collected Worldwide in 2015

WCK 5222 consists of cefepime combined with zidebactam, a bicyclo-acyl hydrazide β-lactam enhancer antibiotic with a dual action involving binding to Gram-negative bacterial PBP2 and β-lactamase inhibition. We evaluated the in vitro activity of cefepime-zidebactam against 7,876 contemporary (2015) clinical isolates of Enterobacteriaceae (n = 5,946), Pseudomonas aeruginosa (n = 1,291), and Acinetobacter spp. (n = 639) from the United States (n = 2,919), Europe (n = 3,004), the Asia-Pacific (n = 1,370), and Latin America (n = 583). The isolates were tested by a reference broth microdilution method for susceptibility against cefepime-zidebactam (1:1 and 2:1 ratios) and comparator agents. Cefepime-zidebactam was the most active compound tested against Enterobacteriaceae (MIC50/90, ≤0.03/0.12 μg/ml [1:1] and 0.06/0.25 μg/ml [2:1]; 99.9% of isolates were inhibited at ≤4 [1:1] and ≤8 μg/ml [2:1]). Cefepime-zidebactam was active against individual Enterobacteriaceae species (MIC50/90, ≤0.03 to 0.06/≤0.03 to 0.5 μg/ml [1:1]) and retained potent activity against carbapenem-resistant isolates (MIC50/90, 1/4 μg/ml; 99.3% of isolates were inhibited at ≤8 μg/ml [1:1]). Cefepime-zidebactam activity was consistent among geographic regions, and only one isolate showed MIC values of >8 μg/ml (1:1). Cefepime-zidebactam was also very active against P. aeruginosa with MIC50/90 values of 1/4 μg/ml, and 99.5% of isolates were inhibited at ≤8 μg/ml (1:1). The MIC values for cefepime-zidebactam at the 1:1 ratio were generally 2-fold lower than those for cefepime-zidebactam at the 2:1 ratio (MIC50/90, 2/8 μg/ml) and zidebactam alone (MIC50/90, 4/8 μg/ml). Against Acinetobacter spp., cefepime-zidebactam at 1:1 and 2:1 ratios (MIC50/90, 16/32 μg/ml for both) was 4-fold more active than cefepime or ceftazidime. Zidebactam exhibited potent in vitro antimicrobial activity against some organisms. These results support the clinical development of WCK 5222 for the treatment of Gram-negative bacterial infections, including those caused by multidrug-resistant isolates.

Pyridone methylsulfone hydroxamate LpxC inhibitors for the treatment of serious gram-negative infections

The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.

Potent inhibitors of LpxC for the treatment of Gram-negative infections

In this paper, we present the synthesis and SAR as well as selectivity, pharmacokinetic, and infection model data for representative analogues of a novel series of potent antibacterial LpxC inhibitors represented by hydroxamic acid.

Prosthetic rehabilitation

Patients with head and neck defects may undergo reconstruction surgically, prosthetically, or with a combined approach. In some situations, prosthetic rehabilitation may be the preferred treatment option. Presurgical treatment planning and evaluation of the patient is paramount to successful reconstruction and rehabilitation. Patient education and assessment of the patient's expectations are essential in the acceptance of a proposed treatment plan. Communication and joint treatment planning early in the process between the surgeon and maxillofacial prosthodontist will optimize results.

Synthesis and antibacterial activity of the C-7 side chain of 3-aminoquinazolinediones

A novel series of bacterial topoisomerase (3-aminoquinazolinediones) inhibitors are described. The side-chain SAR against Gram-positive and Gram-negative organisms as well as DNA gyrase activity is reported.

The synthesis and biological evaluation of novel series of nitrile-containing fluoroquinolones as antibacterial agents

Several novel series of nitrile-containing fluoroquinolones with weakly basic amines are reported which have reduced potential for hERG (human ether-a-go-go gene) channel inhibition as measured by the dofetilide assay. The new fluoroquinolones are potent against both Gram-positive and fastidious Gram-negative strains, including Methicillin resistant Staphylococcus aureus and fluoroquinolone-resistant Streptococcus pneumoniae. Several analogs also showed low potential for human genotoxicity as measured by the clonogenicity test. Compounds 22 and 37 (designated PF-00951966 and PF-02298732, respectively), which had good in vitro activity and in vitro safety profiles, also showed good pharmacokinetic properties in rats.

Conformational constraint in oxazolidinone antibacterials. Part 2: Synthesis and structure–activity studies of oxa-, aza-, and thiabicyclo[3.1.0]hexylphenyl oxazolidinones

A new class of oxazolidinone antibacterials incorporating oxygen-, nitrogen-, or sulfur-containing heterobicyclic C-rings is described. The in vitro potency and in vivo efficacy of these conformationally constrained oxazolidinone analogs are discussed.

Porcelain-fused-to-metal post and core: an esthetic alternative

Custom cast metal post and cores used to retain all-ceramic restorations are indicated in endodontically treated teeth when little clinical crown remains. The metal cores of these post and core restorations block light transmission and create a graying effect when used in support of all-ceramic restorations. This article describes a technique to minimize this effect using custom cast porcelain-fused-to-metal post and cores to achieve a more natural esthetic result.